Rickresource Rickenbacker Forum

Reviving this thread because the replacement speaker in the TR120 also blew. Well, it’s doing some weird fizzy stuff.

My TR35 is also in need of a new driver.

So let me get this straight - I should get an 8 ohm speaker for each amp (obviously with the appropriate wattage)? Both amps have the “minimum 4 ohm” warning on the external speaker jack.

The amps themselves work fine, I ran each of them to an external cab and they sound great.

kennyhowes wrote: Sat Apr 18, 2020 6:06 pm Reviving this thread because the replacement speaker in the TR120 also blew. Well, it’s doing some weird fizzy stuff.

First of all, hope you found a suited new speaker.

Based on info around here (from John Hall), I thought to have understood the TR120B uses originally a speaker with additional terminals (an additional coil for some kind of feedback, so 4 terminals). Can imagine replacement speakers didn't have this, but then there'd be some unused wiring around, is it?

Curious. Also to see a TR120B schematic, how this was originally implemented.

I actually sold my TR120B and my TR35B shortly after this post, and moved over to a more powerful tube bass amp (a Vox V125B).

There's a schematic on the RIC website for a TR35B, but I don't know if there's one for a TR120B handy.

Hi, Ah I see. Yes, I have the TR35B schematic, but the TR120B schematic isn't there.
It'll indeed be pretty alike, but the power-amp for the TR35B definitely doesn't use a 4-wire speaker connection (which the TR120B seems to use).
We'll see when I have the TR120B here, and when I'm able to lift the speaker. (Which I didn't force on the TR35B, speaker of that one also seems glued to the baffle. )

BTW, since you had both types, I wanted to ask about that additional fifth control of the TR120B (w.r.t. the TR35B):
is this simply a level-control for the preamp out jack (so not affecting main signal path towards speaker), or is it some master-volume?
But just happened to find the answer somewhere, it gives the impression it controls the preamp-out level, but actually it happens to control the level of the incoming signal for the power-amp. OK.