Any Dynaco/kit owners here, former, now? Kit builders, fans, haters?

A thing that tells me when the next monster truck rally is happening.

On Sunday Sunday Sunday...

 

You're just talking; burping up all the same noise as all of the other Dynaco detractors (the vast majority of whom, at audio forum pile-ons and group think fests, have never owned, heard or even been in the same room with one), sounds like stuff from magazine reviews; I've been around long enough and read the same diatribes, almost verbatim, from too many folks............it's just noise coming from folks who couldn't operate a soldering iron for a million bucks, let alone explain how a power supply works

No one has answered the question other than to repeat the dogma I've heard from hundreds for years

You've now raised another issue; what does age have to do with it (sound quality and circuit design) Tubes haven't even been manufactured in this country for almost that long as well (your 40 years wise crack, funny guy)

Cite me some of the advances made in tube topology and architecture, since the ST-70, and please, be SPECIFIC, not just generalities like "their power supplies suck" and then we'll have a conversation
We can even do it with PM or personal email
Sound good?
"OK"?

 

Transformer winding, however, has advanced significantly. Capacitor performance has advanced significantly. Better phase splitters with fewer balance problems are thick on the ground. Gentler treatment of tubes is more common. Heck, there's solid state that sounds better than any dynaco if you can afford to take out a mortgage to pay for your stereo.

And of course their power supplies suck. Their power transformers are barely adequate for the specified task and their filtering is negligible for starters. Take a look at something like a Border Patrol power supply -- and maybe listen to a Border Patrol amp -- and then come back and tell me that an ST70 is better. It's not. It's mediocre to poor in comparison. Build something like a Hagerman Cymbal (with its terrible Hammond iron) and tell me ST35 is better. It's not. Heck, go try out K&K Audio's modification kits -- make sure to use the Lundahl iron! -- and tell me that Dynaco's stock design is better. It's not.

After more than sixty years of evidence, modifications, restorations and cultural experience leading pretty much everyone to agree that Dynaco's designs can be improved, you might be the one who needs to provide proof of his claims instead of demanding that others do so

But really, nobody wants to see your proof. It doesn't exist. You can at least stop chiming in on every thread to defend Dynaco's honor. Nobody is saying that Dynaco sucks. I'd wager that ever person on this thread has built and restored plenty of Dynaco tube gear. We're all fond of it, but the ne plus ultra it is not.

 

How so, be specific, provide measurements, not sales literature from winders and vendors
(but I do not think, in fact I know, the raw materials have not and that in and of itself is the most critical component to a good sounding piece of iron) Assuming of course it meets design spec

You are absolutely correct on this one. Capacitance today is cheap, reliable, takes up less space and comes in more values than it ever did 50 years ago
That is why no one thinking clearly would operate an original ST-70 without doing a full re-cap, but that in no way is indicative of a design deficit with the amp, or any other amp from this era
So again with this one I fail to see the "point"?

The current designs have to be (good ones anyway) as, for the most part, current production (modern day) output tubes are poorly constructed, unreliable and are easily over driven into red plating

I don't even see how that's relevant to your continued insistence that the ST-70 is "mediocre" at best

Again, be specific regarding the transformers (more specific than "go listen to this apple and then come back and tell me about that orange" and hold those results forth as any sort of "proof" of anything)
You cannot find fault with a circuit's design (in execution or potential) by tying it to the production capabilities of passive parts 50 years ago
That's as silly an implication as saying that an original "six eye" "Kind of Blue" won't play well on a modern transcription table with a nice moving coil due to antiquated pressing techniques used in making the record; makes no sense and isn't reality

No, just constantly shouting from the roof top, for the displeasure of anyone within earshot, just how half assed it REALLY is if only you're in "the know" and would get with the program (and I'm sorry, I know your word of choice is "mediocre")

I'll take some of that; I bet you are mistaken
What and how much?

 

Whatever, dude. There's worse than Dynaco, and there's way better than Dynaco. Always has been, always will be.

Enjoy your fetish.

 

Correct.

This is especially true of the ST-70: certain other Dyna products are quite a bit better, although none were state of the art at their inception. As someone pointed out, the Mark IV used the ST70 power transformer and power supply with just one of its power sections, and it was a much better product.

Of the solid state power amplifiers, the ones with bipolar power supplies and no output capacitor were decent in their day, but solid state came a long way even in the next 20 years, and today most people just use the chassis, heat sinks and power transformer to build entirely new circuits in them. Along with certain Crown and Phase Linear units they were popular for many years for PA and bass rig use with bands playing bars and smaller outdoor gigs and held up pretty well.

The capacitor output, single ended power supply solid state models are useless for high fidelity purposes, or for anything else as far as I can tell, except maybe a bench test amp or to build a power supply out of, but even that would be a power supply inconvenient for any purpose I know of. (The PT has a single 60 or 70 vac secondary).

The ST70 is the target here of wholly justifiable criticism for modern use in unmodified configuration, especially for the sums unknowledgeable people are now paying for them. This is because the ST70 is around in huge numbers, unlike other Dyna products, and because it is as deficient as it in fact is in so many ways to trap the unwary. More than any other Dyna product it was rigorously cost and weight shaved: the designers not only struggled to get the price low, they wanted to meet a Railway Express package weight target, so apparently they shaved a pound or so off the power transformer. Railway Express is now a distant memory: the shaved transformer is still with us.

The fact that you can buy even crummier amplifiers in containerlot quantity from certain Asian contract vendors cheaply ( if you get on a jet and cut a deal locally) and that people sell these turkeys for even more money at times isn't relevant to me. What is relevant is that one can buy used or better yet construct from parts (if you can find them, particularly the critical link, the output transformers) yourself a substantially better product is substantially relevant to me.

 

Actually, transformer winding hasn't improved that much, because low frequency broadband (three decades in the case of high fidelity audio, which is a LOT) magnetics is largely a forgotten field. Low frequency narrowband magnetics have improved a bunch: large power transformers are significantly more efficient. High frequency narrowband magnetics are orders of magnitude better because of the ubiquity of switchmode power supplies. High frequency wideband magnetics are also substantially better, being used in all sorts of datacom and telecom applications. Outside of recording and live sound +4 dbm 600 0hm line applications and the output sections of the tiny number of tube amplifiers being built, the only other market for LF broadband magnetics is military sonar and passive acoustics. Both are highly classified endeavors: plus which most sonar stuff is in the 10 to 100 kW power level.

The A-470 opt in the ST70, the Mk IV, several Sunn guitar amps, the Kinsman organ amp and elsewhere, is not a truly terrible part. I never said it was, what I did state was that it was a carefully cost engineered part that as compared to Hafler's own Acrosound TO-300 or TO-330 ($24.75 or $39.75 apiece in the middle 1950s: neither exactly matches the A-470, the -300( (20 watts 20-30k, 40 watts 30-20k) having a 6600 ohm primary, the -330 (50 and 100 at same ratings) a 3800 ohm one), or the equivalent, Peerless, Freed, Triad part, is not really comparable. It is limited in the bass particularly, both because of its lighter stack and the difference in copper length between half-primaries. You can make a decent amp out of it, but never one that will drive an Altec 604 or other big motor speaker (big Altecs, JBLs, or Tannoys) as well in the lower register, as a McIntosh, or a Marantz 8B, or most any of the American built amps like VTL from the mid 80s on. For a small bookshelf application it will work fine.

http://www.tubebooks.org/file_downloads/acrosound.pdf Please read the Acro catalog. It is still informative today. Note most all are cathode bias, one area where Dyna was a big improvement.

 

From the folks I'm talking to, the bigger problem is getting the people who know how to wind interested in the minuscule production runs associated with hifi. The small signal transformers, though, are a a huge improvement, and have opened up some practical circuit options that had been dismissed for cost and performance reasons after WWII.

The A-470 actually isn't completely terrible with earlier 604s, although it's completely useless with the ferrite variants. Tannoys are, of course, another story entirely.

FYI: I love that link.

 

So.......anyone care to comment on the outdated sonics of my ST 416 with the c100 cap bank?

 

You are just now adding these qualifiers and quantifiers, this is back peddling and not what this whole call for owning (and substantiating with facts) ones' claims and proclamations has been about from the beginning.
I guess I failed to state in every post that I have made regarding the ST-70 that they were intended for and in reference to HEALTHY, UP TO ORIGINAL SPECS examples. That we don't plug in unserviced 50 years old tube amps should be an understood given to any of those willing to crow about it's "mediocrity" and continue to compare it to "even crummier amplifiers in containerlot quantity from certain Asian contract vendors cheaply" (I assume by this comment you meant even MORE cheaply), but I'm not sure just exactly what it is you are saying from post to post, other than the ST-70 is "mediocre"
By the way, the "containerlot" "Asian contract vendor" tube amps didn't exist in the days of the ST-70, so this is yet another comparison/thinly veiled knock with which I fail to be able to find any relevance to the subject at hand

Also, I still have a hard time with the meaning of the word "cheap" as it appears in many of the posts I read here: are we talking "cheap", as in poorly or shoddily made, or are we talking "cheap" as it would be applied to the relative financial cost of an item or service to another similar item or service (and provides absolutely ZERO guarantee of quality or outcome)

Please provide me a vetted source for verification of this claim as well as the names (besides Hafler) of these "designers" to whom you have referenced several time now involved with the design and development of the ST-70

Thanks

 

I have never heard one but I just looked at some photographs
Beautiful machine, impressive build and specs

 

I have been through this issue in attempts to get stuff wound.

There are roughly fifteen wind shops in the US capable of doing this kind of stuff. Most want minimum runs of between 25 and 100 pieces, this is reasonable, but still a fair amount of money. There are also as you know several one person outfits, but consistency and continuity are big problems as is the fact most have a tendency to only want to do what they want, when they want to, etc. A couple are also extremely difficult to deal with as people, which is another issue.

These shops tend to do a lot of military stuff and all the usual problems of contractor spoilage connected to this crop up: your work gets put aside until they have dead time. There is also the problem that under cost plus contracting, the way they make money is to value their floor time and test resources at insane cost figures, and if they then do work for you at some less insane rate, the inspectors may see this and use it to challenge these insane valuations. I worked at one shop that charged my test tech cycle on a part at a per minute rate equal to my hourly salary. We were working in an old building with a leaky roof and I had about $600 worth of test equipment at my bench, well, it was worth that before the leaky roof water damaged it. It was very profitable, but only for the owner.

The frustrating part is that the quantities needed are possible if someone got enough people interested in any one particular part. Even at the height of DIY tube audio in the US, about the time Ed Dell launched Glass Audio getting fifty people to buy one thing was like pulling teeth. Making a kit would be best-the price of unbuilt Heathkits proves to me there is a market-but at the same time it means dealing with a certain percentage of epsilon minuses and generating a great deal of documentation and parts sourcing logistics.

 

You've listened to it nearly as long as I've been alive. There's a good chance that anything else would just sound wrong if you tried it out.

 

These days I swap it into my main rig occasionally for a change of pace. I don't want to put too many more hours on it due to it's age.

Usually I'm bi amped with 2 Adcom GFA 5800 or 2 Pioneer Elite M 91 amps. That being said I am still impressed every time I press the old ST416 into service.

I'm currently trying to get the ST-150 I built for my friend back in the day from him. For a 75 WPC amp it had a quite impressive build, huge transformer and caps. Light years better than the ST 120.

 

Nice stuff back in the 70's. Built a few myself. Hand full of white crosses and a soldering gun. Whamo !!! Instant stereo.

 

I think Hafler was really doing all the design at that point, but I don't know, so used "designers" instead of "Hafler" personally. Doesn't really matter.

The story about the weight being set by a Railway Express target has been one I have heard many times. I have never tried to determine exactly what the ship weight was on a ST70 kit and what Railway Express weight table was used: probably some foamer website has the old tariff manual if one were so inclined. Exactly why the PT is undersized is not particularly important. It is, everyone agrees it is, and having felt the heat off many of these things personally can attest they run hot. Quite hot, noticeably hot. Hotter than any transformer on any other tube amplifier in good health I have encountered.

The container-lot comment again was not a "knock" on the ST70, it was a comment that their existence today doesn't matter to the discussion. I avoid them, don't want to know a lot about them, and don't know a lot about them. I do know that a stock ST70 was a product that when set up as per the manufacturer's instructions was a unit running at or very close to thermal limits and had absolutely no margin on most of its specs: there was no reserve. By comparison, the Marantz 8B, a fairly comparable unit save for price, was a unit very conservatively rated, that beat all its specifications by a noticeable margin, that ran its transformers much cooler, and that when driving many of the speakers then in fashion would have provided noticeably better perceived sonic performance to most critical listeners. Plus it would have lasted a lot longer.

Yes, I concede that saying "save for price" was a comment like "other than that, Mr. DiMaggio, was '62 a good year?" for many people then. The Dyna was a third the price, meaning many hobbyists that never could have bought the Marantz could and did buy the Dynaco. And the buyers got fair value for money: if they built it to specs it probably sounded halfway decent and lasted a few years. No one expected any of this stuff to last a human lifetime! But to read someone say that the Dyna would "kick the a**" of many much better products is to cause me to reply in the negative.

 

I burnt out a few soldering irons back then. Guys wanted me to go out and party, but I was too busy soldering! I know, boring. But it was a good learning experience for me.

 

Ah, here's the ST 150, it was a very easy build:




the guts made the ST 120 look silly.

 

It was a party for me and a few like minded friends. They were in charge of tunes and I did the gun work. I'm sure a few are still cranking tunes. Could knock one kit out in a session. Good times !!!

 

I've never burnt out a soldering iron. I've had the tips erode, they are replaceable. The heaters go open on ones with separate heaters, usually from dropping them, but they are replaceable. I use Weller WTCPTs and Metcals because they are what McBoeing had for a long time and show up in quantity used. The Metcal tip/heater cartridge is expensive, so I conserve them carefully. I bought twelve of the Weller heating elements new and should be good for life. I also have an enormous American Beauty iron good for sweating RF connectors and small plumbing jobs: I got it at an estate sale from a woman whose late husband was a vet and who used it, with a step up transformer, for horse gelding procedures.

 

OUCH!

 

At least the ST150 was a full complimentary design with a bipolar output supply. It would probably be a good candidate for an update if one were so inclined. The ST120 has a single ended power supply and has a cap between the output and the power rail, a poor design for many reasons. Since there is no center tap on the transformer secondary you can't get a bipolar output from it.

 

I'm a simple, man, what does that all mean in terms of sonics?

All I know is I blew an ST 120 up during testing before delivery to my friend a week after building it. The ST 150 I built after that for him is still in use today.

 

I always liked the looks of the QSA 300, 2 150's on 1 chassis for quad:

 

It actually looks a bit like the insides of a B&K ST-140 or (no surprises here!) a Hafler DH-nnn