Re: JIM, PLEASE READ THIS - Re: check out this '77 jmp 2204 50watt - need advise..



adam79 wrote:
<Chief_Billy@xxxxxxxxxxx> wrote in message news:2c204851-7258-41e4-b744-7926712bd03d@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
VERY nice...the amp looks pristine. Plane on adding EL34 spring
retainers (about $2.50 each) . Why are the EL34 screen-grid resistors
different sizes...one looks like a 1K/1W and the other a 1K/5W..is
this a "pictorial illusion" ?


So you think that the amp is a good deal? Besides the rusted power transformer and the questionable cascaded gain, the amp looks minty. A question for Jim. You said that the two things that you don't like about the amp is the fact that the preamp my not be cascaded and that the power transformer might put out over 460V instead of the under 400V one. I've seen replacement power transformers for around $100. If I bought this amp, it would be possible to replace the rusted power transformers with new ones, and the amp could also be rewired as a cascaded preamp, correct? Besides that, the amp looks great. Please let me know if these changes can be made. If they can be made and turn the amp into the brown distortion amp I'm looking for I'd think it be worth it to buy the amp and make the changes.. i just don't think i'll be able to find another one this clean and with all the original mustard caps. Please advise.

Thanks,
-Adam
adam79@xxxxxxxxx


At that pricepoint, www.ceriatone.com (http://www.ceriatone.com/productSubPages/BSJCM800_2204/BSJCM800_2204Complete.htm plus cab) sure looks good at about $900. Of course, there's no Marshall label on it.
.



Relevant Pages

  • Re: epi vj hammond OT switch complete
    ... Tell us how upgrading a power transformer can influence tone, then tell us how you know that there's a problem with the VJ transformer. ... I am not aware of any layout problems in this amp. ... I just have a lesser amount of the dial for clean.. ... power tube.. ...
    (alt.guitar)
  • Re: Lowering the voltage on tubes
    ... You also need to adjust the bias when you change the B+. ... They use a CT power transformer and have a ... switch that uses half the secondary winding to cut the B+. ... > I took my Laney LC50 into a local amp tech and during conversation I ...
    (alt.guitar.amps)
  • Re: One more question on this amp
    ... so a high B+ would be the 460+V power transformer? ... assuming that Marshall went from the low voltage to high voltage, ... this amp, being a '77, hopefully has the low voltage transformers. ...
    (alt.guitar.amps)
  • Re: Fender Vs. Marshall
    ... Does it warant buying a 5 watt amp for $950? ... This is a simple amp to build. ... The output power transformer can be stolen from an old ...
    (alt.guitar.beginner)
  • Re: epi vj hammond OT switch complete
    ... Tell us how upgrading a power transformer can influence tone, ... I am not aware of any layout problems in this amp. ... I just have a lesser amount of the dial for clean.. ... with because it had the worse sound in the stock amp. ...
    (alt.guitar)