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Your voltages are way out ..
I used a 47k dropping resistor and get around 290-300v before the 220k/1meg combination that I'm using (btw .. hope that's a 330k and NOT 330ohm that you've got there). Also, I think that 347v is too high and will probably cause the distortion/drive to be fizzy when the ef86 tube is driven hard. Try a 47k dropping resistor first, then maybe a 68k if the voltage still isn't right.
You should be in the range of 80-120v on pins 1&6 (depending on the tube and resistor combinations that you use) and around 2-3v on pins 3/8.
Also; don't use any of the current production ef86 tubes. Get a good NOS tube (Philips Miniwatt, Valvo etc) .. they sound MUCH better. The new production tubes sound very grainy and harsh. Hope this helps. Keep me posted.

Barry M

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Barry M

I revised the voltages. Had 22K cathode resistor in there.

EF86 Pin 1 - 57V - 2.2M to B+ side
Pin 6 - 127V - 330K to B+ side
Pin 3/8 - 1.6V - 2K2/25uF to ground.
Pin 2- 7 tied to ground

Got an older EF86 in there as well.

You suggested 80-120v on pins 1&6 and around 2-3v on pins 3/8.

I have 57 on 1 and 127 on 6 , 1.6 on 3/8 . What do you think of that?

Getting close. Definitely louder. I compared it to the other channel and it might be close to the same level.

Time to test drive it!

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

The only thing is that this is based on my configuration (220k/1meg and 47k dropping resistor), so your voltages seem to be ok.
Do some testing and see how it works out.

Barry M

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Barry M

Prototype Pictures Posted at:

[url]http://www.trinityamps.com/phpbb/viewtopic.php?p=6605#6605/ForumGallery/TC15/TC-15f.jpg[/img][/url]

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Which New tubes have you tried?

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

I tried the Svetlana's and the EH's .. both awful! Don't get me wrong, I'm not an "NOS snob", but the difference between these new production tubes and NOS is very distinctive (more so than with other pre's). The new production variety sound very raw, raspy and harsh .. not musical at all. The NOS ef86's have a sweetness about them that is lacking in the new production variety - "fat, rich & round".

Barry M

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Barry M

I wonder what tube brand Dr. Z, Matchless, Bad Cat VOX are using?

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

I called Matchless to ask

They use Svetlana EF86's and Dario Miniwatt EF86's, with the Dario being the better of the two.