I`ve build ACA, Symasym F5 & AlephJ
ACA sounds a Little bit like small Aleph J -SOLD i have a big AlephJ
SymAsym Sound a Little Bit like a F5 -SOLD i Have a big F5
F5 very detailed really amazing -> 95% of time on reserve in shelf
Aleph J mostly running in my main System.
so +1 on Aleph J --->a really fine piece of art
Here's my thoughts:
When I first started DIY amp building (not to be confused with speakers or interconnects), I was excited about the possibility of being able to build something that sounded like expensive commercial gear at a mere fraction of a fraction of the commercial price. Sure it would be ugly and crude but only I needed to judge it's beauty. The only thing that mattered was it sounded better than the mainstream class B stuff I could afford. Of course my first amp was a gainclone.
Then I wandered into the Pass Lab forum and the Solid State forum (Krell KSA clones were making all the fuss at the time) and my next project was Aleph30 using group buy boards.
The thrill and fun of that making music was completely addicting. Did it sound better than the gainclone? I don't know and didn't care. All I knew was I wanted to do it again.
At one point, because I had joined after all the Zen amps were already done, I wanted to (and still do want to) go back and build all the Zen amps from 1-8 (ok maybe not 8), especially after seeing Steenoe's Zen building block lego sets. It looked like it would be incredibly fun and I would learn along the way.
I stopped DIY for a while and just returned recently but I noticed that there is a distinctly different atmosphere now. All the focus is on the next FW release. Nobody cares to try older circuits which should still sound fantastic even by today's standards. Sure some parts are no longer available so some projects aren't possible but I was shocked that there was so little interest in the LU1014D offer. Maybe I'm being nostalgic here but didn't the F3 rule the kingdom for a long time?
The other thing I notice is far fewer attempt at point to point or protoboard builds by beginners. Don't let not having a group buy board available stop you from trying something that scares you because that's how we push our boundaries. Lastly, yes there are many beautiful and meticulous builds being shown but in the end, it's your amp and it's not a beauty contest. All that matter is that you enjoy it and don't stress about it.
The part count of F5 is probably among the lower ones but availability of jfets may be the bigger consideration. If you think you'll be experimenting and are careful about it, you can leave the legs untrimmed and repurpose jfets if you decide to move onto a new project. There are folks selling boards in the Swap Meet for designs which don't even require jfets. Sometimes flea market shopping is the most fun and fruitful. Good luck with whatever you decide and may the force be with you always!
The F3 is one of my 6 complete amplifiers I own. Nice SE example of class A along with Aleph. Still prefer BA-1 over them both with my horns though.
I am a hoarder by nature so yes, they all sit there and keep each other company and I'll listen to one for a few days or weeks and then switch to another one. If I find I don't enjoy one, I'd probably recycle it but I haven't had that problem just yet
.I enjoy the reading, collecting parts and the building very much too. I've burned up a few things too but I'm pretty sure most people are not as foolish as me
That's one of the more fun aspects of building and keeping them too - you can compare them.
ALPHA
Class A, SE design, uses the CCS of the Aleph.
Auto-adjustment bias.
Lots of power, even in 4R.
Gain and damping factor can be adjusted to personal preference.
Class A, SE design, uses the CCS of the Aleph.
Auto-adjustment bias.
Lots of power, even in 4R.
Gain and damping factor can be adjusted to personal preference.
The ACA is a "gateway drug" into this hobby. It beautifully demonstrates a number of things;
- Wow! This amp sounds wonderful!
- Yes, you can build these. It's fun, you'll learn something, and it's very enjoyable and satisfying.
- Power ain't nuttin' but a number, and the "first watt" genuinely is the most important.
- Topology is important, and simple sometimes does sound best
- Yes, there is something special about real Class-A
- You built it, you can play with it.
These amps are a playground to explore - want to try balanced? Easy. Swap capacitors? Sure! You built the thing, it's not like you will invalidate the warranty by opening it up...
Make a linear PSU? Go for it! All of those things are worth exploring. Then once you want to move forward after having fun with these incredibly good sounding ACA amps, take what you learn from those experiences and apply it to one of the bigger amps. They all sound great, the addition of more power is usually beneficial to most people's systems (I.E., the jump from 4W to 25W is huge.) And if you make some smart choices in construction, you can very easily have one chassis and PSU and swap multiple amps in and out and learn which you like best.
After building a gainclone I put together a DCB1 and then a simple Boozehound phono amp.
I had collected parts previously for an F5, but I felt the gain clone and DCB1 documentation made me more comfortable with assembling a power supply.
I also picked up an ACA kit someone didn’t use in the swap meet cheaply... I still feel almost obligated to start with it. However, I am going to build the power supply outlined in the F1 manual to try with the ACA and then reuse it with an F2J. I am using 8” full range drivers in Oris 200 horns.
I had collected parts previously for an F5, but I felt the gain clone and DCB1 documentation made me more comfortable with assembling a power supply.
I also picked up an ACA kit someone didn’t use in the swap meet cheaply... I still feel almost obligated to start with it. However, I am going to build the power supply outlined in the F1 manual to try with the ACA and then reuse it with an F2J. I am using 8” full range drivers in Oris 200 horns.
The ACA is a "gateway drug" into this hobby. It beautifully demonstrates a number of things;
- Wow! This amp sounds wonderful!
- Yes, you can build these. It's fun, you'll learn something, and it's very enjoyable and satisfying.
- Power ain't nuttin' but a number, and the "first watt" genuinely is the most important.
- Topology is important, and simple sometimes does sound best
- Yes, there is something special about real Class-A
- You built it, you can play with it.
These amps are a playground to explore - want to try balanced? Easy. Swap capacitors? Sure! You built the thing, it's not like you will invalidate the warranty by opening it up...
Then once you want to move forward after having fun with these incredibly good sounding ACA amps, take what you learn from those experiences and apply it to one of the bigger amps. They all sound great, the addition of more power is usually beneficial to most people's systems (I.E., the jump from 4W to 25W is huge.) And if you make some smart choices in construction, you can very easily have one chassis and PSU and swap multiple amps in and out and learn which you like best.
Yes, SE watts seems to sound louder. I just switched to SE tubes one year ago from class A/B bipolar amps. After this I was sure never to go back to SS again. But we will see.....have never experienced JFET and MOSFET class A amps so I give it a chance. The bigger amps needs a lot of heatsinks. Then I must say that tubes has a clever way to get rid of the heat.....MOSFETs could learn something here
I just built the ACA using just the boards, for the kits being out of stock so long. I built them as mono-blocks and hooked up to my Fusion-12 Tempest speakers and is definitely powerful enough. I could live with these amps from here on out if I want to be honest with myself.
I really thought this was going to be a stepping stone to fancier circuits/performance but, these things sound fantastic. I aim to use them for all that their worth.
I really thought this was going to be a stepping stone to fancier circuits/performance but, these things sound fantastic. I aim to use them for all that their worth.
Think my speakers' efficiency may be a challenge for a single ACA. Principal use will be on my desktop close monitors that are Totem Dreamcatchers, which are only 89db. My main two channel system has PSB Synchrony Ones, which I believe are also relatively inefficient. Certainly neither are as efficient as horns. Thinking that I need something in the range of 25W minimum and probably better 50W to handle my normal listening levels.
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Has anybody measured the RMS and peak voltage at the speaker output when playing at the preferred listeing level to see how much voltage actual is needed?
When I purchased my first SE tube amp it was demonstrated on Martin Logan speakers which are known to not be the easist speakers to drive. Even a 2A3 SE amp (2 x 3.5W in 8 ohm) could drive them to satisfying level.
Maybe it is not only a question of be able to deliver high voltage but also to deliver current at low voltage levels?
Also has somebody used the ACA and found that it did not play loud enough (assuming that the preamp can drive the ACA to clipping level)?
When I purchased my first SE tube amp it was demonstrated on Martin Logan speakers which are known to not be the easist speakers to drive. Even a 2A3 SE amp (2 x 3.5W in 8 ohm) could drive them to satisfying level.
Maybe it is not only a question of be able to deliver high voltage but also to deliver current at low voltage levels?
Also has somebody used the ACA and found that it did not play loud enough (assuming that the preamp can drive the ACA to clipping level)?
Really easy. Measure with AC meter, true rms meter best but not necessary to split hairs, at the loudest level you ever listen at and use this calculator. Measure peaks, bet you will be surprised. With 89db speakers you should be fine with FW power of 25 watts.
Ohms Law Calculator
Ohms Law Calculator
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