Re: Dr. Frankenstien to amp O.R...paging Dr.Frankinstien

It sounds like a cool find, and something with potential. But your questions go all over the place (no offense intended)!

I'd start by ironing out the "noise" issue. I'm betting you are hearing some 120Hz ripple from old filter caps.

IMPORTANT QUESTION: Do you understand the safety issues of poking around inside of a tube amp? If not, STOP HERE! Don't even read my comments below, they'll only tempt you. Going further could cause much pain, or even death.

If you know the safety issues, and the fact that filter caps can store enough voltage to ruin your day even when UNPLUGGED, then...

Replace the filter caps. Replace the bias cap and any other electrolytics. Check the resistors for off spec (very common in old carbon resistors). Once you do that, see if that eliminates noise. If you cannot test tubes, swap in known good tubes. If something's weak now, you want to see what it sounds like with good tubes.

Get the amp into shape BEFORE you start hacking. You might love it as is! In other words, it may need a tune up, not a transformation.

If you aren't satisfied after tune up, start by tweaking, instead of hacking. Play with plate resistor values, cathode resistors and/or bypass caps for tweaking gain. If you don't like the overall tone, play with coupling cap values.

If this doesn't satisfy you, and you decide to do a complete rework, note your B+ and test the output transformer for impedance ratio before selecting a new circuit. For example, you can't expect it to end up sounding like a Princeton, if you don't have the basic ingredients.

Newbie Doobie wrote:
hi, me are got some new old tube amp to fuch with !
Require Frankenstien proceedural advice.

Translation: I Just found an old (1973) Canadian made "Marlin" tube amp
made by Pine Eletronics (Montreal) a.k.a. Riviera 725 head (not paul
rivera of fender fame).

It is very simple minimal component point to point 2-6V6, 2-12ax7, and
a factory installed ss rect in liew of the intended 5AR4 that the
chassis was configured for but didn't get installed (so I assume the
tranny won't support a tube rect.)

This amp (12-20 watts ?) has promise as the circuit is very much like a
blackface Princeton AA964 without the trem. (so in effect... one less
preamp tube).

This amp is very noisey so requires re-wireing and upgrade a few
components but I'm thinking why not gut the thing and reconfigure the
good parts into a Trainwreck express, plexi, or something else as a one
channel Push Pull tone machine.

SE in class A is appealing but I'm sure the tranny is Push Pull.
(is there a work around this issue ?)

The fact that it has been compared to a AA964.... does this suggest
that it is Class A biased? Having a pair of output tubes has me
thinking it is AB push pull.

Anyone have success with clonning a Trainwreck Express ? Specifically
the A4 version where the author claims it's the nastiest amp he owns on
10 and is sweet and jangley when backed off.
I do own a Fender Princeton II with 6L6 outputs so I do have that
Fender clean Chime going on and might like to instead do something more
in the lines of Marshall meets fender (blackface) tone with this new
project as a recording amp.

Any suggestions which way to go ?

How do the ax84 circuits fair as potential choice ?

Thanks, savy

.

Relevant Pages

  • Re: 6L6 amps?
    ... could be considered a Fender blackface design such as Twin or Vibrolux ... You could also have an amp like a Peavey XXX or 5150 ... 6L6 power section keeps it under control since until you get to deafening ... when the 6L6 power output section starts to distort and do the tube soft clip. ...
    (alt.guitar)
  • Re: 6L6 amps?
    ... some reason their sound has been superior to any other tube output stage! ... could be considered a Fender blackface design such as Twin or Vibrolux ... in the preamp section. ... You could also have an amp like a Peavey XXX or 5150 ...
    (alt.guitar)
  • Re: Fender Prosonic?
    ... >>> The Fender Prosonic is a solid state amp with one tube in the ... Therefore it is inferior to the all tube Traynor. ... > Prosonic is an asskicking amp. ... I dont care what was in back, solid state, tubes, who cared, ...
    (alt.guitar)
  • Re: Dr. Frankenstien to amp O.R...paging Dr.Frankinstien
    ... Look for the Garnet groups, or failing that check with the Traynor Google Group to find out if it is. ... I Just found an old Canadian made "Marlin" tube amp ... rivera of fender fame). ...
    (alt.guitar.amps)
  • Re: Marshall Mk 2 2204 Ann. Series...Blown Output fuse...Why?
    ... Especially not on a 2204 with a blown HT fuse. ... The place of the fuse in this amp opens the discharge path of the first filter cap. ... The Filter Caps are the location of your amp, where the most lethal voltages are stored ... Leave the filters alone in the beginning, and look whether the fuse blows without the EL34s; look for signs of arcing at the sockets and tube bases. ...
    (alt.guitar.amps)
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