SET amp owners thread

[vlamirhabib]

Just bought a pair of Cary 300B SET mono blocks with Western Electric 300Bs. Sound gorgeous with my Quad 57s (which remember were originally designed for the Quad II amps that produced 12 watts or so). But, I’m looking for high efficiency speakers, since everything I have at home is fairly low efficiency. Would love to get some recommendations for the gurus on this thread.

View attachment 95362

Fantastic Amps. Congratulations. What is your room space ?

 

[Carlos269]

Thanks for the advice. Now I just have to find one of those rarities!

Please keep in mind that the F2J amp is only rated at 5 Watts per channel. Although I have not heard one myself, I have been told that the J2 amp is also very special, and it is rated at 25 Watts per channel. As I mentioned before, they each has a different sound. I think that driving these First Watt amps with DHT preamps is key to getting stellar results.

 

[cal3713]

Depends if the SS amp has negative feedback on the output stage (or global). If the damping factor is too high then low Qts woofers all lose too much bass (even horn loaded). Horn loaded low Qts woofers like little to no damping from the amp...as they are already quite well damped. If the F4 is feedback free then the output impedance may not be all that low and there is a chance for decent bass then.

The F4 is feedback free and has a damping factor of 20 with an output impedance of 0.2 ohms.

 

[cal3713]

Please keep in mind that the F2J amp is only rated at 5 Watts per channel. Although I have not heard one myself, I have been told that the J2 amp is also very special, and it is rated at 25 Watts per channel. As I mentioned before, they each has a different sound. I think that driving these First Watt amps with DHT preamps is key to getting stellar results.

I've certainly enjoyed what that combination does in my system.

 

[christoph]

Thanks for the advice. Now I just have to find one of those rarities!

Why not something from Lamm to go with your Lamm Pre and Phono?

 

[godofwealth]

The biggest mistake in the Cary amps is that the first capacitor direct after the rectifier tube is too high - especially when using a 274a rectiver. It should be lowered to my opinion.

Dennis Had has been designing SET amplifiers for 30+ years, so I assume he knows a thing or two about them. In any case, my Cary SET does not use 274B rectifiers, but CV 317s. The previous owner ran it on the same Western Electric 300B tubes for 25 years. He had it recently serviced at Cary and equipped it with a new pair of Western Electric 300B tubes. It works flawlessly — no hum, no hiss, quiet as a church mouse. See no reason why it won’t last me another 25 years! We forget how reliable well designed vintage tube products can last (vintage McIntosh amplifiers sell for 30x their original list price!). My original Quad 57s are working flawlessly 50+ years running. Not like the typical junk that gets mass produced these days. I had a Swedish solid state preamp and amp both fail on me within 2 years. My fancy 8K Dell monitor just died on me, and it’s not even 3 years old. Reliability has gone out of the window.

Dennis has retired from running Cary Audio, but still sells 300B integrated amps on eBay that he builds out of his home, presumably. I had a good chat with him and he sent me his picture that I’m sharing below. Looks happy. Now that gives me some motivation to follow in his footsteps. I have been doing research in AI and machine learning for almost 40 years, and just wrote a long technical article for a journal using an esoteric area of mathematics called category theory. I’m getting to the point when I feel I should not spend every waking moment thinking about mind warping theorems like the Yoneda Lemma, possibly the greatest result in pure mathematics of the 20th century, discovered in an accidental meeting at the Gare du Nord train station in Paris between an eminent American mathematician and a brilliant 20 year old Japanese PhD student who’s name graces the theorem. !t is also the easiest theorem to explain to anyone — it simply says any object can be described by its interactions. Category theory upturned mathematics from being the study of sets to the study of objects with arbitrary but unspecified internal structure. Yoneda showed how it is more powerful than set theory and mathematics changed forever. Here’s a link describing this chance encounter. Not what you were expecting to read in What’s Best, I’m sure.

le lemme de la Gare du Nord – neverendingbooks

And before I forget, here’s Dennis’ picture, looking as happy as a clam.

 

[godofwealth]

Dennis Had has been designing SET amplifiers for 30+ years, so I assume he knows a thing or two about them. In any case, my Cary SET does not use 274B rectifiers, but CV 317s. The previous owner ran it on the same Western Electric 300B tubes for 25 years. He had it recently serviced at Cary and equipped it with a new pair of Western Electric 300B tubes. It works flawlessly — no hum, no hiss, quiet as a church mouse. See no reason why it won’t last me another 25 years! We forget how reliable well designed vintage tube products can last (vintage McIntosh amplifiers sell for 30x their original list price!). My original Quad 57s are working flawlessly 50+ years running. Not like the typical junk that gets mass produced these days. I had a Swedish solid state preamp and amp both fail on me within 2 years. My fancy 8K Dell monitor just died on me, and it’s not even 3 years old. Reliability has gone out of the window.

Dennis has retired from running Cary Audio, but still sells 300B integrated amps on eBay that he builds out of his home, presumably. I had a good chat with him and he sent me his picture that I’m sharing below. Looks happy. Now that gives me some motivation to follow in his footsteps. I have been doing research in AI and machine learning for almost 40 years, and just wrote a long technical article for a journal using an esoteric area of mathematics called category theory. I’m getting to the point when I feel I should not spend every waking moment thinking about mind warping theorems like the Yoneda Lemma, possibly the greatest result in pure mathematics of the 20th century, discovered in an accidental meeting at the Gare du Nord train station in Paris between an eminent American mathematician and a brilliant 20 year old Japanese PhD student who’s name graces the theorem. !t is also the easiest theorem to explain to anyone — it simply says any object can be described by its interactions. Category theory upturned mathematics from being the study of sets to the study of objects with arbitrary but unspecified internal structure. Yoneda showed how it is more powerful than set theory and mathematics changed forever. Here’s a link describing this chance encounter. Not what you were expecting to read in What’s Best, I’m sure.

le lemme de la Gare du Nord – neverendingbooks

And before I forget, here’s Dennis’ picture, looking as happy as a clam.

Sorry, I meant to say the Cary uses CV 378 rectifiers, not 317s. That’s what happens when you type a message in the wee hours of the morning!

 

[Norway]

... one quid:
From left channel mid/high (its a high pas filter) via F4 amp to left channel woofer & filter in low pas ... correct ?

Yes!

 

[Norway]

Yes I don't know what the output impedance and damping factor of F4 is, and how it compares to the 300b that he has. But surely, best thing for him is to listen for himself with both crossovers as it is not expensive. Right now he seems set on this biamping theory of using 300b on midrange and SS to drive 15 inch woofers.

I am not set on or insisting on anything! I am asking an open question. Just preparing for receiving the crossovers.

 

[bonzo75]

I am not set on or insisting on anything! I am asking an open question. Just preparing for receiving the crossovers.

Ok but then suggest to get both. Not only the one on F4. Online opinions matter less in this case as very few have Altec 817 experience especially with F4. You will only get experiences from people with F4 on another speaker.

 

[Maril555]

I am now in dialog with Werner regarding ordering one… I understand from him that it comes av a 3-way network 500hz and 8-10 kHz for a ultra HF unit!? Is 10 kHz the right point on my 288G? I have both a JBL 2404 and Fostex A500.
Another point is that his filters can be bi-wired/bi-amp(filter part for the 515 are separated from 288). Considering to use my First Watt F4s for the 817, letting the 300d SE drive both the 288+HF and also the F4s working the 817. Nelson promotes this idea in the F4 manual, Werner thinks it’s a bad idea but doable… anyone that has experimented with the F4s in this direction ?

I have a very similar, if not exactly the same speakers as you. Double 515s in 817 cabs and 288 in Markus Klug 1505 multicell.
I'm using active X-over (Pass Labs XVR-1) with First Watt F3 driving 515s and Thomas Mayer 6CB5A SET driving 288s.
Works fine. Could F3 be bettered? Likely, I haven't tried.
But with Thomas Mayer 10y line stage and Misho Myronov phono it sounds great.

 

[Maril555]

I have a very similar, if not exactly the same speakers as you. Double 515s in 817 cabs and 288 in Markus Klug 1505 multicell.
I'm using active X-over (Pass Labs XVR-1) with First Watt F3 driving 515s and Thomas Mayer 6CB5A SET driving 288s.
Works fine. Could F3 be bettered? Likely, I haven't tried.
But with Thomas Mayer 10y line stage and Misho Myronov phono it sounds great.

I'm thinking about trying PP tube amp on 817 at about 60-70 Watts. I have a feeling dual 515 need some juice.
I talked to a guy with Ubangi bass cabs (different from Altec 817, but still high sensitivity design) and he used 150 Wt Altec tube amps in bi-amp configuration with I believe 300 B on top

 

[bonzo75]

I'm thinking about trying PP tube amp on 817 at about 60-70 Watts. I have a feeling dual 515 need some juice.
I talked to a guy with Ubangi bass cabs (different from Altec 817, but still high sensitivity design) and he used 150 Wt Altec tube amps in bi-amp configuration with I believe 300 B on top

They definitely do not need grip.

This guy can get them sounding this with 211 and with his AD1 4 watt amp. You require Facebook for this

Thái Bảo

Thật là tưng bừng!!!

www.facebook.com

The guy wfh Ubangi bass cabs had non Altec drivers EV15 if it is Howard you are referring to..

And Misho uses 4 watt amps. He is building 10 watts and a pair of monos to test. But they definitely do worse with more grip.

 

[Solypsa]

I'm thinking about trying PP tube amp on 817 at about 60-70 Watts. I have a feeling dual 515 need some juice.
I talked to a guy with Ubangi bass cabs (different from Altec 817, but still high sensitivity design) and he used 150 Wt Altec tube amps in bi-amp configuration with I believe 300 B on top

I talked to a guy with Ubangi bass cabs (different from Altec 817, but still high sensitivity design) and he used 150 Wt Altec tube amps in bi-amp configuration with I believe 300 B on top

I have a pair if those Altec 1570b/ Tutay amps FS ( maybe even the pair you are referring to as they came from Howard ). But they are in Seattle pretty far away

 

[Maril555]

I have a pair if those Altec 1570b/ Tutay amps FS ( maybe even the pair you are referring to as they came from Howard ). But they are in Seattle pretty far away

That's the guy. At some point I was contemplating to buy those Ubangis, but my room is too small for them, otherwise I would have.

 

[Maril555]

They definitely do not need grip.

This guy can get them sounding this with 211 and with his AD1 4 watt amp. You require Facebook for this

Thái Bảo

Thật là tưng bừng!!!

www.facebook.com

The guy wfh Ubangi bass cabs had non Altec drivers EV15 if it is Howard you are referring to..

And Misho uses 4 watt amps. He is building 10 watts and a pair of monos to test. But they definitely do worse with more grip.

Agree with all of the above.
At the same time 6CB5A SET doesn't produce the kind of bass I think Altecs are capable of.
Maybe it
that's particular tube and lets say 300B of similar power would be different.
Since now I have Mayer line stage and Misho's phono, I should give it another try.

 

[bonzo75]

Agree with all of the above.
At the same time 6CB5A SET doesn't produce the kind of bass I think Altecs are capable of.
Maybe it
that's particular tube and lets say 300B of similar power would be different.
Since now I have Mayer line stage and Misho's phono, I should give it another try.

As I said I think you should first just try two way and then the tweeter. A friend who was trying some play with crossover required lot of power. Then he realized he had an error in phase, and after correcting it became easier to drive

 

[Solypsa]

That's the guy. At some point I was contemplating to buy those Ubangis, but my room is too small for them, otherwise I would have.

Th Ubangi's might not fit but I bet the Altec amps could

 

[Maril555]

Th Ubangi's might not fit but I bet the Altec amps could

I knew you'd say that
I already have three different amps, no space and a wife.

 

[vlamirhabib]

Dennis Had has been designing SET amplifiers for 30+ years, so I assume he knows a thing or two about them. In any case, my Cary SET does not use 274B rectifiers, but CV 317s. The previous owner ran it on the same Western Electric 300B tubes for 25 years. He had it recently serviced at Cary and equipped it with a new pair of Western Electric 300B tubes. It works flawlessly — no hum, no hiss, quiet as a church mouse. See no reason why it won’t last me another 25 years! We forget how reliable well designed vintage tube products can last (vintage McIntosh amplifiers sell for 30x their original list price!). My original Quad 57s are working flawlessly 50+ years running. Not like the typical junk that gets mass produced these days. I had a Swedish solid state preamp and amp both fail on me within 2 years. My fancy 8K Dell monitor just died on me, and it’s not even 3 years old. Reliability has gone out of the window.

Dennis has retired from running Cary Audio, but still sells 300B integrated amps on eBay that he builds out of his home, presumably. I had a good chat with him and he sent me his picture that I’m sharing below. Looks happy. Now that gives me some motivation to follow in his footsteps. I have been doing research in AI and machine learning for almost 40 years, and just wrote a long technical article for a journal using an esoteric area of mathematics called category theory. I’m getting to the point when I feel I should not spend every waking moment thinking about mind warping theorems like the Yoneda Lemma, possibly the greatest result in pure mathematics of the 20th century, discovered in an accidental meeting at the Gare du Nord train station in Paris between an eminent American mathematician and a brilliant 20 year old Japanese PhD student who’s name graces the theorem. !t is also the easiest theorem to explain to anyone — it simply says any object can be described by its interactions. Category theory upturned mathematics from being the study of sets to the study of objects with arbitrary but unspecified internal structure. Yoneda showed how it is more powerful than set theory and mathematics changed forever. Here’s a link describing this chance encounter. Not what you were expecting to read in What’s Best, I’m sure.

le lemme de la Gare du Nord – neverendingbooks

And before I forget, here’s Dennis’ picture, looking as happy as a clam.

Fantastic text. It's great to know about new projects from Dennis Had.
Cary is a fantastic brand, the best for the price. For this reason we work with them for 20 years. I'm very happy with my 805RS, modified with Vcaps, WBT, KRAudio Tubes, etc.