Modify surround sound amplifier to integrated amplifier I – Introduction
Given that the majority of audiophiles disregard outdated surround sound amplifiers, I find it quite regrettable. That’s why the concept of modifying outdated surround sound amplifiers into integrated amplifiers emerged. This approach serves several purposes. Firstly, it contributes to environmental conservation. Secondly, it aims to change the impression that surround sound amplifiers have poor sound quality among audiophiles. Thirdly, due to their eco-friendly nature, outdated surround sound amplifiers can save a considerable amount of money. The models we focus on for modification are primarily from the period between 2000 and 2010, and particularly, not all previous models, especially Prologic surround sound amplifiers, are suitable. Why not choose newer models? The answer lies below. However, what are the uses of these modifications? If there is no application or purpose, the modifications would be futile.
When it comes to the uses, we need to consider the modifications first. In essence, we can convert the surround sound amplifier into a stereo integrated amplifier, stereo power amplifier, multi-channel amplifier, or multi-channel power amplifier, and the highest level would be a mono power amplifier/integrated amplifier. If circumstances permit, audiophiles would prefer to have a separate stereo system and a surround sound system. In this case, the modified integrated amplifier, power amplifier, or mono power amplifier can serve as the core of the stereo system. The modified amplifiers, especially those converted into mono power amplifiers, deliver sound quality that is in no way inferior to conventional amplifiers.
This is a stereo system that uses two Onkyo modified to become mono power amplifiers. (The middle one is another Onkyo temporarily modified for stereo comparison.)
If your setup only allows for one system to be used for both surround and stereo purposes, modifying the amplifiers can provide greater flexibility to your system. Whether you are aiming for a 5.1, 7.1, 5.1.2, 5.1.4, 7.1.4, or even X.4.X configuration, it doesn’t matter much because you can easily add or subtract channels as needed. All you need is a surround sound processor or a surround sound amplifier with preamp outputs, which can be connected to the modified power amplifier. It is well known that combining a surround sound processor with dedicated multichannel power amplifiers produces optimal audio effects. This is something that audiophiles would generally agree upon.
This is a system that utilizes two modified mono power amplifiers and one modified seven-channel power amplifier to form a 5.1.4 nine-channel surround sound system.
From the example above, we can see that this nine-channel system uses Denon’s Atmos surround sound amplifier as the preamp output for surround processing. Two modified Yamaha amplifiers are used as mono-power amplifiers to drive the left and right channels respectively. The modified Rotel amplifier is used as the seven-channel power amplifier to drive the other channels. The advantage of this setup is that when the user wants to listen to stereo sound, they only need to activate the two Yamaha amplifiers as dual mono power amplifiers. When using the nine-channel surround sound, the system operates in a 1+7+1 configuration. The flexibility of using old surround amplifiers as stereo or mono power amplifiers in a multi-channel setup provides better sound performance compared to using a single amplifier of the same level (I will explain this in detail later). This setup can also be easily modified according to space limitations when used in a surround sound combination. For example, the 1+7+1 configuration can be changed to 1+1+6+1, 2+7, 2+5+2, or 4+5. If you have the audacity and your home’s power supply can handle it, even dreaming of a 1+1+1+1+1+1+1+1+1 setup is not too extreme. If you are already using a multi-channel power amplifier, you can use this method to expand the number of channels indefinitely. Even if you switch to a nine-channel setup, you don’t need to give up using the existing five or seven-channel power amplifiers.
Why use old amplifiers instead of new ones? The reason is simple. In recent years, the majority of the cost of surround sound amplifiers has been allocated to processors and additional features. The cost of the amplifier section is so low that it can’t go any lower. Just think about it, initially, putting five channels in the same unit, the high-end models weighed at least 40 to 50 pounds. The era of six and seven channels was similar. Around 2010, the weight of seven and nine-channel surround sound amplifiers did not increase but gradually decreased. This trend is most noticeable in the mid-to-high-end surround sound amplifiers. For example, one of the current generation’s flagship thirteen-channel surround sound amplifiers weighs only 50 pounds (compared to Denon’s AVR5803 in the year 2003, which had seven-channel output but weighed 66 pounds! It had the grandeur of a flagship model in terms of size and weight). We are not talking about Class D amplifiers (this type of amplifier is not my cup of tea, at least not for now. I will temporarily set it aside and not discuss it for now). The mid-to-high-end seven-channel/nine-channel AB class surround sound amplifiers of the current generation weigh only about 20/30 pounds, and the actual output power when driving multiple channels can be reduced from 100 watts per channel to only about 40 watts. As a result, some manufacturers now declare that their surround sound amplifiers guarantee a minimum power output above a certain percentage when driving multiple channels. This is a rather sad phenomenon, similar to the “made with real cheese" label on a cheese cracker box. Many people have debated this power issue, with some arguing that surround sound amplifiers do not need much power when driving multiple channels. I don’t want to argue about this issue here. Amplifiers and cars are actually quite similar. The most powerful supercars today have over 1400 horsepower, while regular cars have around 100 horsepower. Both cars can only travel at speeds below 50 km/h on city roads. In this case, if you can’t discern the difference in engine output between the two, you might think that a low-power surround sound amplifier is more than sufficient. Because in general listening situations, surround sound amplifiers only require a few watts of output. From a technical standpoint, it is more than enough to handle multi-channel output with only a few tens of watts. I’m not accustomed to listening to music at extremely high volumes, and I don’t appreciate genres like Heavy Metal or Hard Rock. But what I need is not just a high-power amplifier; I also need equipment with quality. This aspect cannot be compromised, at least not for me. Generally speaking, high-power, high-current AB class amplifiers require powerful power supply sections and large heat sinks to handle the load. These factors contribute to the weight of the amplifier and sound quality. Amplifiers with lighter power supplies and less quality heat sink components naturally weigh less. To be continued next time.
Paul Kee (04/24)
04/24
環繞聲擴音機改為擴音機之一 – 引言
鑑於絕大部份的發燒友對舊制式的環繞聲擴音機都一屑不顧，我覺得是十分之可惜。所以才產生將舊制式環繞聲擴音機改為合併式擴音機的概念。這種做法第一：可以為環保出一分力。第二：希望發燒友對舊制式還繞聲擴音機音效不佳的印象改觀。第三：舊制式環繞聲擴音機因為是環保價，可以省回不少。我們改的機種大部份集中在2000年至2010年之間，之前的特別是Prologic的環繞聲擴音機並不一定適合。為何不選之後的？答案在下面。但機改了以後有什麼用途呢？沒有出路，沒有用途的話；改了以後如果沒有用途亦是徒勞無功。
談到用途，我們首先要從改機方面考慮。基本而言我們可以將還繞聲擴音機改為立體聲合併式擴音機，立體聲後級，多聲道擴音機，多聲道後級；而最高境界的是單聲道後級/擴音機。如果環境許可的話，發燒友都會希望有一套獨立分開的立體聲系統與還繞立體聲系統。這樣的話改動後的合併擴音機，後級或單聲道後級可以成為立體聲系統的主體。因為改動後的擴音機，特別是改為單聲道後級/擴音機的，音效絕不遜於一般的擴音機。
這是一套使用了兩部Onkyo改成為單聲道擴音機的立體聲系統。(中間的一部Onkyo暫時只改為立體聲作比較。）
如果你的環境只能夠容許你用一套系統作為環繞組合及立體聲用途。這樣的話改動後的擴音機會給你系統更大的彈性。無論你是5.1，7.1，5.1.2，5.1.4，7.1.4甚至是X.4.X也沒有太大的關係。因為你隨時可以加多減少。你只需要有一部環繞聲處理器或有前級輸出的環繞聲擴音機，將它接駁到改動以後的後級/擴音機便可。眾所週知，使用環繞聲處理器及多聲道後級的組合音效最佳。這一點相信沒有發燒友會反對。
這是一套使用了兩部改動後的單聲道後級，加上一部改動後的七聲道後級組成5.1.4九聲道環繞聲系統。
從上面的例子我們可以看到，這套九聲道的系統使用了Denon的Atmos環繞聲擴音機作為環繞處理器前級輸出。兩部Yamaha改為單聲道後級分別推動左右兩聲道。改動後的Rotel則用作七聲道後級推動其他聲道。這種做法的好處是主人家聽立體聲的時候只需要啟動兩部Yamaha作為雙單聲道後級推動。在使用九聲道環繞聲的時候便使用1+7+1的方式推動。正因為我們可以將舊的環繞擴音機改為立體聲或單聲道的後級/擴音機。這種接駁成多聲道後級的方式，在音效方面比你用單一個同級的多聲道後級更佳(我在日後會詳細解釋清楚)。以這種方式將它使用在環繞聲組合的時候亦可以隨時變化，只要你地方許可的話。亦即是說，上面的1+7+1可以變為，1+1+6+1，2+7，2+5+2，4+5亦無妨。若然你有膽量，而你家中的電力可以應付的話；使用1+1+1+1+1+1+1+1+1的夢想都不算得上是太變態。如果你已經在使用多聲道後級，你亦可以用這種方式無限量地增加聲道。就算你現在改用九聲道亦不需要放棄使用中的五聲道或七聲道後級。
為什麼用舊的擴音機而不用新的？理由十分簡單。首先，近年的環繞聲擴音機大部分的成本都花在處理器及附加的功能方面。擴音機部分的成本低到無法再低。試想一下，最初的時候將五個聲道放在同一架機內，當時高級的機種最少都有40至50磅。六聲道與七聲道的年代亦相若。大約在2010年開始七聲道與九聲道的環繞聲擴音機的重量沒有增加反而逐步減少。這種情況在中高價的環繞聲擴音機最明顯。現今這一代一部十三聲道的“旗艦”只有50磅(想當年Denon的AVR5803只有7聲道輸出，卻重達66磅！無論大小及重量均有旗艦級的風範。）。我們講的並非是D類的擴音機（這類型的擴音機並非我杯茶，起碼暫時不是。我暫且將它放開不談。）。這一代中高價的七聲道/九聲道AB類環繞聲擴音機亦只有20/30磅左右，實際輸出的時候功率由每聲道100W可以降低至只有40W左右。所以現在有部分的廠家都聲明自己的環繞聲擴音機在多聲道輸出時最少的功率保証在某個百份率以上。等於芝士餅乾盒子上所標明的made with real cheese是十分可悲的現象。有很多人都有爭拗這個功率的問題，部分人覺得環繞聲擴音機在多聲道輸出的時候根本不需要太大的功率。我不想在這裏爭拗這個問題。擴大器與汽車其實十分相似。現代最強的超級跑車有超過1400匹的馬力，普通的房車只有大概100匹的馬力。這兩架車在市區的道路上行走時大家同樣只能夠行50km/h以下。在這種情況，如果你分辨不出兩者在引擎輸出方面的分別；你可能亦會覺得低功率的環繞聲擴音機足夠有餘。因為在一般聆聽的情況下，環繞聲擴音機只需要數瓦的輸出。從數據上來看，多聲道同時輸出只有數十瓦是應付有餘。我並不習慣以極大的音量聽音樂，亦不欣賞Heavy Metal, Hard Rock之類。但我需要的不單止是大功率擴音機，更需要有質素的器材。這方面不能環保；對我來說是沒有商量的餘地。一般而言，大功率大電流的AB類放大器必須要有強大的供電部分，大面積的散熱器才能夠應付。這些都是重量及靚聲的基礎，沒有份量的供電及散熱重量自然較輕。下期續。
保記 (04/24)
Can Audiophiles Save the Environment? Episode 3 – Kenwood KRV-7060 completed
It is almost impossible to demand environmental friendliness from audiophiles. What I can do is modify discarded surround sound amplifiers into equipment that surpasses the performance of integrated stereo amplifiers. I challenge the common belief that surround sound amplifiers have poor sound quality. In the previous issue, I took the first step in modifying the Kenwood KRV-7060, which involved removing unnecessary circuits. To reduce unnecessary circuits inside the machine, you can simply disconnect the power or remove relevant active components (usually integrated circuits or transistors), depending on convenience or personal preference. This issue will delve into a deeper and more challenging part.
First, let’s set up the configuration on the machine. The Kenwood KRV-7060 is just an entry-level model, as indicated by the spring-loaded speaker terminals at the back. Underneath the fan outlet at the rear of the machine, there is a selection of speakers with an impedance of 8 ohms or above/or less, and I would choose 8 ohms or above. The reason is simple: the machine has two sets of main voltage supply for the power amplifier stage. When selecting 8 ohms or above, the voltage used is 54.2V, whereas for below 8 ohms, it is 40.8V. In simple terms, the 100W power of the Kenwood KRV-7060 comes from a voltage of 54.2V, and when selecting below 8 ohms, the output power will be slightly lower. If you require high power, you must choose 8 ohms or above. Many surround sound amplifiers, integrated amplifiers, and even power amplifiers have similar options. Regardless of the impedance of your speakers, you should still choose the higher-impedance option. This option provides greater power, which is advantageous for driving speakers. In general, the majority of amplifiers can handle this with ease, especially modern ones with various protection circuits, rarely causing damage to the amplifier or speakers. If selecting a particular option frequently triggers the protection circuit, you have to choose otherwise.
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| The back panel of Kenwood KRV-7060 is nothing out of ordinary, spring loaded speaker connections is an indication that it is a basic model. | Impedance selector at the back – suggested to select 8ohm or more. |
In the previous article, we discussed modifying the Kenwood KR-V7060 Prologic receiver into an integrated amplifier, and one of the key points was its four identical amplifier circuits. Why did I choose at least four identical power amplifier circuits (using the same power transistors)? The reason is that we want to parallel two pairs of power transistors together. By paralleling two pairs of power transistors, we greatly enhance the amplifier’s ability to deliver higher current to the speakers and improve driving power resulting in improved sound quality.
Since surround sound amplifiers already have multiple pairs of power transistors, we can make full use of them by converting them into a stereo amplifier using only two channels. Some people might think that paralleling two pairs of transistors should use matched pairs. While using matched pairs would be ideal, in most AV amplifiers, the transistors used are from the same batch, and the differences between them are generally minimal. If you insist on using matched pairs, you can easily find SanKen’s 2SB1560 and 2SD2390.
Fortunately, the design of the Kenwood KRV-7060 has the L and C transistors on the left side, while the R and S transistors are on the right side. With this arrangement, we can easily parallel L with C and R with S to complete the modification.
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| 2 pairs of SanKen 2SB1560/2SD2390 on each side | High quality heat sink has a dimension of 29cmx4.5cmx9cm |
First, we will disconnect R25 and R27 from the center channel. Then, we will connect R25 to the left channel R5 and R27 to the left channel R7. Finally, we will disconnect the center channel protection circuit at R33; cut and connect the center channel CP3 output to the left channel CP1 output. For the jumper wires, I will use Teflon-coated silver-plated copper wire. I believe using Teflon is necessary because it has a stronger texture and is less prone to piercing. Additionally, it can withstand the high temperatures of soldering. Using Teflon wire minimizes the risks involved in internal wiring. As for the silver-plated copper wire, it is a personal preference. The procedure for R and S is the same as that for L and C. For the rear channel, we will first disconnect R26 and R28 from the rear channel. Then, we will connect R26 to the right channel R6, and R28 to the right channel R8. Finally, we will disconnect the rear channel protection circuit at R34; cut and connect the center channel CP4 output to the right channel CP2 output. After paralleling the two pairs of transistors, it is necessary to check and adjust the bias voltage. The recommended bias voltage from the manufacturer is 22 mV. You simply need to connect a multimeter to CP1 (L) and CP2 (R). In general, I would increase the bias voltage slightly to enhance the current supply. It’s worth noting that amplifiers like this have multiple protection circuits, and I would advise keeping all of them. These protection circuits serve specific purposes and have minimal impact on sound quality, making them worth retaining.
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| disconnect R25 and R27 from the center channel | connect R25 to the left channel |
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| R27 to the left channel R7 | disconnect the center channel protection circuit at R33 |
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| cut and connect the center channel CP3 output to the left channel CP1 output | disconnect R26 and R28 from the rear channel |
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| connect R26 to the right channel R6 | R28 to the right channel R8 |
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| disconnect the rear channel protection circuit at R34 | cut and connect the center channel CP4 output to the right channel CP2 output |
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| Cut R25 from the center channel | Cut the output from CP3 of the center channel |
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| Cut the output from CP4 of the rear channel | Cut R26 from the rear channel |
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| After parallel two pairs of output transistors together. | Disconnect R34 from protection circuit for the rear channel |
The driver circuit actually consists of four sets, but we can reduce it to two sets to save power. Since the circuits driving the center channel and rear channels are now completely unnecessary, we will also disconnect their power supply. To remove the power supply for the center channel, we need to remove R153/R159/R161/R149/R147/R145. To remove the power supply for the rear channels, we need to remove R154/R160/R162/R150/R148/R146.
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| We take out all the resistors for suppling power to the center and rear driving sections | Resistors for power supply were all removed |
The only downside of the Kenwood KRV-7060 is its reservoir, which only has two 7500uF 71V capacitors. For a surround stereo amplifier rated at 100W output, this is considered the minimum standard. After thirty years, it is indeed time to replace the capacitors with new ones. You can upgrade them to 15,000MFD 70V or higher. I have tested these two capacitors, and they still have a significant amount of capacity, so it’s worth keeping them. I would recommend adding one 1000uF 70V capacitor in parallel with the B+/B- voltage of each channel, totaling four capacitors shared among all channels.
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| Reservoir from ELNA 7500MFD 71Vx2 | 4x1000MFD 70V were added |
At this stage, all modifications to the Kenwood KR-V7060 have been completed. The modified KR-V7060 retains the same appearance as the original unit, with the only difference being the removal of the tuner circuitry. Remarkably, the positioning of the KR-V7060 is ideal. The placement of the power transformer in the center evenly distributes the weight of the unit. The left and right channels are positioned symmetrically, complemented by the large (relative to the model) high-quality heat sink. This is an ideal design for a stereo-integrated amplifier or even a power amplifier. This is one of the reasons why I chose it. The modified KR-V7060 is a true integrated amplifier now. Its video and surround elements have been completely removed. In comparison to its original sound, it has improved significantly. It easily surpasses other integrated amplifiers of similar value and can even challenge integrated amplifiers that are more than twice its price.
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| KRV-7060 before modification | KRV-7060 after modification |
The modifications made to the KRV-7600 can indeed be considered a resurrection, as it has been saved from potentially becoming scrap metal. It can be seen as a contribution to environmental sustainability, and I hope it can change the perception that surround sound amplifiers are inferior in terms of sound quality. I can confidently say that with the appropriate modifications, a surround sound amplifier easily surpasses the performance of integrated amplifiers or even power amplifiers. The modifications made to the Kenwood KRV-7060 may be considered relatively minor, but they serve as a foundation for more advanced modifications. In the next phase, we will take it to the next level and further achieve performance at a higher level.
Paul Kee (03/24)
03/24
發燒友能否環保之三 – Kenwood KRV-7060 完成篇
要求發燒友環保幾乎是不可能的事，我所做的亦只能夠將被人遺棄的環繞立體聲擴音機改成為比一般立體聲擴音機還要好的器材。推翻一般人認定環繞立體聲擴音機音效不佳的定論。上一期我將 Kenwood KRV-7060 進行第一步的改動。這一部份只是將沒有用途的線路除去。要減少機內的無謂線路只需要切斷電源或除去相關部份有源零件(一般都是集成電路或晶體管)，視乎那種方式會較方便(或個人喜好而定) 而做。這一期會進入較深入亦是難度較高的部份。
首先我們做好機上的設定。Kenwood KRV-7060 只是一部入門的機繼種，從背後彈簧式的喇叭插座便可以知道。機後在風扇岀口之下有一組8ohm以上或以下的選擇，我會選擇8ohm以上。原因很簡單，機內有二組主電壓供應後級的部份。選擇8ohm以上時使用的電壓為54.2V, 8ohm以下的時侯為40.8V。簡單來講 Kenwood KRV-7060的100W功率是來自54.2V的電壓，當選擇8ohm以下的時侯輸出功率便會低一點。需要大功率的話必須選擇8ohm以上。有很多環繞立體聲擴音機，合拼式擴音機甚至是後級都有機會有類似的選擇。無論你揚聲器的阻抗是多了，要選的話亦會一樣選高抗阻的一項。這一選項提供較大的功率，大功率對推動喇叭無往而不利。一般而言絕大部份的放大器都能夠應付自如；何況近代的放大器有多方面的保護線路，甚少會因此而燒機、燒喇叭。若然你用的選項經常導致保護線路跳動的情況，你便沒有選擇了。
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| Kenwood KRV-7060的機背沒有甚麼特別之處，彈簧式喇叭座是入門機的標誌 | 背後的選項必選8ohm或以上 |
上期我們提到將 Kenwood 的 KR-V7060 Prologic 收音擴音機改為合併機其中一個重點是因為它有四組完全相同的放大線路。為什麼我要選擇最起碼四組相同的功率放大線路(最起碼使用同樣的功率管）？原因是我們要將兩組功率管並在一起。將兩組功率管並在一起時大大地增強了擴大器推動揚聲器的電流，達至更佳的音效。既然環繞立體聲放大器內裏已裝置了多對的功率管，我們改為立體聲只用兩聲道的話就可以物盡其用。這一部份很多人會覺得並聯兩對管應該使用配對管。能夠配對的話當然會更好，但因為一般AV擴音機裏面多會用同一批次的管；這個差異一般不會太大。若然你一定要配對的話SanKen 的 2SB1560 及 2SD2390亦不難找。幸運地Kenwood KRV-7060的設計是L與C是在左手邊，而R與S是在右手邊。這樣的話我們便順理成章，將L與C並在一起、R與S並在一起便完成。
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| 每邊二對 SanKen 的 2SB1560 及 2SD2390 | 優質散熱器足有 29cmx4.5cmx9cm |
我們首先將中置聲道進入R25及R27的線路切斷，然後將R25接到左聲道R5、R27接到左聲道R7。最後將中置聲道保護電壓的R33切斷，然後切斷及將中置聲道CP3輸岀接到左聲道CP1的輸岀便可。作為飛線所用的線我會用Telfon的鍍銀銅線。使用Telfon我覺得是必需的，因為Telfon質地比較堅硬不易被剌穿、亦因為它能夠抵受銲搶的高溫會較合適。在機內飛線有一定的危險性，Telfon線能夠將風險降到最低。至於鍍銀銅線這個可依據自已的頗好使用。R與S的做法亦和L與C一樣。我們首先將後置聲道進入R26及R28的線路切斷，然後將R26接到右聲道R6、R28接到右聲道R8。最後將後置聲道保護電壓的R34切斷，然後切斷及將中置聲道CP4輸岀接到左聲道CP2的輸岀便可。將二對管並聯以後需要先檢查及調校好偏壓，原廠指定的偏壓為22mV。你只需要將萬用錶接在CP1(L)及CP2(R) 便可。一般的情况下我會將偏壓調高一㸃增強電流的供應。有一點值得注意的是；這類擴音機都會有不少的保護線路，我會全部保留。這些保護線路有特定的作用而且不大影嚮音效，所以十分值得保留。
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| 中置聲道進入R25及R27的線路切斷 | 然後將R25接到左聲道R5 |
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| R27接到左聲道R7 | 將中置聲道保護電路的R33切斷 |
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| 將中置聲道CP3輸岀切斷並接到左聲道CP1的輸岀 | 將後置聲道進入R26及R28的線路切斷 |
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| 然後將R26接到右聲道R6 | R28接到右聲道R8 |
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| 將後置聲道保護電路的R34切斷 | 將後置聲道CP4輸岀切斷並接到右聲道CP2的輸岀 |
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| 中置聲道進入R25的線路切斷 | 將中置聲道CP3輸岀切斷 |
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| 然後將後置聲道CP4輸岀切斷 | 將後置聲道進入R26的線路切斷 |
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| 兩對管並聯後的其中一聲道 | 連接保護線路的電阻亦斷開 |
而放大線路推動的部份其實亦有四組，我們可以將它減為兩組進一改善提升供電的效能。基於中置聲道及後置聲道的推動的線路現在已完全沒有用途，我們亦會將這部份的供電切除。除去中置聲道的供電我們要除去R153/R159/R161/R149/R147/R145。除去後置聲道的供電我們要除去R154/R160/R162/R150/R148/R146。
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| 需要將中置聲道及後置聲道供電的電阻全部拆走 | 拆走了中置聲道及後置聲道供電的電阻 |
Kenwood KRV-7060唯一較差的部份是它的水塘，它只有二個7500uF 71V的電容。以100W輸岀的環繞立體聲擴音機來說是最低的標準。而且經過三十年的光景亦是換上新電容的時機，你大可以將它換成15,000MFD 70V或以上。我測試過這兩個電容仍然有不少的容量，所以我將它保留。我只是在每聲道的+/-電壓各並聯一顆1000uF 70V的電容，全部共用了四顆。
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| 原機水塘 7500MFD 71V | 多加了四顆1000MFD 70V的電容 |
到了這個階段這部 Kenwood 的 KR-V7060 的改動已經全部完成。改動後的KR-V7060外觀與原機是完全沒有分別，機裏面亦只會是少了整塊調諧器的線路。不得不贊的是KR-V7060的擺位是岀乎意料的理想。放在機中央的火牛將機的重量平均地分佈。左右聲道放在兩旁平衡的位置；再加上巨大(以機種而言) 的優質散熱器。這正是一部至理想不過的立體聲合併式擴音機甚至是後級的擺位設計。這是我挑選它的其中一個原因。經過改動的 KR-V7060 是一部不折不扣的合併擴音機。它的視頻及環繞的元素己經全都被清走。它跟原來的音效，相比之下是升了幾班。它可以輕易勝過原先與它同價值的合併擴音機，甚至可以挑戰比它貴一倍以上的合併擴音機。
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| 未改動前的 KRV-7060 | 改動後的 KRV-7060 |
改動後的 KRV-7600 總稱得上是將它起死回生，原本可能變成廢鐵的總算是有一點的生機。可算得上是為環保出了一番力，亦希望能夠改變一般將環繞立體聲擴音機定性為衰聲的觀念。我可以肯定起說環繞立體聲擴音機只要作適當的改動，音效比合併擴音機甚至是後級有過之而無不及。Kenwood KRV-7060的改動只稱得上是小兒科，但它的改動亦是所有進階改動的指標。下期我們會更上一層樓再進一步邁向更高的檔次。
保記 (03/24)
Can Audiophiles save the environment Episode 2 – Kenwood KRV-7060
I personally feel that environmental protection should be voluntary in nature. The cost of plastic bags when buying things may be insignificant to friends who can afford them, but it can be a burden for those from lower-income backgrounds. Paying for garbage bags is even more burdensome, especially for those who can’t afford it. In this regard, it doesn’t affect those who can afford it at all. The capable ones continue to drive their sports cars and sail their yachts as before. The world’s longest superyacht, the M/Y Azzam, is a staggering 180m long with a fuel tank capacity of one million liters (enough to fill the tanks of six Boeing 747s or refuel an average car 23,800 times!). In my lifetime, I couldn’t possibly use more than 20,000 tanks of gas! What does it mean to be environmentally friendly? The enormous carbon emissions it generates are borne by the lower classes! Unexpectedly, environmental protection has become part of the social inequality. As an audiophile myself, there are many aspects where I cannot prioritize the environment. My pre pre-amplifier, decoder, and CD transport all need to be constantly powered on; each of them consumes a significant amount of electricity because of the huge power supplies in them. Restarting them after disconnecting the main power takes almost a week for them to return to their previous state, and I can’t find a better solution. Amplifiers, whether stereo or surround sound models, also need to be large and as many as possible. I haven’t found any ways to save in these aspects either. I think you have to use what you need. The only environmentally friendly option is to repurpose and refurbish old equipment.
Many audiophiles may already be aware of the reasons behind the subpar sound quality of surround sound receivers/amplifiers. Allow me to briefly explain here: Firstly, a surround sound amplifier is essentially like an all-in-one component – a combination of a turntable or CD player, a tuner, and an amplifier. Having too many circuits together can cause interference between them. Using separate components, such as an independent turntable or CD player, a standalone tuner, and a dedicated amplifier, can generally solve the issue of poor sound quality. We can further divide the amplifier into preamp and power amp stages, or even use separate mono preamp and power amp combinations. Following these principles can help address the issue of degraded sound quality in surround sound amplifiers. If successful, a surround sound amplifier can fulfill the three main requirements mentioned in the previous article. Secondly, all the circuits are supplied by a single power source. Interference between the circuits directly affects the overall sound quality. Thirdly, as the functionality of surround sound amplifiers increases, their impact on sound quality also grows. For example, the number of amplifier channels has increased from five to as many as nine or more. Adding more functions naturally requires economizing on other components. So, how can we make a surround sound amplifier sound better? We need to start by addressing the factors that affect sound quality. To change the fate of a surround sound amplifier, we need to modify its internal circuits, which requires a certain level of electronic knowledge and technical skills. It would be best to find a service manual for the specific amplifier model, which is usually not too difficult to find through a quick Google search. However, modifying the original circuits carries some inherent risks. Our suggestions are for reference only, and the consequences are your own responsibility. We cannot guarantee success, so you need to make your own choices and be accountable for your decisions.
First, we need to choose the right candidate. While some Prologic surround sound amplifiers have good amplifiers inside, they may not be suitable. We require at least four to five channels with the same power output, and only a few later Prologic amplifier models meet this requirement. Most Prologic amplifiers have higher power for the left and right channels, while the remaining channels have lower power. Some later Prologic amplifiers have equal power output for the left/center/right channels, with less power for the rear left/rear right channels or even sharing one channel. Neither of these types is necessarily suitable for our needs. We need a minimum of four channels with consistent power output. Additionally, amplifiers that use IC power amplifiers are not suitable; we need amplification circuits with discrete components. I found a Kenwood KR-V7060 receiver amplifier that meets these requirements, and it also aligns with our basic concept for modification. Any modification in the future will be based on this concept. So far, I haven’t found anyone online who has made the same modification, so let me be the first to attempt this.
Before we begin, it is essential to state that any consequences resulting from the modifications are your own responsibility. You are solely responsible for any changes you make. Whether or not you decide to modify the equipment is entirely up to you. Before starting any modifications, always disconnect the power from the main. A prerequisite for my modifications is to preserve all the original protection circuits of the equipment. After the modifications, it is advisable to test the sound using speakers that have no value. If you end up damaging expensive speakers, you will be solely responsible for the consequences.
Kenwood’s KR-V7060 is a five-channel Prologic receiver with equal 100W output for the left/center/right channels, but only 25W output for the rear left/rear right channels. Wait a minute, this specification doesn’t meet our basic requirements at all. This is why checking the service manual is crucial. Upon closer examination of its service manual, we found out that the rear left/rear right channels share a 100W amplification circuit. In other words, the entire system has four sets of identical amplification components, and the power transistors are the SanKen 2SB1560 and 2SD2390, which are completely the same. Although the 2SB1560/2SD2390 transistors have been discontinued, reputable sellers still have stock available on the market, and they cost only around US$3 per piece. Finding alternative replacements is also not difficult, making it sustainable and meeting environmental requirements. These complementary transistors from Sanken are used in amplifiers of other brands, making them widely applicable. We will modify the Kenwood to either function as an integrated amplifier or as a stand-alone power amplifier, depending on your needs. Moreover, Kenwood’s arrangement conveniently places the left channel and center channel on one side, and the right channel and rear channel on the other side. This layout is crucial for our future modifications, as it is similar to the arrangement of a well-designed stereo amplifier or power amplifier. The two heatsinks inside the unit are also larger than those in comparable integrated stereo amplifiers (approximately twice the size, as there are two large heatsinks). Additionally, the unit is equipped with a cooling fan, so there are no concerns about heat dissipation.
First of all, whether it’s an integrated amplifier or a power amplifier, we shoot for the best sound quality. We will “try our best" to remove any circuits that are not relevant to achieving this goal. We can only “try our best" because sometimes the limitations of the original circuits prevent us from achieving 100% goal. Prologic amplifiers/receivers typically have video inputs and outputs, these circuits are now completely useless (I can’t imagine you’re still using composite video in/out!). Kenwood’s KR-V7060, being a Dolby Prologic amplifier from 1993, is no exception. It has a set of composite video inputs and output. This portion is controlled by IC203 (NJM2279D Video Amp Selector) which is powered by +/-15V. To disconnect the video section, we remove the two resistors R319/R318 (1W 390 ohms) that supply power to it.
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| Remove R318/R319 cut the +/-15V power supply to the Video I/O circuit | R318/R319 removed |
Next, we move on to the Prologic section. The entire surround circuitry is completely useless, including the DSP and Prologic IC. Therefore, they need to be removed as well. It’s important to note that after removing the Prologic section, you will only have audio signal when using the “Straight In" mode. If you don’t select this option, there will be no sound. This section is powered by +12V, and to remove the power supply to the entire surround circuitry, remove resistor R54 (15 ohms 1/4W) that supplies power to it.
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| Prologic (IC4) and DSP chip (IC3) | Cut R54 disconnected power supply to Prologic/DSP section |
The remaining parts are the tuner, phono preamp, preamp, and power amp sections. During the Prologic era, many manufacturers included a rather decent tuner circuitry in their units. However, with the advancements in digital circuitry and the popularity of streaming, tuner circuits have gradually been reduced. Tuner circuits in surround receivers nowadays are far inferior to that of the Kenwood. To achieve the best possible performance, I would recommend removing this section. My suggestion is to remove the entire tuner circuit board (X05-4472-72) to free up space inside the unit, making it more beneficial (less components, better circulation) without any harm. I remove the sockets from the board and reinstalling them on the rear panel. This step is crucial as it preserves the original appearance of the unit. No one wants to see unnecessary holes on the back of the receiver. If you feel that you still need a tuner in your setup (considering space constraints), you can keep this section. However, in my opinion, it is not difficult to purchase a used tuner, they should have better sound and are quite reasonably priced nowadays. An integrated amplifier without a tuner sounds better.
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| Tuner circuit board inside the Kenwood | Compare with tuner circuit of AV receivers nowadays, tuner circuit of the Kenwood is not bad at all |
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| Discrete tuner always sounds better | Discrete tuner has way better design, there is no point to save the tuner circuit inside AV receivers |
Similarly, if you don’t need the phono preamp, you can also remove this section. Ordinary AV receivers (including this one) usually use a dual operational amplifier (op-amp) IC for phono amplification, which usually won’t have the best sound quality. I will use a separate phono preamp instead, as it will improve the sound quality of your turntable and indirectly enhance the performance of the integrated amplifier. A friendly reminder: Many basic phono preamps are designed using a single dual op-amp IC. There isn’t much difference compared to the amplification circuitry inside the receiver. By using a separate phono preamp, you are simply adding an additional power source, which is better than having one less. Removing the phono preamp section is as easy as removing IC8 (JRC’s NJM4580). If you don’t want to remove the entire op-amp, you can simply cut off pin 4 (negative power supply) and pin 8 (positive power supply) of the IC. If you wish to keep the phono preamp section, you can consider replacing IC8 with OPA2134 (there are many other high-quality op-amp ICs to choose from) or two OPA134 single op-amp ICs for better results. I mentioned OPA2134 because it is readily available for me, feel free to choose any op-amp that you prefer as a replacement.
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| Phono amplifier is a single NJM4580 | IC8 removed |
Another section that you may not need is the tone control. The tone control in this unit also uses a dual op-amp IC (NJM4580) – IC203. This section is located inside the front panel. The simplest way to remove it is by disconnecting the cable to CN4 near the main power switch on the main circuit board. I don’t think tone controls is a good option, as it can introduce unwanted coloration to the sound. Personally, I prefer using equipment to tone the sound of the system rather than relying on tone controls. If you share the same preference, then removing the tone control section would be a good decision. However, if you feel the need to retain it for convenience, you can keep it as per your preference.
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| CN4 near the main power switch connects to the Tone Control circuit | Disconnect the cable on CN4 cut the entire Tone Control circuit |
In addition, there are two op-amps in the preamp section. IC1 (NJM4580) serves as the input buffer, you can replace it with OPA2134 or OPA134x2 for improved performance. IC7 (NJM4580) is responsible for a 10dB amplification for the center and surround channels, this section has been deemed unnecessary, you can completely remove this op-amp.
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| IC1 and IC7 are Input Buffer and 10dB amplification for surround sections | IC1 has been changed into OPA2134 and IC7 removed |
At this stage, we have successfully eliminated many unnecessary circuits. In fact, from the beginning of our modification until now, we only needed to remove the excess parts, without much soldering or desoldering involved. It’s rather straightforward. Each reduction in circuitry has contributed to an overall improvement in sound quality. We should be able to hear better separation, more detail, and some enhancement in the high, mid, and low frequencies. However, these improvements are just preliminary.
The next step involves changing the essence of an AV receiver, it is relatively more challenging. If you don’t have electronic knowledge or experience with soldering, I advise against attempting it. I must also emphasize that the consequences will be your own responsibility. Why have I chosen to have at least four identical power amplifier circuits (with the same power transistors and voltage) inside? The answer will be revealed in the next installment.
Paul Kee (2/24)
02/24
發燒友能否環保之二 – 實戰 Kenwood KRV-7060
其實有時總會覺得環保的概念必須是自願的性質。買東西的時候收的膠袋錢，對花得起的朋友來說是九仟牛一毛；對一般低下層來說實在花不來。拋垃圾要用付費膠袋更是百上加斤，這方面對花得起的亦絲毫無損。有能力的還是一如以往駕著跑車風馳電掣，駛著游艇碧海傲遊。世界上最長的 superyacht 是長達 180m 的 M/Y Azzam，油缸的容量為一百萬公升(足夠注滿六架747的油缸，一輪普通的汽車入滿油缸23800次！)！我一生人都沒有可能入超過二萬缸油！什麼叫環保？它耗費鉅額的碳排放就由低下層來低銷吧！勢想不到環保亦成為了社會上不公平的一部份。為了發燒我在很多方面都不能為環保著想。我的前前級、解碼、CD轉盤等全部都要在長開的狀態；每一部都有耗電量龐大的供電。拔去電源重新開機每次都要等差不多一星期才返回狀態，我找不著更好的方案。擴音機不論是立體聲或環繞立體聲的機種亦必須大而多。這幾方面我亦未找到節約的方法。我覺得需要的就去用，唯一可以環保的就只能夠將舊器材改變用途翻新一下。
很多朋友可能早已知釋環繞立體聲擴音機音效欠佳的原因。就讓我在這裏簡述一下：第一，環繞立體聲擴音機就等於一件將唱盤或CD與調諧器及擴音機加起來的三合一或四合一組合。將太多的線路放在一起的時侯彼此互相干擾。這類的三合一組合只要使用獨立的唱盤或CD，單一個的調諧器，獨立的擴音機；大致上都可以解决音效不佳的問題。我們更可以進一步將擴音機分為前級和後級，甚至是單聲道的前後級組合。要解决環繞立體聲擴音機衰聲的問題我們可以遵從上面的原理入手。如果成功的話環繞立體聲擴音機最能滿足到上面的三大要求。第二，全部缐路都由單一個電源供應。線路之間產生串擾，直接影嚮整體的音效。第三，環繞立體聲擴音機的功能越來越多，對音效的影響亦漸次地增大。例如單是放大器的部份由五組增加至部份達到九組之多甚至更多。放多了線路自然要减省其他部份的零件。如何能令一部環繞立體聲擴音機變得好聲？我們要從導致它衰聲的原因入手。要改變環繞立體聲擴音機的命運我們要先改變它內部的線路，要求你有一定的電子知試及技術。最好能夠找到原機詳細的維修線路，Google 一下一般不太困難。改變原機線路有一定存在的危險，我們的提議只供參考，後果是責任自負。我們不保証你一定成功，你需自行選擇及負責自已的決定。
Kenwood KR-V7060 走線圖
首先我們要選擇合適的對象。有部份 Prologic 的環繞立體聲擴音機雖然有不錯的放大器，但並不太合適。因為我們要求希望有最少四至五聲道相同功率的輸出，只有極少數較後期的 Prologic 放大器能夠滿足我們的要求。大部份 Prologic 放大器都只是左右聲道有較大功率，其餘聲道多是較少。部份後期的 Prologic 放大器將左/中/右的功率設計成等同的輸出，後左/後右則較少或者是共用一聲道的放大。以上二類的都未必適合我們的要求。我們需要最少四聲道一致的功率。另一方面使用IC放大組件的亦不適合，我們需要有獨立完件的放大線路。幸運地我找到一部 Kenwood 的 KR-V7060 收音擴音機正正符合這個要求，它亦符合我們改機入門的初階及基本概念。以後更深入的改進都以這個概念為本。到目前為止我未發現網上有任何人做同樣的改進，就讓我率先做這個嘗試。
在未開始之前必需聲明的是後果自負，我所做的改變我自已負責；你決定改機與否亦由閣下自行決定。改機之前一定先拔去電源。我改機的先決條件是必須保留原機所有的保謢線路，改了機之後最好先用沒有價值的揚聲器試聲；你燒壞幾百萬的喇叭都只能夠責任自負。Kenwood 的 KR-V7060 是一部五聲道的 Prologic receiver，左/中/右聲道各有相等的 100W輸出，後左/後右則只有 25W輸出。等一等，這個規格跟本完全不符合我們最基本的要求。這就是維修線路非常重要的原因。我們細看它的維修線路發覺它的後左/後右只是共用一個 100W的放大線路。亦即是說全機有四組百份之百相同的放大組件，所用的功率管亦是完全一樣 SanKen 的 2SB1560 及 2SD2390。儘管 2SB1560/2SD2390 亦早已停產，但在市場有信譽的賣家仍有存貨而且只是 US$3 左右一顆。要找替代品亦毫不困難，絕對是可持續發展的項目-切合環保的要求。這對 Sanken 的對管亦能夠在其他品牌的擴音機中使用，是普遍到不得了。我們會將這部器材改變為一部立體聲的合併擴音機或立體聲的後級視乎閣下的需要。而且 Kenwood 的安排剛好是左聲道與中間聲道在一邊，右聲道與後置聲道在另一邊。這個排列對我們之後的改動異常重要，這種佈局與一部設計得相當好的立體聲擴音機甚至是後級無異。機內的兩個散熱亦比同級的立體聲合併擴音機更大(大約是二倍，因為是兩個大散熱器。)，加上機內裝有散熱風扇；完全不用擔心散熱的問題。
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| Kenwood KR-V7060 | Kenwood KR-V7060 各聲道的分佈 |
首先無論是立體聲的合併擴音機或立體聲的後級，我們都要求靚聲。因此所有與它無關的線路都會“盡量”地除去。我們只能夠“盡量”，因為有時會因為原來線路的限制不能夠百份百達到目的。Prologic 擴音機一般都有視頻輸入及輸出，這個線路現在完全沒有作用(我不能夠想像你現在還在使用 composite video in/out!) 。Kenwood 的 KR-V7060 亦不例外，它是屬於 1993年面世；較後期的 Dolby Prologic 擴音機。它裏面亦有一組 composite video 的視頻輸岀及輸入。這個部份由 IC203 (NJM2279D Video Amp Selector)負責，用 +/-15V 供電。我們只需要切除供電輸入部份的兩顆電阻 R319/R318 (1W 390R) 便切斷了這個部份。
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| Video I/O 線路只需要除去 R318/R319 +/-15V 供電 | 除去 R318/R319 切斷 Video I/O 的供電 |
其次是輪到 Prologic 的部份。整個環繞線路完全沒有用處，而且裏面的 DSP，Prologic IC 等部份之後亦完全沒有作用；因此亦需除去。要注意的是除去了 Prologic 的部份之後只用 Straight In 才有訊號, 不按這個掣就不會有聲。這部份的電源為 +12V，我們只需要切除電源輸入的電阻 R54 (15R 1/4W) 便除去整個環繞線路的供電。
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| Prologic (IC4) 及 DSP chip (IC3) | 除去 R54 後切斷 Prologic/DSP 部份的供電 |
剩下來的是調諧器，唱頭放大，前級及後級的部份。在 Prologic 的年代很多廠家仍然會放一個不錯的調諧器線路在機內。在數位線路的進步及 streaming 的普及之下已逐步縮減。比較起近代的調諧器，這個線路都不太差。但為了要達承最佳的效果，我還是將這部份除去。我的做法是將這部份(剛好是 X05-4472-72 整塊) 的線路板除去；騰岀機內的空間，百利而無一害(減少零件，增加空間通風)。我必然會將原來的插座由板上拆岀來，裝回背板。這個做法非常重要，此舉保留了機的原貌。沒有人希望看到機背有一些不必要的空洞。所果你覺得你需要一個收音擴音機的話(擺放的空間是唯一的考慮)你可以保留這個部份。我的見解是要購買一個比機內更佳的調諧器並不困難，而且價錢亦不貴。沒有調諧器的合併式擴音機會較靚聲。
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| Kenwood 機內的調諧線路 | 相比近代的 AV 機 Kenwood 的調諧線路並非太差 |
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| 用分體式的調諧器更有品味 | 分體式調諧器的線路設計更完善，不需要眷戀AV 機內的調諧線路 |
同樣地如果你不需要唱頭放大亦可以將這部份除去。普通一般的AV機(這部亦不例外)只會用一顆雙運放 op amp IC 來做唱頭放大，不能稱得上靚聲。我亦提議你用獨立的唱頭放大來代替，唱盤的音效會更好，亦間接幫助合併式擴音機的部份有改進。溫馨提示：很多基本的唱頭放大都只是用一顆雙運放 op amp IC 來設計。這與機內的放大線路並無大分別，你只是多買一個獨立的電源；有多一個總好過少一個而己。除去唱頭放大只需移走 IC8 (JRC 的 NJM4580)，非常容易。如果你不想除去整顆 op amp 的話你大可以將 IC 的 pin 4 (-ve 供電)及 pin 8 (+ve 供電)切去亦可。若然你希望保留唱頭放大的部份，你可以用 OPA2134 (有很多其他更優秀的運放 IC 可供選擇）或兩顆 OPA134 單運放 IC 會有更出色的效果。使用 OPA2134 只是剛巧手上有，你大可選取你喜歡的 OP AMP 去代替。
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| 唱頭放大部份亦是簡單的一顆 NJM4580 | IC8 已除去 |
另一部份我覺得完全不需要的，就是 Tone Control。機內的 Tone Control 亦是用一顆雙運放 IC (NJM4580) – IC203。這部份放了在面版的線路上，最簡單的是在主底板上拔去在開關旁的 CN4 便可。同樣地我並無使用 Tone Control 的習慣。我一般會用器材去調聲。用 Tone Control 調聲一般不會太理想。同樣地你覺得有保留的必要是適隨專便。
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| 在電源開關旁的 CN4 連接 Tone Control 線路 | 直接將 CN4 除去切斷 Tone Control 線路 |
另外前級輸入的部份有兩顆 op amp, IC1 (NJM4580) 是輸入的 Buffer, 我們亦可以將它換成 OPA2134 或 OPA134x2。IC7 (NJM4580) 則負責中間及環繞聲道的 10db 放大，這部份已被廢除，我們可以將這顆 op amp 完全除去。
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| IC1 與 IC7 分別為 Input Buffer 及環繞的 10dB放大 | IC1 已改成為 OPA2134，IC7 已除去 |
到了這個階段，我們已經減少了不少多餘的線路。其實我們由開始改這部機到現在都只需要切走多餘的部份，連銲錫/除錫的技巧都不多用；真正是小兒科。每減少一份線路對整体的音效皆有所提升。我們可以聽到更加好的分隔度，更多的細緻，高中低頻都會有一定的改善。這個改善只是初步，最重要的改進在下面。
接著的部份是改變一部AV機的靈魂，難度亦相對較高，沒有電子知識及沒有試過銲錫的朋友請勿嘗試。亦是嗰一句，後果自負。為什麼我要選擇最起碼四組相同的功率放大線路(最起碼使用同樣的功率管及電壓）？答案在下期。
保記 (2/24)
Can Audiophiles save the environment – Episode 1?
(Preface: We have introduced many high-quality software products through “Hi Fidelity" in the past. Since you already possess quite a few high-quality software, you also need outstanding hardware to truly unleash the essence of music. Having exceptional hardware doesn’t necessarily require breaking the bank. We will introduce some unique methods to transform ordinary equipment into outstanding audio gems. Starting from this issue, “Paul Kee" will bring you these one-of-a-kind methods to change the fate of your equipment. This approach seems to have never been published on the internet before. We believe the results are way beyond what we are thinking, so we are pleased to present them to all of you.)
In recent years, many environmentalists have advocated for a Zero Waste Life, emphasizing the reduction of waste. However, for audio enthusiasts who frequently change and upgrade their equipment, it seems that zero waste is not achievable. Firstly, high-quality audio equipment typically consumes a significant amount of electricity. Whether it’s tube amplifiers, Class A solid-state amplifiers, or high-power amplifiers, they tend to have high power consumption and low efficiency. Unless your household uses zero/low-carbon energy sources, it is difficult to claim it as environmentally friendly. Class D amplifiers, which have extremely low power consumption, may not appeal to everyone in terms of sound quality. Personally, I am not a fan of this type of amplifier. Some equipment even requires long warm-up times to sound their best. Would you choose energy efficiency or superior sound quality? I would still choose sound quality. Listening to music is not inherently environmentally friendly. Manufacturing a CD generates a significant amount of carbon emissions and consumes a considerable amount of plastic. The production of vinyl records is even more detrimental. Some argue that streaming is environmentally friendly, but if you stream the same song dozens of times, the carbon emissions produced exceed those from manufacturing a CD. Moreover, the energy waste behind music production is immense. Can you abstain from listening to music for the sake of the environment? It is not uncommon for audio enthusiasts to frequently change equipment; it seems like a natural occurrence. The other half (tiger or little cat) of an audio enthusiast is rarely the first to be informed. The one who forbids you from changing equipment is the formidable tiger, while the cute little cat allows you to make changes any time you want. Requesting audio enthusiasts to be environmentally friendly and refrain from changing too much equipment is almost impossible. When it comes to new equipment, audio enthusiasts naturally lavish attention on them, but many of these devices are quickly abandoned after a period of time. Sometimes, the appearance of some second-hand equipment is truly pitiful, and you can’t even imagine why some equipment has been mistreated to such an extent. Of course, many people still choose to use older equipment. Purchasing second-hand equipment can be considered the only environmentally friendly action for audio enthusiasts. If you use a tube amplifier from the 1950s or 1960s, others will praise your taste. Owning a solid-state amplifier from the 1970s, 1980s, or 1990s, people will say you have insight. However, if you use a surround sound amplifier from the 2000s, your friends will tell you to upgrade. In today’s constantly evolving surround sound standards, it is inevitable that older formats will be phased out. It is very sad to see flagship devices from that era being sold as scrap metal. In this era of environmental consciousness where even a drinking straw or a small plastic bag is unwelcome, we must understand that recycling does not necessarily mean environmental protection. A surround sound amplifier contains thousands of components, not all of which can be fully recycled. Moreover, the carbon emissions produced in manufacturing these components are substantial. Additionally, many of these components contain harmful substances. We hope to find a method that allows audio enthusiasts to upgrade while also saving old equipment and making efforts towards zero waste and environmental protection. We will first focus on amplifiers, as it is challenging to meet all the requirements for other equipment. Our conditions are as follows: first, the price must be within a reasonable range. Second, it must achieve the goal of upgrading. Third, it should align with the concept of environmental protection.
First, let’s take a look at tube amplifiers from the 1950s and 1960s. These types of equipment don’t undergo significant changes apart from replacing parts and tubes. Additionally, these tube amplifiers are priced over a thousand dollars (US), which doesn’t meet our requirements. The second type refers to solid-state amplifiers from the 1970s, 1980s, and 1990s. If these types of equipment have good sound quality and a pleasing appearance, they can be quite valuable. However, the problem with this type of equipment is that they are already considered antiques, and all the capacitors inside need to be replaced. Not only that but finding original replacement parts for transistors or FETs can be extremely difficult. I’ve seen instances where a 1990s amplifier had different transistors for the left and right channels because the repair technician couldn’t find identical replacements and used compatible ones instead. I’ve also seen an amplifier originally using SanKen MT200 power transistors, but both channels were replaced with TO-3P transistors by the repair technician. Without a supply of original parts, the focus is on getting the equipment to function with substitute components. Let’s take the famous SanKen MT200 power transistors as an example. Although they are renowned for their excellent sound, they have been out of production for several years. Now, whether you buy them on eBay, Amazon, Taobao, AliExpress, or elsewhere, 99% of them are counterfeit and come from China. Buying this type of equipment is like buying a vintage car; you may only be buying the shell with a deceiving label. Moreover, these types of equipment don’t offer much room for upgrades, so they are not suitable for our environmentally friendly and upgradable criteria. Recently produced amplifiers do not need immediate replacement, and we hope they can survive a few more years before considering a change. Class D amplifiers are also not suitable due to design and circuitry constraints, making modifications difficult. That leaves us with surround sound amplifiers (surround sound receivers fall in the same category; they only have an additional tuner section, with the other parts being essentially the same). The sound quality of surround sound amplifiers is generally considered inadequate. If old surround sound amplifiers have inputs for multiple channels (5/6/7), most people would recommend purchasing a new surround sound processor and using the old one as a power amplifier for the multiple-channel input. However, this approach offers limited upgrade benefits because if the original surround sound amplifier had poor sound quality, using it as a “pure" power amplifier will not change its essence, as this power amplifier is not truly “pure." This approach is completely different from connecting a separate power amplifier for multiple channels. Some people also suggest using old surround sound amplifiers for stereo equipment. My response remains the same: if the surround sound amplifier has inherently poor sound quality, using it as a stereo amplifier doesn’t offer significant advantages. Even if you use features like Pure Audio or Pure Direct on the equipment, the effects won’t be noticeable. Moreover, regardless of whether a multi-channel surround sound amplifier is powered on for two-channel, 5/6/7/9-channel, or all-channel operation, all the unused channels, other input sections, the surround sound section, the video input section, and all the channels are consuming power unnecessarily. If you use analog input, all the aforementioned unused sections, along with the decoding section, are interfering with your signal and wasting power. From this perspective, surround sound amplifiers are not suitable for our purposes."
To change the fate of abandoned equipment, it will require some innovative thinking. What can be done and how can it be achieved? To be continued in the next installment. Stay tuned.
Paul Kee (01/24)
01/24
發燒友能否環保之一?
（前言：我們一直以來由“高原“介紹過不少高質素的軟件。大家既然擁有不少質素高的軟件，亦需要有效果超卓的硬件去配合才能夠發揮出音樂中的真諦。要擁有效果超卓的硬件，並不一定需要傾家蕩產。我們會介紹一些獨特的方法將平平無奇的器材變成音效突出的精品。由今期開始“保記”會為大家介紹獨一無二的方法，改變器材的命運。這個做法似乎從未有人在互聯網上發表過。我們覺得效果超乎理想，因此向大家介紹。）
近年很多環保之士都倡議 Zero Waste Life 零浪費。零浪費在經常換機、升級的發燒友來說，似乎並不存在。首先，靚聲的發燒器材絕大部分屬於耗電量龐大的產品。無論是膽機也好、A類的原子粒機、大功率擴音機等耗電量龐大效率低。 除非你家中使用的是零/低碳能源，否則根本不能環保。 耗電量極低的D類擴音機， 你是否喜歡它的音色則見人見智。 我自已並非這類擴音機的擁躉。有部分器材甚至需要長開才好聲。浪費電力與好聲？我還是選擇好聲。聽音樂根本就不環保。製造一張 CD 會產生不少的碳排放、耗用不少的塑膠。製造黑膠唱片更甚。有人説 streaming 環保，但若然你同一首歌streaming 幾十篇，產生的碳排放已超過製造一張 CD。而且製作音樂背後所耗廢的能源是超多。你能夠為環保而不聽音樂嗎？發燒友經常更換器材亦絕對不是什麼奇事，似乎是一件理所當然的事。發燒友身旁的無論是老虎或小貓一般不會是最先到得知會的一個。不容許你更換器材的自然是吊晴白額大虎。任由你更換器材的必然是可愛的小貓。要求發燒友環保，不要更換太多的器材幾乎是一件不可能的事。對於新的器材，發燒友當然是寵愛有加，很多器材過了一段時間後很快便被打入冷宮。有時看到一些二手器材的樣貌真是慘不忍睹，你根本都不能夠想像為什麼有些器材會被人摧殘至如斯地步。當然亦有很多人仍然選用舊器材。購買二手器材可說是發燒友唯一能夠做的環保。如果你使用一套五六十年代的膽機，旁人會讚你有品味。擁有一套70/80/90年代原子粒機的朋友，人家會說你有見識。如果你用二千年代的環繞立體聲擴音機的話，你的老友會叫你換機。在環繞立體聲制式不斷改進的今天，舊制式的器材被淘汰是必然的事。眼見一部部當年的旗艦被人當廢鐵賣，這是非常悲哀的事。在今天連一支飲筒、一個小膠袋都不能容得下的環保年代。要知道回收並不代表環保。一部環繞立體聲擴音機裏面動側有過仟的零件，這些零件並不是全部都可以還原的。而且製造這些零件的碳排放量非常龐大。何况這些零件內亦有很多有害的物質。我們希望找到一個方法幫發燒友升級之餘亦可以拯救舊的器材，為零浪費/環保出點力。我們首先集中在擴音機，其他部分的器材很難達到全部的要求，我們暫且不談。我們的條件是：第一，價錢要在萬元以內。第二，一定要達到升級的目標。第三，要符合環保的概念。
當年的旗艦的一例，超過50磅的廢鐵。
我們首先看一看五六十年代的膽機。這類器材除了換換零件及燈膽外，不會有太大的改變。而且這類膽機的價錢都過萬。並不符合我們的要求。第二類是7/8/90年代的原子粒機。這類器材如果它的音效不差，樣貌娟好的話；價值亦不菲。最麻煩的是這類器材已經是古董級，器材裏面的電容基本上全部需要更換。 不單上是這樣，若然器材有問題要找原裝的零件無論是 transistors 或 FET都十分困難。我曾經見過有一部九十年代的擴音機，左右聲道就使用了不同的管。因為做維修的找不到相同的便用相容的完事。 亦見過一部原來使用 SanKen MT200大管的擴音機，兩聲道都被維修的換成 TO-3P 管。沒有原装零件供應之下，總之代用的能夠出聲便算交貨。 就以 SanKen 著名的 MT200 大管為例，它雖然出名好聲，但經已全線停產了好幾年。現在無論是在ebay 買到的也好，Amazon 也好，淘寶也好，AliExpress 亦然；99%是假貨，都是來自中國。你買這類器材相等於買架老爺車，可能只是買個殼，得個睇字。更何況這類器材沒有太大的升級空間，因此亦不適合我們環保又升級的條件。近年生產的擴音機暫時不需要馬上更換，希望它們能倖存多幾年，遲一下再作打算。D類的擴音機亦因為設計及線路的問題，要作改動並不容易。因此它們亦不合適。剩下來的只有環繞立體聲擴音機（環繞立體聲收音擴音機都是同一類，它們只是多了一個調諧器的部分。其他部分基本上完全沒有分別。）。 環繞立體聲擴音機的音效一般都被視為不到位。舊的環繞立體聲擴音機若然有多聲道(5/6/7)聲道輸入的話，大部份人會提議買新的環繞立體聲處理器接駁，舊的用作為多聲道輸入的後級。這種做法只有極其有限的升級效果，原因是環繞立體聲擴音機原本是音效欠佳的話，將它用作為“純“後級並不會改變它的本質。因為這個後級一點也不“純”。這個做法與接駁一個多聲道的純後級是完全不一樣的體驗。有人亦提議使用舊的環繞立體聲擴音機作為二聲道器材使用。我的反應同樣是環繞立體聲擴音機如果根本是音效欠佳的話，用作為兩聲道擴音機同樣沒有太大的優勢。 就算使用機上的 Pure Audio 或 Pure Direct 等亦不會產生明顯的效果。而且一部多聲道的環繞立體聲擴音機在著機後無論是兩聲道也好，5/6/7/9聲道也好、全部聲道都全著。你聽兩聲道時其他的聲道、其他的輸入部份、環繞立體聲的部份、視頻輸入的部份及所有聲道都在幫你浪費電力。你用模擬輸入的話以上所有沒有用的部份再加上解碼的部份都在干擾著你的訊號，浪費你的電力。這樣看來環繞立體聲擴音機根本不是可做之材。
SanKen MT200 大管
要改變被人違棄器材的命運，相信要攪一點的腦汁。甚樣做，如何才做得到？下期續。
保記 (01/24)
12/23
CD 網頁之二十二 – O Mio Babbino Caro
上一期我簡略地介紹過 Patricia Janeckova (1998 – 2023) 短暫的一生。她雖然沒有什麼顯赫一時的錄音，但從粗略的錄影中我們已經能夠欣賞到她的歌聲。她後期獻唱 O Mio Babbino Caro 的一段估計是直接地在台下用手機輯錄。我經常批評的 YouTube 竟然有令我重覆聽了不止幾次的翻聽又再聽的吸引力。無可否認、來自 Puccini 歌劇 Gianni Schicchi 的 O Mio Babbino 是一首非常動聽的詠嘆調。要選十大最受歡迎的詠嘆調，它必佔一席。歌曲本身的旋律動聽外，哀怨纏綿的故事內容亦是吸引的地方。而歌詞與旋律的配合更是一絕，這與意大利文本身是很有韻律的語文有關。意大利文本身的抑揚頓挫，節奏感與唱歌無異；將它和音符配合亦不會是一件困難的事。詠嘆調的名字亦是樂曲的第一句 O Mio Babbino Caro, 樂曲旋律的節奏基本上就與誦讀這句說話的 flow 是一模一樣。意大利文天生的優勢亦成為了意大利歌劇受歡迎的原因之一。如果大家有看過 Brad Pitt 的 Inglourious Basterds，你可能會較易明白。電影其中的一節是描述 Brad Pitt 三人假扮意大利人混入德軍的電影首演。勢估不到的是飾演德國軍官 Col. Hans Landa 的 Christoph Waltz 竟然能夠講流利的意大利話。Brad Pitt 等的三個美國大兵當然露出馬腳，敗露的原因並非是他們不懂得意大利話。只是他們說話時欠缺了意大利人說話時的韻律，他們只是單單說出名字已被識破！Col. Hans Landa 在戲中說了一句: “One more time, but let me really hear the music in it.” Christoph Waltz亦憑著他精湛的演出而贏得奥斯卡最佳配角。意大利文的音樂牲，具韻律富旋律的朗誦，柔和的聲調令它成為意大利歌劇重要的基石。
我們首先了解一下 O Mio Babbino Caro 歌詞的內容。
| O mio babbino caro,mi piace, è bello bello,vo’andare in Porta Rossaa comperar l’anello!Si, si, ci voglio andare!E se l’amassi indarno,andrei sul Ponte Vecchioma per buttarmi in Arno! Mi struggo e mi tormento,O Dio! Vorrei morir!Babbo, pietà, pietà! | Oh my dear papaI like him, he is so handsome.I want to go to Porta RossaTo buy the ring!Yes, yes, I want to go there!And if my love were in vain,I would go to the Ponte VecchioAnd throw myself in the Arno! I am pining, I am tormented!Oh God, I would want to die!Father, have pity, have pity! |
作為最受歡迎的詠嘆調之一 O Mio Babbino Caro 自然不乏演譯者。我找來了五張不同的演譯跟大家分享一下。因為Puccini 歌劇 Gianni Schicchi 受歡迎的程度大大不及裏面的 O Mio Babbino Caro，所以選出來的都是來自雜錦鐳射唱片。
第一張來自 Naxos 的Cinema Classics 1，由 Miriam Gauci 主唱 Alexander Rahbari 領導 BRT Philharmonic Orchestra (Brussels) 的演出。Naxos 將它放入 Cinema Classics 系列之中原因是三項金像奬得奬電影 A Room With A View 選了它作為電影插曲之一。間接地亦提升了O Mio Babbino Caro 的受歡迎程度。Naxos 這張 CD 是九十年代初期的首版，Naxos 九十年代初期的 CD 都在德國印製；音效有一定的保証。
被選入電影 A Room With A View 中的 O Mio Babbino Caro 版本就是由 Kiri Te Kanawa 演唱，Sir John Pritchard 領導The London Philharmonic Orchestra 的演出；這個版本不可不聽。CD 是罕有的 Japan for US 首版，屬於第一代的 CD 由 Sony 在日本印製。CD 內圈為凸字CSR，是最早的版本。
聽歌劇一定不可缺少 Decca/London 的選擇，所選的是來自 Weekend Classics 的 Puccini Weekend。Felicia Weathers演唱 Argeo Quadri 領導 Wiener Opernorchester 的演出。Weekend Classics 是 Decca 八十年代未期推出，當年的平價版本。但因為是首版加上輯錄的大多數是 Decca 黑膠唱片黃金年代的精英，因此這批 CD 有一定的收蔵價值。選來的這一張在 PDO/W Germany 製造，全銀圈02首版。
Decca/London 八十年代未期亦推出了好幾張的 Golden Opera CD，收錄了 Decca 歌劇精英中最精采的歌劇片段。所選的這張 Golden Opera CD，由 Renata Tebaldi 演唱 Lamberto Gardelli 領導 Orcheatra del Maggio Musicale Fiorentino 的演出。選來的這一張在 PDO/Germany 製造，全銀圈01首版。
如果喜歡聽 O Mio Babbino Caro 的樂迷一定不會錯過 Maria Callas 的演唱。Maria Callas 一貫感情豐富的演譯有一定的吸引力，至於有沒有過火都是個人的喜好；但唱功是無容置疑。版本由 Maria Callas 演唱 Tullio Serafin 領導Philharmonia Orchestra 的演出。CD 為美國九十年代初期的出品，音效亦不錯。
我在上面只是隨便找幾個版本給大家体驗一下。如果大家喜歡 O Mio Babbino Caro 這首詠嘆調來比較，找到喜歡的版本一定不困難。或許你亦可以嘗訊由 Patricia Janeckova 開始。
高原 (12/23)
11/23
CD 網頁之二十一 — Patricia Janeckova
决定寫她之前思考了一段很久的時間，對於一個剛剛逝世的人來說；我必需要份外的謹慎及小心。因為這是一份對她最後的專重、敬抑。今年的十月一日只有二十五歲的 Patricia Janeckova (1998 – 2023) 因為乳癌病發而離世。自 2022年二月公佈確診到離世只是短短一年多的時間。在她自己公佈患病的消息時她說 ”Cancer has been, is and will be among us, although I have always thought that youth equals health.” 。十分惋惜的是她竟然打不贏這埸仗！有很多朋友對這位女高音可能並不認識，這正是我覺得需要向大家介紹的原因。現今世代傑出的音樂家少之又少，對於失去 Patricia Janeckova 這類深具天賦的表演者我們覺得心情是異常的沉重，痛惜之餘亦希望將她動人的聲音廣傳後世。
在德國出生捷克長大的 Patricia Janeckova 自幼受到當地濃厚的音樂文化所薰陶。四歲開始唱歌，小學之後在捷克著名的 Janacek Conservatory in Ostrava 修讀聲樂。十歲的時候已經被篩選能夠參與Janáček Philharmonic 的演出。2010年只有十二歲的她在捷克電視台的 TalentMania 中勝出，就連 CNN 都有留意到及報導；因此而一鳴驚人。CNN絕少會報導捷克的新聞，更何况是全無新聞價值的天才表演！(CNN 當年的描述: An amazing performance in Slovakia. Take a look. Oh my goodness. Her voice is amazing and she is just 12. Patricia Janeckova is the winner of the Czech/Slovak Talents Mania television show. Some 1.2 million viewers took part in the final vote; 53 percent favored her and you can bet the music world is taking notice. My goodness.) 她最受注目的表演之一就是她演唱 Ennio Morricone 著名的 Once Upon A Time In The West。我敢說 Patricia Janeckova 的演出，她演唱的難度比Ennio Morricone 禦用的Edda Dell’Orso 還要高。我們先聽聽Patricia Janeckova 這個 Standing Ovation 的演出。
我對 Patricia Janeckova 的認識是在早年由搜尋 Ennio Morricone 的 Once Upon A Time In The West 資料開始。最初在YouTube 聽到她的演出實在是驚訝。一個十二歲的小女孩竟然能夠運氣自如而且有如此宏大的氣量。她豐厚的聲底無論是去到難度再高的音符依然清脆撩亮，縱容不迫。 Once Upon A Time In The West 本身寫的是一個令人感動的故事，Ennio Morricone 利用音符將故事的内容生動地描繪出來。Ennio Morricone 巧妙地運用女聲啍出的樂韻在樂曲之中，這種聲音簡直是來自天堂。每次聽的時候都會不期然地閉上眼睛掉下眼唳。Patricia Janeckova 充滿熱情的演出在腦海中產生十分振撼的迴響，她的聲音不斷地在心靈深處回應；聽者無不動容。這個時間再重温她的演唱感受更是加了幾倍的沉重、百感交集，所有的感覺都昇華起來；刻骨銘心。
捷克這個東歐國家有深厚的音樂文化，孕育出不少的古典音樂家。Patricia Janeckova 順理成章亦是在歌劇這方面發展。她跟隨的Eva Dřízgová-Jirušová 是捷克著名的女高音歌唱家，她除了演出歌劇外亦在Janáček Conservatory in Ostrava 及 University of Ostrava 任教。Patricia Janeckova 使人另眼相看的表演就是捷克TalentMania 决賽中演唱 Puccini 歌劇 Gianni Schicchi 中的 O Mio Babbino Caro。 Gianni Schicchi 是 Puccini 所寫的三套短歌劇的最後一套、亦是最受歡迎的一套。 O Mio Babbino Caro 是其中最受歡迎的詠嘆調，大家都可能有聽過。我們先聽一下Patricia Janeckova 在 TalentMania 演出 O Mio Babbino Caro。
十二歲的 Patricia Janeckova 能夠唱出歌劇中 Lauretta 懇求父親 Schicchi 准許她與愛人見面的深切情懷。第一句的 O mio babbino caro (Oh my dear papa)已經能夠表達出整首樂曲的重點，她殷切的期望令每一個父親都會屈服下來。深情的演譯完全表達了主人翁 Laurette 的情意。O mio babbino caro 這首詠嘆調並不易唱，除了音域廣闊外，句子的起伏亦很大；特別在後面的部份。聽Patricia Janeckova唱出O Dio, vorrei morir (Oh God, I would rather die)，她運腔的圓滑順暢；唱出高音部份的氣量令人目瞪口呆。最後的兩句 Babbo, pieta, pieta (Daddy, have mercy, pity me!) 完美的演譯為樂曲帶來了一個哀怨纏綿的終結。除了是十二歲的她聲線比較嫩之外，我找不到其他可以批評的部份。我們再聽一下Patricia Janeckova 後期比較成熟的演出。這個視頻配上了字幕(意大利文及英文)大家會更容易明白歌曲的意境，有更深入的感受。
比起一般的女高音歌唱家，Patricia Janeckova 的演唱是直接了當。沒有半點的矯揉造作，沒有過火的感情表達；更没有過多的身體語言。她沒有刻意地展示她的唱功，亦沒有人工化的唱腔。她只是真摯地將歌劇中的角色演譯出來，效果恰到好處。
大家如果想對 Patricia Janeckova 了解多一點不妨去看一看她的 facebook，認識多一點她的過去；特別是她抗癌的歷情。
https://www.facebook.com/patriciajaneckova/
正如捷克電視台所說: Although only 25, she left a lasting legacy through her audio and visual recordings. Patricia Janeckova 留下的雖然只有少許的錄音片段，但每一段都刻骨銘心、不會忘記她的每一個段落。生命的可貴、生命的短暫；都縮寫在 Patricia Janeckova (1998 – 2023) 的一生中。
11/23 (高原)
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