SET amp owners thread

[ketcham]

I was saddened to hear about the discontinuation of the Allnic A-311 low wattage series, the amps with which I am most personally smitten. I found better resolution and a dead silent circuit by in part omitting the parallel circuit design. 60W to 7.5W in my personal system missed nothing. But, I use very efficient speakers. The new A-2500 SET MONOBLOCK POWER AMPLIFIERS are now in production, 20W, using either 211 or 845 power tubes. The chassis will be an adaptation of the M-2500 push-pull siblings.

T.H. Park (K.S. Son) describes them as masculine and grave compared to my favorite PX25 tube. At 20W they may bring to the table something wonderful.

 

[christoph]

I love the speaker stands- adds a little punk to the system

Very elaborate and sturdy but lightweight cross joint thermoplastic resin

 

[djsina2]

I love the speaker stands- adds a little punk to the system

You should have seen his previous equipment rack and where he got it from.

 

[guf]

Very elaborate and sturdy but lightweight cross joint thermoplastic resin

sorry you guys....speaker stands changed. Cinder blocks now. Pictures to follow.

 

[advanced101]

I was saddened to hear about the discontinuation of the Allnic A-311 low wattage series, the amps with which I am most personally smitten. I found better resolution and a dead silent circuit by in part omitting the parallel circuit design. 60W to 7.5W in my personal system missed nothing. But, I use very efficient speakers. The new A-2500 SET MONOBLOCK POWER AMPLIFIERS are now in production, 20W, using either 211 or 845 power tubes. The chassis will be an adaptation of the M-2500 push-pull siblings.

T.H. Park (K.S. Son) describes them as masculine and grave compared to my favorite PX25 tube. At 20W they may bring to the table something wonderful.

Keep us updated in the Allnic section.

 

[cjfrbw]

I think one would have to appreciate the SIT3/Pass Defisit types for their unique sound rather than a direct comparison with tubes. The comparison would be on particulars rather than the entire presentation. Sony was guilty of comparing the original VFET amps to 2A3 tubes in the 70's, but the comparison doesn't really hold in real life listening.

I would say the SIT types have even better separation and absolute distinctness of stage addressing than tubes/SET. The tonality is brief, but deep and sweet, certainly better than other transistor types even in class A. With SIT/VFET, you will be able to separate octave related voices and distinguish them without effort. SIT allows clear distinction of instrumental tonal voices.

The SIT/VFET types also have what I find to be very pleasurable intensity. Maybe some audiophiles wouldn't like that intensity. It is the antithesis of SS harshness, and makes me hypnotized to keep listening to what is coming next indefinitely. SETs that I have don't quite achieve that harmonic intensity. I do recommend driving SIT/VFET with a DHT gain stage.

The SIT types don't quite have the velvety, see around the corners elegant holographic presentation of tones and voices that you get with SET, especially with something like the 45 tube. However, compensating virtues seem to equalize the presentation overall. SET have a more palpable harmonic bath.

If you are expecting 'more SET than SET', you are likely to be disappointed with SIT/VFET. SIT/VFET are their own creature.

I don't have to pick because I have both SET and VFET types, and rotate them in and out. However, they are all so good that I convince myself that whatever is in the system at the time must be the 'best', that is, until I rotate the next one back in and that must be the 'best'. I can't complain when everything seems to wind up as best.

 

[guf]

I think one would have to appreciate the SIT3/Pass Defisit types for their unique sound rather than a direct comparison with tubes. The comparison would be on particulars rather than the entire presentation. Sony was guilty of comparing the original VFET amps to 2A3 tubes in the 70's, but the comparison doesn't really hold in real life listening.

I would say the SIT types have even better separation and absolute distinctness of stage addressing than tubes/SET. The tonality is brief, but deep and sweet, certainly better than other transistor types even in class A. With SIT/VFET, you will be able to separate octave related voices and distinguish them without effort. SIT allows clear distinction of instrumental tonal voices.

The SIT/VFET types also have what I find to be very pleasurable intensity. Maybe some audiophiles wouldn't like that intensity. It is the antithesis of SS harshness, and makes me hypnotized to keep listening to what is coming next indefinitely. SETs that I have don't quite achieve that harmonic intensity. I do recommend driving SIT/VFET with a DHT gain stage.

The SIT types don't quite have the velvety, see around the corners elegant holographic presentation of tones and voices that you get with SET, especially with something like the 45 tube. However, compensating virtues seem to equalize the presentation overall. SET have a more palpable harmonic bath.

If you are expecting 'more SET than SET', you are likely to be disappointed with SIT/VFET. SIT/VFET are their own creature.

I don't have to pick because I have both SET and VFET types, and rotate them in and out. However, they are all so good that I convince myself that whatever is in the system at the time must be the 'best', that is, until I rotate the next one back in and that must be the 'best'. I can't complain when everything seems to wind up as best.

Geeze, it’s like I have to get one now. Both is always a great solution.

 

[jeff1225]

This amp has been on my radar for a while now. I've recently been interested in getting a second amp just to have some variety. I ordered a SIT-3 this weekend and it should arrive next week. I'll give a report after it breaks-in. I think I read somewhere that it takes about 100 hours?

There was a huge difference at 48 hours, 100 can't hurt. Honestly it get's better every day, I'm absolutely thrilled with this amp.

 

[Exlibris]

I will be very curious to hear how this amp compares with your mighty Allnic.

The amplifier arrived today. Here is a photo of it. I think I'll leave it in this location but I'll have to find a proper base for it.
The dealer I purchased it from said it requires basically no break-in period but that it wouldn't hurt to leave it on for a few days straight.
Before I comment on the sound I'm wondering if anyone has an idea why I would have to increase the volume attenuator on my linestage by 18dB over the setting I use with my Allnic amplifier to get the same SPLs. The Allnic is 50wpc and the SIT-3 is 18wpc. I wrongly assumed that I would have to turn it up 4dB to 8dB.

 

[KeithR]

It's a very low gain, 11db amplifier - needs a high gain (oftentimes) tube preamp. Normal amps are 26-28db gain.

 

[Exlibris]

It's a very low gain amplifier - needs a high gain (oftentimes) tube preamp. If you just have an attenuator, that won't work.

I have an active tube linestage (just right of the TT in the photo). I seem to remember the gain being 15dB. I could ask Thomas Mayer or maybe he will chime in if he sees this.

 

[Exlibris]

, but deep and sweet, certainly better than other transistor types even in class A. With SIT/VFET, you will be able to separate octave related voices and distinguish them without effort. SIT allows clear distinction of instrumental tonal voices.

The SIT/VFET types also have what I find to be very pleasurable intensity. Maybe some audiophiles wouldn't like that intensity. It is the antithesis of SS harshness, and makes me hypnotized to keep listening to what is coming next indefinitely. SETs that I have don't quite achieve that harmonic intensity. I do recommend driving SIT/VFET with a DHT gain stage.

The SIT types don't quite have the velvety, see around the corners elegant holographic presentation of tones and voices that you get with SET, especially with something like the 45 tube. However, compensating virtues seem to equalize the presentation overall. SET have a more palpable harmonic bath.

If you are expecting 'more SET than SET', you are likely to be disappointed with SIT/VFET. SIT/VFET are their own creature.

I don't have to pick because I have both SET and VFET types, and rotate them in and out. However, they are all so good that I convince myself that whatever is in the system at the time must be the 'best', that is, until I rotate the next one back in and that must be the 'best'. I can't complain when everything seems to wind up as best.

This is my experience of the SIT-3 as well.
The one thing I will add is that with the Odeon No. 33 speakers the integration between the midrange horn and the 12" cone woofer is seamless.
The SIT-3 is shockingly good in my system.

 

[cjfrbw]

SIT-3 uses a jfet impedance buffer followed by an autoformer voltage gain followed by an asymmetric push pull pair:
output is current gain but not voltage gain. The asymmetric output stage consists of a depletion Semisouth SIT coupled with a carefully measured enhancement mode MOSFET that I think makes the arrangement self biasing. The asymmetry produces a particular spray of harmonics that seem to allow the signal to be more easily digested by the hearing apparatus.

My Tokin SIT Defisit is based on the same general topology I.e. SIT and MOSFET in auto biasing push pull arrangement at the output, autoformer voltage gain, JFET impedance buffer. It sounds close to being single ended (i.e. fluid upper midrange with bit of subjective dynamic range expansion). I have never heard the SIT-3.

Pass made in interesting statement that push pull class A circuits can have as much as 80 percent of the 'work' being done by just one of the devices and still be considered push pull. I don't know what they become when the ratio becomes 90/10 or whatever. Maybe that means that particular push pull can approach a single ended paradigm? I wouldn't know, but how this counter intuitive topology occurred to NP I can't even guess.

I was listening to the Tokin Defisit amp using the Analysis Epsilon bass panel as a crossover-less full range driver @ about 88db @ 3.6 ohm efficiency, and even without any tubes in the chain (Yamaha Pre/Pro direct to amp) it sounds phenomenal. It played as loud as i could stand it even at the 25-30 watts or so class A @ 3.6 ohms.

 

[morricab]

This is my experience of the SIT-3 as well.
The one thing I will add is that with the Odeon No. 33 speakers the integration between the midrange horn and the 12" cone woofer is seamless.
The SIT-3 is shockingly good in my system.

Too early for a comparison with the Allnic?

 

[morricab]

SIT-3 uses a jfet impedance buffer followed by an autoformer voltage gain followed by an asymmetric push pull pair:
output is current gain but not voltage gain. The asymmetric output stage consists of a depletion Semisouth SIT coupled with a carefully measured enhancement mode MOSFET that I think makes the arrangement self biasing. The asymmetry produces a particular spray of harmonics that seem to allow the signal to be more easily digested by the hearing apparatus.

My Tokin SIT Defisit is based on the same general topology I.e. SIT and MOSFET in auto biasing push pull arrangement at the output, autoformer voltage gain, JFET impedance buffer. It sounds close to being single ended (i.e. fluid upper midrange with bit of subjective dynamic range expansion). I have never heard the SIT-3.

Pass made in interesting statement that push pull class A circuits can have as much as 80 percent of the 'work' being done by just one of the devices and still be considered push pull. I don't know what they become when the ratio becomes 90/10 or whatever. Maybe that means that particular push pull can approach a single ended paradigm? I wouldn't know, but how this counter intuitive topology occurred to NP I can't even guess.

I was listening to the Tokin Defisit amp using the Analysis Epsilon bass panel as a crossover-less full range driver @ about 88db @ 3.6 ohm efficiency, and even without any tubes in the chain (Yamaha Pre/Pro direct to amp) it sounds phenomenal. It played as loud as i could stand it even at the 25-30 watts or so class A @ 3.6 ohms.

What would still distinguish it from SET is the nature of any handoff between devices, which is never perfect.

 

[Exlibris]

Too early for a comparison with the Allnic?

It's still breaking in but I'm making a few notes. The one thing I'll say now is that the music comes across as not rushed and not forced. It's not that it's slow in any way but it's as if you're hearing the musicians taking their time and being deliberate with every note and every word. You really feel the intention behind everything.

 

[morricab]

It's still breaking in but I'm making a few notes. The one thing I'll say now is that the music comes across as not rushed and not forced. It's not that it's slow in any way but it's as if you're hearing the musicians taking their time and being deliberate with every note and every word. You really feel the intention behind everything.

And how does that contrast with the Allnic? I haven’t heard the ones you have thus my curiosity (not that I would be giving up my Aries Cerat Genus ).

 

[Exlibris]

And how does that contrast with the Allnic? I haven’t heard the ones you have thus my curiosity (not that I would be giving up my Aries Cerat Genus ).

With the Allnic and with my previous 45 SET amp (with different speakers) you don't get as much of that. The sound is slightly more amorphous. You get more of the sound itself and the air around it rather than that intentionality. I'm not sure if I'm explaining that very well.

 

[morricab]

With the Allnic and with my previous 45 SET amp (with different speakers) you don't get as much of that. The sound is slightly more amorphous. You get more of the sound itself and the air around it rather than that intentionality. I'm not sure if I'm explaining that very well.

Trying to wrap my brain about what you are saying...
You are the only guy who is writing about this amp that also has an upper class SET (Jeff’s LAMM is push/pull) to compare against. One of the things I love about Aries Cerat compared to a lot of other SETs is the precision of the sound stage, which is very well defined and structured.

 

[Exlibris]

Trying to wrap my brain about what you are saying...
You are the only guy who is writing about this amp that also has an upper class SET (Jeff’s LAMM is push/pull) to compare against. One of the things I love about Aries Cerat compared to a lot of other SETs is the precision of the sound stage, which is very well defined and structured.

I'll take another shot at it using an example. At the beginning of Mogwai's "Kids Will Be Skeletons" you can hear some notes being played on a guitar at the left of the stage. That's the experience I've always had of the intro to this song. With the SIT-3 you experience a band member very deliberately plucking each string with the intention to convey something with his music. You also sense the time between the plucks and how long each pluck takes.