Audio Valve RKV MKII专辑：介绍、听感、摩机以及驱动KK的效果

davidxtb

交易区新帖推荐

RKV MKII交流群：221946512

一、我自己的RKV升级经验分享：
已经玩RKV有些年头了，和很多烧友也有分享，就RKV的升级来说，可以从以下几个方面入手：
1、运放换成OPA637BP，一般选择BP的塑封效果就很好，后来有烧友测试了OPA637SM说效果很好，细节更丰富一些，但提升并不是很大，和代价不成正比（修正此处关于金封运放的听感表述）
      运放一定从正规代理处购买，上海的易络盟是最安全的购买途径，价格是一对大约六百元。运放需要桥接电容，否则会有高频自激的问题。

2、管子换成TELEFUNKEN PCL805 ；SB ELETRONIK、VALVO富豪和MULLARD大盾、TUNGSRAM天梭。
这几种管子中最喜欢的是SB ELEKTRONIK，声音甜美，在这只管子面前，其他的管子都是俗物。其他管子，风根最为全面，泛音比较多，声音快慢合适，包围感和空气感都很好。大盾则是人声的极品之一。

3、给管子用上瑞宝的TUBESOX管套；
PCL805的管子还是素质有限，所以只能加强了，RKV的管子距离前面板和元器件都太紧了，只能用TUBESOX管套，而且这个是已知的效果最好的管套。

4、电源处保险管换成POWERHOUSE白金；
也许可以试一试其他的，电路板的上保险管可以更换，但需要换那种音染较小的。

5、RKV MKII下垫了ABA中板。

6、RKV对线材颇有要求，可以考虑用声音厚实的电源线。
至于备用品：
1、运放吗，除了原装运放之外，还备有两套，包括OPA627。
2、管子：VALVO富豪三套（17只NOS/NIB），TELEFUNKEN风根PCL805 NOS/NIB 两套（9只），RCA PCL805 NOS一套（4只包装盒略旧），RFT PCL805一套 四只，RSD PCL805一套四只；

二、厂家推荐的升级方案：
看过隔壁那台定制的RKV，如果能定制到那种，可能是更好的升级：
1、升级过的德国E.T.牛；
2、FUSE 升级成A.G.
3、电容升级成台湾国巨0124。
4、调音基本调用了原版调音，有着极强的动态表现能力，声音充实而有厚度。横纵声场控制非常好。比较偏向非流行的听音。声音很暖，没有附带低阻模块，不过可以在德国订制。
机身带有工程师金色签名。


三、RKV摩机的帖子详见梵天火凤兄的技术贴：
1、【金点值得拥有】——记RKV MK2更换级进式电位器http://bbs.headphoneclub.com/viewthread.php?tid=204314&page=1&authorid=141182
2、进一步打磨RKV MK2http://bbs.headphoneclub.com/thread-206148-1-1.html











最近有烧友推荐AD8610这款运放，已经查阅了一些资料，准备下一次试一试
关于这款运放的特点，有介绍：
AD8610整体音色属于厚声的类型，三频的分布相当均匀，层次感清晰，无刻意修饰，且音场非常好，解释力高，大动态表现下的三个频段衔接非常自然紧凑。
精密、低输入偏置电流、宽带宽JFET运算放大器： AD8610/8620
                        图片：

                        AD8620:  精密、低输入偏置电流、宽带宽JFET运算放大器(双路)

AD8610(单路)和AD8620(双路)均为精度极高的JFET输入放大器，具有超低失调电压和漂移、极低输入电压和电流噪声、极低输入偏置电流和宽带宽等特性。与其它许多JFET放大器不同，AD8610的输入偏置电流在整个工作温度范围内都很低。AD8610能够以同相单位增益稳定驱动1000 pF以上的容性负载，在更高噪声增益时则可以轻松驱动更大的容性负载。即使具有1 kΩ负载，AD8610的摆幅也能达到电源电压的1.2 V范围内，从而在有限的电源电压下也能获得最大的动态范围。在反相或同相增益配置中，输出压摆率均为50 V/μs，达到0.01%精度的建立时间不到600 ns。AD8610还拥有高输入阻抗、出色的精度和极高的输出驱动能力，从而成为驱动高性能模数转换器输入及缓冲数模转换器输出的理想放大器。

AD8610和AD8620的具体应用包括：电子仪器仪表；ATE放大、缓冲和积分器电路；CAT/MRI/超声医疗仪器仪表；仪器级光电二极管放大；快速精密滤波器(包括PLL滤波器)；以及高质量音频。

AD8610的额定温度范围为-40° C至+125° C扩展工业温度范围。AD8610提供8引脚窄体SOIC和小型MSOP8表面贴装两种封装。AD8620提供8引脚窄体SOIC封装。MSOP8封装器件仅提供卷带和卷盘形式。

Audio valve RKV Mark II 无输出变压器真空管耳机扩大机两声道独立分隔线路的A类同轴设计架构特殊自动偏压调整线路，能增长真空管的使用寿命 连结端子：两个立体声的耳机插座 (jackets 6.3 mm)
...................................................................................

RKV MKII参数

阻尼系数：3600
总谐波失真：< 0.002 % at 1watt - 200 ohm
最大输出电压：80 V
频率响应：15 Hz-100 KHz
真空管：4 * PCL 805（或者PCL85 or 18GV8），这种管子是电视管，产量巨大，但PCL85或者18GV8是低一档次的胆管，声音和寿命都要差 ）
输出功率：每声道 3 watt (100 - 400 ohm)
外观尺寸：高 14 x 宽 24 x 深 36 公分
重量：10公斤(台)

Specifications:
OTL - transformer outless tube amplifier
Double mono construction
Alps volume control
1 pair 6,3 mm stereo jacket for headphones
Tubes: 4 * PCL 805 (PCL 85 or 18 GV 8 - german old TV "vertikal" ampl. tube )
Power output: each channel 3 watt SINUS,  ( between 100 to 400 ohm loads )  
Bandwide: 15 - 100 000 hz
amping 3600 !
Distortion 0,002 % at 1 Watt-200 Ohm load
Max. output voltage 80V
Sens. 0dBm
IC - fullautom. - controlled bias
Class - A
Power consumption 40 watt
Size 360*200*120 mm (d.w.h.)
Weidht 10kg

      

:::   ultra high end dynamic headphone OTL tube amplifier   :::

:: Audio Valve is celebrating the 26h anniversary of the RKV since 1984 ::

http://www.audiovalve.de/rkv/engrkv.html

Tube amplifier for dynamic headphones – preamplifier and power amplifier at the same time

Up to now the RKV (tube amplifier for dynamic headphones), developped and admitted to our distribution in 1982, is by far the most successful tube amplifier in our product range.

Traditional Tube technology has been abandoned and replaced by completely unorthodox approaches to create a concept which is still unique in the amplifier fabrication. Also it has not been resigned latest semi-conductor technology and so a product occurred which reflects 40 years of electronics. The German patent office has secured this idea 1984 with the number DE 3200 51.

“Why headphone amplifiers” – so the Reader might ask. “Doesn’t my output at the receiver suffice?” The answer is simply No. Good, dynamic headphones have a high impedance. For high dynamic jumps, e.g. from CD-Players, they require much higher voltage levels than the supply voltage of transistor amplifiers, which would otherwise be a possibility. The same applies to Hi-Fi systems. So it was one requirement for the amplifier to bring high levels. Moreover it was important to achieve short-circuit strenght and excellent technical data, under the special note of tube sound. The existing concept possesses all this qualities.

By reason of the conformation to high terminating impedances the OTL principle has been appropriated. This concept is geared now to the classic example of the so-called transformerless power amplifier. With the help of semi-conductor technology it has proved to be a felicitous symbiosis of the last 40 years electro-physics.

Also all negative existing aspects of the tubes, like weathering and tolerance hum, had to be eliminated. The RKV-electronic manages this problems effortless. An Op-Amp in the signal path creates a servo circle that compensates all above mentioned negative characteristics of the tubes.

It is even able to stabilize the operating point automatically, regardless the weathering of the tube, so that even older tubes continue working without problems. This automatic control circuit has no influence on the quality of the sound, even at the abrasion of the parts.

When judging the sound especially the high dynamic of the amplifier and the typical tube sound are to mention.The bass is tight and enormous, the middles are aery and from a liveley transparency and the high range shows an excellent release combined with transparent space.

Other products on the market, which want to force their headphones to diabolic peaks by the use of smaller battery voltages or 40mWatt output power, just fail here. Cost-intensive headphones, for example by GRADO or AKG, require effort and just there the RKV is the only reasonable driver source.

Of course the amplifer comes with all this qualities as well in his function as a pre-amplifer for power amplifiers. In this case the output voltage of the RKV is decreased to his 15th part and laid on another pair of Cinch Sockets on the backside of the amplifier.

But there is even a third way of using the RKV. The performance of nearly 2*3 Watt is also adequate for driving loudspeakers. Therefore we use the so-called “Impedancer”, that reduces the output impedance of the RKV to the size of the loudspeakers impdedance. Basically high-class transmitters which scale down the output voltage. With loudspeakers starting from 93 dB you can receive an excellent musical result.

The RKV as an universal genius in this three category groups of Hi-Fi technology has no competitor that is nearly able to hold a candle to him in this prize class. For all the people who only consider two of this mentioned possibilities for their own use the RKV is already the only right decision.

http://www.audiovalve.de/rkv/2010_t_1.pdf

[url=http://www.audiovalve.de/rkv/2010_t_2.pdf]http://www.audiovalve.de/rkv/2010_t_2.pdf[/url]

[url=http://www.audiovalve.de/rkv/2010_t_3.pdf]http://www.audiovalve.de/rkv/2010_t_3.pdf[/url]

tech. describtion:

• OTL - transformer outless tube amplifier
• double mono construction
• Alps volume control
• 1 pair 6,3 mm stereo jacket for headphones
• tubes: 4 * PCL 805 (PCL 85 or 18 GV 8 - german old TV "vertikal" ampl. tube )
• power output: each channel 3 watt SINUS,  ( between 100 to 400 ohm loads )   
• bandwide: 15 - 100 000 hz
• damping 3600 !
• distortion 0,002 % at 1 Watt-200 Ohm load
• max. output voltage 80V
• sens. 0dBm
• IC - full autom. - controlled bias
• class - a
• power consumption min. 60 watt
• size 360*200*120 mm (d.w.h.)
• weight 6kg
• patent full automatic servo tube biasing

Impedancer unit

• 4 different loads switchable
• 1 pair speaker terminals
• 1 pair 6,3 headphone jackets

以前看RKV的听感，都觉得说的并不是很到位，今天看到刘名振的评价，倒是不错。转贴如下：

勞斯萊斯級的耳朵享受

AudioValve  RKV MarkⅡ 耳機擴大機

http://09047.so-buy.com/front/bin/ptdetail.phtml?Part=new14

焦点：

特殊专利线路并享有100年德国专利法保护.OTL放大，以稳定的性能提供长时间的真空管寿命。声音丰润带着高贵的光泽、音场宽大。低频细节丰富又有控制 力，是示范级的表现。驱动力极强，可展现耳机真正实力。

建议
阻抗在100奥姆以下的耳机，建议搭配同厂的Impedancer使用。搭配越高级的耳机，越能欣赏本机的音质优点。此耳扩声音太美太舒服，没有任何刺耳失真，用家请注意控制音量，以免声音太大伤害听力。
我对耳机扩大机一向有点疑虑：二十年前，音响界根本没有耳机扩大机这东西，而在录音室内，我也没看到录音师鉴听时使用耳机扩大机。我们真的有必要舍弃音响器材上的耳机插座不用，而去买耳机扩大机吗？AudioValve认为耳扩是有必要的（理所当然，不然怎么会生产耳扩呢？）：因为现代的讯源如CD有着极 大的动态变化，而动态的变化在驱动耳机时就是电压的变化，一般扩大机内的耳机输出，根本无法应付巨大的电压变化，因此无法反应讯源或是录音中的优秀表现。

使用特殊真空管
既然耳机扩大机的设计目标很明确，那么AudioValve设计者Helmut Becker就开始研究：什么是最佳的电压放大组件？那当然是真空管。真空管的限制又是什么？要能够输出足够的电流，这样才能应付较低阻抗的耳机。第一代的RKV在1984年诞生，当时就找到了特殊的PCL 805真空管，这是当年给电视用的五极管。

RKV MarkⅡ采用无输出变压器的OTL全真空管差动放大线路。少了输出变压器的影响因素，真空管的表现就很重要了。为此RKV MarkⅡ用上了AudioValve特别为之申请专利权（编号DE 3200 517 ）的特别线路。Helmut Becker认为这线路确实的反应了四十年来音响技术的进步，因为在供电处使用运算放大器，讯号路径上又完全是真空管放大，等于是取真空管与晶体管两方最佳的技术结合而成。这线路以运算放大器构成的直流伺服线路供电，会随着每根管子的状况自动调整。原厂宣称即使在真空管寿命到达尽头时，这个线路仍会让它很 正常的工作。

有细节与控制力的低频
以往本刊喜欢告诉大家应该要「以耳机为师」，但是要能「为师」的耳机再生其实并不容易。耳机没办法像大型喇叭那般发出震撼我们身体的低频能量。以我使用多年的Sennheiser HD-580（阻抗300奥姆）试听，透过RKV MarkⅡ再生出来的低频绝对是肥美丰润又充满控制力与细节，与聆听大型喇叭的感觉已经非常接近。
与我自己的Graham Slee Voyager携带式耳机扩大机比较，我可以第一时间断定RKV MarkⅡ更好听。但是这好听是从何而来？是比较多的细节吗？我快速的在两台耳机扩大机中切换，并不觉得它们在细节表现上有任何差异。但在长时间的聆听后，我开始发现RKV MarkⅡ的优点：它的声音有种宽大、饱满、稳健的基础，这种宽厚又轻松的特质，让人听了非常舒服，一点压力也没有。另外，RKV MarkⅡ的声音有些许温暖、金黄色的光泽，并不会让人觉得是古董管机的声音，但是这一点点的温暖与光泽，就让弦乐听起来更有质感、吉他听起来更有弹性。

驱动力极强
将耳机换成Beyerdynamic DT 990 Pro（250奥姆）后，两台耳扩之间的差异更明显：Graham Slee Voyager需要将音量转到九点钟方向以后才有足够的增益，而且驱动起来声音也不够丰满；但是换RKV MarkⅡ上场后，声音变得大开大阖、动态、稳定性都是第一流的，这才彰显出这款旗舰耳机的身价。至于两款低阻抗的耳机，AKG K240 Studio（55奥姆）与Grado SR60（32奥姆）表现算中规中矩，不过与参考耳扩之间的差异就没有那么明显。AudioValve对低阻抗耳机（100奥姆以下）的搭配方案是请用家 选购Impedancer阻抗匹配器，面板上有切换旋钮，可以从8奥姆到64奥姆作四个档次的切换，机器上还有喇叭输出端子，可以驱动一些很高灵敏度的喇 叭！

耳朵的享受
虽说RKV MarkⅡ的身价不低，但依照我自己的经验，好的耳机器材一用十几年也不会坏，更不会落伍，是个非常保值（而且必要）的投资。

Tube amplifier for  dynamic headphones – preamplifier and power amplifier at the same  time
            
Up to now the RKV (tube amplifier for dynamic headphones), developped and admitted to our distribution in 1982, is by far the most successful tube  amplifier in our product range.
            
Traditional Tube technology has been abandoned and replaced by completely unorthodox approaches to create a concept which is still unique in the amplifier fabrication. Also it has not been resigned latest semi-conductor  technology and so a product occurred which reflects 40 years of electronics. The German patent office has secured this idea 1984 with the number DE 3200 51.
            
“Why headphone amplifiers” – so the Reader might ask. “Doesn’t my output at the receiver suffice?” The answer is simply No. Good, dynamic headphones  have a high impedance. For high dynamic jumps, e.g. from CD-Players, they require much higher voltage levels than the supply voltage of transistor amplifiers, which would otherwise be a possibility. The same applies to Hi-Fi systems. So it was one requirement for the amplifier to bring high levels. Moreover it was important to achieve short-circuit strenght and excellent technical data, under the special note of tube sound. The existing concept possesses all this qualities.
            
By reason of the conformation to high terminating impedances the OTL principle has been appropriated. This concept is geared now to the classic example of the so-called transformerless power amplifier. With the help of semi-conductor technology it has proved to be a felicitous symbiosis of the last 40 years electro-physics.
            
Also all negative existing aspects of the tubes, like weathering and tolerance hum, had to be eliminated. The RKV-electronic manages this problems effortless.An Op-Amp in the signal path creates a servo circle that compensates all above mentioned negative characteristics of the tubes.
            

            
It is even able to stabilize the operating point automatically, regardless the weathering of the tube, so that even older tubes continue working without problems.  This automatic control circuit has no influence on the quality of the sound, even at the abrasion of the parts.
            
When judging the sound especially the high dynamic of the amplifier and the typical tube sound are to mention.The bass is tight and enormous, the middles are aery and from a liveley transparency and the high range shows an excellent release combined with transparent space.
            
Other products on the market, which want to force their headphones to diabolic peaks by the use of smaller battery voltages or 40mWatt output power, just fail here. Cost-intensive headphones, for example by GRADO or AKG, require effort and just there the RKV is the only reasonable driver source.
            
Of course the amplifer comes with all this qualities as well in his function as  a pre-amplifer for power amplifiers. In this case the output voltage of the RKV is decreased to his 15th part and laid on another pair of Cinch Sockets on the backside of the amplifier.
            
But there is even a third way of using the RKV. The performance of nearly 2*3  Watt is also adequate for driving loudspeakers. Therefore we use  the so-called “Impedancer”, that reduces the output impedance of the RKV to the size of the loudspeakers impdedance. Basically high-class transmitters which scale down the output voltage. With loudspeakers  starting from 93 dB you can receive an excellent musical result.
            
The RKV as an universal genius in this three category groups of Hi-Fi technology  has no competitor that is nearly able to hold a candle to him in this prize class. For all the people who only consider two of this  mentioned possibilities for their own use the RKV is already the only right decision.

另：关于在1984年诞生第一代的RKV的相关信息只能看到，胆管用是PCL805，机体中并未将音箱接口分体，反而是做入机体内。具体见下图：

AudioValve RKV mk1-1.jpg

AudioValve RKV mk1-2.jpg

AudioValve RKV mk1-3.jpg

AudioValve RKV mk1-4.jpg

产品说明书：
PDF文档


[ 本帖最后由 davidxtb 于 2013-1-6 23:18 编辑 ]

davidxtb

万元以下，实在是找不到什么更好的选择，这次再入RKV也算是无奈。
台湾音乐的测评：

【Audio valve 德國Hi-End頂級耳機擴大機 RKV MKII─體驗真空管的完美之聲】

類比之聲 無論您是不是一個音響迷，相信都聽過這樣一句話"聽音響還是要聽真空管的最好"，姑且不論此言是否為絕對之理，但至少點出了類比聲音透過真空管放大後的迷人之處。相較於晶體機，真空管擴大機比較容易營造出一股溫暖的氛圍，尤其那滿是韻味的中頻更是容易令人陶醉於音樂之中，德國 AudioValve RKV MKII 耳機擴大器正是箇中翹楚。


華麗於外 首先 RKV MKII 擁有一個高貴華麗的外觀，全機以永不退流行的黑色為基調，烤漆質感細緻而大方，再搭配大型金色音量旋鈕及角墊，黑與金交錯出一股專屬於德國 Hi-End 器材的貴氣。上蓋部分採用厚度達一公分的全透明壓克力版，結構完整外另有一股視覺協調之感。

精華其中 RKV MKII 上蓋採取全透明設計有另一個重要功\\能，使用者對內部線路及用料可以一覽無遺，廠家唯有在對自己產品有百分百信心時才會如此設計。日本大廠 DENON 以及美國重低音品牌 Velodyne 在推出旗艦產品時，專門置於展覽會場的展示機也有採取全透明上蓋之設計，但此舉在量產機型上則相當少見。

音場自然 RKV MKII 給人的第一印象便是音場寬闊而自然，完全沒有將聲音侷限於兩耳之間的感覺；相反的，音場相當輕鬆便跨越過左右耳機單體間的距離，令人感到有如徜徉於大草原般的舒適感，長時間聆聽下來甚至讓人有忘了耳機存在的錯覺。


有血有肉 RKV MKII 的另外一項特長便是那濃濃的類比之聲，這點當然歸功於其真空管放大之優勢。若將音符譬喻為人之骨架，RKV II 便是為其填補了血與肉。以金池的"昨日重現"為例，人聲的部分透過 RKV MKII 顯得尾韻十足，聲音變得鮮活而更有感情。

低頻層次 RKV MKII 不只是韻味過人，在低頻的刻畫上亦有其長處，畢竟已經是到了如此等級的機器，實在不可能偏廢哪一個頻段而忽略了整體表現。RKV MKII 在低頻的層次描繪上相當清晰而有紋理，清楚而明確，這正是其低頻控制力的展現。以發燒演奏片 Faro 為例，Fany Kammerlander 所演奏的低音提琴，其下端頻段的延伸更為精進，許多細微的低頻變化都有如被放大了一般，低頻的細節清晰可聞，令人驚豔。


請君親試 無論再多的文字還是比不上您的親自聆聽鑑賞，RKV MKII 在音悅已經充分 burn-in，隨時保持最佳狀態，歡迎樂友撥冗試聽，感受經典 Hi-End 耳機擴大器 RKV MKII 的迷人魅力。

Consonance Cyber 20 by Opera Audio

Frank P Cheng (gundam91), 7-26,2004, 01:42 AM

I know that many people have been inquiring about this amp from China. I had read the review on Positive Feedback and had inquired about it on the amplifier discussion board on several occasions, but no one seemed to have heard it firsthand. When I found out that my friend could get me one for a good deal in China, I decided to take the plunge.

Before I go any further, I just want to state in advance that every review is subjective. My observations of the amp are based on my personal experience, my prejudice and preference. With that said, I think it is important to describe about my background. I listen to a variety of music from Jazz to Classical to 80's alternative to Chinese. But these days, I listen primarily to Hard Bop and Free Jazz from the 50s and 60s. To this point my primary interest has been on speaker-based systems (since 1992). When I started out this hobby, dynamics and details were two of my top priorities. Through the years, the focus has shifted towards tonal accuracy, good soundstage, and a warmer, lush, and laid-back sound. This transition is apparently in the evolution of my system with the addition of tube based equipment (preamp, phonostage, and DAC) + vinyl front end.

I had been thinking about adding a pair of headphone to my system for a while as I enjoy late night listening sessions, but my wife does not. With a baby on the way, I thought this would be a good time to finalize that plan. I had settled on a pair of Sennheiser HD600s basically based on the good reviews on all the different magazines and the price. I had listened to the HD600 before at Stereophile Shows mainly at software vendor booths for auditioning CDs. The only two criteria I had for the amp was that it must be tube based as I believe the combo of solid state amp and Senn HD600 would sound too bright, based on the listening experiences I had at Stereophile Shows, and the price range should be under or around US$1,000. Originally I had considered the ASL MG Head DT and the Music Fidelity X-Can V3. Both had received pretty good reviews from the like of Stereophile/The Absolute Sound. I then thought about the Earmax, which I had heard at the Stereophile Show in SF several years ago. At last year's Stereophile Show in SF, I searched high and
low, hoping to hear some good headphone setups the software vendors usually set up for show-goers to listen to CDs.

Unfortunately, there was only Shure pushing their new earphones and a software vendor with several pairs of Stax's. When I ventured onto the Head-Fi website several months ago, I got a really good education on how many good amps are out there. After "studying" tons of information, I had come up with a short list of amps that I would want to audition - Audio Valve RKV MkII, Singlepower MPX3 and PPX3, the Earmax Pro, the Rudistor RP5, and also a max-out PPA (I know, it's a solid state amp) since so many people had sung praises about it. During the last mini-meet in San Jose, I brought my digital front end to the meet and had the opportunity to borrow several amps to try on my system. I thought the Emmeline had an overemphasis in the midbass region that made it sounded somewhat artificial. The PPA had good dynamics, extension at both ends with tight, contolled bass. But it sounded bright, and has a very typical Solid State (SS) sound. The three amps that impressed me were the RKV, the prototype SDS Labs/PPA hybrid amp by Head-Fi members amb & morsel, and the Singlepower MPX3. I fell in love with RKV's lush midrange. Female vocal on RKV had me dropping my jaw to the floor. The Singlepower MPX3 had a balanced presentation with speed and good control of the bass for a tube amp, and it was magical with reproducing solo pianos. The SDS Labs prototype also had a very balanced presentation, and good bass "slam". Both are a tad on the warmer side of neutral. I would say the MPX3 edges the SDS Labs prototype slightly in the midrange area. Around that time, a friend who knew I was looking for a headphone amp e-mailed me the review of the Cyber 20 on the positive feedback website. The article peaked my curiousity as the reviewer replaced his long-time reference, the Earmax, with the review unit at the end of the audition.

The unit was packed in double boxes. When I opened the box, I was surprised to find a pair of white cotton gloves and a manual written in simplified Chinese. I browsed through the manual quickly just to make sure I don't end up doing something I would regret, and because I can't really read simplified Chinese characters. Then I donned the white gloves and took out the Cyber 20 and its outboard power supply. The unit itself is not light, the power supply even heavier. I was surprised to find that the tubes were already plugged in place while in the box, and they didn't break off during the trip. The unit is well built, solid ?" thick anodized aluminum front plate with a very heavy volume knob and a high/low impedance switch. The back consists of a pair of gold plated RCA jacks and connector for the power supply. The only complains I have are: 1/ both the amp and the outbound power supply sit on three pucks, two up front and one in the back. When I tried to swap out the tubes, the amp would tilt over easily. 2/ The chassis is of a light creamy gray color. It made the amp look somewhat cheap. I wish it were painted black. But from the front, all you will see is silver front plate. The amp came with a pair of the Russian 6n14n (6pi14pi) tubes and one Electro Harmonix 12AU7. I immediately tested the tubes in my TV-7DU tube tester. The pair of Russian 6n14n tubes was not matched. Prior to listening, I installed Pearl Tube Coolers on all three tubes. (Latest version with Carbon Fiber Sleeves) My first impressions were that the amp sounded pretty good, good detail, good wide soundstage, and good dynamics. It sounded somewhat bright and thin. My immediate thought was that this sounded like a solid state amp. The amp has a switch for high- and low-impedence. I tried both settings with my HD600 and a pair of Grado SR-60. Surprisingly, I did not agree with Positive Feedback that low-impedance setting sound better. For the remaining review, I just left it at high-impedance setting. The background was dead silent, even when I turned the volume knob all the way up, pitch black, not a hint of any hum. The volume does drop when you plug two headphones into the amp. I let the amp burned in for over 10 hours using XLO/Reference Recordings Burn-in CD. It still sounded bright to my ear. After doing some research on Head-Fi.org, I suspect the cause to be the Russian tubes. I immediately swapped out the tubes with a set of the Russian 6n14n-EB and an RCA 12AU7 cleartop. I let the amp burned in for another 10 hours or so. It helped reduced some of the brightness, but not by much. I later swapped the Zu Mobius cable with the Cardas cable, and that made a big difference. I think the Zu Mobius was too revealing and did not work well with this combination. I also tried the Clou Red Japis. It sounded congested as the soundstage was "squeezed in". Overall, the Cardas cable seemed to have the best synergy (with my system).

A pair of GE 7189As (gray oval plate) which I had purchased on eBay arrived few days after the amp did. They passed the test on my TV-7DU tube tester as a matched pair. So, I immediately plugged them into the amp, with some high-temperature resistant silicone o-rings. I let the tubes warm up for about 20 minutes before listening. Oh, my lord! What a difference. The smoothness was still there, but the brightness was gone. The midrange magic associated with NOS tubes was definitely there. The dynamic range was not as good as with the Russian tubes. The bass is typical of tube amps, on a sluggish side. But the overall tonal balance and presence gave a sense of realism, and the amp sounded more musical.

I had spent a good amount of time with the SinglePower MPX3 and the Audio Valve RKV MkII at the San Jose meet. In my system, Cyber 20's sound signature is somewhere between these two fine amps. It's speed and extension on both ends doesn't quite approach that of the MPX3, but sounded slightly warmer in the midrange than the MPX3. But female vocals did not sound quite as seductive as the RKV MkII. With NOS tubes, I would say this SET amp exhibits all the virtues typically associated with tube amps. These assessments are based on what I remembered from the meet, so another round of side by side comparison would be required to verify these assessments.

Associate Equipment:
Sonic Frontier SFT1 (transport)
Mark Levinson #36 (DAC)
Seismic Sink CD Sink (for SFT1)
Audio Selection Cones (for ML#36)
1 ?" thick wood block (under the Cyber 20)
Powercords: MIT Z-Cord II, switched to PS Audio Statement(Cyber 20); John Rische DIY PCs for SFT1 & ML#36
PowerVar 1200 AC Conditioner
Standesign Rack.
MIT MI-330HE Interconnect
MIT MI-330 Reference Digital Interface Cable
Sennheiser HD600 + Cardas/Zu Mobius replacement cables

This system was part of my second system which was in the room that we had converted into the baby's room. I packed away the preamp (ARC LS-1), the amp (Pass Lab Aleph Os), and the speakers (Unity Audio Signature 1s). The original system sounded very different than my main reference system, in that this system is more musical (in relative terms), it had the warmth usually associated with the tube equipment, and is more laid back, and spacious. I would attribute this characteristic to the amp (Pass Lab Aleph Os) and the speakers (Unity Audio Signature 1). I enjoy listening to female jazz vocals on this system.

My reference system consists of the following component:
Analog Front: Michell Orbe SE + SME V + Shelter 901 + Cardas Golden Reference cable
Digital Front: Mark Levinson #37 (transport) + Genesis Digital Lens + Sonic Frontier SFD2 MkII
Amplification: ARC PH3 SE (phono) + ARC LS2B MkII + Mark Levinson #333.
Speakers: Thiel 3.6
Cables: Illuminati D-60 digital/Kimber KCAG (analog)/MIT MI-330 Proline balanced/Transparent Ultra
PS Audio PP300; Ultimate Outlet 20A; Audio Prism ACFX; Electra Glide Reference II PCs on digital fronts; John Rische
DIY PCs on phonostage; two separate dedicated 20A AC line.

Test CDs:
Jane Monheit - In the Sun Tsai Chin - Chance Encounter (this CD, piano solo + vocal, was the rave in Asian Hi-End
circle for the past few years. The music was great, and the recording was excellent. It was a standard demo CD at every
hi-fi store and every Hi-Fi show, JVC XRCD2 reissue). Sonny Rollins - Saxophone Colossus (JVC XRCD2 reissue)
Yo-Yo Ma - Solo
Originally written on July 6, 2004; Revised on and off during the next 4 months.
Update 1: July 23,2004

I have had the Cyber 20 in my system for about 3 weeks now. My son was born a few days after the amp arrived.Contrary to what I thought it would be, I hadn't turned on my headphone amp at all during that time, but my main system has been on almost 24/7. He's still got the day/night mixed up. So he's usually wide awake between 1am and 3am. I played a lot of classical music for him, and he seems to like piano sonatas the best. They really keep him calm at those hours.

I have assembled quite a bit of 6BQ5 tubes in the past 3 weeks including some current productions: Electro Harmonix, JJ/Tesla, Ei (Yugoslavia), and some NOS: GE, Sylvania, RCA, Raytheon, Mullard. I have not had a chance to try them all yet as I've only had the opportunity to turn on the headphone amp twice in the past three weeks. I liked the sound of the GE 7189A (USA). I had just fired up the amp the other night with a pair of Sovtek EL84Ms which I borrowed from a friend. I would assume that these had been burned in previously. I allowed the amp to warm up playing a CD for about 45 minutes before listening to them. To my surprise, these tubes sounded darn good, unlike the Sovtek 6DJ8/6922 tubes which had received bad reputation for sounding bright and lean. I had paired the Sovteks with an RCA 12AU7A cleartop. The word luscious comes to mind in the midrange. The amp did not sound so analytical as it had before with those Reflektor 6n14n tubes. I was impressed with the excellent overall tonal balance as well. The bass is a tad more sluggish, (softer?) when compare to the 6n14n tubes, but it sounded great with that acoustic jazz bass, really brings out the luscious wood sound.

I think this amp is a good contender in its list price range (US$699). It's a hell of an amp at US$350. I am hoping to have a chance to bring this amp to one of the local meets so I can compare it with some other amps. The amp responds significantly to tube rolling. Depending on what your taste in music is, I think you can find a set of right tubes to tweak the sound to your liking. If you get one and you listen mostly to classical music, jazz, or acoustical music, take out those Reflektor tubes and replace them with either the Sovtek EL84M which can be had for about $20/matched pair or some NOS tubes. I think it's a must. If you listen mostly to Rock, I think those Reflektor tubes would do just fine, but you might find ear fatigue an issue after listening for a period of time.

Update 2: mid September
I went crazy the past few weeks and started to purchase 6BQ5/EL84 tubes from online vendors and eBay. At last count, I think I have over 60 NOS tubes from Amperex, Mullard, Sylvania, GE, RCA, and Reflektor. Yeah, I think that calls for a few sessions with the Audio Asylum resident psychiatrist to control my spending impulses. I had cycled through a pair of Amperex EL84s and currently a pair of Amperex Bugle Boys 7189 with "D" getter from 1949. I had also switched the input tube to one Amperex 12AU7 with orange globe logo. On all three tubes, I used the Bluenote Midas tube dampers.

After 20 minutes of warm up, oh yeah, baby! It sounds sweet! The bass on "All or Nothing at All" sounds deep and full. As mentioned before, bass is somewhat sluggish and bloated, typical of tube amps. But her voice sounds just SWEET, and somewhat "emphasized". One thing I enjoy about tube amp is that you can tweak the sound just by plugging in tubes from different manufacturer. I've also found that different tube dampers also change the sound in different ways. I had replaced the Pearl tube coolers you see in the pictures with some Midas tube dampers. These tightens the bass, but also made the midrange sounded somewhat lean. At the end, the best solution I found was to use the Midas tube damper on the 12AU7 signal tube, and silicone O-rings on the EL84 driver tubes. I gave it another listen with the two impedance settings. For the Senn HD600, the switch seems to affect the overall
balance of the sound. When switched the high impedance, there seems to be a lot more bass, to a point I think it is slightly too much for my liking. When switched to the low impedance setting, the volume goes down by a few dB. When I turned the volume up to try to match the previous volume, I noticed that it sounds leaner in the bass. The midrange is not as bloomy. I would describe it as more tonally accurate/balanced. And it gives the impression that the bass is tighter in comparison to high impedance setting. Which setting is better? I guess that depends on what music you listen to and what your mood is like at that moment.
Update 3: 11-13-04
I got to compare the amp with a Headroom Max today. The result was the classic tube vs. solid state battle of the titans. Eweitzman, who brought over the Headroom Max, and I both agreed that the Max is probably more tonally accurate, balanced, has more control in the bass region, and better dynamics. The Cyber 20, on the other hand has a warmer midrange, and sounds more "natural", and has a more expansive soundstage. I got a good sense of the soundstage with the Cyber 20, but the placement of each instrument was not as well articulated as that of the Headroom Max. The Cyber 20 cost 1/5 of that of Headroom Max, but I would put it in the same league in terms of performance, albeit the fact that they are two very different animals. I've seen so many posts on Head-Fi.org asking which amp is the best at certain price point, or which mates the best with which headphone. At this stage of the game, it's not which is better, but which one you prefer, i.e. Porsche vs. Ferrari, BMW vs. Mercedes Benz. The difference was best demonstrated in the Holly Cole
CD where she was doing a piano solo. Her voice sounded "weightier" with the Cyber 20. With the Max, her voice sounded colder and leaner, and I could hear some sibilance through the Max. The piano, on the other hand, sounded more accurate with the Max. At the end of the comparison, I still prefer the sound of the Cyber 20. It was less fatiguing, and has a pleasant relaxing sound, which mate well with my digital front end and the type of music I listen to
to a pair of Mullard EL84s. The powercord swap gives the system a tighter bass. But I think changing from the Amperex to the Mullards added the bloom to the midrange, and the loss of some dynamics. So far, I think the Amperex fares the best in this amp, although I still have some GEs, RCAs, Sylvanias, Electro Harmonixes, and E.I.s to try out. Below are his comments about the showdown:
"After getting through some very minor differences in tonality, noise, sibilance, etc, the most striking result was that the Consonance was totally different from the other three [referring to Headroom Max, stock HP-100A, and modified HP-100A]. It clearly had some distortion in it compared to the others, but it managed to open up the soundstage to about 3 times the size/depth of the others. Where the others were flat/wide but had no real soundstage, the Consonance pushed things up, down, back, forward. It was literally like the difference between vinyl and digital: open and spacious on one hand, flat but with more precise definition on the other.
I read this last night from a long marketing paper by Floyd Toole of Harmon: If a room's reflections are "energetic", the sound is perceived as open and spacious with a good sense of depth, but specific images are rather vague. In other words, like real concerts. This is precisely what I've been struggling to describe, what I hear when comparing CD to LP. I've had trouble nailing down the fact that on LP, the images are vague. Sure, you can tell where in the soundstage a voice or instrument is, and it may even have some bubble of spaciousness around it, but normally not as well defined as on CD. The one time the Consonance's presentation fell on its face occurred when playing a wall-of-sound rock recording (Pet Shop Boys). It was confused sounding and muted compared to the others. I've theorized that the spaciousness of LP was due to random phase changes caused by vibrations bouncing around in the mechanical system of the record player. Hearing this tube amp produce the same type of sound field, I'm wondering if it's a type of added signal delay that is perceived, psychoacoustically, as a reverberant field, tricking our minds into "hearing" a performance space which is not there. Then again, the amp could have some very cool delay-crossfeed "spatializer" circuitry in it.
Back to the amps: I can certainly appreciate the allure of the Consonance, but I prefer what I believe to be the accuracy of the other amps. The HeadRoom is superior in terms of clarity, uncolored sound, and noise level, and it had a weightiness to the bass that none of the others matched."
Final thoughts: The Cyber 20 is a good product, I have compared it to several products in the $1000+ range, and I can honestly say that it is a competent amp capable of challenging amps costing few times more and still stand its ground. It is not perfect in any sense. But I think it really comes down to personal preferences and system synergy. With some good NOS tubes, this amp can really sing. I think I have found the perfect amp that matches really well with my digital front end.
Eweitzman commented that it has an "LP-like" sound, not fatiguing, produces a great sense of space, and sounds very musical. At the end of a stressful day, when I listen to some of my favorite CDs, and relax on my lounge chair, this system simply transports me to another dimension. And that is what it is all about. And those Russian tubes, I think I will keep them close to the amp for those times when I feel like "jamming" with some good rock/pop.



Head-Fi (Headphone Hi-Fi and Portable Audio) > Equipment Category Forums > Amplification > Featured Full Reviews of Amplification Components > Preliminary review of Consonance Cyber 20 by Opera Audio
Copyright 2004, Frank P Cheng.

[ 本帖最后由 davidxtb 于 2012-8-4 09:19 编辑 ]

mayao11

又入一台啊，恭喜

t1174

再入RKV...lz 對 rkv 真是滿滿的愛. 利用上次的經驗, 其望 lz 的新 rkv 表現更上一層樓吧.

[ 本帖最后由 t1174 于 2010-6-1 15:22 编辑 ]

fashao319

情人还是老的好！
恭喜

davidxtb

audio valve

RKV Mark II headphone amplifier

as reviewed by Carlo Flores

Let me tell you one of the reasons I like Dr. Jan Meier. After he read my review of his HA-2 headphone amp, he told me that I favored tube sound (I do), and asked if I had heard the Audio Valve RKV Mark II.  A week or so later, PFO received one for review. I do not know of another instance in which one manufacturer offered another's product for review, although I should point out that Dr. Meier distributes Audio Valve products in North America. Meier seems to care more about his customer's needs than he does about hyping his designs. I mention this because I consider the HA-2 the standard for performance/price, against which I must measure the RKV.

Audio Valve's RKV Mark II is an OTL tube amp that measures a little over 5 x 9 x 12 inches in size and is priced at $1050 shipped. According to Audio Valve's website (www.audiovalve), it was designed by Helmut Becker to drive any load between 32 and 2000 ohms, but it could not quietly drive my 40-ohm Grado HP-1 headphones without a transformer (an option packaged as the $180 Impedancer), so I used my Sennheiser HD580s. Finding replacements for the RKV's set of four Tungstram PCL805 tubes is said to be easy, although I believe that tube rollers will find limited options. The amp's piano black finish with gold trim is more garish than elegant—it would look sharp in Snoop's crib, but a picky girlfriend may give grief. Its paralleled pair of single-ended inputs means that it can act as a two-source headphone amplifier or function between a source and preamp. An IEC receptacle and two headphone jacks are included. The top lid is made of a transparent material and is secured with metal thumbscrews, which allows easy access to tubes and fuses as well as amorous glances at its sexy red PCBs.

There's a lot I like about the amp. It was so good during the first month that I felt seduced. I think of music reproduction as a three-part process—attack, body, and decay—and I give the RKV good marks in each. It has an almost lush sound, full but not bloated. Even when paired with an average-sounding digital source like my modified Sony CE-775, the amp contributed an analog-like reverb to strings. It sounded noticeably fatter and sexier than the HA-2. For example, Pulp's Intro—The Gift Recordings has lots of crazy riffs that sound electric and awesome with most amps, the HA-2 included, but dominating with the RKV. For you audiophiles, Norah Jones sounded huge.

I can't overstate that the RKV makes music sound damn good. It's all about midrange, bass, and decay, though I'm not saying that the high frequencies suffer, because they don't. I am not talking about impact or detail, but about finding the music. The word that comes quickest is "wet." Notes sound wet when played through the RKV. A groovy acoustic guitar, such as Jonathan Richman's, has adequate groove, which is an accomplishment for a system featuring the HD580s. I'm also talking about the kind of soundstage that makes me forget I'm wearing headphones.

Magnifying this is bass performance that pushed the Sennheisers to their limit. I prefer a quick midbass and a direct relationship between the lowering of frequency and a note's thickness, and the RKV gives me what I want. The Sonics' foundation, Serge Gainsbourg's pace, and Mos Def's beats just sounded right, and involved me as a listener. I've heard more expensive amps mess up the lower notes. Unlike them, the RKV ‘s separation between bass notes is distinct, and while their impact is somewhat weak, instruments have adequate weight.  When the foundation of notes is this good, I find myself turning into a bass head.

What did I lose to get that scale? A great amp gives up very little, if anything. HA-2 doesn't even try to sound big, preferring to achieve frequency balance, and it offers Dr. Meier's cross-feed to recordings that need consolation. The RKV ignores audiophile sensibilities, offering gray backgrounds and little resolution at low levels. While the stage is very wide, placement within that stage is fuzzy at best. It's easy to focus on one instrument—to ride a stringed instrument or be caught in a piano—and get lost when listening to the RKV. However, place that instrument in relation to the others, and things turn messy. As with badly set up speakers, the image of each performer is soft and indistinct. People who want scale in a small room with reflection problems know what I'm talking about—the nuance is gone. Albums sound good, but hardly ever interesting. If you owned this amp, why would you invest in high-quality recordings when you cannot hear their full potential? This is a music lover's amp, not an audiophile's.

I have not mentioned my reference headphone source, the Audio Note 2.1x CD player, because it does not complement the RKV and the HD580. Instead, it yields an unbalanced but juicy sound, appealing at times (Nick Cave's piano in the song "Into My Arms") and irritating at others (Nick Cave and The Bad Seeds' album Murder Ballads). Unlike the HA-2, which mates well with even the most flavored sources, the RKV gets in the way. In the end, the RKV is a designer Band-Aid that will help a system that needs to add flesh to notes. It probably would have been great with my old reference, an Arcam Alpha 9, or other typically dry British sources. The RKV only disappears at moments, depending upon song and instrument. As much as I like this amp, I believe it has too many flaws—its inability to drive low-impedance headphones, its high noise floor, and its lack of balance—at $1195. The HA-2 can be the foundation of a system. Find the headphone you want and it'll drive it. Choose a flavored or unflavored source and you'll hear the characteristics the designer wants you to hear. It costs almost half as much, and it comes with cross-feed. For me, this just isn't a contest.

After about a month and a half of listening to the RKV, I received an Impedancer for review (to the left of the RKV above). The Impedancer is a passive device meant to match its load to its input. It is a stand-alone product that will work with other headphone amps. It has a small footprint, and will fit comfortably next to an RKV in a standard-width stand. The Impedancer's rotary bypass control is a gold knob that matches the RKV's volume knob. On the front face are gold-plated speaker binding posts, turning this into an integrated amplifier for high efficiency speakers, which I did not try. There are also two headphone outputs on the front face. Most importantly, the Impedancer allows listeners to use the RKV with the dynamic headphones that matter, including Joseph Grado's HP-1000 series and Sony's R-10s.

The Impedancer and RKV together are quieter than the RKV alone. I found that I listened at my lowest levels using the two together. Considering the price of cables nowadays, $180 makes the Impedancer a no-brainer, even when using high-impedance headphones. Nevertheless, the Impedancer did not drastically change my opinion of the RKV/HD580 combination. After listening to the RKV with my Grado HP-1s, I realized that the soft-sounding Sennheisers, paired with the RKV, were more mush than lush. While the HD580s' and RKV's flaws overlap, the HP-1s' focus and leading line gave a sense of balance. Side-to-side placement was better than adequate, and the RKV's depth was in proportion to the HP-1s' somewhat shallow stage. On some recordings—Tom Waits' Blue Valentine, Aimee Mann's Bachelor #2, and Dylan's Time Out Of Mind, to name a few—the combination yielded a haunting and spatially interesting sound. Perhaps it was more pretty than natural, but I like that. The HA-2, Headroom Max, or Sugden Headmaster amps don't make me sink into a song quite like the RKV can with certain recordings.

Everything that was good with the RKV stayed good with the Impedancer and the HP-1s, especially bass. This was where the lowered noise floor of the Impedancer made an impact. My perception was that the top was faster and the bottom thicker. Still, other amps can go lower, and I can only wonder how this amp would sound with a completely black background. Again, the HP-1s complemented this amplifier, and the combination rocked. Hell, I spent a day listening to The Sonics and The Zombies because this system rocked so much. Not many amps feed my love for distortion and wicked midbass.
Yet I would not call this amp fast. It does better with sultry electronica (Tricky's Maxinquaye) than with trippy and fast electronica (Aphex Twin). Transient information doesn't pop out of the black, as it does on quieter components. Are excellent macrodynamics worth the loss of microdynamics? Is scale more important than subtlety? The RKV will always sounds like the RKV. I listen to albums I know and things sound different. Then I think about how good womens' voices sound with this system, and I reach for a Joni Mitchell album. I see why so many like the RKV.

The Impedancer is a required option, even if using it means only that so you can divorce yourself from Sennheisers. That makes this a $1230 system.  The RKV is at least the equal of the Headroom Max, though you will give up the Max's pitch-black background and winning linearity. I'd take the RKV over the Sugden Headmaster and many other amps, but I couldn't have it as my primary amp, and I don't think of it as a reference unit. Flavor doesn't matter unless the basics—again, black background, linearity, and separation—are addressed. The RKV, even with the Impedancer, only gets two correct. She's a nice change of pace, but not the girl I'd marry.

Update
After completing this review, I found out that an RKV Mark III is in the works. The Mark II is still available, but Positive Feedback is glad to pass along the first picture of its replacement. As you can see, the amp is still in the prototype stage. Dr. Meier told me that Helmut Becker has focused on low-impedance loads and a substantially lowered noise floor, eliminating the need for the Impedancer. As you can see, the input tubes are no longer the same as the output tubes, and while their type/family hasn't been released, they are more common than PL805s. This will be the first all-tube amp with cross-feed, and its price will be lower than the Mark II.  While this is exciting, I am skeptical about getting everything I want at a lower price. Still, this may be our first glimpse of one of the great sub-$1000 headphone amps. Carlo Flores
Audio Valve
web address: www.audiovalve
Meier Audio
web address: http://home.t-online.de/home/meier-audio
RKV MKII本身可用於32-2000ohm的耳机, 阻抗匹配器是针对特定常用的阻抗如8/16/32/64ohm四个档位进行调节，所以那个阻抗匹配器也就是只有四个定位，再扭就扭不动了。

阻抗匹配器还有一个最广泛的用途就是用上面的四个金色输出端子接AKG的k1000(或小功率需求的喇叭!), RKV MKII推k1000 的功力也是很著名的.

KK一向以难推著名, 耳扩中除一些特别设定的之外, 很少有能将KK推的好的, 一般都是出动到综扩, 但力道够并不代表声音必然好. 在驱动KK的二房中，RKV算是不错的一台。当然更好的应该是Cary SLI-80/CAD300SEI了。

RKV驱动KK在音乐性及细节方面表现不错, 换了管子和运放后，表现还能更进一步, Cary SLI-80/CAD300SEI和RKV最主要的表现差异是当在聆听大编制的音乐时气势会相 对强的

如果是驱动K701的话，连接在低阻适配器上，并调节到64ohm档位上，在RKV驱动下的K701声音大气饱满。两万元之内比RKV强的二房屈指可数了。


AKG KK转接线的接法：
1 白 左＋
2 黑 左－
3 红 右＋
4 兰 右－




[ 本帖最后由 davidxtb 于 2012-8-4 09:13 编辑 ]

Flysoftter

在哪买的？多少钱？我也有意！

fsscn

唉，那个杀千刀的就这样跑了？RKV确实好物，听过两次念念不忘，可恶某人不肯卖我

沉迷

恭喜LZ，有机会一定欣赏下:D

长风破浪

LZ买这个很容易？怎么我们这边还有人打听到哪儿去买啊？

schpeltor

RKV现在多少钱了？

anythrk

这耳放看上去很漂亮啊。请教熊大，适合推什么耳机呢？ 正在为PSK寻觅耳放中

看门人

无坚不摧，可以用来形容RKV。

但这句话不是我的原创。

沉迷

推T1应该会很扎实澎湃

davidxtb

PCL805   

Identical to	PCL805
Similar Tubes	Normally replaceable-slightly different:PCL85
First year	1968 Tube leaflet collection E.Erb Analysis by original leaflets
First Source(s)	May.1968 : Funkschau (FS) 1968, Heft 9
Predecessor Tubes	PCL85
Base	Noval, B9A
Was used by	Radio/TV-reception etc.
Filament	Vf 17.5 Volts / If: 0.3 Ampere / -: Indirect  / -: Series,  AC/DC  /
Description	Usually used as field oscillator and output in TV receivers. The PCL805 was issued with dual markings with the same data applicable to both (Mullard data Nov 1968)    However the PCL85 was a very badly designed valve which failed repeatedly. The replacement PCL805 was better - these tended to have a shortened life, though, if the cathode bias resistor which had been badly cooked by its predecessor hadn't been checked and replaced if necessary. (These carbon composition resistors tended to drop in value quite considerably and seriously over-ran the replacement valve if not replaced.)
Dimensions (WHD) incl. pins / tip	22 x 79 x  mm / 0.87 x 3.11 x  inch
Tube prices	0 Tube prices (visible for members only)
Literature	Manufacturers Literature

买管子的时候一定要看明白了是PCL805还是PCL85，两者的素质有明显的差异，虽然可能价格方面不会有什么差异。

[ 本帖最后由 davidxtb 于 2011-3-8 18:25 编辑 ]