Jerry Garcia’s McIntosh amp

“Bud Man” was the amp ... MC2300.  Google it.

Good luck on staying clean.

There are many, many sites to be found which detail the gear well.  Here's one that I forgot about which shows a PL700 sitting atop a stack of MC3500s - http://www.epicdimensions.com/gdgear2.html

The amp was correctly called in post #2 - an MC2300.  McIntosh amps comprised the Wall of Sound, not Phase Linear.  (48) MC2300 and a handful of MC-3500s were used.  Numerous drawings, photos, threads, and videos (including the one referenced just above), and even the Grateful Dead movie show the amps.  McIntosh even developed a bit of a marketing campaign around the fact that both Woodstock and the Grateful Dead chose McIntosh amplification and an even opened a Gradeful Dead exhibit at the R&R HOF - https://www.mcintoshlabs.com/brand/news/Grateful-Dead-Exhibit-at-Rock-and-Roll-Hall-of-Fame

Reportedly, Jerry played through one channel of the MC2300 only while on stage.  The particular MC2300 he was seen most often with has a sticker on it of a guy playing the guitar.  This was known as the Bud Man amp.  Just google "bud man mc2300" for many pictures of Jerry's setup.

Also reportedly, the MC2300(s) that Jerry played through were modified.  Some claim that Alembic removed the McIntosh sentry monitor circuit entirely.  Others claim that not to be true.  Rear panels had banana jacks added to them to facilitate quicker connections to the speakers.

At some point, after McIntosh introduced the MC2500 in 1980, Jerry did try one of these.  There are a handful of photos of him playing on stage with an MC2500 and not the Bud Man MC2300.  This didn't last long however.  Try as I may, I've been unable to determine why.

I met Bear in the 1990s, after running an ad on the Grateful Dead's website looking to purchase the McIntosh amps used in the WOS.  What an eclectic personality.  I sure wish I would have had the foresight to archive that convo . . . 

I have a bunch of these amps . . . 2300s, 2500s, and 2600s even.  The hype is real.   Have fun.  

rh67 - there was definitely a time the band used Phase Linear amplifiers, unfortunately it’s simply not well documented.  I for one would love to see some pics just out of curiosity.

Really, there isn’t much to “claim” when there are literally thousands of photos to support just a google query away.  AudioKarma must have ten threads devoted to the Dead’s setups and in at least one of those threads is a gentleman who also spent time with the band.

FWIW, neither he or Bear had much good to say about the McIntosh power amps.

Sure.  No problem.  I’ve seen more than one guy build a setup inspired by Jerry’s.  An MC2300 is a LOT of amplifier and it has two channels (which can be strapped together for mono operation with double the power of a single channel).  They weigh in at 128lbs and presently sell at a premium on the used market.  Keeping these old behemoths in service requires a serious commitment and a local McIntosh tech would be a must as shipping them is cost prohibitive as they need be double boxed and palletized for LTL transit.  Regular shippers just destroy them.

You may find that a MC250 or MC2100 is just more accessible.  Each sound indistinguishable from the big brother MC2300.  McIntosh also offered both of those in single channel versions - the MC50 and MC100 (rare, but they do come up) - as well as glass  faced versions, the MC2505 and MC2105.  The last two were stereo models aimed squarely at the HiFi market and cannot be operated in mono without a modification to do so.  Neither stopped Bill Hanley from using MC2105s at Woodstock and on the road in general.

Whatever you decide, these amps are getting up there in years and McIntosh issued many TSBs on the driver boards over the years to make them more stable.  A qualified tech should give the amp a once over with that info at hand.  That being said, I’ve had a pair of 2300s in daily service for two decades now and have owned a few dozen in all.

Have fun!