I just recently picked up a Mesa Dual Rectifier. I am looking for any information on mods for it, and had a couple general questions. When re-capping the amp, do people use Black Gates like they do in HiFi? I Also keep hearing about "orange drops" which were known in guitar amps.
Anybody have any good info or leads? I have done a lot of searching.
Anybody have any good info or leads? I have done a lot of searching.
Hi,
I'd be tempted to leave well alone unless its had very hard use.
Unlike HiFi amplifiers, better components are not usually an improvement.
Obviously poor quality components are a bad idea, replace like for like.
Ugrading components will subtlely affect the sound, if you don't like
the sound I suggest you'd be better of looking for a different amplifier.
/sreten.
I'd be tempted to leave well alone unless its had very hard use.
Unlike HiFi amplifiers, better components are not usually an improvement.
Obviously poor quality components are a bad idea, replace like for like.
Ugrading components will subtlely affect the sound, if you don't like
the sound I suggest you'd be better of looking for a different amplifier.
/sreten.
A major upgrade to nearly every amp
There is one major upgrade to most amps: FRED-diodes.
If you have an amp with rectifier tubes in it, you have all you need. It you have an amp with FREDs allready in it, be happy. If you have an amp with the standard diodes in thre rectifier board (such like the 1N4006 or 1N4007 diodes) you should think about changing these to a setup with FRED-diodes. FRED means fast recovery epitaxial diode. The effect is, that you get all the punch, smooth and equally brilliant top end, better responsiveness that you would get with fully tube-featured rectifier (which was standard in the old vintage amps in the fifties and sixties). The standard diodes, which are used in 99% of the production amps bring a certain harshness into the sound and they lack punch and sensitivity. You get improvements with FREDs in tube-amps and solid-state amps. I just finished a general part upgrade (including FREDs) in an old MusicMan Bass Amp which is solid-state in the preamp and tube in the power-amp.
I also changed all coupling caps, all buffer and supply caps, most of the resistors and most of the OP-amps. The amp now performs and sounds better than ever before - possibly better than any MusicMan amp ever sounded. I use it mainly for bass, but have modified one channel for guitar and some people asked, if it was an all fully tubed vintage amp, because the clean and distortion was like that (remember it is a solid-state preamp with OP-amps and an integrated diode-distortion).
Part upgrades can really make a huge difference, but you should know, what you are looking for and which parts meet your purpose.
As regards you Boogie amp you can be shure, that the people at Mesa Boogie usually use good parts. Á replacement of the coupling caps might not be necessary - at least if the amp already features polypopylene caps. If not you might think about a replacement. Orange drops add a certain character, Xicon Polypropylene are more neutral and cost less. Another very good choice are Solen Fast caps, which might be able to add even more punch and sensitivity.
If the amp is a little older I would however replace the electrolytic caps (Sprague Atom for the big supply caps and for the caps at the cathodes of the tubes, there are some other good brands as well). The electrolytic caps age pretty fast and after some years a refreshment should be done.
If your Boogie Amp features the standard-diodes, you might think aabout a FRED-upgrade. But be carefull: You must be absolutely shure, what you are doing. If you mix the cathode/anode of the diodes you can imagine what happens, if you switch on the amp the next time which puts at least 400 V on the diodes. If you made a mistake it might kill the amp.
If you are familiar with high voltage and diodes, there is no problem.
There is one major upgrade to most amps: FRED-diodes.
If you have an amp with rectifier tubes in it, you have all you need. It you have an amp with FREDs allready in it, be happy. If you have an amp with the standard diodes in thre rectifier board (such like the 1N4006 or 1N4007 diodes) you should think about changing these to a setup with FRED-diodes. FRED means fast recovery epitaxial diode. The effect is, that you get all the punch, smooth and equally brilliant top end, better responsiveness that you would get with fully tube-featured rectifier (which was standard in the old vintage amps in the fifties and sixties). The standard diodes, which are used in 99% of the production amps bring a certain harshness into the sound and they lack punch and sensitivity. You get improvements with FREDs in tube-amps and solid-state amps. I just finished a general part upgrade (including FREDs) in an old MusicMan Bass Amp which is solid-state in the preamp and tube in the power-amp.
I also changed all coupling caps, all buffer and supply caps, most of the resistors and most of the OP-amps. The amp now performs and sounds better than ever before - possibly better than any MusicMan amp ever sounded. I use it mainly for bass, but have modified one channel for guitar and some people asked, if it was an all fully tubed vintage amp, because the clean and distortion was like that (remember it is a solid-state preamp with OP-amps and an integrated diode-distortion).
Part upgrades can really make a huge difference, but you should know, what you are looking for and which parts meet your purpose.
As regards you Boogie amp you can be shure, that the people at Mesa Boogie usually use good parts. Á replacement of the coupling caps might not be necessary - at least if the amp already features polypopylene caps. If not you might think about a replacement. Orange drops add a certain character, Xicon Polypropylene are more neutral and cost less. Another very good choice are Solen Fast caps, which might be able to add even more punch and sensitivity.
If the amp is a little older I would however replace the electrolytic caps (Sprague Atom for the big supply caps and for the caps at the cathodes of the tubes, there are some other good brands as well). The electrolytic caps age pretty fast and after some years a refreshment should be done.
If your Boogie Amp features the standard-diodes, you might think aabout a FRED-upgrade. But be carefull: You must be absolutely shure, what you are doing. If you mix the cathode/anode of the diodes you can imagine what happens, if you switch on the amp the next time which puts at least 400 V on the diodes. If you made a mistake it might kill the amp.
If you are familiar with high voltage and diodes, there is no problem.
Re: A major upgrade to nearly every amp
THank you very much for you post. I however do not think I have enough electronics genius to understand everything you wrote. I wouldn't even know what to look for to see if Mesa already uses those or what parts are needed to replace.
The Mesa Rectifier has a switch on the back that you can either use the tube rectifiers or the "hi-power silicon" diodes. I assume these are to which you are referring should get changed with FRED-diodes.
I need to do more research. Thank you
T
Doc Blues said:
THank you very much for you post. I however do not think I have enough electronics genius to understand everything you wrote. I wouldn't even know what to look for to see if Mesa already uses those or what parts are needed to replace.
The Mesa Rectifier has a switch on the back that you can either use the tube rectifiers or the "hi-power silicon" diodes. I assume these are to which you are referring should get changed with FRED-diodes.
I need to do more research. Thank you
T
[Q]I just finished a general part upgrade (including FREDs) in an old MusicMan Bass Amp which is solid-state in the preamp and tube in the power-amp.
I also changed all coupling caps, all buffer and supply caps, most of the resistors and most of the OP-amps. The amp now performs and sounds better than ever before - possibly better than any MusicMan amp ever sounded. I use it mainly for bass, but have modified one channel for guitar and some people asked, if it was an all fully tubed vintage amp, because the clean and distortion was like that (remember it is a solid-state preamp with OP-amps and an integrated diode-distortion).
[/Q]
Just wondering, after changing this amp to FREDs and also all the caps and most of the resistors and op amps, how on earth could you decide what part of that improvement was due to the FREDs?
I also changed all coupling caps, all buffer and supply caps, most of the resistors and most of the OP-amps. The amp now performs and sounds better than ever before - possibly better than any MusicMan amp ever sounded. I use it mainly for bass, but have modified one channel for guitar and some people asked, if it was an all fully tubed vintage amp, because the clean and distortion was like that (remember it is a solid-state preamp with OP-amps and an integrated diode-distortion).
[/Q]
Just wondering, after changing this amp to FREDs and also all the caps and most of the resistors and op amps, how on earth could you decide what part of that improvement was due to the FREDs?
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