Tube Sources for Exemplar 3910?


Hi,

I have an Exemplar-modified (Denon) 3910 and need tubes. I've been using GE NOS 6829s since I bought the unit (new) 3 years ago. Does anyone know of a good source for these tubes? (Andy at Vintage Tubes was recommended to me by one person). And, ALSO, does anyone know if the 6829s are still the best tube to use with this player?

Thanks!
John
jfz
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I have many Amperex 7062s and think they were for the 3910 and 5910s when I had them. In the Tube Substitution Handbook, I looked up 6829 and found 12AV7s and 5965, which is noted as not working in all circuits, but this is not relevant in this case. The 7062s are shown to substitute for 5965s and E180CCs. So I think you can use 7062s for the 6829s. I think that is why I have so many.

I would check with John Tucker at Exemplar, however.

I should note that the 6829 and 7062s are shown on the Brent Jessie page as lower gain than 12AV7s.
Here is what John Tucker says you can use:
6829 (standard), 5965(recommended by John), 7062, E180CC, or CV8431 optional direct plug ins.

You don't need to go crazy and spend uber dollars. John designed it that way.

For convenience, here is a some general info on each tube:

5965:
This industrial tube is close enough to the 12AT7 that audiophiles have started buying them up and commenting on the low noise of this tube. It most likely is because it has a lower gain, a mu of 47 compared to 60 of a 12AT7. It is kind of like using a 5751 in place of a 12AX7--the lower gain being the main difference. These tubes are still plentiful, and are really well made. GE made a fine version of this tube in their "5-Star" broadcast line. A few have an extra mica spacer on top, known as "triple mica" and noted for lower microphonics. There is also a rare Telefunken version of this tube with long plates.

E180CC or 7062:
Most often found in European types, typically Amperex or Philips, this tube is virtually the same as a 5965 in regard to electrical specifications. Audiophiles have been seeking it out since the price is generally lower than the premium ECC81 NOS prices currently. Like the 5965, it has slightly lower gain than the 12AT7, and has the added advantage of a 10,000 hour heater life to make it another audiophile "secret" tube. A super bargain when you find them, since they are musical and smooth to listen to, and actually sound better than many standard 12AT7 tubes. Better grab them now while the prices are still low! This tube is about a half-inch taller than the standard 12AT7, so chassis space is an important consideration.

6829:
Yet another industrial tube that is very similar to the 5965. This one has a mu factor of 47 so it is slightly lower than the typical 12AT7. Those I have heard are rich, detailed, warm, and thanks to the lower mu, very quiet and low in microphonics. GE made these in their 5-star and military line so they are a rugged and long lasting tube. Like the E180CC, this tube is about a half-inch taller than the 12AT7, so you need to consider overhead chassis or cabinet space when swapping a 12AT7 with one of these. An excellent audio bargain now, but prices may soon climb as audiophiles discover them!
Thank you very much, M297904! Is the 5965 a relatively recent recommendation of John Tucker's? I had a 2900 or 2910 in which I was using 5965s or 7062s, per either John's or Tbg's recommendation. When I bought the 3910 3 years ago, after what I believe were the last modifications John made to the 3910, it came with 6829s; and the dealer told me this was what John recommended. I ask because my understanding is that John has moved on to modifying other, different, non-Denon players.
When I called John Tucker about a year ago to ask your exact question, that's what he told me. I think he likes to tinker and will try different caps and tubes to see what combo works best. For exampole, I found out one unit could have Dynamicaps, another may have Audicaps. I suspect the difference will not be too dramatic.
Jfz, I talked with John. He somewhat prefers the 6829 but says the 7062 give better detail and bass. The 5965s are at the bottom of the heap.