EL34/6CA7s + 6GH8A + ECC83/12AX7s ... Superb !

[Synergy]

Sweetest sounding amp with EL34 / 6CA7s + 6GH8A + ECC83 / 12AX7s and all selfmade transformers.
Added a stereo bluetooth though, but its switchable.
Demo video

 

[zackthedog]

Very nice! It would be interesting to see some square wave responses or frequency response plots.

 

[Synergy]

Would get them soon.

 

[mcheinstein]

would love a pic of the equipment you used to wind the transfos too!

 

[Synergy]

would love a pic of the equipment you used to wind the transfos too!

will do

 

[ceylon]

Sweetest sounding amp with EL34 / 6CA7s + 6GH8A + ECC83 / 12AX7s and all selfmade transformers.
Added a stereo bluetooth though, but its switchable.
Demo video

this is so cool.

 

[TriodeLuvr]

Congrats! That's a lot more DIY than most people would attempt!

Jack

 

[Synergy]

A Big Thanks to everyone for your interest and appreciation, here's the info you requested:

Test results of the JT-70
The pics show the waveforms and output voltage into to a dummy 8-ohms load.
Sine frequencies: 20, 200, 2,000, and 20,000 Hz.
Sqwave freq: 400Hz
Output level: 2.2volt AC
The amplitude response is flat 20-20,000 Hz (@ 2.2V rms approx).
Also included is the winding machine, and a possible 807 future build, just for the hec of it

 

[Synergy]

Just to let everyone know I dont understand why AK shows me as "new member" tho I joined in 2007

 

[opnly bafld]

Just to let everyone know I dont understand why AK shows me as "new member" tho I joined in 2007

Based on posts (23).

 

[Synergy]

Based on posts (23).

Ahan ...tks

 

[zackthedog]

Looks nice. There's quite a bit of ringing in the square wave, though. It would be helpful to see 10kHz at 1 watt. You might want to add a step filter, or at least a phase-lead cap across the feedback resistor to tame the ringing. You could run into stability issues without something to tame that.

 

[Synergy]

Looks nice. There's quite a bit of ringing in the square wave, though. It would be helpful to see 10kHz at 1 watt. You might want to add a step filter, or at least a phase-lead cap across the feedback resistor to tame the ringing. You could run into stability issues without something to tame that.

Glad you brought it up, the ringing is due to the uncompensated scope leads since a proper rf probe wasn't used. I will repeat testing on a Tektronix soon, and also at 10khz.

 

[zackthedog]

Glad you brought it up, the ringing is due to the uncompensated scope leads since a proper rf probe wasn't used. I will repeat testing on a Tektronix soon, and also at 10khz.

That's good to know! ;-) Looking forward to the corrected results.

 

[knotscott]

Very cool stuff! Great job!

 

[peterh]

Glad you brought it up, the ringing is due to the uncompensated scope leads since a proper rf probe wasn't used. I will repeat testing on a Tektronix soon, and also at 10khz.

You might have a future selling output transformers. Is that a possibility ?