Hi there!
I am fairly new to the DIY scene and have so far only built an ACA, but with great success. I really enjoy the sound of this little amplifier as it draws me into the music like no other solid state amp I heard before. Only thing I miss about it is more authority and punch in the bass region like for example I have with from my NAD C316 bee V2. So after reading a lot about the First Watt F5/6, M2, Aleph builds I am wondering which of these more mature sounding amps with more power is comparable to the sweet sound of my ACA whilst having more punch in the low end? Can anyone help in this regard? Or do I need to choose the honey badger and leave the world of Class A amplification? Thanks in advance!
I am fairly new to the DIY scene and have so far only built an ACA, but with great success. I really enjoy the sound of this little amplifier as it draws me into the music like no other solid state amp I heard before. Only thing I miss about it is more authority and punch in the bass region like for example I have with from my NAD C316 bee V2. So after reading a lot about the First Watt F5/6, M2, Aleph builds I am wondering which of these more mature sounding amps with more power is comparable to the sweet sound of my ACA whilst having more punch in the low end? Can anyone help in this regard? Or do I need to choose the honey badger and leave the world of Class A amplification? Thanks in advance!
Hmmm.. It may help if you talk a little more about the rest of your system. Thing is that those larger amps you mentioned have somewhat different character and capabilities. The only one I haven‘t built is the F5. So I can say the M2x, F6, Aleph J and VFET lottery amp are all special in different ways. Plus the M2x and VFET have multiple Front End options.
Yes, it can get out of hand.
My reference amp is the Aleph J. The VFET has a special sound for small ensemble acoustic / electric instruments. You may end up with different preferences.
Yes, it can get out of hand.
My reference amp is the Aleph J. The VFET has a special sound for small ensemble acoustic / electric instruments. You may end up with different preferences.
My room is about 20 sqm, I mostly listen to music via a Raspberry Pi, streaming music to my IFI iDSD micro DAC into Amp Camp Preamp into power amp. Power amp at the moment is ACA (self built) or Aleph 3 (borrowed and not the best quality build, using a SMPS). Speakers are Proac Studio 100 clones rated at 88dB. At the moment I prefer the ACA because it sounds more detailed, sweet and airy. Might be because of the bad power supply of the Aleph 3, which sounds 2 dimensional and boring to me. Plus it does not produce a lot of bass especially tight bass. That is also what I read in many different forums about the Aleph 3. I do not only listen to Jazz music, vocals and instruments but also Electronica, Hip-hop and Rap music. So the punch or slam needs to be there too! Otherwise it's no fun.
Much of what you are looking for in a new amplifier is going to be determined by its power supply. That may seem counter intuitive. While the various FW clones (F5, F6, M2, Aleph J) all have their own character, they depend on a well built, low impedance power supply to deliver punch, impact, bass extension and definition.
That means you will need to assemble the AC mains inlet, line fuse, primary side thermistors, toroidal power transformer, diode rectifiers and capacitor filters. Twice. One complete PSU for each channel , joined only by the power inlet. If you feel comfortable with that challenge, then I can confidently recommend the F6 or Aleph J. The F6 is best with a couple modifications. The Aleph J can be built straight as is, taking care in selecting the best components.
** The F5 needs a more extensive “turbo” build for your needs. The store version of the M2x is a tinkering dream, but kind of a rabbit hole and too distracting as a first 25W Class A amplifier. I feel the extra effort of building the dual-mono PSU described above is enough for this project.
That means you will need to assemble the AC mains inlet, line fuse, primary side thermistors, toroidal power transformer, diode rectifiers and capacitor filters. Twice. One complete PSU for each channel , joined only by the power inlet. If you feel comfortable with that challenge, then I can confidently recommend the F6 or Aleph J. The F6 is best with a couple modifications. The Aleph J can be built straight as is, taking care in selecting the best components.
** The F5 needs a more extensive “turbo” build for your needs. The store version of the M2x is a tinkering dream, but kind of a rabbit hole and too distracting as a first 25W Class A amplifier. I feel the extra effort of building the dual-mono PSU described above is enough for this project.
In my opinion using a non-smps supply helps a lot with regards to 'grip'. Using IRFP150 instead of IRFP240 is also a step in that direction, and finally playing with R12 has a surprisingly big influence on the 'fatness' of the sound. 90K was the right value for my ears (speakers).
The ACA really is a gem, and fairly easy to change to suit your needs.
The ACA really is a gem, and fairly easy to change to suit your needs.
That is very interesting, thank you! I know that the power supply is important but didn't know how much the impact could be. So I will surely go for a dual mono power supply. I am thinking about purchasing this Aleph 3 you can see below for 400 Euros and give it a better power supply. Or should I start from scratch and build an Aleph J (unfortunately no PCBs are available at the moment)? 400 is a good price but only if I keep the populated PCBs. Otherwise I pay 400 only for the case which is too much.
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Oh okay! So you would suggest building a non-smps power supply for the ACA instead to give it more authority and punch?
Yes. It's a starter amp but a really good one at least to my ears and to many others too. Not sure if it makes sense though to spend the money on a power supply for ACA instead of one for Aleph. Trying to keep costs low!
You need to stay far away from that amp with the Chinese “Pass Aleph” boards. They are not well made.
The ACA can certainly be made to sound better with a good linear PSU (and a few other mods). It will not be the equal of any of the 25W Class A amps.
Either the F6 or AJ will run well from a pair of 200VA to 300VA transformers with 20V secondaries. If you wish to start sooner, and not wait for the Aleph J boards, the the F6 will be a good way to go. I recommend ordering a set of eight FQH44N10 Mosfets, to have some spares available. At that quantity they will tend to be from the same lot, and matched well enough. Read the F6 Amplifier thread for the trick on using small green LEDs for the voltage references.
The ACA can certainly be made to sound better with a good linear PSU (and a few other mods). It will not be the equal of any of the 25W Class A amps.
Either the F6 or AJ will run well from a pair of 200VA to 300VA transformers with 20V secondaries. If you wish to start sooner, and not wait for the Aleph J boards, the the F6 will be a good way to go. I recommend ordering a set of eight FQH44N10 Mosfets, to have some spares available. At that quantity they will tend to be from the same lot, and matched well enough. Read the F6 Amplifier thread for the trick on using small green LEDs for the voltage references.
I also wouldn't get that A3; you'll only be able to keep the case. 🙂
There's a new Aleph J board designed by Zen Mod that has some nice modifications. If you're interested in the Aleph J, you might contact 6L6 to see if he can hook you up with a pair.
There's a new Aleph J board designed by Zen Mod that has some nice modifications. If you're interested in the Aleph J, you might contact 6L6 to see if he can hook you up with a pair.
I built three aca amps, so i am not biased against.
First pair was original monoblocks, i used as headphone amp.
Second, stereo chasis, used for desktop speakers.
Third aca, in foam board, with vu meters, currently rests on the shelve.
None had punch, hence my advice.
Sweet, sure, but no punch.
I doubt putting linear power supply on it will improve that.
Well, you can built proper fw power supply, +/_ 23 volts, and use half of it and see. You can then build Aleph J or any other fw amp later and use it. Even f3, without ground.
First pair was original monoblocks, i used as headphone amp.
Second, stereo chasis, used for desktop speakers.
Third aca, in foam board, with vu meters, currently rests on the shelve.
None had punch, hence my advice.
Sweet, sure, but no punch.
I doubt putting linear power supply on it will improve that.
Well, you can built proper fw power supply, +/_ 23 volts, and use half of it and see. You can then build Aleph J or any other fw amp later and use it. Even f3, without ground.
Well,what about building another Amp Camp Amp and running them Parallel Mono or Bridged?
I am running a ACA pair in paralell mono, and boy do they play wonderful, powerful juicy and tightly controlled bass that truely sings.
Superior to my Rotel 2x200W A/B amplifier, or EL34 class A tube amp.
I havent listened to any other Pass DIY, yet.
Now Building 2 Aleph J:s 😇
If your speakers are playing a smidge to fat, weak and sloppy to begin with, you might consider building/bying much bigger and better speakers.
Or buy/build a very dry amplifier - Well dont do that. 🙂
A lot of good suggestions here. I have only built the F6 but I have owned/heard a lot of amplifiers. It is definitely a very, very good amp.
In it's stock form, it is still a terrific amp. You will have to source parts for the power supply board. The universal power supply board is out of stock at the moment. If you eventually order it (most commonly used and very good quality) get a couple.
If you are still fresh to amp building, I would stick with one transformer, one power supply board and the stock kit. All of the mods mentioned are relatively cheap and easy to go back to. This will also keep the cost down as you mentioned you were on a budget.
If you want to do the dual mono setup as well as use the universal power supply and populate the diode section, get the a larger case than the standard 4u mentioned in the store. It can probably all fit in the 4U with some creative ingenuity but it would be a lot simpler with the larger case.
Pay attention to what Zeners you use on the bias circuit for Z1 and Z2. Use the 6.0v ones in those positions on both boards. The 5.1's have caused biasing issues. I did Pico Dumbs LED bias mod which is again, cheap and easy to double back to. You would need 12 of these for pico's mod.
https://www.mouser.com/ProductDetail/859-LTL-4231N
You will have to order parts to populate the power supply board. You can go with the little bridge rectifier blocks, something like the GBPC3504 or you can build out the rectifier section of the power supply board. Parts availability may have it's influence.
In it's stock form, it is still a terrific amp. You will have to source parts for the power supply board. The universal power supply board is out of stock at the moment. If you eventually order it (most commonly used and very good quality) get a couple.
If you are still fresh to amp building, I would stick with one transformer, one power supply board and the stock kit. All of the mods mentioned are relatively cheap and easy to go back to. This will also keep the cost down as you mentioned you were on a budget.
If you want to do the dual mono setup as well as use the universal power supply and populate the diode section, get the a larger case than the standard 4u mentioned in the store. It can probably all fit in the 4U with some creative ingenuity but it would be a lot simpler with the larger case.
Pay attention to what Zeners you use on the bias circuit for Z1 and Z2. Use the 6.0v ones in those positions on both boards. The 5.1's have caused biasing issues. I did Pico Dumbs LED bias mod which is again, cheap and easy to double back to. You would need 12 of these for pico's mod.
https://www.mouser.com/ProductDetail/859-LTL-4231N
You will have to order parts to populate the power supply board. You can go with the little bridge rectifier blocks, something like the GBPC3504 or you can build out the rectifier section of the power supply board. Parts availability may have it's influence.
TungstenAudio, how much of a sound difference did you notice by stepping up to the 20v transformers vs the stock 28v?
Thank you very much for your advice, will do and not buy it. That is exactly what I was thinking. So for now I will just give the Aleph back.
Thanks for your advice!
Had ACA monos and sold one of them. Maybe a mistake, but to me the sound signature changed quite significantly towards more punch - of yourse - but for a price I was not ready to pay: It lost the sweetness and warm character I so enjoyed with only one ACA. Maybe that is just the price to pay?! I am getting the feeling though that the Aleph J (built with properly selected components, maybe even linear dual mono power supply) as a single ended transistor amp (as the ACA is, too, right?) is gonna be the right choice for me. Having more punch and authority, excellent dynamics whilst not being too "bright" or "present" in the high frequencies. Can someone confirm that?