View Full Version : Dynaco ST70 VS Macintosh MC250

01-10-2010, 08:48 PM
Any thought if both were with $50.00 or so of each? Both are in great working shape and around $500.00 each.?

Which to go with JBL L100's and Mcintosh C26 Preamp?

01-10-2010, 09:01 PM
The Dynaco is about ten watts more powerful. The McIntosh has a stellar reputation, and $500 is way below market value. You can get an ST70 almost any day of the week for about $500.

01-10-2010, 09:06 PM
I agree with Isotonic's post, though I prefer to own tube gear mostly because I enjoy and am able to repair and maintain it while SS gear is more difficult for me. If you don't have a reason to strongly prefer a tube amp I guess I'd have to say the Mac is a better deal - though I've never heard the MC250 myself.

Steve O
01-10-2010, 09:48 PM
The Dynaco is about ten watts more powerful. The McIntosh has a stellar reputation, and $500 is way below market value. You can get an ST70 almost any day of the week for about $500.

Actually, the MC250 ought to be good for at least 60W/ch and maybe 70. The ST70 will barely make 35W/ch with a tailwind. And maybe not, even with a tailwind

My opinion: For L100s and a C26, go with a nice MC250. I think the 250 has a "tubey" sound even if it is SS. And it has AUTOFORMERS to boot...mmm, mmm, mmm!

FWIW, MC250 resale $$ will probably be better in immediate future too.

01-10-2010, 11:03 PM
OOPs, I read McIntosh 225, not 250. I would say that they are of equal value and possibly merit. I have both and love both. If you are into tubes and mods I recommend the Dynaco. The Mc 250 is also great sounding. I like that it has autotransformer outputs. It makes the McIntosh friendlier to a wider variety of speakers. My 250 seems to sound good on all of my speakers.

From a maintenance point of view, the 250 is fairly simple to work on and easy to refurbish. It doesn't have a lot of electrolytics and it's designed for easy service.
I ran mine plugged in for about 15 years. It was the amp for my PC system, so it got lots of use. It just started acting funny, so I will now do a complete refurb.

Oh, and the Dynaco is 35 watts per side, while the McIntosh is 50 per side.

01-10-2010, 11:08 PM
Just read your post Steve O. Didn't mean to rewrite what you said already. I got started on my post when I realized I had misread OP.

Steve O
01-11-2010, 11:53 AM
Just read your post Steve O. Didn't mean to rewrite what you said already. I got started on my post when I realized I had misread OP.

Not to worry. Clearly, great minds mostly think alike. Here we have further proof. :D

01-11-2010, 01:40 PM
I recently owned a restored (by me) ST70, a Mc 2100 and a Mc 7100 all at the same time and compared the sound on my Heathkit AS-101's (Altec Valencia's).

Disclaimer: I am an old retired electrical engineer (with an attitude!) who had not done any real electronics since college (I worked in a nuclear plant). I don't buy into virtually any audiophile hype, in fact, I remember when Monster Cables came out in the '70's and just rolled my eyes; it has gone down-hill from there IMHO. I absolutely came into this little adventure refusing to believe that a tube amp could sound different, let alone better, than a solid state amp that "had better specs".

I can't believe I'm writing this, but I could tell the difference and actually preferred the sound of the ST70 on my speakers (obviously very efficient and not needing tons of power) over the two Mc amps so YMMV.

I absolutely could not tell the difference between the two good-sounding Mc amps. But the ST70 "just did it for me", the bass sounded more natural, etc". I wish I could say more "but I'm an engineer, not a writer". Who knows, maybe I'll come around some day on Monster Cables and $10,000 power cords (NOT!)...

Now, just where did I put that voodoo doll and bottle of snake oil???!!

01-11-2010, 01:48 PM
If the MC-250 sounds like the MC-2100 (which I believe it to)... definitely pick up the ST-70. Well, definitely IMNSHO. I am not a huge fan of either, but the ST-70 has considerably more potential (literally, of course, being a vacuum tube amp with considerably higher B+, but I am speaking figuratively). The MC-250 is what it is: an early solid state product (autoformers notwithstanding) that just doesn't quite make it.

Again, my opinions are based on the MC-2100, but I believe the MC-250 is awfully similar in topology and performance. I will also concede that a freshly spruced up Mac transistor amp will sound better than a 30-plus year-old amp running all original passive components.

I think you should forget both and find an MC-225 if you can afford it or an ST-35 if you can't :-) Use 'em on rustnot's Valencias and you'll find yourself smiling a lot. Just sayin...

01-11-2010, 06:24 PM
Like rustnrot, I too have an MC2100, MC7100, and rebuilt ST70 in the stockpile. I've also got an MC2505 (MC250 with meters) that was just recently rebuilt by Terry D. I completely rebuilt the ST70 two winters ago, replacing every socket, cap, and resistor. I used the Triode Electronics cap and driver boards (EF86 version). I went with the Triode driver board because it is somewhat similar to the original topology, just using EF86/12BH7 in place of the 7199.

Anyhow, I've listened to all of these amps quite a bit on a set of Snell EIVs which I've had for over 10 years. I can't really say that I like one amp more than any of the others (maybe that's why I'm having a hard time parting with ANY of them...). The ST70 does have a different sound which I find very pleasing, but the McIntosh amps are also very nice sounding and noticeably more powerful especially when playing bass heavy tracks. They all sound great to me!

For now I'm using the MC7100 as my primary amp because it is much more family friendly than the ST70. Coincidentally, I just this weekend acquired a nice set of JBL L166s. This is the only other set of serious speakers I've owned beside the Snells. The L166s are somewhat similar to the L100 (??) but unfortunately I haven't had a chance to do much listening with the L166s yet, so I can't really provide much feedback there. My initial impressions are that they sound quite nice with the MC7100. I'll have to hook up the ST70 at some point and report back.

I don't think you can wrong with either the ST70 or the MC250. If you like to rock out and play loud, the McIntosh will probably be a better fit (in my opinion, of course). Either way, you should plan to get them refurbed for safety and optimal performance.


01-11-2010, 06:32 PM
To flip I'd by the Mac, to listen to, the 70.:yes: