First Watt SIT 5

[jeromelang]

How do people reconcile with the fact that first watts amps accept unbalanced inputs only and that they would be needed to be placed closed to upstream electronics to minimise transmission loss?

As a long time Pass user who has always placed the power amplifier closer to the loudspeakers driven by a long XLR cable from a balanced pass pre-amp, this create some no small problem.

I am looking for a lower powered, but purer Class A option from the x350.8

Will be operating the Aleph P (MK 2) at full volume with the 2 gain knobs at the minimum.

 

[Paul49720]

A couple of observations after listening to the 60.8 (which I’ve had for ~18 months) and swapping them out with the SIT 5:

1. The 60.8 just sounds a lot more solid state - still relatively warm but with relatively no bloom. Grainy and dull.

2. The SIT has much more holographic depth and texture with greater precision of detail across the sound stage (left to right, and front to back).

3. There seems to be a lot more musical information getting through which makes for greater realism and ultimately listenability. Just a magical sonic bloom. Anyone familiar with the other FW SIT amps knows their character, but they have never been available with this much power.

To be clear, I’ve been very impressed and pleased with the 60.8. While I’ve used the Pass XA25 as well as FW J2, F8, SIT 3, & SIT 4, the 60.8’s power made it the best all-rounder of that group even though all of the FW amps share the SIT 5’s superior sonics vs the PL amps. The trade-off has generally been power and with rock/pop/classical at elevated volumes the other FW amps simply lack the dynamics/overhead that come with more power.

The SIT 5 far more than any other FW bridges this gap and to such an extent that aside from crazy loud, the better sonics of the SIT are no longer qualified. It’s better across the range with all types of music. Better mid and highs are most evident but even tonality of the bass is better - again I cannot underscore how much more musical info gets through on the SIT vs the non-SIT Class-A Pass amp. It’s not a small thing despite the impressive starting point of the 60.8.

But given how important system synergy can be, my observations are all heard through Wilson Alexia 2 loudspeakers (and Nordost cabling). Some (including a very prominent reviewer) have been surprised by the positive synergy between FW with Wilson Audio. As many know, Wilson speakers are nominally a 4-ohm speaker and all but the SIT 4 make 30+ watts at that load and Nelson has frequently referenced that many are surprised by what only a few watts can produce. In short, all of these amp easily drive the speakers to reasonably loud listening levels although most are limited by their modest power. Again, I can only speak for my experience but the Alexia 2 as well as the Watt Puppy 7 have been a stellar match. Despite modest power, all of these FW amps have performed magically when paired with my speakers.

Hope this makes sense and there should be some forthcoming reviews to expand on the new FW.

Axel

Hi, thank you for posting your findings: serving 104dB efficiency horns, do you have a sense the SIT 4 would give all the musical sound and spatial character of the SIT 5 you describe ? (I presently use a 4w + 4w ADI tube SET (Yamamoto) which provides more than enough power through a TVC, typically using the first 3 - 5 indents of 24). ( EDIT: I quickly read one of the reviews which notes - "in the manual Nelson also mentions that we shouldn’t expect the two SITs to sound the same"). So there's an indication ! Thanks.

 

[Axel C]

Hi, thank you for posting your findings: serving 104dB efficiency horns, do you have a sense the SIT 4 would give all the musical sound and spatial character of the SIT 5 you describe ? (I presently use a 4w + 4w ADI tube SET (Yamamoto) which provides more than enough power through a TVC, typically using the first 3 - 5 indents of 24). ( EDIT: I quickly read one of the reviews which notes - "in the manual Nelson also mentions that we shouldn’t expect the two SITs to sound the same"). So there's an indication ! Thanks.

While there are differences to be sure, I think the recent SIT amps (3, 4, & 5) all share excellent sonic characteristics. I think each is terrific and believe the new Tokin based models take it a step further. IMO, both seem to have more oomph than the Semi South SIT-3. But to answer your question, yes I think the 4 gives a lot of what I like about the 5.

 

[MRubey]

Hi, thank you for posting your findings: serving 104dB efficiency horns, do you have a sense the SIT 4 would give all the musical sound and spatial character of the SIT 5 you describe ? (I presently use a 4w + 4w ADI tube SET (Yamamoto) which provides more than enough power through a TVC, typically using the first 3 - 5 indents of 24). ( EDIT: I quickly read one of the reviews which notes - "in the manual Nelson also mentions that we shouldn’t expect the two SITs to sound the same"). So there's an indication ! Thanks.

Right, slightly different topology. The SIT4 has the sonic signature that moved the needle well beyond where it had been with the 3, per the press. It is hoped the SIT5 captures enough of that. Sounds to me like people love it so it’s close enough.

From HiFi Knights
“The stereo version’s two key Tokin SITs operate in the Common-Source mode, where they supply both voltage and current gain. Each SIT5 mono houses a single SIT transistor that operates in the Common-Drain mode, where it only has to follow voltage, which secures lower output impedance, lower measured noise (30uV versus the SIT4’s 75uV) and higher bandwidth (5Hz-200KHz versus the SIT4’s 5Hz-80KHz). In the manual Nelson also mentions that we shouldn’t expect the two SITs to sound the same.”

FirstWatt SIT5 – HiFi Knights

This is the www.hifiknights.com review of FirstWatt SIT5 mono amplifier. Author: Dawid Grzyb. Enjoy!

hifiknights.com

 

[Alpha121]

Right, slightly different topology. The SIT4 has the sonic signature that moved the needle well beyond where it had been with the 3, per the press. It is hoped the SIT5 captures enough of that. Sounds to me like people love it so it’s close enough.

From HiFi Knights
“The stereo version’s two key Tokin SITs operate in the Common-Source mode, where they supply both voltage and current gain. Each SIT5 mono houses a single SIT transistor that operates in the Common-Drain mode, where it only has to follow voltage, which secures lower output impedance, lower measured noise (30uV versus the SIT4’s 75uV) and higher bandwidth (5Hz-200KHz versus the SIT4’s 5Hz-80KHz). In the manual Nelson also mentions that we shouldn’t expect the two SITs to sound the same.”

FirstWatt SIT5 – HiFi Knights

This is the www.hifiknights.com review of FirstWatt SIT5 mono amplifier. Author: Dawid Grzyb. Enjoy!

hifiknights.com

Do all these SITs have the negative phase second harmonic baked in?

Isn't that the part of the sound signature that is so appealing?

 

[Rumpole]

Do all these SITs have the negative phase second harmonic baked in?

Isn't that the part of the sound signature that is so appealing?

Looking at the FirstWatt webpage, the SIT-3 and SIT-4 do have the negative phase second harmonic, and I think they all do. In the SIT-3 manual Nelson says it is the signature that they preferred in the previous SIT amps. In his interview with Steve Guttenberg, Nelson said:

"but we saw to it that it had the negative phase character on that second because we found that that was that was an important element if you have (and this is a common perception, I can't say that everybody experiences the same thing) but a negative phase second harmonic tends to give an apparent expansion to the sound field so that things move out a little deeper and farther. If you go positive phase it kind of moves in and becomes a little more intimate maybe a little more detailed - it's totally any illusion but there it is, and we also found out that most of the customer base liked the negative phase"

There is no mention yet of the SIT-5 on the FirstWatt webpage. Is there any news on when they will be available? I really don't need another amplifier but I'd like to hear them.

Edit: The SIT-5 are on the webpage now

 

[jpwelcher]

Is the SIT 5 sound stage presentaion like sitting in the front of a venue, middle of the venue or at the rear of the venue.
Thank You

 

[MRubey]

Hey Axel C.
Have you seen that Srajan is quoting you extensively in the SIT5 review. It’s in the under construction list at 6 Moons.
You’re 3 seconds into your 15 minutes of fame!

 

[Axel C]

Hey Axel C.
Have you seen that Srajan is quoting you extensively in the SIT5 review. It’s in the under construction list at 6 Moons.
You’re 3 seconds into your 15 minutes of fame!

Haha!

 

[sensitivemonk]

@Axel C @Alpha121 @Rumpole The SIT 5s came in today and I got them set up. They do have similar characteristics as the SIT 4 but the extra power makes it more assured and effortless. Amazing how revealing the 5s are without making less than ideal recording sound unlistenable. I also think the 5 is better than the 4 at keeping complex passages defined and detailed. I don’t know with any certainty if they’re using negative phase on the second, but given how immersive and deep it sounds, I’d guess yes.

 

[Paul49720]

After a brief exchange with @sensitivemonk, does anyone have a reflection on the narrowed (or just closed?) gap in character of sound between the SIT 4 (or 5) design versus an / any SET ?

Of course, so many factors will affect this, from basic design to the differing material and physical property of SIT devices versus the metal, glass and vacuum (a space !) of valves, not to mention the character and capability of each type.

The background to my question is my comparison of FW’s earlier J2 design with my 4w +4w SET (EML AD1 output pair and AZ4 regulator) with 104dB single driver horns.

The J2 gave a little more delineation and layering of information, nearly all else was equal, yet the ss device did not quite have that call of the SET, where one wants to stay listening for longer. So is SIT 4 (or 5) now in this zone, with perhaps still greater scale and command than an SET, given the industrial application of the SIT device, and Nelson’s design nouse ?

 

[Hubert]

A couple of observations after listening to the 60.8 (which I’ve had for ~18 months) and swapping them out with the SIT 5:

1. The 60.8 just sounds a lot more solid state - still relatively warm but with relatively no bloom. Grainy and dull.

2. The SIT has much more holographic depth and texture with greater precision of detail across the sound stage (left to right, and front to back).

3. There seems to be a lot more musical information getting through which makes for greater realism and ultimately listenability. Just a magical sonic bloom. Anyone familiar with the other FW SIT amps knows their character, but they have never been available with this much power.

To be clear, I’ve been very impressed and pleased with the 60.8. While I’ve used the Pass XA25 as well as FW J2, F8, SIT 3, & SIT 4, the 60.8’s power made it the best all-rounder of that group even though all of the FW amps share the SIT 5’s superior sonics vs the PL amps. The trade-off has generally been power and with rock/pop/classical at elevated volumes the other FW amps simply lack the dynamics/overhead that come with more power.

The SIT 5 far more than any other FW bridges this gap and to such an extent that aside from crazy loud, the better sonics of the SIT are no longer qualified. It’s better across the range with all types of music. Better mid and highs are most evident but even tonality of the bass is better - again I cannot underscore how much more musical info gets through on the SIT vs the non-SIT Class-A Pass amp. It’s not a small thing despite the impressive starting point of the 60.8.

But given how important system synergy can be, my observations are all heard through Wilson Alexia 2 loudspeakers (and Nordost cabling). Some (including a very prominent reviewer) have been surprised by the positive synergy between FW with Wilson Audio. As many know, Wilson speakers are nominally a 4-ohm speaker and all but the SIT 4 make 30+ watts at that load and Nelson has frequently referenced that many are surprised by what only a few watts can produce. In short, all of these amp easily drive the speakers to reasonably loud listening levels although most are limited by their modest power. Again, I can only speak for my experience but the Alexia 2 as well as the Watt Puppy 7 have been a stellar match. Despite modest power, all of these FW amps have performed magically when paired with my speakers.

Hope this makes sense and there should be some forthcoming reviews to expand on the new FW.

Axel

Been following this for a while without jumping in until now.
I'd like to use some of your insight please. Got some amp choices to make to drive my Tannoy Westminster GR. On my short list are the XA25, the XA60.8 and the SIT5. I've also got the Spec top range monoblocks which actually are my ultimate choice, but another price range too which I'm not sure to reach at this stage.
So if we stay in the FW and Pass game, and if you have some experience with these big efficient Tannoy, which one of these amps would you recommend?
Thanks

Never said it was a problem, it was a reaction to its price. We are allowed to have reactions, no?

Now to explain why I reacted in that manner, my personal approach is keep components somewhat proportional to each other in terms of price bucket. Granted the SIT-5 is said to be close to $10k, however for the other First Watt amps which are significantly less.

For further clarity, I view the pre-amp as the heart of the whole system given it will manage various source inputs and amplifier outputs. In that vein I would spend more on the pre-amp than perhaps a few other components in the chain.

What preamp would you suggest for the SIT 5? I’ve heard the SIT 4 with a Shindo monbrison which was great. Would the SIT 5 need something different?

I would suggest you have a look into the Coincident Statement Line Stage preamp. Totally underrated and one of the best value preamps out there. Will play far above many at triple or quadruple its price range. The minus is their double mono step up volume doesn't allow for a remote.

 

[Hubert]

The First Watt amps inspired Jeff Day to say that we are living in the golden age of solid state amplification. Comparable to the 1920s being the golden age of tube amps. He said this because of the purity and tonality of these minimalist designs. I’ve never pulled the cover off of my SIT 3 but from photos I’ve counted 17 parts per side in the signal path of the amp. I think it’s worthy of any level of upstream electronics to include the $86000 Solution 757 DS Audio compatible as well as conventional phonostage/linestage. The FirstWatt amps are second to none among SS amps for their intended speaker loads. Compare them to the EM/IA silver wound type 50 and that is a different conversation.

If I remember correctly, Jeff yet preferred the XA25 over the SIT4!

 

[Hubert]

How do people reconcile with the fact that first watts amps accept unbalanced inputs only and that they would be needed to be placed closed to upstream electronics to minimise transmission loss?

As a long time Pass user who has always placed the power amplifier closer to the loudspeakers driven by a long XLR cable from a balanced pass pre-amp, this create some no small problem.

I am looking for a lower powered, but purer Class A option from the x350.8

Will be operating the Aleph P (MK 2) at full volume with the 2 gain knobs at the minimum.

He uses single ended because of amp design doesn't require balanced and an additional transformer for that, I guess.
But cable wise, Benchmark Media Systems recommends to use coax rca cables for longer runs.

 

[sensitivemonk]

If I remember correctly, Jeff yet preferred the XA25 over the SIT4!

@HDDG SIT 3 or 4? I can only find a review comparing the 3 to the XA25, and I only see a preference for the XA25 for rock. Please let me know if I missed something.

 

[sensitivemonk]

Been following this for a while without jumping in until now.
I'd like to use some of your insight please. Got some amp choices to make to drive my Tannoy Westminster GR. On my short list are the XA25, the XA60.8 and the SIT5. I've also got the Spec top range monoblocks which actually are my ultimate choice, but another price range too which I'm not sure to reach at this stage.
So if we stay in the FW and Pass game, and if you have some experience with these big efficient Tannoy, which one of these amps would you recommend?
Thanks



I would suggest you have a look into the Coincident Statement Line Stage preamp. Totally underrated and one of the best value preamps out there. Will play far above many at triple or quadruple its price range. The minus is their double mono step up volume doesn't allow for a remote.

Thank you. Will look into it.

 

[MRubey]

If I remember correctly, Jeff yet preferred the XA25 over the SIT4!

Jeff Day hasn’t reviewed a SIT4.

 

[Axel C]

Been following this for a while without jumping in until now.
I'd like to use some of your insight please. Got some amp choices to make to drive my Tannoy Westminster GR. On my short list are the XA25, the XA60.8 and the SIT5. I've also got the Spec top range monoblocks which actually are my ultimate choice, but another price range too which I'm not sure to reach at this stage.
So if we stay in the FW and Pass game, and if you have some experience with these big efficient Tannoy, which one of these amps would you recommend?
Thanks



I would suggest you have a look into the Coincident Statement Line Stage preamp. Totally underrated and one of the best value preamps out there. Will play far above many at triple or quadruple its price range. The minus is their double mono step up volume doesn't allow for a remote.

I've spent the past few days listening to the SIT-5 and XA60.8 back to back (using Nordost Tyr 2 RCA on both to eliminate that factor). In retrospect I may have been a bit harsh on the 60.8. While it's definitely missing the greater holographic imaging and texture of the SIT, it's not really grainy and dull - just less good especially in the highs and mids.

I cannot speak to synergies with your Tannoys and it may depend on your music preferences. I suspect Nelson may offer an opinion as he's familiar with them.

As a side note, a friend recently asked how the SIT does when really pushed with challenging music. To those surprised that they mate well with Wilson Alexias, while I listen mostly to classic jazz and pop up to moderately loud volume levels, to answer my friend I played the Scorpion's "Still Loving You" full tilt. The vocals demand everything from the highs and mids, and when the percussion/bass come in the lower end is comparably challenged. All I can say is that at ear-splitting volume it put a smirk on my face - gives very little away to the 60.8 in bass slam, etc.

As Nelson says, there's no perfect amp, so along that philosophy if I were primarily listening to rock and/or other challenging music at high volume, I'd go with the 60.8, but for jazz/instrumentals/vocals it would be the SIT - no question. The SIT will play loud with exceptional performance in the upper range, giving away something in shear dynamics/overhead but it's magical with richer texture, detail, holographic imaging, etc.

 

[Tangram]

I’ve owned an XA30.5 and currently own an XA25, so I appreciate the comments here on the SIT 5monos. There’s an old thread that’s just been resurrected, “Who are the most talented audio designers today?” Nelson Pass absolutely gets my vote. Not only do I appreciate his minimalist amplifier philosophy. I apply it to my complete audio chain.

 

[Hubert]

@HDDG SIT 3 or 4? I can only find a review comparing the 3 to the XA25, and I only see a preference for the XA25 for rock. Please let me know if I missed something.

My memory failed me, you are correct!
Thanks