Hi guys,
I've been looking at ACA, but the PCB as well as full kit is out of stock from diyaudiostore and not sure when it will be available.
Anyways, I'm looking for proper A-class amp ~12-20W for small speakers that wouldn't take tons of space. I read a lot of great stuff about Pass amps and would be very interested to build one.
Any suggestions would be very helpful.
Thanks !
Simonas
I've been looking at ACA, but the PCB as well as full kit is out of stock from diyaudiostore and not sure when it will be available.
Anyways, I'm looking for proper A-class amp ~12-20W for small speakers that wouldn't take tons of space. I read a lot of great stuff about Pass amps and would be very interested to build one.
Any suggestions would be very helpful.
Thanks !
Simonas
What is your budget and how much is 'tons' of space to you? All the Firstwatt clones go in full size cases that have to have open space to the sides for cooling so they aren't compact.
Have a look at The diyAudio build guides as they will show what is involved with the larger builds. The ACA is really straight forward for the build, most of the other amps take a bit more reading and ordering separate parts.
The store currently has F5 parts kit, JFETs and boards (just ordered them) you'll still need to get the case and build the power supply too. They have the M2X boards now, you just have to order the parts from somewhere like digikey or mouser.
I built the M2 with very little experience. I also fried a couple things in the process but now it sounds amazing. I have trouble getting work done on the computer because I just close my eyes and listen to the music and the M2 is connected to just a $100 DAC and 30 year old Paradigm speakers.
Have a look at The diyAudio build guides as they will show what is involved with the larger builds. The ACA is really straight forward for the build, most of the other amps take a bit more reading and ordering separate parts.
The store currently has F5 parts kit, JFETs and boards (just ordered them) you'll still need to get the case and build the power supply too. They have the M2X boards now, you just have to order the parts from somewhere like digikey or mouser.
I built the M2 with very little experience. I also fried a couple things in the process but now it sounds amazing. I have trouble getting work done on the computer because I just close my eyes and listen to the music and the M2 is connected to just a $100 DAC and 30 year old Paradigm speakers.
Last edited:
Simonas,
I haven't built the ACA yet, but from feedback on the forum, it seems like a wonderful project for a beginner. No wonder the kit keeps on getting sold out from the diyAudio store.
For a 20-25 watt Class A amplifier, my understanding is that the chassis will not be very compact. These amplifiers need big heat sinks for the output devices they use, and most of the builds I see are 4U height and 300 mm depth. Besides the ACA, the Pass M2 and F6 are also pretty simple builds and the parts count is relatively low. Moreover diyAudio member 6L6 has created very well illustrated build guides. The more knowledgeable members might be able to provide guidance on how you could maybe build lower power versions of the available designs that Mr. Pass has so graciously shared with the DIY community.
I haven't built the ACA yet, but from feedback on the forum, it seems like a wonderful project for a beginner. No wonder the kit keeps on getting sold out from the diyAudio store.
For a 20-25 watt Class A amplifier, my understanding is that the chassis will not be very compact. These amplifiers need big heat sinks for the output devices they use, and most of the builds I see are 4U height and 300 mm depth. Besides the ACA, the Pass M2 and F6 are also pretty simple builds and the parts count is relatively low. Moreover diyAudio member 6L6 has created very well illustrated build guides. The more knowledgeable members might be able to provide guidance on how you could maybe build lower power versions of the available designs that Mr. Pass has so graciously shared with the DIY community.
Last edited:
The ACA is out of your Watt range.
So i would suggest the common suspects. F5 and any Aleph both with lower bias so lower power. M2 +lower bias will maybe fit too.
F5 is so easy you could do it P2P or on a breadboard.
(If you Need ideas i have done my on breadboard and can give you my notes)
Or mini Aleph with Chipamp PCPs if you could get them somewhere.
And if build with irf parts at inputstage no hard to get JEFTs
This would be an idea i would try an inverted aleph J with 2sk2145 as Frontend and lower bias to meet your Wattage.
PCBs will be a Problem, you will have to do them by your own.
I own a Aleph J and F5 both are very good.
greets alex
If he Need less than 12-20 an ACA will be fine.
Will depend on Speakers. High Efficiency is mandory. Or ears like an lynx
I had an ACA too. but for me not enough power. Mostly noticed in not so good bass. But was an very nice amp, but sold.
Could also build with SMD parts 2sk209 but have to make your own PCBs.
Need an Layout to etch it by your self? maybe i could help too.
Or P2P for such an low parts design.
This is a link to the breadboard f5 Pictures of your diy Pass amplifier
Heh, you're right, thought it's 12W
Anyways, I guess for the first build I'd be fine with 8W as well. I'd prefer though not building the PCB myself, would get it from diyaudiostore. I'll buy the chassis with heatsinks and the parts separately.As I understand Firstwatt F4, F5, F6 and M2X are all an options for the build. What would be the best build for the beginner?
BTW, the amp will most likely be used in combination with full-range speakers.
I think a beginner could build anyone of the amps you listed and to me would come down to how patient you are. If you’re looking at lowest parts count I think the F5 has least parts to solder or at least one of the least. I’d go with the F5, M2-X or Aleph J with the Aleph J being a little bit more tedious of the 3.
Yes you are right. You could build any of these amps. My first Amp was the Aleph J. Take care, triplecheck everything and buy no Fake parts and you could build one too.
But if you have never worked at mains voltage. Ask someone who knows how to work safe with it, to instruct / train you.
And how to build safe Equipment.
Its easy to kill yourself or others by mistake.
good night
I have build the F4, F6, and M2. They all share the same power supply design. I used the store 4u deluxe case. Personally they are so similar it really is up to the builder for the sound signature he/she is looking for. My favorite is the F4, possible downside is a preamp with a 40v P-P output needed. Second is the M2 followed by the F6.
I always suggest M2. Easy build, self bias so you don't have to be twiddling on fire up, just set off set, measure a few points to ascertain all is well and put in sound system.
Also, if using Mark's boards for M2, it is easier to acquire parts without tracking down the increasingly difficult to locate Toshiba devices....
F5 gave me more fits as a first time build than all the others put together. Once you figure out the back and forth of the pot adjustments it isn't too bad. If that is your direction, I would suggest BA3 power amp with the complementary outputs.
1. M2, or Aleph J
2. Whichever you didn't build in 1. Above.
3. BA3
This is personal preference, but having listened to all the amps in my signature with 85 dB 2 way monitors, 90 dB MTM types, Econowaves of 95 or so dB, Tekton Enzo with mid to high 90's dB and Altec A7 with over 100 dB, I favor the M2, Aleph J and BA3 over F5 or F6. Just my preferences. I like the warmer, richer 3D tilt rather than the possibly more accurate but to me less platable sounds of F5 and F6. Dont misunderstand, I would not feel bad if F5 or F6 was all I had by any means as they are excellent amps. These are just my own tastes in First Watt clones.
Russellc
Also, if using Mark's boards for M2, it is easier to acquire parts without tracking down the increasingly difficult to locate Toshiba devices....
F5 gave me more fits as a first time build than all the others put together. Once you figure out the back and forth of the pot adjustments it isn't too bad. If that is your direction, I would suggest BA3 power amp with the complementary outputs.
1. M2, or Aleph J
2. Whichever you didn't build in 1. Above.
3. BA3
This is personal preference, but having listened to all the amps in my signature with 85 dB 2 way monitors, 90 dB MTM types, Econowaves of 95 or so dB, Tekton Enzo with mid to high 90's dB and Altec A7 with over 100 dB, I favor the M2, Aleph J and BA3 over F5 or F6. Just my preferences. I like the warmer, richer 3D tilt rather than the possibly more accurate but to me less platable sounds of F5 and F6. Dont misunderstand, I would not feel bad if F5 or F6 was all I had by any means as they are excellent amps. These are just my own tastes in First Watt clones.
Russellc
Last edited:
I love the M2. I still occasionally jump when a song I'm not really familiar with has a long section before the vocals start. There is a brief moment of 'who's there?'
Thanks for the advice ! I am planning on getting quality components for the build so should not be an issue.
Well, there are bunch of ways to injure or kill yourself in DIY activities
Just have to be extra careful with 220V.Is the M2 you guys refer to is the M2X? Are these two different amps or the X is just an updated version? Looking at M2X there are several input stage options - any preference?
I've read a lot through the forum and I am leaning towards the Aleph J build.
What would be your suggestions for the transformer and PSU? Also, would dissipante 4U work with Aleph? Deluxe is bit out of range with the price :/
Simonas
Thanks for the advice ! I am planning on getting quality components for the build so should not be an issue.
Well, there are bunch of ways to injure or kill yourself in DIY activities
Is the M2 you guys refer to is the M2X? Are these two different amps or the X is just an updated version? Looking at M2X there are several input stage options - any preference?
I've read a lot through the forum and I am leaning towards the Aleph J build.
What would be your suggestions for the transformer and PSU? Also, would dissipante 4U work with Aleph? Deluxe is bit out of range with the price :/
Simonas
My first build was an Aleph J. I used a steel Deluxe 4U and power supply board from the store. Most use a 18-18, 300va transformer from Antek but there’s other brands to choose from. Read 6L6s build guide from front to back, multiple times if needed. You’ll probably need to build a lightbulb tester as well. Take your time and you can build one
Simonas, to keep my costs down I used the base Dissipante 4U chassis with 300 depth when I built my Aleph J. It has a thinner aluminum front panel but is still very nice (to me) and I’m happy with the look. It also has a steel back plate as opposed to aluminum which some people find harder to work with. The only thing I would have done differently is to mount the transformer vertically to make more room inside the chassis.
Dissipante 4U – diyAudio Store
I’d also suggest purchasing a baseplate to mount your power supply boards, rectifier blocks (if you decide to go that route), and transformer. It has mounting holes that make mounting things easier (no drilling required).
Chassis Baseplate (Galaxy, Dissipante, Slimline, Pesante) – diyAudio Store
Happy building!
Dissipante 4U – diyAudio Store
I’d also suggest purchasing a baseplate to mount your power supply boards, rectifier blocks (if you decide to go that route), and transformer. It has mounting holes that make mounting things easier (no drilling required).
Chassis Baseplate (Galaxy, Dissipante, Slimline, Pesante) – diyAudio Store
Happy building!
M2 is the original FirstWatt Amplifier, of Nelson Pass Fame. Here, we build clones that have received his blessing. There are a few versions of these approved boards, Grimberg made some and offered them, Teabag did as well.
Most recently, Mark has offered his boards, the M2X...the interesting point of his boards is that the input buffer section is on a separate daughter card, and he has several different versions, all but one (the original circuit) do not use the increasingly hard to source Toshiba Jfets. You can build all the cards and plug and play with them. Several are commenting on them quite positively, which is excellent news for builders here. I suspect he knew all along he was on to something....
Russellc
I just finished an Aleph J amplifier - and honestly, it is a step up over the pair of bridged ACA amps that I'm running. ie, the Aleph works better with my 6-ohm, 86dB Wharfedale speakers.
The ACA amps, however, are no slouch.
Problem with building the Aleph is tracking down 2SJ4s - be prepared to pay for these ever increasingly rare JFETs.
The ACA amps, however, are no slouch.
Problem with building the Aleph is tracking down 2SJ4s - be prepared to pay for these ever increasingly rare JFETs.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.