Tweedle Dee build

[bepone]

video of the amp..:

[pompeiisneaks]

Wow that toan! Very beautifully done Bepone.

~Phil

[bepone]

thx, it is nice amp, good also pedal platform, test was for Italian trafo(first use) which works without complaints..

during tweaking it was noticed that tone depends a lot on the voltages, it is not the same if is +-10V..

the best are working V like on HAD design, so leaved like that

[Stephen1966]

Hi bepone,

That's a great blues tone, nice saturation, and sustain, and the reverb just opens it up nicely but he is right about the sound pressure... we were running mine in a stereo delay with a Fender Deluxe Reverb the other night and it was a job to get the balance. The Tweedle has a load of gain! Good idea with the 3P NFB switch for controlling the break-up - what values did you use, if you don't mind me asking?

[bepone]

Hi bepone,

That's a great blues tone, nice saturation, and sustain, and the reverb just opens it up nicely but he is right about the sound pressure... we were running mine in a stereo delay with a Fender Deluxe Reverb the other night and it was a job to get the balance. The Tweedle has a load of gain! Good idea with the 3P NFB switch for controlling the break-up - what values did you use, if you don't mind me asking?

sorry didnt see the question.. 56k is the nfb resistor, to V2 tube, pcb is designed that way, there is ON, OFF, and Bypassed cathode res. option

[Stephen1966]

Mods/ drifted from HAD:

SS rectifier - with care that voltages are correct
Power tubes screen resistors 470R
Power tubes cathode - 300R
3P NFB switch
Pre PI Master volume (tried trainwreck MV but it was horrible)

Normal channel – coupling cap – 4,7nF

Cathode R - 2,7K
Anode R - 220K
Bypass cap - 0,68uF
Added HI /LO inputs

Bright channel – coupling cap 10nF

Grill vents are to be printed and installed soon

With a SS rectifier, I am guessing that the secondaries voltage (off the PT) was lower than found normally. What kind of voltages did you get with your home-wound PT?

Also, SS rectifier! Isn't the tube rectifier part of the sound!? Mid and high end sound awesome, but I'm thinking of the low end.

[bepone]

PT was ok, voltages are in ballpark, SS rectifier selected because my friend doesnt like compression at all
also tube rectifier means, rattling, unreliability, flashing, compression, sag, replacing with time (expensive).. all not wanted characteristics in this project..

[bepone]

there is one more friend who built combo version, the same board, with expensive Jensen P12Q speaker and rectifier.. it is different yes, i will put some recordings here for comparison

[Stephen1966]

... rattling, unreliability, flashing, compression, sag, replacing with time (expensive)...

Haha Most days are like that for me now.

I get the point about the compression though. the thing about the coupling caps MrD used was that it tightens the bass response and even though I'm using a tube rectifier, I don't get farting-out when it's flat out in overdrive. It's true, however, I had to replace the GZ34 with a lower gain 5Y3 because it was red-plating like mad even when I adjusted the cathode bias right down. I think I have something like 350ohms in there at the moment. Loads of gain! The saturation is still pleasant though and can be dialled back using the guitar's volume even with the amp dialled all the way up to 11. Between 11 and 12, does get darker, but we don't need to go there. I do like the tight bottom end you get with a SS rectifier though and in these days of tubepocalypse it is a whole lot more sensible to use a handful of cheap rectifier diodes. Cheaper, less likely to fail, and space-saving. It just needs a power transformer that doesn't put out such a high voltage or zener diodes to drop the voltage.

I've been looking at the Hammond 290BEX

290BEX.pdf

What do yo think?