George Moneo said
My point is that $7,000 -- while out of pmotz's price range (and certainly mine, as well) -- is not unreasonable for a dual-mono amp. I wish it would be less expensive but I know exactly what Paul is saying about "mission creep" and pricing. I greatly admire the "I am all in, go strong or go home" ethos. It's what makes great products that folks like us will buy again and again.
You nailed it, George.
A $7,000 amp which truly can play with the big boys would be a gift. And I certain very exciting to design and build.
If they can make it sound competitive with a $70k Halcro or a $100k+ Soulution then $7k would be an absolute bargain.
Yes, it will have a trigger, no it won't have a display. You can buy one of these and use the 5VDC trigger to run the meter. You can then rig up a button to reset the meter when you switch tubes. I bought one just for this purpose.
Photos of the afore-mentioned hour meter mounted on a 2 1/8" by 1 3/8" box with 4 trigger jacks and one reset button. I connect one jack to the ‘master’ trigger controller (in my case the preamp) and then have 3 ‘slave’ trigger jacks available for PWA and P10. The hour counter runs whenever the 12VDC trigger is ‘on’ and maintains the count in memory when the trigger is “off” I recessed the reset button to avoid inadvertent resets. Note it took a lot to cram everything into the tiny enclosure. There’s the unit sitting on top of my sub with the first 0.1 hours on it.
The 6H30 in my preamp are replaced after 4000 hours. Hopefully the 6H23’s last as long. So I’ll start with that, but if they die sooner at least I’d know how long they’d last for the next set. Without the meter I’d just be guessing. I only put on about 700 hours a year on my system, so it’s nice to have the meter.
A good plan. I was guestimating 1,000 hours a year on which I based my suggestion of replacing the tube every two to three years as a conservative approach.
I can see it would be fun just to know how many hours you play the system, even without thinking about tubes.
Of course, there is a tube hour meter in my preamp and I suppose I could have just have as easily used it by actually writing down when I reset the preamp meter and keeping a mental note of the difference, but this way it’s easier to use the preamp meter for its tube life count and use the new meter as a dedicated unit for the PWA.
Still, it was fun to make it, only took two hours.
Since the new amp with have a tube in the front end, I’d like to put in a shameless plug for the person I’ve found to be best for vintage tubes. Andy Bowman at Vintage Tube Services in Grand Rapids, MI. http://vintagetubeservices.com/ Phone 616-454-3467. I’ve yet to meet anyone more knowledgeable and passionate about vintage tubes. He not only offers advice and the most thorough & accurate I.D. and testing services, he sells only tubes he’d own himself.
Andy’s website is horribly out of date wrt to inventory and he pretty much doesn’t answer emails. He prefers you call to actually discuss your needs.
My only connection to Andy is as a very satisfied customer of his I.D. & testing services for tubes I already own as well as purchasing some others. There might be some cool finds in his inventory for this new amp…
I was unaware of Andy. There are a number of excellent sources for NOS tubes, as well as high quality contemporary production. One such source is Kevin Deal at Upscale Audio.
Elk said
I was unaware of Andy. There are a number of excellent sources for NOS tubes, as well as high quality contemporary production. One such source is Kevin Deal at Upscale Audio.
I have had the opportunity to converse with many "tube guys" and vintage sellers over the years and still go back to Andy for the bottom line. I've never met a seller more brutally honest and ethical. As they all do, Andy has his biases, but he backs them up with facts. His services and products work best for me, but, as always, ymmv. Give him a call sometime when you're researching tubes and see what you think.
It just seemed to me that the new amp will allow tube rolling at a reasonable cost since there’s only one (per channel, I assume)! Since vintage can get expensive, I just wanted to throw a reliable name into the ring.
As an interesting point of reference I had the chance today to hear the new Constellation Inspiration amp and preamp at the local dealer. They were playing over Magico S3’s. I say “point of reference” since the amp circuitry (and that of the Performance series Centaur) was designed by Bascom King. I have no idea if the Constellation circuit design is similar to the PS Audio circuit design, the rep wasn’t divulging details, but I wouldn’t think it a stretch that the sound of the circuits isn’t much different. Since the system was completely different from my own I can’t make any direct comparisons or conclusions, but the amount of detail, being presented was just wonderful. The Magico’s are well known for this, but the amp and preamp have a big hand in that too. My only hesitation was a tendency to brightness with some recordings, but I would not hazard a guess at which components (or the music) were responsible. I know this comparison is a big leap, but I thought it worthy of note. Makes me really want to hear Paul’s amp, maybe if I think about this long enough that $7K price won’t seem so daunting (dream on…). I will say the price of the Constellation is $10K, so $7K for the PS Audio amp could be a “bargain” (I think I’ve read too many reviews, $7K a bargain, hah).
Paul McGowan said
BTW, once this tube circuit is working and voiced the way we want, it'll then become the basis of our new preamp. "Just" add a volume control and input switching and you're good to go.
Paul,
I discovered PS Audio last Fall when shopping for an external DAC and a friend sent me Youtube links on the DirectStream DAC, I bought one and have been smitten ever since. A few weeks ago I replaced my Furman power conditioner with a P10 Power Plant, and to my pleasant surprise, my system sounds even better.
I’m in the midst of auditioning speakers, maybe replacing my monitors in a bit.
I am one of those “tube & vinyl bigots”, not much for either. I do appreciate the “warm” sounds that tube amps produce, but ions ago, when I worked selling equipment, was floored at how tube amps deteriorated so quickly. Still not much for listening to pops & clicks in the way of my music.
Having said all that, I am told by people that know way more than I do about audio equipment that tubes are excellent in low-power applications, not their strength to handle high-power applications, so the design of your new power amp is intriguing!
It’ll probably take a few months for me to settle on a new set of monitors. I’ll be checking your website to see about the progress developing the new pre-amp and will most-likely be snagging your new pre & power amps in the foreseeable future!
You’ve really partnered with some amazing engineering talent!
And you are absolutely correct. In low level preamplification, or in the input circuit of a power amplifier, tubes are wonderful - not just “warm” - but musical in a way transistors simply are not.
Amen to that. I’ve long used tube pre-amps (a c-j Premier 17LS before my current Rogue Athena). They just sound more natural and the tubes don’t need to be replaced all that often. I don’t know how much of the improvement my new BHK 250 made over my Classic 250 (PSA’s prior statement amp from about 13 years ago and a stunner in its time) is attributable to the tube input section but the overall improvement is HUGE. I don’t notice any of the drawbacks I associate with tube amps (my personal inventory includes an old VTL ST85, an even older Dynaco ST70 (with self-installed Van Alstyne mods) and a recently semi-restored Fisher 400 all-tube receiver (which actually sounds quite good)).
Paul McGowan said: . . . this circuit is actually a diff pair - which, of course, uses two.
Yes!
Paul McGowan said: our Asian customers won't buy a standalone power amp without a matching preamplifier.
This is interesting. In the U.S. we like to mix and match, although there is a contingent that insists upon matching equipment.
Would there be any value in providing direct access to the output stage of the amp for those with a PS Audio preamp? Or is this a bigger headache than I am imagining?
Paul McGowan said
I am with you Elk. I could never bring myself to have a visible window for the tubes. It reminds me of a place I once visited in Amsterdam where they had these poor women hookers displayed in windows for the leering eyes of prospective customers. That was just degrading and cheezy and I could never bring myself to do that.
I want to keep this simple so I don’t think we will have a tube hour counter. I’ll request the 5v trigger, it’s a good idea.
Two tubes are used, one for each channel. Each tube is really two in one, but this circuit is actually a diff pair - which, of course, uses two.
As to the preamp. Yes, indeed, it will be yet another stage between DirectStream and the amp - just as any preamp would be. But there are two reasons we want to do this. In some cases the preamp sounds better than straight in. Not sure why, but there it is and if you’re going that route, might as well stay within the ecosystem.
Secondly, our Asian customers won’t buy a standalone power amp without a matching preamplifier. Not sure why that is but that’s what we have to deal with. If we’re going to be successful selling amps to our Asian friends, they require a matching preamp. Who am I to refuse?
Mmm, so glowing tubes remind you of the working girls from Amsterdam…
I don’t know if there’s a cure for that…
And…what were you doing there mr. McGowan ?
BTW.: I’m from Amsterdam and never think of tubes when I’m in the red light district.
It hasn’t a good answer. The one John reviewed came back and we replaced the fuse, it worked perfectly. No damage. We tried every test we could imagine without success. That very amp would not go unstable. We contact JA and he told us the exact setting on the AP he had used and we entered those into our own AP. After one hour of torture with this test, finally, we saw the same instability John had seen.
We then tested other units with the same tests and they never became unstable. We still don’t know why the first unit did this - and it was easily fixed by adjusting the loop ever so slightly - but since no person ever using the BHK under any condition other than this one test, on this one unit, on an AP, would ever encounter this problem that would cause the fuse to blow and have to be replaced, we decided not to spend any more engineering time on it.
What we have done is added this test to our AP test procedure for all BHKs going through production. Of the hundreds produced since, not one has displayed any issues.
