Here's a Mullard transistor amp schematic

[RLBJR65]

A little help please! I can't find any information on the transformers used in this.
Anyone know what they should be?
R2 needs decreased?
Any other changes needed to make it work with guitar?

I wish I had the Mullard manual that might help, but all I got is this one page a friend emailed me.



Thanks
Richard

[R.G.]

Finding any info on those transformers would be an exercise in archeology. The Mullard manual *might* give winding details on them, as that was common for such transistor manuals back then, then being the late 1950s. But since they refer to "Colne transformers", I suspect that they just expected you to buy them

If you have one of these and it works, it should work OK with guitar.

Since this thing puts out 1W and runs from 9V, a good replacement would be the LM386, which will do the same job, and is actually available. "Available" is not true about either the transformers or the transistors in the Mullard schemo.

[Johan]

hmm..doesnt that look suspiciously like the  Brian May's "Deacy" amp? http://www.pisotones.com/Deacy/Deacy.pdf  from this thread about a year ago.. http://www.diystompboxes.com/smfforum/index.php?topic=38129.0

johan

[RedHouse]

hmm..doesnt that look suspiciously like the  Brian May's "Deacy" amp? http://www.pisotones.com/Deacy/Deacy.pdf  from this thread about a year ago.. http://www.diystompboxes.com/smfforum/index.php?topic=38129.0

johan

Looks like the same schem-o

[burnt fingers]

That's funny.  I love Brian May and his tones.  I can't believe somone would post a reference manual schmatic as the "deacy" amp. 

Scott

[cd]

That's funny.  I love Brian May and his tones.  I can't believe somone would post a reference manual schmatic as the "deacy" amp. 

In all likelihood, that's where it's from.  Deacy = busted up car radio amp, and that amp is typical for the time period.

[Dan N]

You could probably find working interstage and output iron in an old taperecorder, transistor radio, record player, whatever... If fact, you might find a circuit very similar to that in one of those too!

[RLBJR65]

Thanks!
I was asked to build one for a recording project. Yep deacy amp artical prompted request. Don't know if its right but I'm going to give it a try. I'll let you all know how it sounds if I can get it together.

Richard

[birt]

i've got the transformers you need. from a gutted germanium push pull amp pcb.
i don't know what i can do with those myself except for building such an amp.

[RLBJR65]

Birt, thanks for the reply. I have possibly located a pair already. I'll keep you in mind though.

Rixhard

[Gilles C]

That's funny.  I love Brian May and his tones.  I can't believe somone would post a reference manual schmatic as the "deacy" amp. 

Scott

Don't forget that the first Fender amp was based on a RCA amplifier circuit found in their tube application manual, and that it became the original Fender sound (the circuit was modified regularly though) many guitarists love.

Gilles

[Torchy]

http://www.brianmay.com/brian/briannews/briannewsjun05.html