New Tube Not Bad

You guys who know how to make adjustments in the circuit to suit various tubes have my envy. My Elekit TU-8850 uses 12au7 drivers, I wanted to maybe try an adapter so I could use the 6sn7 tube like I use in my VTA ST-120 and SP14 preamp. I asked the question at DiyAudio and Victor surmised it might work but later stated it wouldn't be ideal. So, yeah one is 12V and the other 6 Volt tubes and noval vs octal pinout.
 
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geode said:
You guys who know how to make adjustments in the circuit to suit various tubes have my envy. My Elekit TU-8850 uses 12au7 drivers, I wanted to maybe try an adapter so I could use the 6sn7 tube like I use in my VTA ST-120 and SP14 preamp. I asked the question at DiyAudio and Victor surmised it might work but later stated it wouldn't be ideal. So, yeah one is 12V and the other 6 Volt tubes and noval vs octal pinout.
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When it comes to using adapters starting with an octal socket is ideal. Going octal to noval is no big deal. Going the other way can be done but you have to be more careful. The heater voltage isn’t as big a deal since the 12sn7 could be used instead of a 6sn7. The bigger problem is that the *sn7 heaters draw a lot more current.

You could still do it if you buy the right equipment. Here’s one that I have:

IMG_0480.jpeg

This particular supply can from 2v-13v and up to 10 amps. This particular adapter allows me to use a 12sn7 instead of a 6sn7. You could get (or make) a similar one to go from 12au7 to *sn7. I would suggest taking advantage of the lower priced 12sn7 if you did that. I usually use a different one that can do up to 30v and ten amps. You can buy various Chinese DC supplies for cheap that do a good job. Those typically only have one set of outputs instead of the 6 the pictured one has. When I had my amp built I had the heaters wired up to banana jacks so I can use external supplies. So one set of outputs from the supply works fine for me. Regular amps usually need a supply with multiple outputs. I suppose you could make your adapters with stackable banana jacks but I would make the last tube connected with non stackable ones to make sure there are aren’t any hot connections just sitting out in the open.
 
Well, HuH! I had planned on pulling the JJs after some hours of playing and listening, then reinstall the Teles again. This time I got out the Qtip and Deoxit and cleaned up the pins. The Qtip was fairly dirty after the treatment. Reinstalled and I can't believe these are the same tubes. They do sound quite good. The midrange is back. Placebo effect, maybe. I guess I should have cleaned them first. I can't say they sound better than the JJs, yet. More listening :music:
 
I've tried tele's both EC82 & 83's. I found them to be very well natured top to bottom, Very warm and smooth. But they seem to lack the dynamics I was looking for in my Primaluna pre-amp, or DAC. They're back in the box of also ran tubes. I personally prefer the 5814 & 6189 tube type. I'm currently running 1954 CBS 5814A. To me they sound the best. But I do have a pair of NOS Tung Sol 6189's in reserve. I enjoyed rolling tube's for a few years, but once I found my flavor I settled in to enjoying the music.
 
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