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Old 28th October 2007, 01:34 PM   #61
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Would a 6W6 work in place of the 6V6? I am 6V6 poor at this point in time. What changes?
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Old 28th October 2007, 02:05 PM   #62
Salas is offline Salas  Greece
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I have never had 6W6s in my hands. For sure it needs to see 200V max plate voltage and has a much stronger heater. What kind of power transformer is handy for you? So we can speculate some values.
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Old 28th October 2007, 02:20 PM   #63
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I have a Thordarson T22T34 which is a 400-0-400 unknown current rating but would guess 100mA.


I also have an unknown brand which is also a 400-0-400 / .1A

Picture of unknown
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Old 28th October 2007, 02:37 PM   #64
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Hmmm...With this transformer you don't have enough heater current for even one 6W6 at 6.3V. Again 2x400 is way too much. You would have to throw away too much energy and heat on RC to go down to 350VDC. Anyway if you get a 350V B+ somehow, you may try 12K//12K 5W each for plate load and 680R+680R in series for cathode bias for each 6W6GT.
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Old 28th October 2007, 02:42 PM   #65
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There is one winding on the left side of the picture that is 6A/6.3Vand another that is 4A/6.3volt.

Wasting voltage is easy enough. Any idea on the other transformer?
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Old 28th October 2007, 02:46 PM   #66
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Quote:
Hmmm...With this transformer you don't have enough heater current for even one 6W6 at 6.3V. Again 2x400 is way too much. You would have to throw away too much energy and heat on RC to go down to 350VDC. Anyway if you get a 350V B+ somehow, you may try 12K//12K 5W each for plate load and 680R+680R in series for cathode bias for each 6W6GT.
Is this for the circuit in post #8?

How many mA for each tube?
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Old 28th October 2007, 02:48 PM   #67
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Aha, it has enough heater current to the left. I did not look there, bcs they normally depict primaries. As for the other transformer, it has the same secondary HT, so nothing more to think.

It is for post #22. Again 22mA, I targeted. But its only speculation. I don't have 6W6GTs so to tell you more. Its up to you to verify with measurement if you gonna get 30V on cathode and circa 225V on anode (my targets for R values I gave) when you gonna put it together.
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Old 5th November 2007, 10:26 PM   #68
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Default About new production valves.

I have been asked about using new production valves in this project. The answer is: No sonic degradation by using new production with this project. I got the chance to test an EH pair. They perform flawlessly with very good clarity and coherence. Best part is that microphonics are very very low. Seems that 6V6 is a very nicely behaving type as used here, just flavor changes, and the main performance envelope is always in frame. I will see about JJ 6V6s too, given a chance.
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Old 13th November 2007, 11:00 PM   #69
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Finally got those JJ 6V6 on my hands, they look really nicely built, hope they sound as they look.

Iím in the process of finishing other projects at the moment so it will take some time to do this one. First also Iíll redo the 417A to a 12B4 this will also serve as a comparison bed. Gee, Iíve done so many toob lines during the years, but Iím missing the parallel 6922 now that I remember.
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Old 13th November 2007, 11:45 PM   #70
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So you are charged with the noble task to check out the JJ for us.
Use o rings between 6V6 valve bases and chassis if you will not be making a decoupled sub chassis. It pays off.
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