Beiträge von david_djd

Re: help me please with my A15Mk1

Martin.. the problem is solved!! ;D ;D

just a broken ground wire (of the power tubes next to the solder).. hard to see bur when I try to find the problem I have seen that sh*t.. If isn't that problem it worked at the first time..

Maybe you ask why the two of them have the same problem.. but you'll see when I post some photos.. (surprise)

I don't need of the DC heater that I have asked you.. the amp is pretty noiseless..

Now I have justo to ajust the Bias.. and ROCK IT..

Thanks for everything Martin.. And sorry for my bad bad english

Re: help me please with my A15Mk1

Hi Martin
I'm gonna do that.. thanks once again..

Finaly I finish him... but.. no sound
I hear the trafo in the speakers.. (just a little) and when I touch the plug of guitar cord I hear a BZZZ.. (just a little) if I plug a guitar I hear the sound but I have to put my head into to the speaker to hear it ;D .. everything seem to be wired Ok.. the tubes have a normal glow... no smoke etc etc.... He do this in every settings..

plus... I have builded two of them.. and the same problem is in the other one... ??? ???

I'm gonna re-confirm once again the wiring..

Update: the voltage at the output of the rectifier is 355v and at pins 3 & 4 of the both 6V6 is 363v ??? ???

DC heaters for A15Mk1

well Martin... my Madamp is a MADamp ;D and is just for hum prevention.. 'cause I don´t even try if it make´s hum or not.. (after 6 months I didn't have finish him :-[... I don´t have much time to build it) It's almost ready.. I have just to re-confirm all the wiring before to make it scream!!.. ;D I'll post some photos soon...

what are the conections to the sockets? (pin wiring of the 12AX7 and 6V6 for the DC heaters..)

how can I "transform" the AC heaters into DC heaters? and some schematic of how to do this is wellcome

Re: A15Mk1 with Hammond 125ESE

shame on me... that's true! ;D

Hi..
I'm collecting information about the A15Mk1 (slowly assembled (2 of them) on my almost none free time.. more some weeks and I finish them.. ::) )
I read somewhere that an exchange for the OT Hammond 125ESE improve the sound of the A15Mk1 (by Mr. Olaf himself).. my question is.. how? what are the differencies? can I make the 4/8Ohms wiring the same way that I make with the Hammond 125SE? thanks for the awnsers..

Re: A15Mk1 impedance

but with 16Ohms the output volume decrease.. that's why I prefer run into 8Ohms.. but with 2 A15Mk1 and 4 speakers with 8Ohms is impossible unless I use another transformer to drop the 8ohms to 4...(or changing to another output transformer to have 4, 8 and 16Ohms options)

I have buy two A15Mk1 and I want to run it in stereo into 8Ohms (2x12" speakers 8Ohms each) but I want to make a 2x12" extension cab so then I have a problem with the impedance... :-\

-I don't gonna have any major problems if I plug a 4Ohms load into the 8ohms output of the Amp?
-Do I have to put an external impedance transformer to change the 8Ohms into 4Ohms?
-Or, is it better to changes the output transformer of the amp?.. (in this case sugestions for the model are needed, pleeease).. is it simples to make that mod?

Thanks for the awnsers