[sdiy] sources of hum and hiss in a solid state guitar amp (LM1875) (slightly OT)

[DSL FODA01]

I don't know if this has been mentioned before now, but if anyone is looking
for a good source of guitar amp DIY info, especially tube amps, I would
recommend checking out  www.AX84.com  especially in the forums.


Dave



----- Original Message ----- 
From: "anthony" <aankrom at bluemarble.net>
To: <synth-diy at dropmix.xs4all.nl>
Sent: Saturday, August 12, 2006 9:23 PM
Subject: Re: [sdiy] sources of hum and hiss in a solid state guitar amp
(LM1875) (slightly OT)


> I should add that the PCB was really a basket case when I fixed it. If it
> weren't for the reverb or the tweed I would have taken it back to the pawn
> shop. I mean the force that broke the PCB also broke the pot that I had to
> replace. It looked like there was some water damage too. Actually it
looked
> like it fell out of a truck into a ditch and they didn't find it 'til a
week
> after they lost it. (But because of the tweed it still looks rad.) I pride
> myself in being able to breathe life into hopeless cases. I mean you
should
> have seen the Hotfoot when I found it in my basement.
>
> I am fixing this amp to a useable level, but I think I'm more and more
> leaning towards ultimately putting a single-ended tube amp inside. I'd
love
> to put in a push-pull with reverb, but I don't want to have to cram a lot
of
> wiring into a small space like that. Add to that the fact that I'd rather
> have a 12" speaker in this sort of combo... Well anyway...
>
> Here's a twist: it might be too much trouble to bother doing for a small
> guitar amp, but I have some 2SA1265's and some 2SC3182's that I got out of
> an Alpine V12 car audio amp. I think I should be able to get about 70
watts
> from a comp pair. Hee hee! No no I have those eramarked for a big PA amp
> with a tube preamp using 12AU7's (did I mention that I have a number of
> sweet RCA side-getters? I'm sure I have before...). Actually at one time I
> had thought of using EL84's as drivers in this amp. Does that sound cool
or
> just stupid?
>
> Also I love it when people remind me to use my scope. I don't know what it
> is - it seems to be a thing with many people who have scopes they just
don't
> think to use them - sometimes at a time when a scope is really the only
> thing that would work. And mine is right on my bench, right here next to
my
> PC. I'm twisting knobs right now even...
>
> Hey what does "CHOP" do? There's no "PUREE" or anything...
>
>