good clean fun...

[DummyLoad]

this is on one of the breadboards. very nice sounding alternative to a twin reverb, sans reverb, of course.


i'm driving a custom built closed back 15" & 12" cabinet loaded with a EVM-15L and a EVM-12L. 


--pete

[kagliostro]

Hi DummyLoad

Nice Standel divagation

Please, can you explain what is happening between V2b and V3a, I'm not able to follow the path of the signal

I have a lack of memory and don't remember how that part of the circuit acts

Franco

EDIT: OK, now I remembered something, some time ago I asked about the 25L15 schematic draw by Napkin in this tread

http://el34world.com/Forum/index.php?topic=14263.msg148981#msg148981

and Sluckey and HotBluePlates give me answers about

[HotBluePlates]

this is on one of the breadboards. very nice sounding alternative to a twin reverb, sans reverb, of course.

That looks familiar! I don't know if you get the same ultra-clean with that, but I imagine you could...

Please, can you explain what is happening between V2b and V3a, I'm not able to follow the path of the signal

V2a output goes to V3a input.
V3a has 2 outputs; the main output goes to V3b.
The other V3a output goes left to the tone circuit and V2b, and is a feedback loop.
V2b alters V2a's response due to the shared cathode resistor.

[kagliostro]

Thanks HotBluePlates

I remembered your previous explanation, this may be useful for those who give a look to the schematic for the first time

and are not able to follow the path of the signal as I wasn't

Franco

[DummyLoad]

That looks familiar! I don't know if you get the same ultra-clean with that, but I imagine you could...


somewhat: mostly same as the hand drawn preamp schema floating around in cyberspace. many mods, PS, PI, no countour control, no cut control, fixed bias, NFB added, 100W of EL34 LOUD.

i was tempted to use 4 x KT88 in cathode bias, pentode mode, but the hassle of the PS requirements took precedent, so the easy_to_drive EL34 won in the end because i had the parts to make it happen.

--pete

[kagliostro]

Ciao Pete

Have you a Layout for this beauty ?

Franco

[DummyLoad]

Ciao Pete

Have you a Layout for this beauty ?

Franco

ciao franco, i started one but the interested party lost interest when gave him a price. i'll finish it for you: give me a day or two...


--pete

[kagliostro]

Oh, many thanks Pete

Thank you for the offer to complete the job you have available, I would not give you too much trouble


Franco