Tube Amp Archive

Yeah, I also replaced the 15K, but I think all I had in my toolbox was a 30 or 31K resistor; still too much bias voltage. I will parallel another 30K and see what happens.

I'm looking forward to hearing your mod. I assume it's crucial to change out the pots to 1MA's on the Bass channel side?

Thanks Billy for the help! Well, I've finally been able to fire this Bassman head up. I've been so busy and no time to work on it. I got all the filter caps changed and the bias cap. I'm leaving the bypass caps for now. This bassman head is an early silver trim SF so it's got the good Mallory blue t...

Thanks, I may have to do a little speaker switching then. Do you have a preferred speaker for this head? I'm leaning toward a good ceramic Celestion, maybe V30 or G12H30 or a combo of both.

Billy, etc... Do you have any problems running a Bassman head into an 8ohm load? In my experience with other Fender's they have been able to handle 100% mismatch load with no problem. It's not that I particularly want to stress the amp or looking for a tonal change; most all of my cabs are 8ohm.

I did notice that Billy and I also noticed the increased feedback tail resistor that's usually 100r, sometimes 1K5 in some Fenders. Now, will I need to flip the OT primary leads when I change that feedback circuit?

Thanks Billy and Steven. Billy, I was thinking about doing maybe some sort of mid-boost for the deep switch; something maybe kinda raunchy there, don't know. Split load is interesting!

Thanks Billy! Have you made a comparison between the parallel triode vs using the extra triode as a cathode follower?

Hi all. For those of you who have modded the AB165 Bassman heads, can you describe the tonal differences between the various mods? I'm probably going to start out with doing the Andy Ruhl AB165/AA864 hybrid mod. I've heard it really opens up these heads. It's just something in me that hates to leave...

I've got one, an EP3 off of Ebay several months back. You kinda have to baby them by cleaning, demaging and so forth. I actually sent mine off to OrbitElectronix and they took care of the servicing. I got them to retape my cartridge and align the heads, etc. They also informed me that I had the "com...