Yes, I prefer hard wiring the amps I build, if a tube develops a short on a PCB it could cause quite a bit of damage to the board its mounted on. Although, I would have thought that if AR had received many unreliability reports related to PCB mounted tubes they would have stopped this practice by now.corndog71 wrote:mijohn wrote:
I don't think Audio Research would agree with you. They mount their tubes on the PCB in many of their power amps and they produce some of the best tube amps in the world.
https://www.stereophile.com/content/audio-research-reference-150-power-amplifier
I’ve heard from people who have dealt with them. Power tube sockets on pcb’s are a bad idea.
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Canadian company has acquired the "Dynaco" trade name ?
mijohn- Posts : 119
Join date : 2013-06-19
peterh- Posts : 1861
Join date : 2012-12-25
Location : gothenburg, sweden
Reason for board-mounted sockets is : COST. Mounting sockets is labor intensivemijohn wrote:Yes, I prefer hard wiring the amps I build, if a tube develops a short on a PCB it could cause quite a bit of damage to the board its mounted on. Although, I would have thought that if AR had received many unreliability reports related to PCB mounted tubes they would have stopped this practice by now.corndog71 wrote:mijohn wrote:
I don't think Audio Research would agree with you. They mount their tubes on the PCB in many of their power amps and they produce some of the best tube amps in the world.
https://www.stereophile.com/content/audio-research-reference-150-power-amplifier
I’ve heard from people who have dealt with them. Power tube sockets on pcb’s are a bad idea.
and when costs are cut less reliable solutions pops up.
As for AR, yes they mount sockets on boards. In spite of cooling holes around
tube sockets they still sometimes get problems with heat destruction and brittle boards.
Tuberollers will confirm this, i have myself had a AR D75A and can confirm the weakness.
Just say no to board-mounted sockets!
mijohn- Posts : 119
Join date : 2013-06-19
I agree with you entirely Peterh, but you would think that at a retail price of $13,000 in the case of the Reference 150, cutting production costs in this way wouldn't be necessary!
peterh- Posts : 1861
Join date : 2012-12-25
Location : gothenburg, sweden
mijohn wrote:I agree with you entirely Peterh, but you would think that at a retail price of $13,000 in the case of the Reference 150, cutting production costs in this way wouldn't be necessary! :D
bean-counters will always save expenses. And the price of an item has very little relation
to the cost of manufacturing, but is set by surrounding competitors and market surge.
To assure good products a balance between bean-counters and engineers is needed. Too
much of either will put the success in danger. Add to that good marketers and you
might have a successful product.
mijohn- Posts : 119
Join date : 2013-06-19
Those same forces that you describe are obviously involved in the ST-70 Series 3.
audiobill- Posts : 425
Join date : 2014-03-13
Location : Albany, NY
"bean-counters will always save expenses. And the price of an item has very little relation
to the cost of manufacturing, but is set by surrounding competitors and market surge.
To assure good products a balance between bean-counters and engineers is needed. Too
much of either will put the success in danger. Add to that good marketers and you
might have a successful product."
And competitors have great power over pricing - too high, and few will buy your product. Why should a manufacturer key pricing to materials cost when there's more profit available?
to the cost of manufacturing, but is set by surrounding competitors and market surge.
To assure good products a balance between bean-counters and engineers is needed. Too
much of either will put the success in danger. Add to that good marketers and you
might have a successful product."
And competitors have great power over pricing - too high, and few will buy your product. Why should a manufacturer key pricing to materials cost when there's more profit available?
Bob Latino- Admin
- Posts : 3271
Join date : 2008-11-26
Location : Massachusetts
Some readers may think that I am trying to knock a "competitor" when bringing up all this info on the Dynaco ST-70X. Not true .. The ST-70X is a WIRED amp. 90% of the amps that I sell are KIT amps. I don't compete with them at all. My gripe with them is their price of $2999 USD for a 35 watt per channel amp. It will never sell well at that price. Too much competition. Note that the USA made Rogue Audio Cronus Magnum is also $2999 and is a 100 watts per channel amp. See link below ..
Rogue Cronus Magnum
Ok - so what did Radial Engineering do when they started (temporarily) selling their $2999 amp at the $1499 "promotional" price (that they can't really make a profit on). They are trying to unload stock and they are trying to get some amps out into circulation. They are hoping that those in circulation now will get good reviews. At $2999, they won't sell well. What will happen.
1. At some point they may put the remaining stock on "promotional sale" again, flush them out and stop production.
OR
2. They may do what I said earlier in another post > Start dropping the price gradually like$2999, $2499 $1999 etc. until they reach a point where the amps do start to sell ? Check the price at the link below from time to time and see if it does drop ?
Dynaco ST-70X current price
Bob
Rogue Cronus Magnum
Ok - so what did Radial Engineering do when they started (temporarily) selling their $2999 amp at the $1499 "promotional" price (that they can't really make a profit on). They are trying to unload stock and they are trying to get some amps out into circulation. They are hoping that those in circulation now will get good reviews. At $2999, they won't sell well. What will happen.
1. At some point they may put the remaining stock on "promotional sale" again, flush them out and stop production.
OR
2. They may do what I said earlier in another post > Start dropping the price gradually like
Dynaco ST-70X current price
Bob
mijohn- Posts : 119
Join date : 2013-06-19
Although most of us on this forum know that the VTA ST-70 is a superior amp in most respects and one can have fun building it and save money at the same time, for those people out there who are influenced by such things, there is one thing from a marketing point of view, going for the ST-70X
That is, the review in The Absolute Sound and subsequent Product of The Year award will probably mean it will be included in the 2019 TAS Editors Choice Awards as well and $3000 won't look so bad in that company!
That is, the review in The Absolute Sound and subsequent Product of The Year award will probably mean it will be included in the 2019 TAS Editors Choice Awards as well and $3000 won't look so bad in that company!
rjpjnk- Posts : 262
Join date : 2018-07-18
mijohn wrote:Although most of us on this forum know that the VTA ST-70 is a superior amp in most respects...
mijohn,
What is your basis for this statement?
Do you mean compared to the ST-70 Series 3?
I am not trying to defend or criticize either amp. Just collecting data as part of my personal evaluation process. I have both sitting right here in my living room and have been comparing them for a while now. I would not say either is clearly superior since each excels at different things. What has your experience been with these and how did you come to this conclusion?
peterh- Posts : 1861
Join date : 2012-12-25
Location : gothenburg, sweden
Looking forward to an evaluation!rjpjnk wrote:mijohn wrote:Although most of us on this forum know that the VTA ST-70 is a superior amp in most respects...
mijohn,
What is your basis for this statement?
Do you mean compared to the ST-70 Series 3?
I am not trying to defend or criticize either amp. Just collecting data as part of my personal evaluation process. I have both sitting right here in my living room and have been comparing them for a while now. I would not say either is clearly superior since each excels at different things. What has your experience been with these and how did you come to this conclusion?
Bob Latino- Admin
- Posts : 3271
Join date : 2008-11-26
Location : Massachusetts
To rjpjnk > Rich - Your amp is about a year old and is probably well broken in. I did remember that you did not have cap upgrades with your amp. If you want to post here your thoughts on any comparison between the two amps, you are welcome to do so. Question > You probably did buy the ST-70X at their promotional $1499 price. Would you have purchased this amp if it was priced at $2999 ?
Bob
Bob
Guest- Guest
audiobill wrote:"bean-counters will always save expenses. And the price of an item has very little relation
to the cost of manufacturing, but is set by surrounding competitors and market surge.
To assure good products a balance between bean-counters and engineers is needed. Too
much of either will put the success in danger. Add to that good marketers and you
might have a successful product."
And competitors have great power over pricing - too high, and few will buy your product. Why should a manufacturer key pricing to materials cost when there's more profit available?
What audiobill said, i.e., balance is always key. I don't know why folks throw bean counters under the bus simply for doing their job--without them shareholders would never get their fair return and employees, including engineers, would never get paid.....
rjpjnk- Posts : 262
Join date : 2018-07-18
Bob Latino wrote:To rjpjnk > Rich - Your amp is about a year old and is probably well broken in. I did remember that you did not have cap upgrades with your amp. If you want to post here your thoughts on any comparison between the two amps, you are welcome to do so. Question > You probably did buy the ST-70X at their promotional $1499 price. Would you have purchased this amp if it was priced at $2999 ?
Bob
Hi Bob, I added the Russian K40Y-9 PIO interstage capacitors later. Also upgraded the 4 big electrolytics on the board to 100uf if I recall correctly, and installed stepped attenuator and that really nice lucite cover you offer as well. Here is a picture from a several months back. I am so proud of how this amp turned out. It was a ton of fun to build and your instructions were perfectly clear. Thanks for this awesome kit!
Yes, I bought the new ST-70 Series 3 while they were 1499. It kept tempting me for months at that bargain price and I knew one day it would disappear, maybe forever. I eventually caved and decided I had to try it. No, I would not have bought it at 2999.
Thanks you for inviting my review comments here. One day I may put together a detailed comparison. For now I will just say that both amps sound excellent, and are actually much more similar than they are different sonically.
One thing I did notice is I prefer the sound, (with either amp), using the JJ E34L tubes that came with the Series 3 rather than the reissued Mullards I had in the VTA. Unfortunately, I don't have 8 matching output tubes to equal the playing field so I have had to swap back and forth. Even with the tubes swapped I still notice the above mentioned differences in the sound between the amps, but to a lesser degree.
One clear advantage of the VTA is price, and the experience of building your own amp is very rewarding and hard to put a value on. Also, the upgradability and online support for the DIY route makes for years of adventure. On the other hand, the new Dynaco has some serious good looks (again completely subjective I suppose).
Here is my VTA with the PIOs in place. So pretty I hate to cover it up
mijohn- Posts : 119
Join date : 2013-06-19
Maybe I was a bit glib in phrasing that sentence, I should have written "many or some of us on this forum..." I made the superiority comment based on the assumption that most people on this forum are here because they are connoisseurs of the original Dynaco amplifiers or are looking to buy a classic VTA Dynaco amp. The original and VTA ST-70 are different amplifiers to the new Series 3 which has largely been redesigned, both the circuit and obviously the cosmetics. I think the VTA 70 is superior in it's hard wired construction to the Series 3 with it's mainly PCB construction which, as discussed earlier in this thread, may cause reliability problems down the track.rjpjnk wrote:mijohn wrote:Although most of us on this forum know that the VTA ST-70 is a superior amp in most respects...
mijohn,
What is your basis for this statement?
Do you mean compared to the ST-70 Series 3?
I am not trying to defend or criticize either amp. Just collecting data as part of my personal evaluation process. I have both sitting right here in my living room and have been comparing them for a while now. I would not say either is clearly superior since each excels at different things. What has your experience been with these and how did you come to this conclusion?
The Series 3 will appeal to consumers who are aware of the Dynaco name and pedigree, but want a modern styled amplifier. I like the use of LED's and no multimeter to adjust the bias, that will will appeal to consumers. Which amplifier has superior sound quality, the VTA ST-70 or Series 3, you rjpjnk, are in a good position to tell us.
Last edited by mijohn on Sun Apr 14, 2019 11:14 pm; edited 1 time in total (Reason for editing : grammer corrections)
mijohn- Posts : 119
Join date : 2013-06-19
rjpjnk, if Dick Olsher's conclusion to his review in TAS is anything to go by, you may well have got a bargain. On reading it, I concluded that the only thing the original ST-70 and the Series 3 have in common is that they share the same name! They probably appeal to different markets and with you having a foot in both, it will be interesting to read your impressions.
Guest- Guest
.
Last edited by PeterCapo on Fri Dec 04, 2020 2:00 pm; edited 4 times in total
rjpjnk- Posts : 262
Join date : 2018-07-18
I am starting to warm to the idea that solid state might be best for power supplies. Wouldn't it be a simple matter to modify a 5AR4 based amp to a SS B+ supply? Or would the voltage be too high without the rectifier tube drop? If we have to load up the circuit with resistors to reduce the voltage doesn't that introduce issues with voltage "firmness"?
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Bob Latino- Admin
- Posts : 3271
Join date : 2008-11-26
Location : Massachusetts
Apparently the Dynaco ST-70X is no more .. If you go to the Radial Engineering web site now, you cannot find the Dynaco ST-70X for sale anymore. If you look for products on > https://dynaco.com/index#products you get a 404 error. If you read through this thread from the beginning you can see some of my posts about this amp. My problem with the amp was not its looks. It probably also sound pretty good. My problem was the price of this 35 WPC amp > $2999.99. You can't sell a 35 watt per channel "Dynaco" amp for $3000 USD ? You can't take the Dynaco name and "upscale" it. This was tried in the 1990's with the Dynaco ST-70 Series II and it didn't work. When they weren't selling at $3000, they dropped the price to $1500 and they did start to sell a few. This $1500 price only lasted a few months. They wanted to get a few of these amps out there and maybe they would catch on ? Yes - they caught on at $1500 but very few must have been sold at $3K. They probably decided to just pull the plug. They shut down the web pages that were selling these and now they are no more. RIP Dynaco ST-70X. The audio world will bury you right next to the Dynaco ST-70 Series II which went belly up in the mid 1990's.
Bob
Bob
rjpjnk- Posts : 262
Join date : 2018-07-18
Hi Bob, Yes, I noticed that too. No more Dynaco ST-70 Series 3.
I am so fortunate to have bought one of them when they were 1499. I continue to be amazed every day at its classy looks and it's wonderful rich sound. This is the sweetest EL34 amp I've ever listened to. I love the VTA amps too, of course, but they have different strengths. Radial must have put an amazing amount of R&D into those output transformers, and no doubt lost a bundle of money when it didn't sell.
In any event, I am truly sad to see that this endeavor failed, but as you point out, it was just too expensive. There is way too much competition at 3K from established brands for this amp to have ever caught on. However, I think it was a ridiculous bargain at 1499, and those who picked one up are truly lucky. I'm sure over the years we will see these pop up on the used market. I think they may become a collectable. Luckily I was able to obtain a schematic in case I ever need to fix it.
I am so fortunate to have bought one of them when they were 1499. I continue to be amazed every day at its classy looks and it's wonderful rich sound. This is the sweetest EL34 amp I've ever listened to. I love the VTA amps too, of course, but they have different strengths. Radial must have put an amazing amount of R&D into those output transformers, and no doubt lost a bundle of money when it didn't sell.
In any event, I am truly sad to see that this endeavor failed, but as you point out, it was just too expensive. There is way too much competition at 3K from established brands for this amp to have ever caught on. However, I think it was a ridiculous bargain at 1499, and those who picked one up are truly lucky. I'm sure over the years we will see these pop up on the used market. I think they may become a collectable. Luckily I was able to obtain a schematic in case I ever need to fix it.
Bob Latino- Admin
- Posts : 3271
Join date : 2008-11-26
Location : Massachusetts
I just Emailed Radial Engineering about this.
They did confirm to me that they pulled the plug on this amp due to poor sales.
Bob
They did confirm to me that they pulled the plug on this amp due to poor sales.
Bob
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Hops- Posts : 87
Join date : 2019-09-21
Location : South Detroit, Michigan
If you want to use SS Rectification, a Weber Copper Cap plugs in where the Tube Rectifier goes. I use a WS-1 with thermistor. Bob recommends a different Weber, I am sure they both work fine.
MechEngVic- Posts : 107
Join date : 2019-01-16
Bob Latino wrote:I just Emailed Radial Engineering about this.
They did confirm to me that they pulled the plug on this amp due to poor sales.
Bob
Reading this thread was like reading the biography of the little amp that couldn't. Too bad. I think the more tube gear that exists in the market the better. Anyone who knows Dynaco knows that VTA is where the ST-70 has gone to grow up. But I can't help it, I still love my SERIES II !! It does a lot of things very well! This new and now dead series III shared as much with the series II as it did with the original. They even used a bunch of the same language in the series III manual that was in the series II manual. They should've left the input RCA's in the front.
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alanhuth- Posts : 40
Join date : 2020-07-06
Location : Chicago
Bob, in the interview with their design engineer, he went to a lot of trouble to explain the lengths they went to to improve the transformers in the Series 3. You would be in a good position to determine whether they actually succeeded, so I’m wondering, since they have discontinued the amp, whether they would be willing to send you a few transformers for testing, and if they are actually better, maybe that could also become an option for VTA??? They seem to be communicating with you. Win win?
MechEngVic- Posts : 107
Join date : 2019-01-16
The Series II used a bigger power transformer and the same output transformer. I believe the Series III did the same. From the Series II manual:
alanhuth- Posts : 40
Join date : 2020-07-06
Location : Chicago
They claim to have done much more than that on the transformers. Here is A pretty detailed description by the design engineer:
https://forums.stevehoffman.tv/threads/review-new-dynaco-st-70-series-3.807980/page-3
Starts about half-way down three page
https://forums.stevehoffman.tv/threads/review-new-dynaco-st-70-series-3.807980/page-3
Starts about half-way down three page
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