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Grateful Dead Music Forum

A place to talk about the music of the Grateful Dead 

 #108985  by Jon S.
 Sat Feb 04, 2012 5:39 pm
Curious as to whether there were any SS power amps built around the time of the "Jerry McI's" with similar construction and tone. By way of analogy, Gibson made some amps in the late 50's/early 60's that were similar to circuitwise, if not indistinguishable from, tweed Fenders. Same with Traynor - the original YBA-1 is very close indeed to a JTM-45 which in turn is very close to a tweed Bassman. That's what I'm asking. And to minimize controversy up front, let's agree nothing sounds exactly like a McIntosh ... but is there anything by Fisher, Marantz, Motarola, etc. that falls between a vintage McI. and today's SS power amps? Thanks for any info./suggestions at all.
 #108987  by SarnoMusicSolutions
 Sat Feb 04, 2012 7:07 pm
You could look into the Phase Linear 400 and 700.


Back in 1988/1989 I built a Jerry-rig that had a Schecter strat with three Dimarzio dual sounds each on a toggle for single or series, a blaster for a buffer, a custom fender-like preamp (no reverb), Alesis reverb, 2 jbl d120f's, an MXR Dist+, phase 90, mutron, mutron octaver all in a rack shelf with home made remote relay switcher box, Ibanez rack delay with time and mix on two remote EB vol pedals, full OBEL wiring, and a Phase Linear 400 power amp. That amp was brutally loud and clean and my ears still pay today for what that amp did to me on stage. I was pretty obsessed with Jerry's rig at the time. It's amazing how much easier it is today to find good info on the topic compared to in the '80s.

Phase Linear amps are good, but don't abuse them too harshly. They didn't earn the nickname "flame linear" for nothing.

B
 #108990  by Jon S.
 Sat Feb 04, 2012 9:40 pm
Did the Phase LInears have autoformers, too? I ask, as a non-engineer, because those seem to be associated with the "McIntosh sound."
 #108992  by SarnoMusicSolutions
 Sun Feb 05, 2012 12:09 am
I don't believe you're gonna find autoformers on anything but the Mac's. That is a central part of their character. Really, the Mac transistor amps are somewhat textbook and basic and not all that wildly special or unique in their fundamental design, other than the use of autoformers. They were well engineered, well implemented designs, high power for their time, conservatively rated, robust in permanent installations, and quite clean in the sound, kind of a military spec mentality in a way. Their tube amps, on the other hand, had some ingenious/revolutionary ideas going on and they wound some very special design and high quality transformers to facilitate these design ideas.

All that said, the transistor Mac's do deliver the transistor era Jerry guitar sound as good as you're gonna get it. It's the real thing and there is definitely a warmth and bigness to their tone.

You can find autoformers out there and it would be cool to experiment with attaching these autoformers to other amplifiers' outputs and see what you get. Although it's not likely that these stand-alone autoformers will be wound with nearly the quality and performance of the Mac's.

Also, another idea worth pondering is that Jerry used the 2-ohm tap on the Mc2300. This tap also happens to be the point where the autoformer was connected. So basically, Jerry's speakers were wired directly to the output transistors and got the least autoformer interaction possible from that amp. Still, the fact that the autoformer was tied to the outputs surely had some effect, but we can tell that it was minimal by the nature of using the 2-ohm tap. So maybe there are some other amps that would do a good Jerry. But we also know he surely tried a lot of amps and always came back to the Mac. I strongly believe that the real test and the zone of use/abuse that kept Jerry coming back to that amp was in how it sounded and behaved when it was banged on and abused, driven to its power limits and forced to squish and distort a little. That's where clean power amplifiers show their true colors. Some will simply go to shit when abused, some will get harsh sounding, some will get unstable, some will sound wimpy, some will become fuzz boxes, some will fry, some will catch fire, but the Mac seemed to take it well enough and feel and sound good for guitar the way Jerry played it.

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 #109001  by hippieguy1954
 Sun Feb 05, 2012 8:39 am
Jon S. wrote:Have you seen Patrick Quilter's (the Q in QSC) new amp?

http://www.quilterlabs.com/products/micropro-200.htm
Yes, and it's funny you should mention it. I was doing some research on the QSC company before I bought the QSC PLX 1202. The first thing I saw was that Patrick Quilter started the company and the next thing I saw was that new combo amp. It's probably a great combo amp, but I'm lovin the SMS Jerry with the PLX 1202!
:smile: :smile: :smile:
 #109038  by jeffm725
 Mon Feb 06, 2012 11:47 am
Max Creek used these in their Mini "Wall of Sound" in the late 70's and Scott Murawski used one in his guitar rig for quite a while. They are supposed to be quite similar to the Macs:

Accuphase P-300
Image



Read the specs here:
A lot of the same characteristics of a MAC are described:
http://www.accuphase.com/cat/pcten.pdf
 #109075  by SarnoMusicSolutions
 Tue Feb 07, 2012 7:30 am
Thanks for the Accuphase info. That's a very cool amp. Actually pretty different from a Mac, electronically speaking, but perhaps every bit as cool, or maybe even more so. They seem to draw high dollar to collectors. I'd almost be more afraid of hurting an Accuphase than a Mac. It's a MOSFET power amp with a LOT of output devices driving it all. All discrete, early '70s design. Plenty of power for our purposes. Here's the data:

http://www.accuphase.com/cat/p-300ven.pdf



B
 #109114  by jeffm725
 Wed Feb 08, 2012 7:52 am
SarnoMusicSolutions wrote:Thanks for the Accuphase info. That's a very cool amp. Actually pretty different from a Mac, electronically speaking, but perhaps every bit as cool, or maybe even more so. They seem to draw high dollar to collectors. I'd almost be more afraid of hurting an Accuphase than a Mac. It's a MOSFET power amp with a LOT of output devices driving it all. All discrete, early '70s design. Plenty of power for our purposes. Here's the data:

http://www.accuphase.com/cat/p-300ven.pdf
From the Stories Scott tells its a pretty robust unit. He tells a story (might have even been on this board) of a time when he was playing and heard the drummer drop out, so he turned around and the drummer was trying to put out a speaker fire in his guitar cabinet! He said he never would have known otherwise cause the accuphase kept pumping signal through the fire!