jjai
New member
This may be territory that has already been covered, but I haven't been able to find anything in the archives--
I recently purchased a Roland Bolt 60 guitar amp (which is the only tube guitar amp that Roland ever made). It's a 60W 2x6L6GC power amp with a 12AT7 phase splitter. It sounds decent, but the preamp, which is solid state, sounds HORRIBLE, especially when overdriven.
I had the crazy idea of grafting a 2 channel tube pre onto the power amp, and eliminating the existing SS preamp completely.
I wanted to check to see if you all think this is worth the effort/possible/how difficult it'd be? (I'm not a total newbie but I'm not a guru. I've built a couple stompboxes, mics, and various little gizmos, but have very little knowledge about tubes.)
Specific questions are:
- could/should the preamp tube(s) share the same transformer as the power amp/where would the pre get its power from?
- are there any plans for a suitable 2 channel tube pre that I could use as a model?
- I don't have a schematic for the amp, and can't locate one. Is that reason alone to abandon this project?
- What about the idea of grafting in a solid state pre, just one that sounds better?
I fully understand that the smart thing to do would be to just plug an off- the shelf pre into the power amp in on the back of the chassis.... but that wouldn't be any fun!!
-jerry
I recently purchased a Roland Bolt 60 guitar amp (which is the only tube guitar amp that Roland ever made). It's a 60W 2x6L6GC power amp with a 12AT7 phase splitter. It sounds decent, but the preamp, which is solid state, sounds HORRIBLE, especially when overdriven.
I had the crazy idea of grafting a 2 channel tube pre onto the power amp, and eliminating the existing SS preamp completely.
I wanted to check to see if you all think this is worth the effort/possible/how difficult it'd be? (I'm not a total newbie but I'm not a guru. I've built a couple stompboxes, mics, and various little gizmos, but have very little knowledge about tubes.)
Specific questions are:
- could/should the preamp tube(s) share the same transformer as the power amp/where would the pre get its power from?
- are there any plans for a suitable 2 channel tube pre that I could use as a model?
- I don't have a schematic for the amp, and can't locate one. Is that reason alone to abandon this project?
- What about the idea of grafting in a solid state pre, just one that sounds better?
I fully understand that the smart thing to do would be to just plug an off- the shelf pre into the power amp in on the back of the chassis.... but that wouldn't be any fun!!
-jerry