• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

My Decware Zen "Clone"

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#63
maybe a negative rail, then run the front end with the grid leak and cathode resistor down there instead of ground. If you bias the 6N1P right so the plate is at ground potential it should work, but may need some funky attention during warm up.
 
#64
This will be initial schematic and psu.
zenv1.jpg
 
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#68
Bas Horneman said:
shown here is the hazen mod in place.
Click to expand...
Thanks, I was not aware of this mod!

I've listened to a fair numbers of triodes and triode wired EL34's over the past 20 years and each has it's strengths. The triode is not categorically superior to the triode wired EL34 as some would think. However when the suppressor grid of the EL34 is modified with the cap there is a huge difference in the presentation of the amplifier for the better, despite the fact that typical measurements show no substantial change has occurred. I think one of two events are taking place: A) the phase angle of the AC component on the suppressor is modified resulting in a deceleration of the electrons as they pass through this sparsely wound suppressor grid on their way to the plate resulting in less dislodged electrons in the first place. B) the electrons that are being dislodged from the plate are being absorbed by the suppressor grid. In case A, there are less electrons being dislodged from the plate so there are less secondary electrons being re-assembled on the plate. In case B, there are the same amount of electrons being dislodged from the plate, but less secondary electrons being re-assembled on the plate, giving us the same result as case A.
Click to expand...
source: https://www.decware.com/newsite/paper146.html

Does it work only for triodes?
 
#74
Hello Bas:
Regarding the Hazen mod. I used it on a 6p15p in my RH84 circuit and really like. I had previously left the suppressor grid unconnected, the difference was night and day.
Nice design I hope it works out I am likely to follow in your footsteps on my next SE build.

I hope this helps
 
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#80
very lovely Bas:

I really like the juxtaposed contrast between the 5u4G and the novel tubes. Your presentation looks very good.

May I suggest you do not use glue and sand-dust for your filler. In stead use your finishing oil and very fine sand-dust as the filler. Reason being is the glue will not oxidize the same as the rest of the finish and will show more intensely as time goes on. I have done both and found great success in in using the same finishing oil I used on the sides mixed with 320 grit sanding dust as the best way to go. Make a wet paste rub it in leave it for a couple of days to harden then hand sand. I also sand out to 320 grit before spraying on the top coat of urethane. I have also used the top coat finish (urethane) as well to make a filler paste as it hardens the same as the sides if I am not using an oil to colour the wood.
Just an idea.

Or sometime wood is wood and does not need to look like anything at all. Leave it as is.

Looking forward to your impressions of the sound, and some voltage measurement once it settles down and stabilizes.

I hope this helps
 
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