My quest for amplification landed a McIntosh 2100 in my living room today, the first "Mac" I've ever heard! Seems a bit brighter on the mids and highs than even the Phase Linear I recently added but still with enjoyable bass control. It's in pretty nice shape although someone along it's path through time decided to keep the cool McIntosh badge from the side of the case as a keepsake or something. Swapped one of the GFA-555s I had for it. Hoping to sell the other GFA-555 and maybe my GFA-5500 and convert the cash into a McIntosh with the cool looking meters on it! That might replace the Phase Linear in my collection.

Would love to try biamping my DQ-20is with the Mac on top and the PL400 handling the bass but the PL sounds like it has a much different input impedance... it is the loudest amp I've had this year at any given pre-amp level by a wide margin.

(Click thumbnail for larger image)

What are you running it through, or am I misunderstanding something and it's the DQ's?

I had five different amps in my living room this afternoon, three adcoms (two 555s and a 5500), my phase linear pl400, and this mac 2100 and we listened to all of them. All the amps with the exception of the phase linear produced similar dbs at the same low input levels from the preamplifier. The phase linear is markedly louder at the same input levels than any of the others.

It is, if you are not familiar with the 400 series 1, a very no frils amp with the exception of the vi meters. No input gain adjustments, not even a power switch. Is something out of adjustment internally or does my pre simply have the wrong impedance for it or? I can't get it in to my tech for a couple of weeks yet so I don't know. It still sounds great, just isn't a very good match for any of my other amps at the moment...

Ideas? Suggestions?

how does it sound on its own? i'm thinking the 9Lsi's might like it.

Both the mac and the pl sound great on my ARs, slightly different but with more in common than with the adcoms that preceded them. Highs and mids most notably and while I think the phase linear has more oomph to bring the bottom end alive I think I prefer the sound of the mac in general.

My dqs image better than the ars and while they don't have the bottom end that they do at least they are biampable. I read a review of the dq-20i one day that said they made them biampable for a reason and I guess it got
me curious to try it...

I know I am on an amp kick lately... VU meters are the sort of eye candy I've always enjoyed and I'll likely end up with a big mac one day if I can make the right deals happen. Amps for me are a very subjective thing and I really try had to a/b them quickly, for short periods of time, and then trust my gut on "first impressions". I worry no small amount that spending too much time and concentration trying to really discern an amps strengths and weaknesses will eventually introduce my imagination into the equation.

Speakers on the other hand are of course much easier to compare. I'm very pleased with both of my main pairs but think that if I had to sell one the DQs would probably be what I would keep although in all honesty it feels very much like a "sophie's choice" kind of decision!

Anyway, I guess I am working on the pure hypothetical that the ARs go one day and the DQs sound best biamped. So then, what two amps? Another phaselinear 400? Another mac? Something else?

Great score. The 2100 is worth double the GFA-555 and is definitely the better conversation piece. I bet a new badge is available from Mac but will cost you.

I'd bi-amp with the same model amp. Amps have different speeds and coloration so you will want consistency.

You will probably need to sell a bit more than the two Adcoms to get a McIntosh with meters, unless you were planning to add some additional cash on top. There aren't a lot of metered Macs to be had for under $1000, and I doubt the Adcoms will bring in that much in today's economy.

BTW, you should send a note to McIntosh and inquire about the lettering for your amp. I understand that they are very good about having replacement parts.

Rob

Congrats.
If someday i'll get my hands on a McIntosh, certanly i'll give a party.....
That's one of my dreams, you know. Very hard to g$t in Europe.
I concur with Sam. Bi-amped with the same model.
BTW, is it an integrate amp? How old is it? Don't let any cranky capacitor destroy those priceless transformers.

Thanks! Mac's have been a dream of mine too. This one has no meters but as pointed out those that do tend to sell for much, much more even here in the states. Even the 2105 which is basically the exact same amp I have, plus the meters and glass face cover, can sell for twice as much or more than the meterless model that I have! I love meters and really want some Mac blue and green in my system but I don't know if I really want to spend an extra US$400-500 to get them.

Nope, just a straight power amp. 1973 I believe, 105wpc or bridged into 200 with Mac's unique speaker selection where you can select your speaker impedance on the back of the amp by wiring them to 4, 8 or 16 ohms (2, 4, or 8 in mono) terminals.

I haven't pulled the cage off it yet but what I can see looks very good. I should say nothing looks bad, burnt, brown, leaking, swollen, corroded, etc. I enjoyed reading this short, little walk through in 2100/2105 basic inspection and maintenance:
http://www.circlestereo.com/info/brands/mc...?content=mc2100

I think there's two potentiometers in the pic you'd post...are those gain controlers?!

Yes, they are. Right and left channel input gains with a stereo/mono switch above them. They work properly and are as I type, maxed out.

Plugged in the DQ-20is today and boy, do they love that Mac! I thought Dalhquists imaged well before... holy smokes! Maybe a second 2100 (or a 2105 so I can have some meters) biamped for the DQs is my golden ticket to audio nirvana. l

On a tangent the guy that I got the mac from had never heard any of the big Teledynes... I think the first amp we ran yesterday was the phase linear with my ARs... I think he asked me two or three times, in different ways, if that was truly only two channel music we were listening to! He kept eyeing the center channel between the ARs and suspected I was demoing in some surround mode or something... Nope! Pure two channel. Hats off to the ARs! I don't think they image as well as the DQ's but that doesn't mean they image badly either

Nice grab there. You've got quite a nice collection of gear and glad you were able to add another dream piece to your collection!

Thanks! I love this hobby and of course the net result, music, is the air my soul breathes.

I wish I could afford the $$$ or the storage to keep all of it but it's not realistic in either sense at this point in my life. Anyway half the fun is trying new stuff! Is it bad when you dream in McIntosh green? Maybe I can snipe a 2105 off of the bay to biamp with the 2100

We're not supposed to keep the stuff . Dang! I need to make a note of that. Admittedly though, metered models are nice. Good to hear your opinion on the sound. I picked up a Mac unit several months ago. Ended up needing some repair. Due to a favourable turn in traffic court I have the funds just need to find the time to drop it off.