Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Danfrank on August 23, 2024, 08:49:26 pm
-
Hi everyone!
About a year or so ago I picked up an old YBA-3A bass amp, the first version without the master volume. Main reason I bought it was to take measurements/specs of the output transformer, mainly the primary impedance of the OT.
I was going to reply to a thread on this board that asked the same question but it’s over 10 years old so I decided to post as a new topic.
Drum roll please:
Primary impedance of the YBA-3A super custom special is 1050 ohms from plate to plate. This is the amp that uses the 6KG6 sweep output tubes. So, there you have it for anyone that’s still interested in OT info for that amp.
For those of you that haven’t heard one of these amps, they are loud with a lot of mids. Painfully loud! The note attack of this amp is like no other, this is why I describe the sound as painfully loud.
Mine is the first version but I did change the circuit to the 2nd version which is the better sounding of the two. The first version as is, is nothing special but the extra gain stage in version 2 really makes this amp sing. I would put it up to any other tube bass amp. I’ve had original SVTs, Sunn 300 bass amps, etc and nothing comes close to the power and note attack that this Traynor has. It is the only amp that caused our next room neighbors in the rehearsal space to beat on the wall so we would turn it down! Lol! It’s a crazy loud amp.