dynaco st 35 vs mcintosh mc30

[Pio1980]

Just for giggles, I did a websearch on the better known and ranked vintage tube amps, and a few tended to dominate. The MC30s are contenders acccording to some with the Marantz 8/8B and the MC225. The quest for even more power leads thru the MC240, MC275 and HK Citation 2. The MC30 are amongst enduring favorites, and availability and price would determine which you might choose without the opportunity to compare them. Chances are, you would be delighted with well sorted out examples of any of them.

 

[Selmerdave]

I think the MC30 monoblock was the first of the type to make it into the consumer market. It had a lot going for it in quality and performance, poised against mainly Williamsons. I mentioned the. Marantz amps earlier, which were as the model 2 monoblocks no-compromise Mullard 5-20 based. The model 5 were "steamlined" model 2 monoblocks, and the 8/8B dual model 5 stereo amps.
The MC30 wasn't extravegantly costly and sold very well, there was just a lot of competition at all levels with each proclaiming their virtues, actual and aspirational. Mac was justifiably proud of performance that could be verified in the lab as well as the field. Few suffered spontaneous organic failure from transformer failure, a not uncommon end to some of the overstressed overrated competition.

Do you mean first UC design? Amps like Fairchild 275, 255, 260 and Radio Craftsmen C500 were pretty early designs and I would think competitive with MC30 though the RC is somewhat lower power.

 

[Pio1980]

Do you mean first UC design? Amps like Fairchild 275, 255, 260 and Radio Craftsmen C500 were pretty early designs and I would think competitive with MC30 though the RC is somewhat lower power.

The first of the McIntosh consumer single chrome chassis amps, there were prior dual chassis industrial UC amps.
I'm aware of the Fairchild, Soundcraftsman, and others that weren't as well known or widely sold as the amps I mentioned. I'd rather not send folks looking for the unicorns in favor of the stuff that is somewhat readibly findable by comparison. The variety of the good stuff that was available in the golden age post WW-2 is awsome, much of it obscure nowadays. A lot of the stuff was Williamson by default before the simpler more elegant Mullard 5-## driver appeared and replaced it as the default choice. There were of course proprietary circuits other than the McIntosh UC, some not so good. Ed Laurent came out about the same time as the Mullard with his elegant single envelope pentode gain plus triode splitter 6AN8 driver, and this soon became a widely popular default. Other single envelope drivers used twin triode tubes as either gain plus splitter cathodyne or gain plus inverter paraphase. McIntosh continued making their complex UC amps to the end and beyond, the MA230 being an exeption.

 

[nj pheonix]

McIntosh continued making their complex UC amps to the end and beyond, the MA230 being an exeption.

I had one for a bit. No slouch either. Probably as nice as well regarded Fisher, Scotts, Sherwoods, Eicos....
Also probably tested better. It was notorious for eating 7591s.
Also One of the first hybrids with a SS Pre section.

 

[UncleBingo]

The Stereo 70 would be more comparable powerwise, especially with upgraded power supply.

The Dynaco ST-70 isn't a fair comparison sonically imo. ST-35 is much better sounding amp. MC-30's do have a very nice midrange, but I've think the bass a bit loose.

I preferred the MC 240 after recapping it to the MC-30's. May come down to what music you listen to. My MC240 has pretty tight low bass- moreso than I expected and I run it with Altec horns and a single Altec 15".

 

[nj pheonix]

In fairness the MC30 was about 2.5 x the price of an ST 70. Today a single MC30 goes for 3 times the price of an ST70.
I once had an SCA 35 but not an ST35. I do have a restored 70 (based on the base line article). I restored a pair of MC40s for another member and i have a pair of MC60s,
While i prefer the Macs, The properly set up Dynaco is no slouch. I've heard some prefer the ST35 to the 70. I've been tempted on several occasions to buy and or build one. Oddly they go so high unrestored. I think new kit (with the AR boards Dave is marketing makes more sense.
(i keep forgetting i'm supposed to be downsizing though and i'm doing a bad job of it)

 

[Pio1980]

Reviving an old thread.
I've had a 'thing' for vintage naked chassis era Mac tube amps since first seeing them in the 1960s, worked on a couple of them, and strongly considered getting an example until recently after continued research.
Reading a multitude of postings on which tube amps are "best", which tube Mac amps are best, which Mac amps of any type are best or preferred by resident Mac folk and other users, a state of confusion and indecision results. Some say the early gen S/S Macs sound the same or better than almost any of the tube Macs, others say they all sound the same. Still others delineate listening differences between model and generational examples. Contemplating a generous offer for a pair of fully refurbed MC30, I revisited a thread on the Dyna ST-70, an amp I owned and liked in past years with satisfaction, except, you know, "the quest" for "better". While I know S/S generally offers a more solid, extended bottom end, some amps just get it mostly right, drawing one into the musical involvement experience. Vacuum electron valves (tubes) have a reputation for doing that in many critical respects, and the prospect of repossessing and refurbishing a non exotic simple to maintain common amp of proven design and engineering competence at a literal fraction of the cost of the MC30s appealed greatly as a practical low-cost alternative experiment, so that's what I did instead. And, in a relatively modest setup, I'm impressed how simple and easy it is to get this degree of what the end result of what the quest should be all about with reasonable expectations. Add the economics of simple changes and the availability of good quality tubes and the ease of maintaining an amp that gets generally long service out of the 3 amplification tubes per channel, I have nothing to desire that cannot be addressed with an active subwoofer system if I want more deeper in the bottom end without losing the "good stuff" upstairs.
No, I won't get the chance to compare it with a properly functioning 'exotic' amp, but with this as my endgame midpowered valve amp, I'm at the point of just enjoying the music and less experimenting.

 

[Pio1980]

With an EFB board an ST-35 will do an honest 17 watts per channel. Stock its closer to 13 with both driven. Its more a limitation in the bias system design than the amp being grossly over-rated. In stock form it will actually do ~17 a channel but only with one channel driven.

http://www.tronola.com/html/a_new_look.html

Power-wise the ST-70 is a more fair comparison to an MC-30. Completely different design though so thats about where the comparison ends. Having never heard either one, I can offer no thoughts on what that means exactly.

The Mac unity coupled amps were and are brilliant, yes. However, in light of @dcgillespie thread on base line testing the Dyna ST-70, I'm reminded of comparisons to German vs American engineers, using a half dozen parts in place of a couple to accomplish essentially the same purpose, tho one must grant Mac credit for stringent unambiguous performance ratings.
In the end and off the bench, it's about the listening.

 

[RS Steve]

The Mac unity coupled amps were and are brilliant, yes. However, in light of @dcgillespie thread on base line testing the Dyna ST-70, I'm reminded of comparisons to German vs American engineers, using a half dozen parts in place of a couple to accomplish essentially the same purpose, tho one must grant Mac credit for stringent unambiguous performance ratings.
In the end and off the bench, it's about the listening.

Totally agree, I'm big on comparing and testing different brands and models. Although I'm gun shy to post any of these comparisons since it will draw the ire of the "not scientific testing, therefore needs disclaimer" responses. I do it for fun, and just a way for my listening education.

That being said, I recently did some comparison listening between my ST-70, Eico HF-87, Eico HF-89, MK-III's, and a pair of Mac MC-30's I restored for a relative. All are restored and the Eico's have EFB and upgrades that were designed by Dave Gillespie. My ears certainly were treated to quite a variety. I actually liked the Eico HF-89 / 87 units for best all around performance, the MC-30's were second just barely beating the ST-70 by having what seemed like better clarity in the mids. The MK-III's were right there with the others, but has a bit more background rushing noise present, so someone had to come in last.

Anyway, it was interesting to hear them all being played hooked to my Erhard modded PAS preamp, AR-58B speakers, and Luxman turntable. No disappointments at all, just a very impressive showing from the Eico amps, and it validated what BuzzK said by informing me that the Eico's become world class with the mods.

 

[trainbuftony]

Well, right at this very moment, I have freshly rebuilt examples of both units.
A ST35 (built in a custom chassis but 100% stock) which I finished last week, and a pair of McIntosh Mc30 amps which were completely overhauled about 2 years ago.

Both amplifiers have been rebuilt in such a fashion that the only original part is the transformer set.

Both sound great.
The 30 sounds about 3 octaves greater.

 

[Pio1980]

Reviving an old thread.
I've had a 'thing' for vintage naked chassis era Mac tube amps since first seeing them in the 1960s, worked on a couple of them, and strongly considered getting an example until recently after continued research.
Reading a multitude of postings on which tube amps are "best", which tube Mac amps are best, which Mac amps of any type are best or preferred by resident Mac folk and other users, a state of confusion and indecision results. Some say the early gen S/S Macs sound the same or better than almost any of the tube Macs, others say they all sound the same. Still others delineate listening differences between model and generational examples. Contemplating a generous offer for a pair of fully refurbed MC30, I revisited a thread on the Dyna ST-70, an amp I owned and liked in past years with satisfaction, except, you know, "the quest" for "better". While I know S/S generally offers a more solid, extended bottom end, some amps just get it mostly right, drawing one into the musical involvement experience. Vacuum electron valves (tubes) have a reputation for doing that in many critical respects, and the prospect of repossessing and refurbishing a non exotic simple to maintain common amp of proven design and engineering competence at a literal fraction of the cost of the MC30s appealed greatly as a practical low-cost alternative experiment, so that's what I did instead. And, in a relatively modest setup, I'm impressed how simple and easy it is to get this degree of what the end result of what the quest should be all about with reasonable expectations. Add the economics of simple changes and the availability of good quality tubes and the ease of maintaining an amp that gets generally long service out of the 3 amplification tubes per channel, I have nothing to desire that cannot be addressed with an active subwoofer system if I want more deeper in the bottom end without losing the "good stuff" upstairs.
No, I won't get the chance to compare it with a properly functioning 'exotic' amp, but with this as my endgame midpowered valve amp, I'm at the point of just enjoying the music and less experimenting.

Things change, sometimes unexpectedly. A sorted-out custom build VTA-70 has indeed replaced the thoroughly rebuilt Dyna STEREO 70 as being comparatively preferable. This is the amp I would like compared to the"better" alternatives as being commonly available and comaratively affordable.

 

[crispycircuit]

Isn't Mac amps class B. However, they keep the distortion low with there special wound outputs. There certainly are plenty of amps to compare and no set standards for comparing, but I enjoy opinions. Thx for the entertainment...

 

[mcgjohn]

Just for giggles, I did a websearch on the better known and ranked vintage tube amps, and a few tended to dominate. The MC30s are contenders according to some with the Marantz 8/8B and the MC225. The quest for even more power leads thru the MC240, MC275 and HK Citation 2. The MC30 are amongst enduring favorites, and availability and price would determine which you might choose without the opportunity to compare them. Chances are, you would be delighted with well sorted out examples of any of them.

Yes, pretty hard to argue with your findings as far as vintage toobe amps go. I have copies of all mentioned. Would also include the MC60s in this list. Better sound than the MC75 or the MC275.
Of the MAC amps with sand rectifiers, would say the nicest sounding is the MC225. the 225 is one of those amps you can listen to all day, and the next day, and the next day and never tire of it. I bought a 2nd copy of the 225 to try as monoblocks, but most of the 225 magic disappeared so would not recommend that route.

The MC30 was one of the few MAC amps that did not come with a choke, If you add one, you can lower the power supply noise floor by about 8-9 db. Pretty impressive.