I am building a circuit from an old (1961) article in "Electronics World". Stereo, dual 5AR4, 7591 in PP AB1, 0A3 for screen regulation and 6AN8 for gain/phase splitting.
5AR4 and 7591 are JJ (current production) and have heard that they sound very good. Already bought, think I will be pleased with those.
0A3 and 6AN8 still not purchased. I can find RCA for 0A3 and I have let myself offer 2 Marconi-Citation and 2 Channel Master. I want to alternate 6AN8's pair for my personal appreciation. I will ask for triode matching 5% tolerance.
Can I substitute 6AN8 with 6AN8A or 6GH8A.
Don't know Channel Master tubes except they are manufactured by Matsushita, Japan. Any comments.
Note: I am located in Canada and have a lot of hard fun to find NOS tubes here.
Your comments are appreciate.
Thanks.
HugoR
5AR4 and 7591 are JJ (current production) and have heard that they sound very good. Already bought, think I will be pleased with those.
0A3 and 6AN8 still not purchased. I can find RCA for 0A3 and I have let myself offer 2 Marconi-Citation and 2 Channel Master. I want to alternate 6AN8's pair for my personal appreciation. I will ask for triode matching 5% tolerance.
Can I substitute 6AN8 with 6AN8A or 6GH8A.
Don't know Channel Master tubes except they are manufactured by Matsushita, Japan. Any comments.
Note: I am located in Canada and have a lot of hard fun to find NOS tubes here.
Your comments are appreciate.
Thanks.
HugoR
6AN8/A has a unique pinout, with no other subs, so you'll want to get a few spares. 7199 is the classic choice for this circuit - another unique pinout. 6GH8 isn't as linear, but that won't matter much in a split-load phase inverter. 6BL8 might be better, same pinout as 6GH8. I have been meaning to try 6BH8, 6AU8, 6BA8 for this.
As explained above, the 6AN8 has a unique pinout and there is no direct substitute (except for the 6AN8A). If you are building the amp from scratch, I would suggest wiring the socket up to accept the tubes that are pin compatible with the 6U8. These include the 6U8, 6EA8, 6BL8, 6GH8, and others. That way you have many different tubes to choose from.
I am not familiar with your particular circuit, but I built a clone of an old Scott Laborotory Standard amplifier that used a 6BL8 as a gain stage / phase splitter driving EL34's although I used KT88's. I tried numerous tubes in this circuit, adjusting the resistor values for best operation with each particular tube. The best sounding standard tube was the 6BL8 with the best sounding brand being Amperex. There was a 4 digit " boutique" tube that was sold as a replacement for the 6BL8. It looked nothing like the 6BL8, but sounded really good. Unfortunately, they were in the amp when I sold it, and I can't find the number.
I am not familiar with your particular circuit, but I built a clone of an old Scott Laborotory Standard amplifier that used a 6BL8 as a gain stage / phase splitter driving EL34's although I used KT88's. I tried numerous tubes in this circuit, adjusting the resistor values for best operation with each particular tube. The best sounding standard tube was the 6BL8 with the best sounding brand being Amperex. There was a 4 digit " boutique" tube that was sold as a replacement for the 6BL8. It looked nothing like the 6BL8, but sounded really good. Unfortunately, they were in the amp when I sold it, and I can't find the number.
Dear Friends,
I will bring to life this relatively old topic.
I am starting to build a Dynaco Mk3 amplifier, so require a pair of 6AN8 lamps. I can't really find them in the local shops (Russia), only on e-bay.
Can you advise a substitute (if any) or a shop in EU | USA where I could by them for postage to Europe? thank you!
I will bring to life this relatively old topic.
I am starting to build a Dynaco Mk3 amplifier, so require a pair of 6AN8 lamps. I can't really find them in the local shops (Russia), only on e-bay.
Can you advise a substitute (if any) or a shop in EU | USA where I could by them for postage to Europe? thank you!
That's probably a 7643. Filament current of 330mA (verses 450mA) and a shield between sections.
at ESRC
Electron Tube List 6A3 - 6CZ5 @ ESRCVacuumTubes.com
ESRC will send wherever US Postal Service will take them
Electron Tube List 6A3 - 6CZ5 @ ESRCVacuumTubes.com
ESRC will send wherever US Postal Service will take them
AnatolyAA,
As Tubelab wrote above: “I would suggest wiring the socket up to accept the tubes that are pin compatible with the 6U8. These include the 6U8, 6EA8, 6BL8, 6GH8, and others. That way you have many different tubes to choose from.”
There are great Euro equivalents in the ECF series tubes, which you probably could find easily. ECF80 is equivalent to 6BL8 and ECF82 is 6U8. I am personally using ECF82 with excellent results in Dave Gillespie’s SCA35 mod (Tronola DIY Electronic Projects and More).
However, unless you have nostalgic reasons I think there are better circuits than the Dynaco Mk3 to build. Dyna was designed to be cheap and acceptable, but not superb. Do a search on Dynaco Mk 3 modifications and note all the alternative designs to “improve” the Mk 3.
As Tubelab wrote above: “I would suggest wiring the socket up to accept the tubes that are pin compatible with the 6U8. These include the 6U8, 6EA8, 6BL8, 6GH8, and others. That way you have many different tubes to choose from.”
There are great Euro equivalents in the ECF series tubes, which you probably could find easily. ECF80 is equivalent to 6BL8 and ECF82 is 6U8. I am personally using ECF82 with excellent results in Dave Gillespie’s SCA35 mod (Tronola DIY Electronic Projects and More).
However, unless you have nostalgic reasons I think there are better circuits than the Dynaco Mk3 to build. Dyna was designed to be cheap and acceptable, but not superb. Do a search on Dynaco Mk 3 modifications and note all the alternative designs to “improve” the Mk 3.
Hi AnatolyAA,
I understand the logic of the advice to start with Dynaco Mk. 3 and “move up to better”. But I am impatient and for my money I would start with “better”. I suggest you look at a fine Mullard modification implementation of the Mk3, called Poseidon, as shown on: http://www.diytube.com/unidriver/poseidon.pdf
I have been using my Mk3s with Poseidon PCB since 6-7 years now and they are superb (better than better
. (I prefer the 12bh7 as direct drop-in replacement in stead of the stock 12au7). Unfortunately the PCB is no longer available from diyaudio.com, but it could be purchased from Triode Electric, see: Driver Boards for Dynaco Mark II and Mark III
My purpose of mentioning the Poseidon is to point out what “better than 6an8” could be like. 12ax7, 6SL7 voltage amp, 12bh7, 6sn7 long-tailed phase splitter with CCS (constant current source) to ensure great balance and drive .
I understand the logic of the advice to start with Dynaco Mk. 3 and “move up to better”. But I am impatient and for my money I would start with “better”. I suggest you look at a fine Mullard modification implementation of the Mk3, called Poseidon, as shown on: http://www.diytube.com/unidriver/poseidon.pdf
I have been using my Mk3s with Poseidon PCB since 6-7 years now and they are superb (better than better
. (I prefer the 12bh7 as direct drop-in replacement in stead of the stock 12au7). Unfortunately the PCB is no longer available from diyaudio.com, but it could be purchased from Triode Electric, see: Driver Boards for Dynaco Mark II and Mark IIIMy purpose of mentioning the Poseidon is to point out what “better than 6an8” could be like. 12ax7, 6SL7 voltage amp, 12bh7, 6sn7 long-tailed phase splitter with CCS (constant current source) to ensure great balance and drive .
PC board for Dynaco MkIII is available at : PC-1 MKIII CC Resistors - Dynakit Parts They also have MkIV ( 4) boards both for 7199 and 6U8 variants. This board could be used as alternativ to PC1 for use with U8/6BL8/6GH8 tubes All boards are available as board only kits or mounted.
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