Yesterday I was at my friends place listening to his new amplifier on his AvantGarde Uno hornloadspeaker.
After several try-outs at his place with amps like the Rowland 625, PassLabs XA30.8, Atmasphere MA-60, Cello Encore 50 at last a Firstwatt SIT2 had its debut on his 100 dB Avantgardes.
To be short: Best amp I ever heard on his set and probably the best amp we both heard in our thirty year quest for the perfect amp. And yes there's no perfect amp that's perefect in every situation for everyone but the sheer musicality, precision, rendering of space and modesty (the not in your face mentality) of presenting it was just astonishing and totally relaxing.
This deserves although 4 days too late a real congratulation to its designer.
Questions:
1. Apart from having two chassis a bias meter and bias knob, what's the use of having the SIT 1 mono's if they don't deliver more power?
2. Why can't they deliver double power at 4 Ohm, so I can use it on my Infinity's QLS-1 mid/high part.
3. Why can't we have a lot of these transistors in a parallel configuration so people a speaker without a 100 dB at 1 W/m like Avalons.
4. Why does ist sound so unbelievable relaxed and just right?
Thanks, my friend is now cured from his audiodepression that made him almost sell his whole setup ...
After several try-outs at his place with amps like the Rowland 625, PassLabs XA30.8, Atmasphere MA-60, Cello Encore 50 at last a Firstwatt SIT2 had its debut on his 100 dB Avantgardes.
To be short: Best amp I ever heard on his set and probably the best amp we both heard in our thirty year quest for the perfect amp. And yes there's no perfect amp that's perefect in every situation for everyone but the sheer musicality, precision, rendering of space and modesty (the not in your face mentality) of presenting it was just astonishing and totally relaxing.
This deserves although 4 days too late a real congratulation to its designer.
Questions:
1. Apart from having two chassis a bias meter and bias knob, what's the use of having the SIT 1 mono's if they don't deliver more power?
2. Why can't they deliver double power at 4 Ohm, so I can use it on my Infinity's QLS-1 mid/high part.
3. Why can't we have a lot of these transistors in a parallel configuration so people a speaker without a 100 dB at 1 W/m like Avalons.
4. Why does ist sound so unbelievable relaxed and just right?
Thanks, my friend is now cured from his audiodepression that made him almost sell his whole setup ...
Thanks for the congratulations (this seems to be the week for it).
To answer your questions,
1) The SIT-1's are more of a curiosity piece, allowing some playing with the
operating point (knob and meter) which tweaks the character of the
2nd harmonic. If you bypass the input buffer, which most do, then you
find that there is only the one transistor anywhere in the circuit, as the
current source consists of a big bank of power resistors taking most of
the dissipation. I know, it's excessive.
2) The single-ended circuit will not deliver a peak greater than the output
bias current, so that maximum power (peak) is that current squared times
the load impedance. That current is about 1.6 A.
3) The SITs used in this were custom made at enormous cost for the occasion
by a company that went out of business. Other SITs (aka VFETs) are also
scarce and costly. Apart from that, there is no reason in principle why you
couldn't scale these up with multiple parts. The VFET amps we made for
Sony's commemorative used a pile of their VFETs and deliver 100W/ch
into 8 and twice that into 4 ohms.
4) That's a good question whose answer probably comes in parts. They do
have a nice "Triode" character, and they can deliver low distortion with
minimal parts and feedback. At the same time, they demand a lot of
consideration and expense for the hardware that surrounds them.
😎
To answer your questions,
1) The SIT-1's are more of a curiosity piece, allowing some playing with the
operating point (knob and meter) which tweaks the character of the
2nd harmonic. If you bypass the input buffer, which most do, then you
find that there is only the one transistor anywhere in the circuit, as the
current source consists of a big bank of power resistors taking most of
the dissipation. I know, it's excessive.
2) The single-ended circuit will not deliver a peak greater than the output
bias current, so that maximum power (peak) is that current squared times
the load impedance. That current is about 1.6 A.
3) The SITs used in this were custom made at enormous cost for the occasion
by a company that went out of business. Other SITs (aka VFETs) are also
scarce and costly. Apart from that, there is no reason in principle why you
couldn't scale these up with multiple parts. The VFET amps we made for
Sony's commemorative used a pile of their VFETs and deliver 100W/ch
into 8 and twice that into 4 ohms.
4) That's a good question whose answer probably comes in parts. They do
have a nice "Triode" character, and they can deliver low distortion with
minimal parts and feedback. At the same time, they demand a lot of
consideration and expense for the hardware that surrounds them.
😎
1. SIT 1 - double heat for same power , comparing to SIT2 , so case dissipation limits dictates one per channel
2.bloody pure class A , besides that SE , so double bloody pure class A
3.perfume is more expensive when in small bottles ; much cheaper when bought in quantity ; besides , Papa doesn't enjoy in too much perfume
4.made of Ambergris ; besides that maturity of designer and him hanging with right ppl are often influental to designing choices
edit: damn , he's faster ...... again
2.bloody pure class A , besides that SE , so double bloody pure class A
3.perfume is more expensive when in small bottles ; much cheaper when bought in quantity ; besides , Papa doesn't enjoy in too much perfume
4.made of Ambergris ; besides that maturity of designer and him hanging with right ppl are often influental to designing choices
edit: damn , he's faster ...... again
Thank you very much for your swift and informative answer.
So you bought a lot for $ 300k and that's it. No more then that and the scarcity dictates a fair distribution of course and that's why it's a good thing that we only get one of these jewels per chassis😀
You've turned 65 now and what's your opinion about the continuity of the companies you've started after you pass away?
Don't get me wrong, I wish you will live long and happy forever but maybe apart from Way Colburn pre-amp designs, you're the main driving force behind PassLabs and FirstWatt and in that sense the operation stops after you do I gather.
So you bought a lot for $ 300k and that's it. No more then that and the scarcity dictates a fair distribution of course and that's why it's a good thing that we only get one of these jewels per chassis😀
You've turned 65 now and what's your opinion about the continuity of the companies you've started after you pass away?
Don't get me wrong, I wish you will live long and happy forever but maybe apart from Way Colburn pre-amp designs, you're the main driving force behind PassLabs and FirstWatt and in that sense the operation stops after you do I gather.
Good heavens man, the guy's fit as a fiddle and sharp as a tack, let's not go there. Besides, in another 30 years we'll be uploading ourselves into the matrix. 🙂
You probably right, and whenever I'm consulted by potential buyers for a good choice of highendaudio I do recommend Passlabs because besides the quality of their products in every parameter the service is just the best there is because you can bother the designer himself and he answers immediately even when it's his old stuff from Threshold.
But the fact remains that whenever a company is pretty much relying on the creative resources of one person, when that persons leaves for one reason or another that knowledgedrain constitutes in most cases the end of the company.
All I wanted to express, and I did that probably in a blunt way so apologies ar in order here: - I apologize sincerly for that - it would be sad that the sheer experience of NP in the field of amplifier technology would vanish when he's gone. See what happened to Threshold Inc. when NP left in 1991...
My comment wasn't meant to make you feel bad. I was just making light. It's what I do 🙂
I know, no offence taken, I just myself felt bad about it re reading it so I had to give some more insight about the grounds for my remarks.
Actually I spent less than $300K on the first batch. The second batch was
to be $300K, but I decided against it, lucky for me as it would have been
50% down and the company folded.
Continuity, that's an interesting thing. My experience is that it's easy to
screw companies up, but hard to kill them - witness ESS and Threshold.
That said, nothing lasts forever.
😎
If you haven't noticed, he is training an army of Oompa Loompas right here at diyaudio.
Quote from your Aleph 0s manual to put it in perspective:
"The amplifier does not require any maintenance. While the design is conservative, this is a hard running amplifier, as single ended Class A operation is the least efficient operating mode. In fifteen years the electrolytic power supply capacitors will get old. Depending on
usage, you will begin to have semiconductor and other failures between 10 and 50 years after date of manufacture. Later, the sun will cool to a white dwarf, and after that the universe will experience heat death."
You probably wrote it yourself didn't you?
ESS and Threshold are merely tradenames nowadays like Infinity.
People should believe in people not in shareholder value.
According to my Buddhist friends, impermanence is one of the three marks of existence.
When that inevitable change results in lower quality it's a source of dissatisfaction for all but those who profit from it.
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