Grateful Dead Music Forum

I know that for a goodly bit of the band's run, Jer used the preamp sections of 2 Twin Reverbs (one black, one silver) into a Mac, but I have never seen any discussion of how that 2-pres>one-power-amp thing worked. Could someone explain, please? Was one a back-up, was it set up for A/B, were they daisy-chained in series? In parallel? What's the straight poop?

Thanks.

I use to know the answer to this. The heads were modded for the preamp out. The power section of the amps was not used. Someone will post info and some pics im sure, but once you see how it was setup itll all make sense. Before I sold my twin head a year or so ago, i almost had a friend of mine mod it so i could run it like Jerry did. As much as that would of been cool, it just made more sense to get the SMS CTP. I didnt want to modify a late 60's Twin.

Basically the SMS is a Twin Reverb preamp section in a rack form and you connect it to a power amp. The way Jerry used his Twins was the same concept, he only used the preamp section of the Twin. Makes more sense to just buy the SMS imho. But hey thats just like... my opinion... man...

Darkstar860 wrote: ↑Sun Sep 25, 2022 4:26 am I use to know the answer to this. The heads were modded for the preamp out. The power section of the amps was not used. Someone will post info and some pics im sure, but once you see how it was setup itll all make sense. Before I sold my twin head a year or so ago, i almost had a friend of mine mod it so i could run it like Jerry did. As much as that would of been cool, it just made more sense to get the SMS CTP. I didnt want to modify a late 60's Twin.

Basically the SMS is a Twin Reverb preamp section in a rack form and you connect it to a power amp. The way Jerry used his Twins was the same concept, he only used the preamp section of the Twin. Makes more sense to just buy the SMS imho. But hey thats just like... my opinion... man...

Yeah, I understand about the preamp-out mod (I think, but am not sure, that the power sections were completely removed); what I wonder about is how the 2 together worked; I mean, I've seen one pre into 2 power amps, but 2 pres into 1 amp baffles me.

Ahh gotcha. I know the sound your hearing from Jerry is just the preamp and the mcintosh. Your not hearing the power section of the twin. Also he may have had one twin pre into Left channel input on the power amp and the other twin pre into the Right channel input on the power amp. Run in stereo ? <----This i am not sure about.

As i said before im sure someone will post info and some pics etc.

Sorry i couldnt be more helpful

Only one of the twin preamps was wired to Budman, the MC2300. The other preamp was used as a backup in case of some type of failure.

^ Aha ! This is what i thought, i didnt think he was running both at the same time in stereo etc. Anyone have pictures of the back of the units ? I use to have some pictures of behind Jerry and Bobbys rigs thruout the years.

sfmaverik wrote: ↑Sun Sep 25, 2022 8:40 am Only one of the twin preamps was wired to Budman, the MC2300. The other preamp was used as a backup in case of some type of failure.

Thank you.