Earlier versions of the Bass Master were even influenced by the tweed Fender Bassman mistakes, and featured 7027 output tubes with a tube rectifier and 20uF filtering. No sir, thanks in part to the careful design of the output stage. I'd definitely suggest getting this amp to a tech who can sort all these issues out for you. This will not alter the amp's original tone. That would defeat the whole point of these two channel amps, the bassist plugging into one channel and the guitarist plugging into the other. In the picture, it appears as though somebody replaced the series filter capacitors with single capacitors that have a working voltage of 450V.
Thanks for chipping in everyone. Original from the previous post only has a 430V supply and will do about 40W at clipping. Are there any other mods worth trying to improve the overall tone? All the way up is like you don't have a cap in there at all. Undefined low end could be a symptom of the filter caps needing to be replaced. In this application they were able to claim 250 watts from them. This one has to be reliable, it is a studio amp at. I know what all the symbols are but have a hard time matching a chassis layout to a schematic.
You could see how this would be a bigger issue with four power tube amps because switching from 6L6 to 6550 for instance would increase the heater current draw in the output section alone from 3. No, I usually plug in to the bottom left jack Vol I? We have made no reference to the power ratings of any of our amplifiers. In this application they were able to claim 250 watts from them. Some people would have you believe good tone can only be achieved through the extensive use of chicken bones, expensive coupling capacitors and oxygen free speaker cable. As you increase volume the effect of the bright cap diminishes. Originally Posted by Kindness I the Ox.
The filter caps look to be yellow 'mustard caps'. My observation has been that unless you jump the channels, or modify the amp to internally jump the channels, the signal doesn't somehow leak from one channel into the other. If the electrolytics are not recent, that's something to do right away and will probably fix your low end problem unless whoever did the unknown mods to this amp did other stuff to mess with it. The bright channel on its own is definitely bright. The bright channel on its own is definitely bright. David Thanks for the replies! This amp had very overspecified transformers which allowed for this. This seems normal for Hammond transformers of today to have same or better specs but be much smaller than the old 60s 70s transformers.
That 560r resistor looks like a modern one as opposed to the other power resistors in the picture and the ones I have in my Mark 3. Pedro58, thanks for the advice. They will eventually fail because selenium rectifiers increase in resistance over time. Not sure what to use to replace the Mallory 'dynamite sticks' which are 80uF x3. That's probably where your treble problems are coming from, I'd guess.
I would pretty much always jump the channels and then blend the treble and bass knobs to get the right tone. This amp had very overspecified transformers which allowed for this. But thank you for bringing this up. In any case, I haven't been able to locate this resistor though. Probably the 1986 Superbass actually. Also looks as if someone has soldered a cap and resistor from pin 1 of the preamp tube to ground presumably to drain residual voltage when switched off? I'm guessing Xicon or Ohmite or something. I'm looking at the various schematics but not sure if I'm seeing this resistor value.
Last four digits: Numbered unit produced within that year? I will get some pictures of the circuit up soon. If the amp is drawing 90mA's at idle, the 560r resistor will drop about 50V. Have you already replaced all the electrolytic caps? Good luck, Traynors are fantastic amps when they're working right! And another thing that is said to mess with the bass is if the two power tubes aren't well matched. Master Volume Ampegs are loud and have lots of gain so installing a Master volume if you are a guitar player is a good idea. Indeed it's best left up to a tech if there are any questions.
Fasten your seat belts and let the fun begin. The placements holes and copper traces are already on the circuit board, but, for some reason cost? This amp was designed to have 7027 power tubes which are not as wide so I guess it would not have been such an issue with the original tubes. Fx Loop Enables the use of line level processors such as delay and reverb. High enough that people will complain about how loud it is. I think I'll try the 1M pots in the volume positions when they arrive, although if anything I would have thought they will make the amp sound brighter than the original 500Ks. If you started with 540V, that would put 490V on those capacitors.
Maybe 85% or 90% of max, give or take. It's difficult to say for sure by looking at the picture, but it looks like the 560r resistor is between the diodes and the plates. These amps started out running at higher voltages and the higher wall voltages today only makes it worse. Or can I just remove it completely? I'm a beginner when it comes to amp stuff so maybe point A is wrong. If this gets over 6. Check out the flyback diodes they have going from plate leads of the power tubes to ground.