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I've finished a TC-15 and fired it up. Sounds good so far. But, I'm running at voltages that are pretty high relative to those listed in the build docs and others listed in the forum. For instance, I'm getting 378 at pin 7 on v4 and 376 at v5 (not 300). Pin 1 v3 is 270 (not 190). The 5ar4 is running at 387. The plate voltage on the EF86 is 140v. Also, the layout shows that the junction of R34 and R33 at 200, I'm getting 370 here. Any thoughts? I'm not anxious to burn anything up....

As I said, it sounds sweet in preliminary testing, but I'm suspicious that I've missed something ....

Lee

Are those voltages measured with the tubes inplace?

Yes, tubes are in. The ones that really look high are the plates on the EL84s.

Lee

Here are the rest:

Stephens docs say the B+ is about 350VDC so 387 on the plates doesn't sound right?
Whats the mains voltage at your house?

Coming in is 123.1v. Pretty hot.

If you look in the TC15 resource section, another builder posted his voltage results and his AC mains were the same as yours. His readings are very close to yours too!

Thanks Stoo,
I see that now (I swear I looked for that before?) and the only thing that stands out to me at this point is on V7, the EF86 -- most notably the plate voltage is 140 in my amp and the cathode is a bit lower at 1.65v (vs. 1.9). As long as the tube can handle it, I probably won't worry about it. Most EF86s can handle 200v so I'm well within that. I need to check the the rest of the math, though....

For the EL84s I'm using Genalex Gold Lion Re-issues, which like most EL84s are rated at 300v. I'm thinking that I may have to use something a little more robust (e.g., military equivalent 7189s are rated for 400v) that can take the higher voltages. The Gold Lions sound very good though. At $55 a pair they are not hideously expensive, but I'm not anxious to toast 'em unnecessarily. They do seem to have lot's of 'sparkle' for lack of a better description. My ASAT Classic semi-hollow has never sounded better.

Lee

That rating value seems to have nothing to do with reality. There are umpteen thousand Vox, Matchless and Marshall 18W amps in this world and they all run regular EL84s at anywhere between 320 and 360V, and as long as the tubes are biased correctly they last a good long time. You really only need the EL84Ms and 7189s for amps like the Marshall 20watters or Mezza F-30, which run their EL84s at 400V+. Stay with the Gold Lions. They'll be fine.

_________________
Great tones come in small glass jars!

Excellent! They sound sweet!

Thanks,
Lee