So I have a late 72/early 73 Traynor YBA-1 Bassmaster that I'm working on. I am in the process of replacing the original Mallory 40/40uf cap cans with a pair of 50/50uf F&T cap cans and relocating the Pre/PI grounds to the input jack. A previous tech replaced the bias caps, replaced the 39K to ground in the bias circuit with a 33K resistor in series with a 10K pot, defeated the ground switch, pulled out the accessory power jack, and put in a 3 prong cord. This isn't totally original since he drilled the chassis for the bias pot and I drilled it to put in cap can holders so I'm not afraid to do little things that slightly change the originality.
This particular YBA-1 is late 72 or early 73 so it has a smaller output transformer (about the size of a Tweed Bandmaster transformer as far as I can tell - significantly smaller than the one in my early 72 or my 69 YBA-1s). It also has no cathode caps on the first 12AX7 whereas the early 72 has the 250uf caps. I think it is mostly original and since I have the others I'm interested in keeping the character of this circuit compared to the others. However, I want to make sure to do anything I can to make the amp reliable, make it not eat tubes, or do anything that will be dangerous to me or the amp. I know they are loud amps so I will be running it hard with an attenuator to get any breakup. I know it originally had Mullards but I'll probably be using EH 6CA7s so I want it to be reliable with new tubes. There is one thing that concerns me is the shared 470ohm 10 watt screen resistor. Would it be better to also add a 2.2K resistor to each tube for additional dropping or is that being overly careful?
I'm looking for any suggestions to make the amp more reliable/make it play better while retaining the original character. Thanks!
Topic: 72/73 Traynor Bassmaster Questions (Read 2237 times)