Which Nelson design has most transparent HF?

Sure, but he was asking about amplifiers.
F4 is buffer.

Well.... are we including ZM here?

I got a Sissy SIT, an F4, a few power resistors and a big heatsink. The plan is to do it sometime in the next two months.

I also got an F5.... hmm....

Then you got the BA3 with the bridged F4s.

Is the OP interested in the "standard" Nelson amps or the variations?
 
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I am still enjoying my own take on the F5m. High transconductance Mosfets, high bias current, special gate stopper resistors. I voiced the amp for my preferred balance between an airy and sparkley treble.
The takeaway here is to try some tweaks to your amp of choice (or expediance). There is a surprising amount of room for adjustments.
What mosfets and the aforementioned gate resistors did you use?
 
Well.... are we including ZM here?

I got a Sissy SIT, an F4, a few power resistors and a big heatsink. The plan is to do it sometime in the next two months.

I also got an F5.... hmm....

Then you got the BA3 with the bridged F4s.

Is the OP interested in the "standard" Nelson amps or the variations?
Anything and everything. What's the deal with F4? Something magical about the highs? I need tiny amount of power. If it's a follower for my DAC/preamp, it just might be enough output voltage.

And if it's not enough for my tweeter, I would be able to use it somewhere probably eventually, I had something in mind that I needed more current for.
 
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Technical data for JT025TI1-4 is hard to find (impossible?) but it's a tweet, how hard to drive it can it be. Ofc I would try playing some other things too, from full range speakers to very low sensitivity planar magnetic headphones, but the main purpose here is this tweeter. I love this tweeter, I think it's great and some say the best JBL ever made. It is fun.
 
Something magical about the highs?

Every Nelson Pass designed amplifier listed on this thread would not disappoint anyone serious about listening to music. The "magic" is not just the design, but the output devices AND the design. The "magic" names seem to be Harris, Fairchild, SemiSouth. My favorite is SemiSouth, yes they are very expensive compared to MOSFET's available from Mouser, yet dirt cheap compared to 300B output tubes, let alone output transformers. You can still find them for around $300 a pair.,

I built the ALEPH J using the SemiSouth JFET's and will listen to Chick Corea on piano with Gary Burton on vibes for hours on end. Clarity without my ears bleeding, I even continue to listen to other music for the rest of the night.

No matter which amplifier you decide on, try to buy the best sounding output devices you can find/afford.

I started with a pair of ACA's, they are still the amp's I lend out when friends want to hear what I'm always talking about when we discuss audio.
 
You guys are a fun group of people, but I feel like I have to correct myself, because when I said the most transparent HF I wasn't really aware that that would mean the lowest distortion. That's not my goal or first priority. What I need is something that sounds alive (in the sense that it's energetic and in your face), not veiled, but also, I must admit that I like it when it sounds rich and perhaps bigger than life and a bit bombastic, not necessarily strictly true to the source. But I find that detail never diminishes any of those, so while I may struggle to define the sound I'm after, if I at least get the most detailed circuitry to attempt to reproduce, I'll have something worthwhile on my hands and then I can go from there.

Tl;dr I'm sorry maybe not the most transparent then, but most detailed and then alive/energetic (MOSFETIC?), but not harsh. So, insane and relentless but sweet 😂

I want it to make me ask myself "what is this magic? I didn't know that was even possible from my transducers". So definitely not laid back or relaxed, but not cold or sterile either 😭

I want it to produce artifacts that would just hang there in the room unexplainably.
 
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Any of the 1st W clones will fit what you are asking for to some degree.

In the least, go dual PSes to help with channel separation.

The higher the damping factor, the more control over the bass. The lower, the more woolly, thumpy the bass.

Bigger than life, crank up the volume.

If anything, go M2x and try the different daughter boards to see what flavor fits your fancy.

https://www.firstwatt.com/products/
 
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Anything and everything. What's the deal with F4? Something magical about the highs? I need tiny amount of power. If it's a follower for my DAC/preamp, it just might be enough output voltage.

And if it's not enough for my tweeter, I would be able to use it somewhere probably eventually, I had something in mind that I needed more current for.

The F4 have no sound of their own. I have not been able to detect it. I got a CJ ET3SE and PV9, both with teflon caps. And an Iron Pre Balanced.

Driven SE with my CJ tube preamps ( 20Vrms ) they make the speakers sound beautiful... Your hear the tube preamps with no other coloration. With 20Vrms, the SE F4s are putting out their max... about 38 wpc.

With the BA3 FE in balanced mode to bridged F4s you get 100 wpc with true balls. In my case I run an Iron Pre Bal in balanced mode into it and I can "hear" the Iron Pre... which is an extremely transparent front end!

So with the F4 you choose how they sound by their front end combination.

That's why I want to use the Sissy SIT as FE for the F4. I want to hear the sound of a 38wpc SIT. The F4 as a current buffer sounds like the ticket.
 
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I've built 3 VFET's: P channel lottery amp, N channel VFET 3, ZM Singing Bush
3 MOSFET amps: M2x, ACA v1.8 monoblocks, F5t v3 Balanced Monoblocks with seperate power supply enclosures
3 SemiSouth amps: J2 (EUVL clone), ALEPH J (codyt recipe), F6 w/ matched quad of 063's
So let me be clear, you are saying that from all those amplifiers, tokin is the most transparent one?
 
I've built 3 VFET's: P channel lottery amp, N channel VFET 3, ZM Singing Bush
3 MOSFET amps: M2x, ACA v1.8 monoblocks, F5t v3 Balanced Monoblocks with seperate power supply enclosures
3 SemiSouth amps: J2 (EUVL clone), ALEPH J (codyt recipe), F6 w/ matched quad of 063's
Are you talking about this amp?
 

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I've built 3 VFET's: P channel lottery amp, N channel VFET 3, ZM Singing Bush
3 MOSFET amps: M2x, ACA v1.8 monoblocks, F5t v3 Balanced Monoblocks with seperate power supply enclosures
3 SemiSouth amps: J2 (EUVL clone), ALEPH J (codyt recipe), F6 w/ matched quad of 063's
Except F6, I am familiar with the sound of all above amplifiers. Some in many variants with various outputs.
Plus F4, F1J in few variants, F3, multiples of F5.
I still believe that my answer in post #2 is valid. The most transparent to me are F5 and F3. To my ears in my systems.
Offcouse most transparent is Wolverine, got two, but that's not Mr. Nelson's design, so I did not mention it.
 
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