Hello friends,
I need a very specific criteria meeting design which would most importantly optimize for these parameters:
1. Extreme high frequency clarity, airiness, whatever you want to call it. I want most importantly the extremest version in terms of fidelity. When the high frequencies have intensity and bite, like electric guitars have intensity and bite or most any mental strings or cymbals, small bells etc. but I don't want that to come with the cost of harshness. So extremely intense with non-smothered transients, but smooth and perhaps even warm at the same time. Energetic! Or maybe forget all that, what I am looking for is the most "musical" and "magical" amplifier in terms of the high frequency character.
2. I don't care about power output, it can be anything from 2 to 30 Watts.
3. I don't care how efficient it is or how much power it consumes even 300W is fine if that'll improve the sound.
4. I don't care about bass performance more or less.
5. Preferably as simple a design as possible with as few stages as possible.
6. Only single ended class A with only N channel MOSFETs as the output stage unless that would limit the criteria above.
(7.) Balanced would be a plus, but completely tertiary in importance.
I've been reading for the past days about the different Nelson's designs. There's just an insane amount to learn and on top of that, I have no listening experience to any of them, hence I come to you to seek guidance.
If I understood it correctly, the Zen variants although the most simple, do not offer the same high frequency clarity as Aleph or F series.
Are active current source designs mostly made for reducing the negative effects that low frequency signals cause in terms of voltage swings at the output mosfet collector? Would it be wise to avoid active current source design (I intend to build very capable and clean PSU anyway) if I am not going to play any bass frequencies or alternatively use the amplifier for high impedance low current loads like planar magnetic headphones? The main purpose of the amplifier would be to drive either passive speakers at low volumes or the JBL JT025TI1-4 tweeter from ~1.6kHz-20kHz in an active system. Am I correct to assume that the lower input capacitance MOSFETs would be the best for my application. Many people have good words to say about the Exicons, but they are high power application designs. Any recommendation in terms of exact MOSFETs to use? How about voltage? I don't care about how much power it dissipates, but would higher current, lower load resistance work better for me or high voltage, higher load resistance?
Any insight in what designs and what series of Nelson's designs would be the most relevant to me, would be much appreciated. Any comments, just anything you could say if you have experience with any of it. And especially listening experience comparing the different models. But also, any design experience or understanding of how the different design choices would affect the outcomes I'm looking for. Or just general familiarity with Nelson's designs, and guidance in regards to them, would be amazing.
I need a very specific criteria meeting design which would most importantly optimize for these parameters:
1. Extreme high frequency clarity, airiness, whatever you want to call it. I want most importantly the extremest version in terms of fidelity. When the high frequencies have intensity and bite, like electric guitars have intensity and bite or most any mental strings or cymbals, small bells etc. but I don't want that to come with the cost of harshness. So extremely intense with non-smothered transients, but smooth and perhaps even warm at the same time. Energetic! Or maybe forget all that, what I am looking for is the most "musical" and "magical" amplifier in terms of the high frequency character.
2. I don't care about power output, it can be anything from 2 to 30 Watts.
3. I don't care how efficient it is or how much power it consumes even 300W is fine if that'll improve the sound.
4. I don't care about bass performance more or less.
5. Preferably as simple a design as possible with as few stages as possible.
6. Only single ended class A with only N channel MOSFETs as the output stage unless that would limit the criteria above.
(7.) Balanced would be a plus, but completely tertiary in importance.
I've been reading for the past days about the different Nelson's designs. There's just an insane amount to learn and on top of that, I have no listening experience to any of them, hence I come to you to seek guidance.
If I understood it correctly, the Zen variants although the most simple, do not offer the same high frequency clarity as Aleph or F series.
Are active current source designs mostly made for reducing the negative effects that low frequency signals cause in terms of voltage swings at the output mosfet collector? Would it be wise to avoid active current source design (I intend to build very capable and clean PSU anyway) if I am not going to play any bass frequencies or alternatively use the amplifier for high impedance low current loads like planar magnetic headphones? The main purpose of the amplifier would be to drive either passive speakers at low volumes or the JBL JT025TI1-4 tweeter from ~1.6kHz-20kHz in an active system. Am I correct to assume that the lower input capacitance MOSFETs would be the best for my application. Many people have good words to say about the Exicons, but they are high power application designs. Any recommendation in terms of exact MOSFETs to use? How about voltage? I don't care about how much power it dissipates, but would higher current, lower load resistance work better for me or high voltage, higher load resistance?
Any insight in what designs and what series of Nelson's designs would be the most relevant to me, would be much appreciated. Any comments, just anything you could say if you have experience with any of it. And especially listening experience comparing the different models. But also, any design experience or understanding of how the different design choices would affect the outcomes I'm looking for. Or just general familiarity with Nelson's designs, and guidance in regards to them, would be amazing.
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You seem to be familiar with many of Nelsons design. F5's high bandwidth and diy friendly fits the bill. Adjust P3 to your liking. F5m is the latest evolution that most folks build. You can purchase in diyaudio store. Easy to acquire parts/pcb you'll be up in no time. Give it a try and let us know, post your build here in this thread. Good luck.
I think I would prefer single ended and I don't really need much power. Isn't Aleph 3 or J more detailed, transparent and better in transients than F5? I've read people highly regarding F6 and F8 too, but it's so hard to choose having not heard them or really understanding how different design choices affect the sound. But as far as I understand, F5 is not the King in detail even if it's perhaps the most versatile and enjoyable in most cases. And I would like to avoid the extra complexity of using both N and P channel output MOSFETs. I don't know. The recommendations are nice and they help me to understand the general consensus, but what would help even more is some reasoning behind the suggested choices. Or perhaps why and where each amp trying the most.
The F5 is probably the highest fidelity in regards to highs. Now that doesn't mean sparkle... As mentioned above, super high bandwidth, relatively high damping factor for such a simple design. It has a good amount of feedback and can be considered to be a bit dry sounding... The F5m probably has a bit more sparkle as the output stage has been altered in such a way that gives it that. Lower feedback, lower damping factor, simple design... These are not SE designs though.
If you want a SE design, easy pickings would be an Aleph J. Otherwise you could start to look into the SIT related stuff but that is a rabbit hole.
The Non-J Alephs tend to not have as much refinement in the high frequencies compared to the Aleph J. However, they do their own thing and the highs are not bad per-se.
Having listened to plenty of the Pass Labs amps, the F5 does bring a lot of detail to the table. I would shoot for the F5m.
I have been playing with sort of my own X version of the F5m which is probably much more complicated than you are interested in. It has some resistors on the output stage which act as a constant current source and give it a bit of SE class A. Now this amp has some really great highs. 🙂 I need to take some measurements of it but it is sounding really nice.
If you want a SE design, easy pickings would be an Aleph J. Otherwise you could start to look into the SIT related stuff but that is a rabbit hole.
The Non-J Alephs tend to not have as much refinement in the high frequencies compared to the Aleph J. However, they do their own thing and the highs are not bad per-se.
Having listened to plenty of the Pass Labs amps, the F5 does bring a lot of detail to the table. I would shoot for the F5m.
I have been playing with sort of my own X version of the F5m which is probably much more complicated than you are interested in. It has some resistors on the output stage which act as a constant current source and give it a bit of SE class A. Now this amp has some really great highs. 🙂 I need to take some measurements of it but it is sounding really nice.
Thank you, especially for bringing up non-J Alephs. I was also considering Aleph 3 or 30 so your a comparison especially helps. So I guess I'm pretty much down to F5m and Aleph J which were always the ones I read most about and had the highest interest in (well, I thought about F5 turbo initially, but I don't think I need that), but when I started reading Nelson's articles and forums, I kind of lost confidence a little bit in terms of what would actually sound best. Lost the big picture so to speak. If I have the chassis and the heat sinks and the power supply, perhaps it wouldn't add too much additional costs to install both amps into one chassis and to operate one at a time. This way I would know for sure which one I prefer and how each of them sounds.
Now if you had to choose one amp for not necessarily fidelity, but highest factor of magic, sparkle?
If I build the F5m, I'd be curious to hear more about your experimentation on version X. I'd keep it simple first.
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It is hard to say. The F5m was the most recent that I have heard. it has been a while with the Aleph J. With the F5m, I was especially enamored by it's sense of air and how female voices like Birdy sound exceptional. Bells ring nicely etc. I would be. The Aleph may lend itself to being more colored and tube like.
If I had to choose one for myself, I like the F5m a bit better. It is inexpensive, very simple, and if you feel like playing with the feedback, that will alter the sound quite a bit. Like increasing the feedback resistance by say 10%-15% can make the sound have less air but a more control, maybe a bit more compressed. Lower by 10% and the sound gets a bit more warm but rich, more harmonics are accented but less control of the bass and less detail. An interesting thing to play with in small dosese. Not to mention the F5m is a push pull which means it will have more bass control and better efficiency than the Aleph.
Both are great. The Aleph is single ended so it has that sort of sound.
If I had to choose one for myself, I like the F5m a bit better. It is inexpensive, very simple, and if you feel like playing with the feedback, that will alter the sound quite a bit. Like increasing the feedback resistance by say 10%-15% can make the sound have less air but a more control, maybe a bit more compressed. Lower by 10% and the sound gets a bit more warm but rich, more harmonics are accented but less control of the bass and less detail. An interesting thing to play with in small dosese. Not to mention the F5m is a push pull which means it will have more bass control and better efficiency than the Aleph.
Both are great. The Aleph is single ended so it has that sort of sound.
What about the M2 that's highly regarded by Zen Mod? Anyone have experience with it relative to AlephJ or others? What are it's strong quality(ies)?
make M2 with Cinemag, and you're in Heaven
make Babelfish M25 with Cinemag, and you got location of Workshop in Heaven
though, F5m, with slightly lower rails and Iq, and with IRF510/9510 is probably way to go, low-ish power for tweets
simplest, quickest, least mumbojumbo with hardware
make Babelfish M25 with Cinemag, and you got location of Workshop in Heaven
though, F5m, with slightly lower rails and Iq, and with IRF510/9510 is probably way to go, low-ish power for tweets
simplest, quickest, least mumbojumbo with hardware
OP, in title mentioned HF, synergy between HF/Midrange and bass is essence.
OP- What are the network or crossovers like?
It was stressed to me that HF and midrange should have some topology.
F5 is considered as most transparent amongst First watt line up, F5M should cater to that aspect of OP.
F3 is famous amongst horn based HFs.
Rest, ZM has mentioned his picks.
Do read about ZM's F8 babelfish WIP. I am waiting for it.
OP- What are the network or crossovers like?
It was stressed to me that HF and midrange should have some topology.
F5 is considered as most transparent amongst First watt line up, F5M should cater to that aspect of OP.
F3 is famous amongst horn based HFs.
Rest, ZM has mentioned his picks.
Do read about ZM's F8 babelfish WIP. I am waiting for it.
High order digital crossover that I will design myself, a few iterations at various Xover points probably until I arrive at the best solution. Topping DM7 8ch DAC.
If it's ok, I won't go into detail about things below 1.5-2kHz yet. Crossover will be in between that range. Except I can mention that ultimately I would like to drive my bass below 100-200Hz with something like purify class D or cheaper and more powerful class D, perhaps open baffle, perhaps huge horns, but that's quite a bit later down the line, for now it's just gonna be a two-way design. I'd be happy to share more about my system, let me first achieve some good results and have something to share. The speakers aren't quite finished yet, they're something I am reworking and I haven't even began playing with digital crossovers. I'll probably use REW as it is freeware.
Thank you very much everyone for your input.
If it's ok, I won't go into detail about things below 1.5-2kHz yet. Crossover will be in between that range. Except I can mention that ultimately I would like to drive my bass below 100-200Hz with something like purify class D or cheaper and more powerful class D, perhaps open baffle, perhaps huge horns, but that's quite a bit later down the line, for now it's just gonna be a two-way design. I'd be happy to share more about my system, let me first achieve some good results and have something to share. The speakers aren't quite finished yet, they're something I am reworking and I haven't even began playing with digital crossovers. I'll probably use REW as it is freeware.
Thank you very much everyone for your input.
The best one is the next one.... When you don't know what to build, and you're curious / interested about all the different variations, you build everything. It's a hobby and it's fun to build stuff, learn, gain experience, and just enjoy the journey. Rather than obsessing on "the best". Once you have a nice big chassis / heatsinks and a First Watt style power supply (most $$ part of this), you can just swap amplifier boards in and out to your hearts content. Most are built around the "UMS" standard on the mounting holes to make that easy, eliminating the not-so-fun drilling and tapping routine.
Indeed, and watch out for Sophie's Choice. Who gets sacrificed for the next one is a tough decision. 
@Hotep. What output transistors do you actually have? Before you pick amp you will build, ask yourself what is actually possible.
Do you have original SemiSouth R100s? Not fake? If not, that eliminates half of amps.
Do you have LU1014 power jfets? If not, that eliminates some amps too.
Before you ask gazillion questions about distortion, highs shimmering or other sound qualities, look into your parts stash and find out what transistors you have or can obtain which are not fake.
This should narrow down the selection.
M2, may have some buzz on highly sensitive speakers. Step up transformer introduces lots of pleasing distortion. You asked about low distortion, which eliminates M2. Besides you can only build M2 clone, not original.
Do you have original SemiSouth R100s? Not fake? If not, that eliminates half of amps.
Do you have LU1014 power jfets? If not, that eliminates some amps too.
Before you ask gazillion questions about distortion, highs shimmering or other sound qualities, look into your parts stash and find out what transistors you have or can obtain which are not fake.
This should narrow down the selection.
M2, may have some buzz on highly sensitive speakers. Step up transformer introduces lots of pleasing distortion. You asked about low distortion, which eliminates M2. Besides you can only build M2 clone, not original.
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These five from Vishay for example I can get. Perhaps they are similar to IRF510 recommended by Zen Mod. The others I haven't researched yet, but surely where there's a will there's a way. And anyhow, just because a specific transistor is unavailable, does it really mean that no substitute is worthwhile, no substitute is worthy of the amp? I have more or less no JFETs or MOSFETs at the moment except buz90 I bought in a hurry just in case I would need to test some circuit and would find myself without any mosfets. Also, I'm not sure if they are useful, but I can get these JFETs in the picture.
Somehow, I'm pretty confident I will find something. Europe is not Africa and even if so, nowadays global shipping exists.
As for what I actually need, I'm leaning pretty strongly towards F5N right now and will soon probably start looking for parts. If I still find myself obsessed about something after building it and enjoying, I would continue on to try and build something like M2 or Aleph J, something single ended. Perhaps another Aleph, but the J is getting most praise usually and ITT too.
Somehow, I'm pretty confident I will find something. Europe is not Africa and even if so, nowadays global shipping exists.
As for what I actually need, I'm leaning pretty strongly towards F5N right now and will soon probably start looking for parts. If I still find myself obsessed about something after building it and enjoying, I would continue on to try and build something like M2 or Aleph J, something single ended. Perhaps another Aleph, but the J is getting most praise usually and ITT too.
Attachments
take F5m from Store, with all parts
replacing big output mosfets with smaller ones is optional, if you go to smaller power
replacing big output mosfets with smaller ones is optional, if you go to smaller power