Thoughts on the First Watt SIT Amps

Has anyone bought the First Watt SIT amp (either model)? If so, tell us your thoughts compared to previous amps you've had.

I owned the First watt SIT-2 amp for about a month. It was driving a pair of Avantgarde Duo Primo loudspeakers that are 107 db efficient. Unfortunately, an issue developed and I was forced to return it.

When I initially received the SIT-2, it was dead quiet. After three weeks, it started intermittently making a crackling static noise in the right channel. That went away, but a short time later, it started constantly making the crackling static noise in the left channel. It was noticeable during soft passages of music. I thought the amp had developed an issue. I was sent out a second another SIT-2 amp. The second SIT-2 amp immediately made the same static crackling noise in the right channel. I was told that SIT amp does make a popcorn type noise that can change over time.

I ultimately returned the SIT-2 and got back my First Watt M2 amp, which was/is very quiet. I was a little bummed-out because the SIT-2 was dead quiet when I first received it is an absolutely fantastic unique sounding amp. However, the First Watt M2 is very close and has a couple of advantages.

The SIT amp is an extremely open sounding amp. The most open sounding solid-state amp that I have ever heard. It throws a huge soundstage. The SIT's midrange sounds like it is lit-up and glows from within. Music and voices sound very intimate and real. With the SIT amp, vocals tend to be more diffuse and further back in the soundstage. With the M2, vocals are more dense and slightly more forward. This quality in the M2 allows you to make out words in songs easier. The M2 is definitely more dynamic with harder hitting bass than the SIT amp.

After owning the SIT amp for the month, I'm a little surprised at how close the SIT and M2 are to each other. If you could combine the attributes of each, you would probably have the perfect solid-state amp.

I would like to say that Mark at Reno Hi-Fi gave me fantastic customer service! He was attentive to the issues and took care of me immediately. He even paid all of the shipping charges for multiple amps each way! I couldn't have asked for better service. Who says you can't get great customer service these days? He has customer for life.

Very informative. Thank you for the write-up!
Any further experiences with these amps? I am thinking of trading in my XA30.5 for the SIT-2 to drive a pair of Druids.
I'll say at the outset that I do not think the Pass 30.5 mates well to Zu speakers, so having heard both, I think the SIT amp will be a clear improvement.

The SIT amp is very smooth and articulate. It is among the two or three most natural solid state amps available at any price; and to put it another way it is one of the two or three least objectionable solid state amps you can buy. Within its power limits, it's listenable and satisfying -- if you've never had a better tube amp. Even on Zu at 101db/w/m, the amp's dynamic compression is evident at high but not deafening SPL. Its primary deficiency compared to a range of good tube amps is that while the transient events are defined, impactful and clear, decay is over-damped. You don't get "the whole note," compared to more complete amplifiers. But the SIT amp does have much more tonal depth natural space than the XA30.5 (which is exceedingly clean in its own right).

That's my view of it. If I were committed to solid state for Druids, SIT and Lavardin would probably be my contending choices.


would you agree with Phil and say the SIT is over damped? Does the SIT have any magic or is it more SS and a little devoid of the life a great SET would have?
Phil wrote,
"Decay is over damped. You don`t get the whole note".Phil I appreciate your input/impression very much.The SIT amplifier does intrigue me but I really wonder if it can duplicate what the Coincident Frankenstein(or other really good SET amps)do so well. I`m referring to full body tone,weight,harmonics,decay, inner nuance etc. In other words those qualities that make good SET so natural and real sounding compared to most other types of amplifiers.
Phil were you able to hear the SIT in your system? I know S.Ebaen of 6 Moons prefers it to any DHT SET amplifier.I do respect his opinions but we may very well have different listening preferences and sound/music presentation priorities.Exceptional SET amps IMO provide that 'breath of life' quality that many other amps seem to lack.
I heard the SIT in a friend's system I know well, on the same speakers as mine -- Zu Definition IV. I gave it every benefit of doubt and *wanted* to like it more than I do. It is very good solid state. However, the SIT amp cannot, will not, does not equal the tonal integrity, harmonic completeness, natural note decay and depth of nuance that well-implemented SET topology does. There are SET amps that I wouldn't buy which the SIT amp can beat, but those amps are irrelevant. The SIT amp won't satisfy someone already accustomed to SET at the level of implementation achieved in the Frankenstein, nor any SET amp Audion makes, for example.

It really isn't persuasive to me what anyone at 6Moons thinks. No one there has more listening experience than I do, so I have no particular reason to defer to Ebaen for time spent in audio nor range of gear. On the other hand everyone has different experience regardless of cumulative time in the pursuit, and 6Moons generally seeks musicality. If SIT works for him, fine. It falls considerably short for me. If for some reason I absolutely had to abandon tubes for transistors, then SIT is one of two or three next best alternatives. But I'm not abandoning SET nor tubes. Even a properly re-tubed pair of Quad II amps (push-pull, remember) with healthy capacitors will beat SIT in every musically-significant way except deep bass definition.

Hello Phil,
I also like the 6 moons approach with their emphasis on musicality and feel that Srajan is very effective at putting into words what he hears. I don`t view him or anyone as a 'guru' however. Your further description of the SIT amp is what I suspected(short of hearing it myself).Your familiarity with the Frankenstein amp obviously adds relevance in my situation. As you clearly explain, there seem to be exclusive qualities in the 'good'DHT SET amplifiers(that matter most to me)that are very difficult for other amps to duplicate(even though they have other strengths of their own). Thanks again for your up close insight.
Let me add something about the SIT amps. I listened to the SIT-2 stereo amp. When asked, I advised the gentleman who ordered it to instead buy a pair of SIT-1 monoblocks. He was going to spend that much on a different amp anyway, so why not? I always endorse monoblocks over same-design stereo, but an interesting thing happened. The dealer insisted that there's "no difference" between SIT-2 and SIT-1, so "save the money and get SIT-2." So that's what my friend auditioned and what I heard at some length.

Now, I know in my bones that SIT-1 will sound different and I think very likely it will sound better even though the monoblocks output the same power per channel. For one thing, separate power supplies on the same circuit virtually always sound better and certainly sound different in discernible ways. But additionally, the SIT-1 has a user-adjustable bias control.Sure, there's a reference point on the meters for optimal bias, but you're free to shade it + or - the reference setting. I've *never* heard an amp that doesn't sound variable according to whether its bias is shaded hot or cold, off center. Sometimes the differences can be quite dramatic, depending how far out of "normal" you change bias and trade device longevity and stability for sonic bliss.

I know from some third party conversations and from what can be inferred thus far in his published review, that Srajan at 6Moons believes SIT-1 has sound possibilities SIT-2 can't equal. So while I'll say that I heard nothing in the SIT-2 amp to suggest that this solid state device can fully deliver the organic life that quality SET can, it's reasonable to surmise that SIT-1 can get substantially closer, especially if associated gear is chosen carefully.


You make quite valid points between the two versions of the amplifiers. Is your friend`s view of the SIT-2 amp the same as yours or is he happy with them in his system?

Does your friend plan to try the SIT-1 amps to see for himself?

Is he a former DHT SET amp owner?

He did not keep the SIT-2 beyond the agreed trial, due to the traits I noted. He returned to tube amplification. I recall his comment being, "I'm done with solid state."

Upon rereading the 6moons review, it does not seem to argue that the SIT amps are a replacement for tubes as implied by Phil. The reviewer did state that

While this SIT platform does bridge transistors and tubes, it doesn't clone the latter. It remains distinctive. Depending on your triggers and their sequence and what music you fancy, you still might prefer valves.

I am seeking just a bit of that SET tube magic myself, so I still want to hear a few more views on these amps.
As I explained in the review, you can get better than SET performance from the SIT if you precede it with a single-stage DHT preamp. Those are rare critters but I listed a few models from Coincident, Jeffrey Jackson, Trafomatic and Wavelength. Now you hear a direct-heated triode in an ideal circumstance (no harmonic dilution from a driver tube, no massive turns ratio for the output transformer and the valve is driving a stable amplifier input impedance rather than reactive loudspeaker load), far better than the tube would sound in a multi-stage power amp. This combo of DHT/SIT goes places most SETs can only dream of. No noise. More bandwidth. More control in the bass. More resolution. More linear THD. And, the THD can be strategically shifted.

The SIT by itself doesn't sound like transformer-coupled tube amps at all. It's much more linear and far quicker and more open. If you reference an OTL however it gets much much closer...
Hello Srajan,
I thought you made these points clearly in your review. I believe also that phil heard what he so very clearly described. All this means to me is the two of you simply value different sonic attributes and as a result individual preference hierarchies will naturally exist.

I suspect my listening /sonic taste probably(even though I use a DHT single gain preamp) are more in line with phil(as those differences he heard the DHT SET excel matter most to me). As always horses for courses.Thankfully there are choices for nearly all taste.I`d still like to hear the SIT amps if the opprotunity arises.
I'm going to make it a point to hear the SIT-1 monoblocks with a DHT preamp in front of it. I have listened to DHT preamps and have heard the SIT-2, but have not heard the two sequenced together. I'll give Srajan benefit of doubt, and I do believe the adjustable bias monoblocks will get closer to being musically convincing than the SIT-2 regardless of what's in front of it.

At the moment I have no reason to believe that putting a DHT preamp in front of the SIT will correct truncated note decay, nor the dynamic compression due to limited power and headroom. I agree the SIT amp has better bass control than any SET amp I can think of. I don't agree that it meaningfully outresolves every SET amp (though certainly many or even most), at least not in any way consistent with how instruments actually sound instead of how they sound close-mic'd and hot in the mix. But there's another thing: It's not just ears and mind but the body. There is a state of engagement, involvement -- full-body response, that I reliably experience listening to live performance. I have never had the identical full body response to recorded music played through transistor amplification nor through any push-pull vacuum tube amplifier. Nor, of course, to live music heard exclusively through electronic processing and conventional amplification. I did not have it with the SIT-2 either. The sound was "over there." I have the same full-body response listening to recorded music that I can have with a live orchestra, for example, only with a small range of exceptional SET amplification and crossoverless speakers. It's not "similar." It's the same organic response. I don't even have to analyze what I'm hearing. I feel it, in binary fashion. It's there or it's not. It's always been that way for me. Many times when I have noticed a small change in a sound system, it's because of what I felt before hearing something I can immediately pinpoint. Give me a solid state amp that can induce the same full-body engagement in recorded playback that I can get with certain SET aplification or upon hearing it live, and I'll buy it.

I am intrinsically interested in hearing proof that the SIT devices can compete with high-grade SET implementations. I want Nelson Pass' adventurism to pay off. He's always pushing in the right direction for the right reasons. I'd like an electrically more efficient and consistent successor to a high-heat triode tube if the sound warrants. Put another way, I am predisposed to like the SIT amps but the actual sound hasn't moved me yet. It's closer than other solid state options offered so far so I'll give it every chance to convince me.

When you do get the chance to hear the SIT-1 amp with a DHT single stage preamp I`d love to read your impressions. If you lived nearby(Michigan) I`d certainly lend you my Coincident Linestage for comparison(and Frankenstein amp also).
Charles - I'm in Los Angeles. Put your Coincident under your arm and saddle up. Will update the thread when I eventually arrange this.

I look forward to this report.I`ll be patient.
Is there room for Shindo to join this listening session? I'm in Long Beach so just a stones throw from LA.

Room for anything. The hard part is getting a pair of SIT-1 and a DHT preamp in my house at the same time. Working on it, and will come back to let you know.

I ordered a pair of SIT-2 amps a few months ago for bi-amping the horns on my Avantgarde Duo Omega G2 speakers. The amps won't be delivered until mid-August at the earliest, so in the meantime I'm looking forward to read about your findings.
Jcote- I would love to hear your Cortese at some point.

I've had the SIT-2, various SETs, and many others in my Zu Def4-based room. I currently am using Quads.


Hi Phil,
Reading Srajan`s complete review of the SIT-1 amplifier, he made the distinction of "single gain stage" DHT linestages as opposed to merely DHT tube based. Will you be able to get a single stage version?I may have to saddle up my horse and head west with the Coincident Linestage.
What is your opinion of the SIT-2 amplifier driving the Zu Defs? Do you have an interest in auditioning the SIT-1 versions?

Sorry, for not coming back and answering your question. I was out of town for couple weeks. After a few weeks, I thought this thread had disappeared. Anyway, no I do not think the SIT amp was over damped, but remember I was coming from the First Watt M2 to the SIT. If I was coming from a tube amp, then maybe I would think differently. I owned a number of nice (BAT, Art Audio, Cy Breeneman, and etc.) tube amps and just got tired of the hassle of tubes. Yes, the midrange and emotional impact is excellent, but the drawbacks (maintenance, reliability, colorization of sound, mediocre at frequency extremes, and etc.) just got to be too much. Convenience and hassle-free operation is important to me. That's why I got rid of my turntable in 1986, and never looked back.

I have had my differences with Srajan's writing style, but I think he eventually got the SIT-1 review right. Although, the last few pages of the review he rambled and was all over the map. Remember, Srajan was one of the biggest tube amplifier proponents for years. He has listened and reviewed every one of the First Watt amps and he seems to understand the character of each amp in his system. I'm sure in other systems the character of these amps might slightly change. That's why I think potential owners need to demo and listen to them in their own system.

The SIT 2 was/is the finest sounding solid-state sounding amp that I have ever heard with my horns. I have domed, owner and/or heard very one of Nelson Pass' low Watt offerings. The SIT is special. If the noise issue hadn't reared its ugly head, then I would still own the amp. If Nelson or I can figure out what was causing the noise in my system and alleviate it, then I will more than likely be the owner of the SIT-1 or SIT-2 amps.
Brawny and Phil with different perspectives (no surprise, different ears).Chad you`re going to have to bite the bullet and hear this amp in your system. It`d be very interesting how it compares to your modified Yamamoto SET amplifier.
>>Anyway, no I do not think the SIT amp was over damped, but remember I was coming from the First Watt M2 to the SIT.<<

Adjacent to the FW M2, which is very good SS in its own right, the SIT-2 sounds liquid and lingering by comparison. So from that perspective of amps sequence I fully understand Brawny's view of it.


I read the SIT review and felt you were claiming that the SIT could possibly replace a DHT SET in most areas. I am interested in the SIT but suspect its the same old SS compromise.

I have been chasing the ultimate amplifier for many years. Probably like many here.

I surprised myself when I settled for a Yamamoto A08s. I installed it with EML mesh 45 and EML mesh 80, then with modified power caps (mundorf tube & silver gold in oil) and the coupling caps replaced (DuelundVSF copper). These mods & tubes I believe have taken the A08s as far as it can go.

The A08s is as you know it, but with more width,depth, slightly cleaner,less grain and a striking organicness. I believe this very adictive organic sound is helped by the duelunds coupling caps, & the extra detail is down to the mundorfs forcing more info to these coupling caps, but the duelunds remove any etching the mundorf can add. I tried many allternates before settling here.

Many amps (Tom Evans Linear/Halcro DM/ Yamamoto A011/Audio note conq/etc etc) have come to drive my AGs, and some do somethings things better. I.e lower noise floor.improved bass control, image size and so on. But within hours I'm bored by these amps. Whether they are tube or SS.

There is a harmonic beauty in the 45 tube especially with the mesh plated EML which helps music speak. Upon reading your review of the SIT I suspect this harmonic magic is not available to the SIT. Although you gain the usual SS attributes. Would you agree?

I think the Tom Evans is a excellent amp on my Trios though possibly a little forward. Would you say the SIT is more in the Tom Evans vain?I.e clean, fast with harmonic texture, but not as beautiful as a DHT SET.

I just wish for an amp that would remove the need for tubes.
Why the need to avoid tubes? They obviously provide that something special your prior SS amps lacked or you`d kept one of them. Your Yamamoto SET is very simple,straight forward and reliable like my Frankenstein(minimal fuss). The tubes in these amps last for thousands of hours. Just continue to enjoy your wonderful system.I`ve been in pure musical bliss since I discovered SET amps with high efficient/easy load speakers.People talk about SET colorations, I can`t speak for all SET amps but the Frankenstein is more accurate to real instruments and voice than any SS amp I`ve heard. I`d imagine you feel the same regarding your Yamamoto.Realism and natural/organic- holistic sound is most important to me.This is what generates the emotion and utter involvement of music.Good luck finding that with SS amps.Could the SIT-1 be it finally?

I want to avoid tubes for a few reasons.

1 they are inconvenient.
2 they are inefficient.
3 they are expensive to replace.
4 they are noisey.

But some tube amps & tubes do sound excellent. I am with you regarding the SET organic & holistic sound. I cannot seem to be able to beat my 2w amp for sonic bliss.

The systems that have lasted the longest & provided the most joy for me have been with tube power amplification. With all the new technologies and ideas that have come in the many years since the tube was invented, I find it hard to believe tubes have not been superseded in all areas.

As for luck finding an SS amp that's capable of such virtues? I have found absolutely none...yet.

Can the SIT be the start of this road? By the sound of it probably not (pardon the pun).

Why has no one got an SET a logarithm that comes on a chip? You plug it into a highly efficient amp stage with earth shattering spec and job done. You decide if you want a 45 mesh sound or a 300b or whatever to drive any speaker?

Come on its the 21st century. Do I really have to continue with this 100 year old glassware from an age of steam engines?

I liked the SIT-2 very much, although wondered if it was a bit dynamically limited- above 92dbs or so I could hear it distorting in my room. It doesn't have tube decay, so is still a different sound than tube- but it has a very similar midrange to great SETs. I was really astonished by it's sound at times.

I ran it with a McIntosh C2300 tube preamp w/ NOS teles, so clearly not a DHT preamp. I really don't have interest in the monos as they don't increase power. Doesn't seem like anywhere worth 2x the $, bias adjustment or not. The gem of the line is the stereo version imo.
Thank you for your insight.
It seems Phil`s impression nailed the essential differences between the amplifiers and in the end it will boil down to taste and sonic vitues that are cherish most.Complete note substain-decay is a quality I won`t compromise, this loss is too significant in order to get bass a bit tighter or faster.It`s easy to understand the variance between Phil and Srajan.
Noise is`nt an issue in my system at all.With your 107db sensitive speakers(mine are 94 db) It could be. As to expense, yes my Takatsuki 300b pair is very expensive. Their perforformance is extraordinary! and I`d continue to buy them again in a heartbeat for the sheer joy and pleasure they provide. When SS amps equal this ability I`ll be very interested.
This thread has been very interesting and thought provoking. I believe the Frist Watt SIT amp is an exceptional product and genuine achievement. I also believe it will out perform many SET amplifiers,It all depends on one`s reference point and past SET amp exposure.There are noticeable quality/performance levels among these amps and a certain hierarchy is in place. Some SET amplifiers are indeed colored,slow,soft, too warm,rolled off etc, Others will demostrate supreme speed,openess,tone,dynamics etc.

My feeling is the true top tier SET amplifiers will out perform the SIT amp in certain vital areas of music reproduction and tactile realism- emotional connection. The SIT amps may have certain advantages in the 'hifi' realm/parameters i.e. image focus,transient speed,'tight' bass(perhaps less natural bass bloom or texture?).
Well `I`m off to see jazz trombonist Delfaeyo Marsalis who`s in town for a few days. This jazz club acoustic instrument venue will always be my reference point.I wish more high end designers would model their sound/components to mimic this type of natural sound rather than the direction some have chosen.

when I say noise, I don't mean the old school noise from bad circuits. When I talk about noise here, i mean when compared with that tomb like silence one can get from SS or class D efforts.

Ok my speakers are very revealing due to their sensitivity, but I don't mean I hear hiss or hum from the yammy. Just a kind of glow around instruments.

Let's face it if that SS amp turns up that's capable of the magic we would all jump ship. Apart from the hair shirt brigade of course...
While I'd love to hear the SIT amps it looks like you need to spend a lot of money ($10K for monoblocks plus additional for single stage DHT preamp)to essentially approximate what a good SET already gives you for a lot less. On top of that, you will also be stuck with a sonic signature that you can't change. If I want to alter the sound in any of my tube amps I can simply change brand of tubes. Will keep an open ear on the subject but have been disappointed in my ventures into the land of high end SS amps. I really want to hear a SS amp that I can love - at least for the summer months so I can avoid using my tube space heaters.
Does that "tomb like silence" seem natural to you? I find the 'ultra' silence or blackness artificial, as no background is that quiet(like outer space vacuum). I believe tube background ambience is the more realistic one in nature. Just an opinion that`s all.
Can I say I was ahead of the curve? I spent the last 3-4 years trying to get more info on these amps, but only a couple were being manufactured in Japan.
Well I had the yamaha B2 amps, which were great. Unfortunately I did not have it long enough to experiment.
The sound I rememeber is is definitely ss, but without the harshness, more liquid and smooth. What drove me to this technology was the rise time, it's very similar to tubes also it's switching characteristics.
If you are interested in SIT amps and are not sure, I would definitely try the DigitalDoMain B2a amps. I guess there in a pedigree in this tech. If you are adventurous, I would also look into Maxonic, they may make a new amp, hybrid tube and SIT.

Let me know if something comes to fruition, i'd be happy to lug over my Shindo Cortese for comparison.
Hi charles1dad,

If the recording has a tomb like silence then surely the playback of the recording should too? In other words if there is nothing there, there should be nothing, & if there is something there should be something.

I have had amplifiers like the Halcro where the recording leaps out at you from nowhere.

Even the Tom Evans Linear A (which is tubed) did this. I'm not sure the SET, for all it's positives, can do this. Even though the linear A is a kind of SET! But you understand what I'm getting at? Anything else is masking detail.
Hi Chad, I understand your point,but even in a recording studio that enviroment is not the so called'ink black' background of silence. But really overall it`s just a minor point I had thoughts on. Ultimately what ever one desires in their audio playback they should pursue.(no arguement there).
Hey Chadeffect,

Nice system! Do you have the basshorns with your Trios? How big is your room? I've got the Avantgarde Duo Primos, which is one model down from the Trios. At the time I purchased them, I was contemplating getting the Trios with basshorns. I was told that the Duo Primos were easier to set-up and did not require as big of a room to sound their best. Have you thought about acoustic room treatment for your listening room? Professional acoustic room treatment (ASC, RPG, & etc.) was/is, by far, the biggest upgrade I made to my system. I know it sounds like hyperbole, but the room treatment transformed my listening experience.

The Audiopax Model 88 tube amplifiers (look like toasters:) were probably the most natural and best sounding amps that I heard on the Avantgarde line of loudspeakers. However, those amps didn't/don't do the creamy three-dimensional harmonic tube thing (like a good 45 amp) that many tube guys tend to seek out. The SIT amp is the best solid state amp that I heard on my Avantgarde loudspeakers. If the SIT had one weakness I thought it was in the dynamics department, which I thought was a slight weakness with Audiopax Model 88's.

I'll try not to make this into a tubes versus solid-state debate since I like both. I don't want the music I listen to on my system highly influenced, changed, colored, or editorialized by tubes, cables, electronics, power, and by the room. I believe that the best sounding tube and solid-state amps sound a lot closer than most people would be willing to admit. Tube amps by Coincident, Audiopax, Art Audio PX-25, Wyetech, and Yamamoto along with solid-state amps by First Watt, Pass, and Sugden are all great sounding amps that share many of the same attributes.

Hi Brawny,

thank you.

I will try not to divert this thread, but in answer to your question I do not have the bass horns, but obviously have their active subs which work very well & cut in around 90hz.

There is alway an element of set up to get the best out of any speaker. But once you get a feel for what they do it's ok. There was a period of break in & understanding what sounded best.

I have not tried the audiopax but have read good things about it. I've also heard about problems with them too.

I have been lucky enough to have tried many great amps on the AG. Many I could have lived with including the Tom Evans. I was told that the 45 would not power the Trio due to the xover. But I have had no problems in my room which is an average size. Maybe in a bigger room i would have problems.

To get back on topic if I had a concern it would be about the usual tube issues.

The bass on the Trio with SS is mind blowing. It's so present. But the 45 had such wonderful texture that I don't mind losing some crispness. This is why I had high hopes for the SIT.

My feeling is amps should sound similar as they should just amplify. But unfortunately this is not true. Hense the long journey
Thanks for the response. I never purchased the Audiopax amps because they had reliability and major service issues. When the folks representing a company have a hard time getting service I can only imagine what customers had to go through to get service. It's a shame because Eduardo from Audiopax was/is a talented designer. However, there is much more to running a business than designing product.

I owned and demoed a couple of 45 amps in my system. With Jazz, blues, and vocal type music they sounded fantastic. When music got complicated and needed power and drive the 45 amps faltered a bit. I listen to a lot of rock, classic rock, and classical music. Often times loud and sometimes very loud :) Even though Avantgarde loudspeakers are very efficient, I find they still need more than 10-20 watts to get them to really open up. I once heard Avantgarde Duos driven by BAT VK-150SE tubes amps and they sounded effortless. Dynamics that smaller amps just can not do. Musical preferences and type of presentation the listener is looking for are huge determining factors that influence an amplifier choice.

I found that the SIT amp met most of my needs in an amp. It could use more power and drive and in my case less noise. If you ever do demo the SIT amp, please let us know your thoughts and if you run into the noise issues that I ran into. FYI, Reno HiFi that represents First watt gave me great service.Take it easy.

I know this discussion is about current production SIT, but I had a Sony TA 5650 VFET amp in the day for ten years before it failed and was very fond of it. SIT and VFET are different designations for the same kind of voltage controlled transistor type.

I have had a variety of tube amps, both push pull and SET and own several SET amps at the moment and three DHT based preamps.

I recently acquired one of the Sony TA 4650 VFET amps to use as a phono amp in a second location.

The phono amp uses a small signal VFET in the RIAA gain circuit, which then goes to a single small signal FET gain stage, and then feeds the push pull amplifier stage in this model. One can switch in or out the tone control stage which adds another small signal FET stage.

My thoughts about the VFET on hearing it again is that it most definitely is superior to most standard solid state amps.

The sound is very "fast" with the ability to image with enormous specificity in the sound stage in three dimensions.

The tonality is natural, with a non fatiguing character, unlike most transistor devices. The VFET has an analog sounding pulse response.

The dynamics are open and liquid, like DHT tubes.

Where it differs is that it does not quite have the "charm" factor of good DHT designs, and the tonal decay is sharper, without the more sumptuous resonant tails that SET designs have. The tonality of the VFET device is natural but a bit on the shallow side compared to tubes.

I have found that coupling DHT preamps with good solid state amps is an outstanding combination for some reason. I would not have thought that DHT preamp would synergies well with solid state amps, but they do, and sound very good that way.

Haven't tried the DHT preamps with the VFET yet, they are at different locations, but may get another VFET to try with Manley 300b preamp*.
I imagine that Allnic L5000 DHT linestage sounds fantastic.
Just off topic but I read your comments on Audiopax. I agree that there was a period when Audiopax may have lost their way - I believe in part due to the fact that Eduardo is best placed to be allowed to design and create and to leave customer support to others. The company has now been restructured and I believe many agree that they are much more responsive to providing proper customer service. I am of course heavily invested in the product so cannot say I do not have any skin in the game - but I do believe they are wonderful amplifiers from the new version of the Model 88 to the Maggiore 100 which I have purchased.
Hi Vicks7,

Sorry, I have responded to your post sooner. I was on vacation for few days. Audiopax was sold and distributed hear in the U.S. for a years. Jim Smith initially did a great job of promoting the Audiopax amplifiers. Unfortunately, Audiopax managed to develop a reputation for poor customer service during that time. I know one customer who waited months to get his Model 88's repaired. I know a Audiopax dealer who had to wait 11 months for one of his amps to get repaired. I came very close to purchasing a pair of Model 88's myself. A friend in the industry, convinced me not to because of Audiopax 's poor reputation for service.

Eventually, Audiopax ran into U.S. distribution and dealer issues. To make matters worse, their U.S. retail prices sky-rocketed in a short amount of time. The devaluation of the American dollar didn't help either. In addition, Audiopax was constantly fiddling with the designs. Often swapping out different parts. It got to the point where no one knew what version of the product they had received or getting because no two were alike.

There is no doubt that Eduardo De Lima is a really nice guy and a very talented designer. However, it takes a lot more than these attributes to run a successful company. Performance, value, quality, and service is what I look for in a company. And I always initially look for these things from domestic companies. I do understand that Audiopax restructured. That still does not change the past. I do hope they get it together, and develop a track record for great customer service. Until they do, I would be very hesitant and cautious in purchasing any Audiopax product. It's just too much money to gamble with. I wish you the best of luck with your new amps!
An update on my experience with the First Watt SIT:

I had an opportunity over the weekend to hear a pair of SIT-1 mono amps in a system separate from the one in which I heard the SIT-2, but sharing some characteristics.

Both systems are in Rives-treated rooms and both are built around Zu speakers. The more completely Rives-treated room housed a system built around Zu Dominance loudspeakers. The other room had a system built around Zu Definition Mk 4 loudspeakers. I heard the SIT-2 in the Definitions system, and the SIT-1 in the Domance system. Both systems used digital sources, Meridian with Dominance and Berkeley with Definitions. I'll say that the DACs share essential traits of very clean presentation, quiet noise floor and tonal asceticism. The Meridian/Dominance system used a Pass preamp. The Berkeley/Definition system used a McIntosh C2300 preamp.

For context, let me say a few things about the speakers. Dominance is easily the finest speaker I've heard by any maker, under any circumstances in my entire audio life. It possesses the essential Zu qualities of crossoverless behavioral unity, frequency neutrality, tone density, convincing spatial dimensioning, revealing resolution, dynamic agility, scalar integrity, amp friendliness and easy drive -- all honed to an extreme level of aural competence. Dominance does more right in the presentation of music than any speaker I know of. It demolishes the pretense of the industry's most egregiously expensive efforts. That said, Definition 4 clearly inherited the essence of Dominance and sounds amazingly similar within its scalar limits, given Definition is about 1/4th the price. Where Dominance vaults beyond Definition 4 is in focus and precision of the spatial presentation (including the solidity of the aural holographic illusion), complete absence of cabinet talk, greater dynamic accommodation before congestion, even more authority and agility to the bottom end, generally even less coloration and I believe Dominance is a bit more efficient. Take everything good about Definition 4 and improve it linearly, then add new capabilities in focus, burstiness and (despite more drivers) behavioral unity. Let me put a finer point on it: Dominance is the first and only loudspeaker I've ever heard that impresses me as a lifetime purchase. Buy them; install them; you're done. So, did I hear the SIT-2 through better speakers and into a more corrected room? Yes. But the two systems had similar basic properties that were useful for rough and impressionistic evaluation of the two SIT amps.

Having heard both, I stand by my earlier expectation (and general rule) that when the same topology is implemented as stereo or mono amps, the monoblocks will be better, if you can afford the difference. In this case, SIT-1 monoblocks are $10,000/pr., against $5,000 for the stereo amp. In this case, the Dominance system is in a somewhat over-damped room, whereas the Definitions system is in a room that has a lighter Rives treatment, eats bass, but is still on the lively side elsewhere. With only 10w per channel available from either SIT amp, the dual power supplies give the SIT-1 perceptibly more dynamic ease, especially when crescendo dynamics hit both channels at once. For me, this is valuable, especially with low-power amplifiers. But this is the minor improvement of SIT-1 over SIT-2.

Where SIT-2 left me disappointed by the way it tamps down the finish of a note compared to a well-designed SET amp, SIT-1 has a variable that lets you get closer to genuine SET musicality. The SIT-1 manual bias control introduces a measure of tunability to the amp's musicality that drives differences more than subtle and less than stark. The basic traits of the SIT prevail: clean, absence of grain and grit, very good tone for solid state, deep and agile bass, effective aural neutrality. But you can favor 2nd order harmonics, roundness and warmth, or push the sound in the direction of pentode-like definition with the speed of simple circuits....or anything in between. The perception of tube-like note decay is variable too, and while getting the "whole note" isn't as complete an experience as with a well-implemented SET circuit, you can get appreciably closer than with SIT-2 and its static configuration. Ironically, the owner of the amps and I preferred mildly-different settings, but both were within the same realm of essential rightness. He owns solid state but preferred his bias controls set for warmth and 2nd order harmonic profile; I own fast and transparent SET but preferred the bias controls set for more elevated definition while keeping good tone. Within its dynamic limits, the SIT-1, in a stereo pair, is the best communicator of music through solid state amplification I've heard, and you get some latitude for how much you want it to emulate a clean and ascetic Pass SS amp, for example, or towards the amber tint of the most romantic triodes. SIT-1 is never going to sound less than highly credible, however you voice it. But you are voicing it regardless where you prefer the bias control be set. It wold further benefit in this system, from a more expressive preamp.

I wouldn't give up my Audion SET amps for a pair of SIT-1s. But for someone (like the owner) who is acutely bothered by the slightly higher noise floor of SET or has other reasons to eschew vacuum tube amplification of any topology yet appreciates tube sound for its convincing musicality, SIT-1 allows you to get closer than does SIT-2, and by a margin that I consider significant enough to say that I hear SIT-1 as being a higher value point at $10,000 than SIT-2 is at $5,000. Put another way, I would not own SIT-2, but if I didn't already have excellent SET amps, SIT-1 would be satisfying. I can only say that about the McIntosh MC1.2kw (specifically), the Larvardin, and now this SIT-1 -- and it's the SIT-1 that sounds tonally most authentic among these. Its major weakness is its power limit. Neither SIT amp delivers the sense of headroom and grace near clipping that a good tube amp does. I'd love to hear a parallel single-ended SIT amp.

I still want to hear SIT-1s driven by a DHT preamp, to hear whether Srajan's postulate about the leap in results is true for me. But this was one step further in gaining experience with these amps.

One more thing: the Dominance system I listened to also had a QOL processor connected. I switched it out (bypass) for all of my evaluations of the amplifiers and speakers but did some comparative listening, QOL engaged and disengaged. Spatially, the QOL is entertaining. In that respect it seemed like a vastly-refined implementation of the early SRS outboard processors. It expanded the soundstage width only marginally, but it tended to expand the spaces between instruments/performers within the soundstage, and anything away from the center was pushed further away from the center and toward the soundstage perimeter. The presentation of holographic depth was enhanced but not always realistically. The spatial effects would be thoroughly entertaining with movies. It was expansively entertaining with music but not in a way that impressed me as more realistic. With the QOL switched in, I thought the sound became tonally less authentic though dynamically more exciting. Any voice sounded tonally more human with QOL out than in. Leading trainsients of notes and percussive events are definitely enhanced in positive ways. The dynamic clarity and transient precision are improved but the downside is that the balance of attack v. decay is altered from what sounds most authentic, at least to me. In nearly three hours of listening, there wasn't any music that the QOL made sound more authentic to me, but it was consistently able to make any disc sound more exciting, whether the "excitement" was in the original recording or not. I do agree it seems to recover some definitional information that sounds like it's not artificially derived. If that quality could be better isolated from the less natural spatial warps and disturbances to the attack/decay balance, it might prove aurally valuable. But not yet, for me. It has the trait, upon immediate swithover from engaged to disengaged, to make make either one sound incorrect for a lingering moment. But lingering always led me back to having QOL out of the circuit. Others may have a different preference. Hearing the QOL makes it obvious why it's controversial.