SET amp owners thread

[bonzo75]

What do you have to say about the Riviera hybrid ? thankyou.

It is very good on cone speakers if you swap a Mullard. @gian60 can tell you which mullard. Just changing that valve made a Wilson grand Slam set up of his friend's in Milan highly musical.

I would not recommend it for Devore or for horns or speakers that can take lower watt SETs.

 

[Klonk]

I am not @gian60, but I think it is the Mullard M8136.

 

[tommylion]

Antique Sound Lab Tulip 2A3, Audio Note AN-E/Ls

 

[Mike Lavigne]

Antique Sound Lab Tulip 2A3, Audio Note AN-E/Ls

hi Tommy, welcome to What's Best forum!

 

[markgarm]

Ked always speaks in absolutes, but it is true that unless you've listened to your speakers with a low-powered option, you're only guessing at the SET limitations.

I had Coincident Super Eclipse IIIs, first with a Pass INT30A, and then with the 8W Coincident Frankenstein 300b SET monoblocks and the SETs were better in every facet. I later upgraded to the Coincident Pure Reference Extremes and they were less efficient. After much amp auditioning (Digital, SET, OTL, Class A SS) I ended up with First Watt F4 monoblocks.

All to say that reading only gets you so far. In home listening on your system, with your source, in your room, with your ears is the only way to truly know.

Best of luck, either with new speakers, or by perfecting the DeVore balance.

I have the PRE as well . I'm biamping with Franks at the top and Dragons at the bottom . I wish I had more bass but I don't want to lose the congruity and seamlessness either .
What is your opinion of me changing to 300 watt tube monoblocks for the low end ? I actually see a pair of CJ's for sale online .

 

[Legolas]

Ked always speaks in absolutes, but it is true that unless you've listened to your speakers with a low-powered option, you're only guessing at the SET limitations.

I had Coincident Super Eclipse IIIs, first with a Pass INT30A, and then with the 8W Coincident Frankenstein 300b SET monoblocks and the SETs were better in every facet. I later upgraded to the Coincident Pure Reference Extremes and they were less efficient. After much amp auditioning (Digital, SET, OTL, Class A SS) I ended up with First Watt F4 monoblocks.

All to say that reading only gets you so far. In home listening on your system, with your source, in your room, with your ears is the only way to truly know.

Best of luck, either with new speakers, or by perfecting the DeVore balance.

Interesting journey. I too have had SET Monoblocks some years ago, from Audio Note and Line Magnetic and others, including some kits / DIY.
I think it comes down a lot to speaker efficiency, impedance across the wave band, and enough current delivery by the power supply. If these are done right, great results can be had. In the case of the Audio Note Conquest silvers, which were Monoblocks 300B as parallel with 18W, it was possible to get good results. However core saturation did happen, and bass drive and control was never acceptable to me in the end. A 'glimpse' of SET magic but too many weaknesses for my ear.

Speakers at that time were around 95dB, but had 12 inch drivers, so though efficient did need plenty of control in the low end.

I would go for 211, 813 type amplifiers and built like a tank.

At the moment I am using the Ianus Essentia Monoblocks from Aries Cerat, and they are a dream device. They really do hit the spot for top SET sound but have amazing current drive and control, don't get hot, and have only 2 small tubes per monoblock. They use a special Triode Fet gain stage. I am NOT hearing anything that wants me to go back to a full tube SET, and that is something I thought I would never say with a 'non tube' amplifier design.

 

[LL21]

I have the PRE as well . I'm biamping with Franks at the top and Dragons at the bottom . I wish I had more bass but I don't want to lose the congruity and seamlessness either .
What is your opinion of me changing to 300 watt tube monoblocks for the low end ? I actually see a pair of CJ's for sale online .

Interesting...I think CJ came out with new 160-watt Triode monos? Very expensive but perhaps something worth considering?

New Conrad-Johnson ART108A Amplifier

Mono & Stereo High-End Audio Magazine: Magico - Nagra - Tidal Audio - Wilson Audio - MSB - Totaldac - Living Voice - Taiko Audio - Aries Cerat -Thrax

www.monoandstereo.com

 

[morricab]

Interesting...I think CJ came out with new 160-watt Triode monos? Very expensive but perhaps something worth considering?

New Conrad-Johnson ART108A Amplifier

Mono & Stereo High-End Audio Magazine: Magico - Nagra - Tidal Audio - Wilson Audio - MSB - Totaldac - Living Voice - Taiko Audio - Aries Cerat -Thrax

www.monoandstereo.com

THat's not a SET though...

 

[LL21]

THat's not a SET though...

No its definitely not...but the request was for a 300 watt tube monoblock...and mentioned CJ specifically, so I thought given the discussions around SET that perhaps the new CJ 108 160-watt triode could be an interesting option sound-wise/power-wise. See below:

I have the PRE as well . I'm biamping with Franks at the top and Dragons at the bottom . I wish I had more bass but I don't want to lose the congruity and seamlessness either .
What is your opinion of me changing to 300 watt tube monoblocks for the low end ? I actually see a pair of CJ's for sale online .

 

[Legolas]

Various high powered tube amps around, and with the market flooded with low efficiency speakers... Push Pull is not SET, there is a magic to SET that I find intoxicating...

If I was setting up or even building DIY as multi amp system, I would probably go in the direction of SET for mids and treble sections, and Class D or A/B SS for the bass. Yes tube powered bass can be great as well, but class D would be a cheaper way to do it IMO. Lot of tweaking and time delays, phase shifts etc etc. Can be done though.

The DIY horn + bi-amping sector of this hobby is a big and fascinating subject. If you have the skills, space and a workshop to do it, I say go for it!

 

[morricab]

Various high powered tube amps around, and with the market flooded with low efficiency speakers... Push Pull is not SET, there is a magic to SET that I find intoxicating...

If I was setting up or even building DIY as multi amp system, I would probably go in the direction of SET for mids and treble sections, and Class D or A/B SS for the bass. Yes tube powered bass can be great as well, but class D would be a cheaper way to do it IMO. Lot of tweaking and time delays, phase shifts etc etc. Can be done though.

The DIY horn + bi-amping sector of this hobby is a big and fascinating subject. If you have the skills, space and a workshop to do it, I say go for it!

Class D bass sounds so different that I don't think it is a good blend with SET in the upper ranges...just IME...

 

[Legolas]

Class D bass sounds so different that I don't think it is a good blend with SET in the upper ranges...just IME...

Yes. It depends on the crossover points. SS Class A next best idea, but more expensive generally and lot of heat / energy bill.

 

[Legolas]

Brad, what do you think of the Avante Garde bass blend? Isn't that active class D? As well as the timbre and character of the bass, we also have the challenge of the speed of horns, if we used a horn for the mids / lower mids. Getting the blend is a challenge. Even mega budgets don't always manage it, remember that huge Cessaro speaker we heard at Munch 2019, oh dear, not happening.... room problems come into it, but the AC room was worse as regards acoustic challenges IMO and that sounded simply amazing!!

 

[Atmasphere]

Class D bass sounds so different that I don't think it is a good blend with SET in the upper ranges...just IME...

The trick is to keep the sub below 80Hz so it won't attract attention. Then you can run class D no worries. But keep in mind that not all class D amps sound the same! IME some of the older ones don't play bass very well (and don't do that well with the mids or highs either...). Others play bass just fine and so will blend easily. But if you get above that 80Hz area, there comes a need to align the woofer with the mids and highs and it turns into a nightmare.

 

[morricab]

Brad, what do you think of the Avante Garde bass blend? Isn't that active class D? As well as the timbre and character of the bass, we also have the challenge of the speed of horns, if we used a horn for the mids / lower mids. Getting the blend is a challenge. Even mega budgets don't always manage it, remember that huge Cessaro speaker we heard at Munch 2019, oh dear, not happening.... room problems come into it, but the AC room was worse as regards acoustic challenges IMO and that sounded simply amazing!!

I think the older models used Class A/B amps but the new ones have DSP and Class D amps. I liked the older Duo and Trio but the new XDs, at least with Avantgardes own amps, sound too forward and somewhat aggressive...at least in the setups I heard.

 

[cal3713]

I have the PRE as well . I'm biamping with Franks at the top and Dragons at the bottom . I wish I had more bass but I don't want to lose the congruity and seamlessness either .
What is your opinion of me changing to 300 watt tube monoblocks for the low end ? I actually see a pair of CJ's for sale online .

Personally, I have never liked biamping with my PREs.

This was true even when I hand constructed identical amplifiers (again the FW F4s) to separately run the head and bass units. I found that I didn't gain anything from the additional power and lost coherency at the crossover point. I find the 25W totally sufficient. I've also tried paralleling F4 amplifier boards to double the power, but found no gain and some slight smearing and loss of clarity. That's the benefit of the DIY approach... you can just try all the options and the PREs will always let you know what the truth sounds like.

I also found the bass lacking on the PREs and after iterating through various amplifiers and trying all these different power and biamping options, finally got a calibrated mic and used REW to measure my room. Turns out my room just had a huge double digit db cutout right at 40hz. The only way to fix it was to get Duke's Audio Kinesis Swarm and use the multiple subs to even out the room's standing waves.

So, based on my experience, I'd recommend settling on whatever monoblocks (tube, SS, whatever) sound the best to you from the midbass on up and running the PREs full range with them, and then dealing with the bass/room issues separately.

Of course, everyone has different ears and rooms, so as always, YMMV.

Also, feel free to PM me if you want to discuss the PREs more in private. I've replaced all internal wiring with solid core silver in teflon, replaced a broken midrange driver, removed all binding posts, changed out the tweeter caps (Jupiter, WIMA, and Duelund), and played all the above amplifier games plus some more... so I feel like I've got a pretty good handle on them at this point.

 

[cal3713]

Interesting journey.

Thanks, glad to hear it.

At the moment I am using the Ianus Essentia Monoblocks from Aries Cerat, and they are a dream device. They really do hit the spot for top SET sound but have amazing current drive and control, don't get hot, and have only 2 small tubes per monoblock. They use a special Triode Fet gain stage. I am NOT hearing anything that wants me to go back to a full tube SET, and that is something I thought I would never say with a 'non tube' amplifier design.

And this is interesting... this design sounds a lot like where I've ended up as well (albeit via the much cheaper DIY route). My FW F4s have no voltage gain and only use a single stage direct coupled MOSFET design to add current. All voltage gain is provided upstream by the single stage DHT preamp (just the SET tube, a couple resistors, and a nice amorphous core Monolith output transformer).

And as you suggest, I've also gone for the "built like a tank approach"... my amplifiers have outboard power supplies with 4 separate 400v transformers (one per rail per channel), 384,200uF of total capacitance, and inductor filtering. The amp boards have Vishay naked z-foils throughout the signal path, solid-core silver wiring, and MOSFETS hand-matched at operating temp and voltage. My preamp has separate outboard power supplies for each channel as well.

Playing with DIY, I just kept finding that power supply improvements really mattered. Every modification and step up would take a little layer of distortion out of the signal. Basically imperceptible, except that I was able to relax into the music a bit more each time... a little less jaw tension.

 

[AB76]

I just love the 300B tube. I miss it when I don't have it in the chain. Not sure quite why compared to other tubes I've heard, though I'm sure I've not heard as much as many. There is just this rightness, it's not what bigger amps do with really pushing the drivers etc. and getting all dynamics. It just has this sound that is so pleasing and tonally right to me. As always, tradeoffs with everything and all that

 

[Legolas]

Thanks, glad to hear it.

And this is interesting... this design sounds a lot like where I've ended up as well (albeit via the much cheaper DIY route). My FW F4s have no voltage gain and only use a single stage direct coupled MOSFET design to add current. All voltage gain is provided upstream by the single stage DHT preamp (just the SET tube, a couple resistors, and a nice amorphous core Monolith output transformer).

And as you suggest, I've also gone for the "built like a tank approach"... my amplifiers have outboard power supplies with 4 separate 400v transformers (one per rail per channel), 384,200uF of total capacitance, and inductor filtering. The amp boards have Vishay naked z-foils throughout the signal path, solid-core silver wiring, and MOSFETS hand-matched at operating temp and voltage. My preamp has separate outboard power supplies for each channel as well.

Playing with DIY, I just kept finding that power supply improvements really mattered. Every modification and step up would take a little layer of distortion out of the signal. Basically imperceptible, except that I was able to relax into the music a bit more each time... a little less jaw tension.

Well done. I would love to find both the time and expertise to tackle a DIY project.

It is interesting how many top systems at shows end up bi-amped. Possibly for a display of what is possible? It is not so practical and can be very expensive of course.

The Aries Cerat Ianus Monoblocks IMO bridges the gap between end game tube power amplifiers with solid state bass and control. That is a huge subject, but I feel that is what I am hearing with them. It is a superb solution to the SET enigma, the best of tubes in a 'solid state form' plus current drive and control. I have heard other attempts at this, and there are many hybrid designs around. The Ianus is something quite new, and is not technically a hybrid. I think that is key to it's outstanding transparency and speed.

 

[DasguteOhr]

Class D bass sounds so different that I don't think it is a good blend with SET in the upper ranges...just IME...

Buy a old yamaha studio amp, great punch good sounding bass most them have a xover for sub.Please not the ones with switching power supplies, they sound much worse.my tip this exsample or P Series.