I went for a walk on the web and a pair of DIY Aleph 2 monoblocks followed me home. It was like I fell into a mid ‘90’s time machine.
They were originally built by a builder we all seem to know, using the Brian GT boards. Of course, one mono worked and the other did not. I tried the one that worked and it played music without much enthusiasm or substance.
I got a new pair of the Brian GT boards from a generous diyaudio member but they seemed a bit kludgy and I felt there might be better options. I also found PCBs on various sites but they all seemed a bit suspect.
With a bit of luck and a touch of persuading, I convinced rhthatcher (longtime leader of having a certain type of amp follow him home for repairs and updates) to create 2 sets of Aleph 2 Front end boards and daughter boards. Randy also provided me with the matched mosfets, matched 313s and answered many of my texts and emails as I figured things out and worked through the usual start up issues. A true Diyaudio member and gentleman.
I disassembled the non-working amp down to the chassis. I think I only kept the donut, switch and jacks, (for the moment). I got proficient at drilling and tapping 3mm threaded holes for the 24 mosfets that the two chassis use. I made a rookie builder mistake when I could not get my dimbulb tester to dim when I fired up the first amp. It turned out that my 150 watt bulb was not going to dim when your amp sucks down 300 watts. Once #1 was finished, #2 went much quicker except for that cold solder joint on the power supply.
My goal was to build a pair of amps for my vintage ADS 910 speakers. 6 ohm and not Maggies but not the easiest, either. I figured the Aleph 2 would pair nicely with the 910s. Plus, it would be nice to give a bit of love to the Aleph line and get these orphans working and set up properly.
How do they sound? First weekend impressions- they are authoritative. Neutral in color, not sweet or dry with my B1R2. Bass and pace are strong. They wake up the speakers in a way I haven’t heard them before. I’m guessing this is what the speakers must have sounded like to the ADS crew during the Design process.
Many thanks to Papa for his skill, support and generosity! And of course thanks to Randy for his skill, knowledge and patience supporting my windmill tilting Aleph 2 quest!
They were originally built by a builder we all seem to know, using the Brian GT boards. Of course, one mono worked and the other did not. I tried the one that worked and it played music without much enthusiasm or substance.
I got a new pair of the Brian GT boards from a generous diyaudio member but they seemed a bit kludgy and I felt there might be better options. I also found PCBs on various sites but they all seemed a bit suspect.
With a bit of luck and a touch of persuading, I convinced rhthatcher (longtime leader of having a certain type of amp follow him home for repairs and updates) to create 2 sets of Aleph 2 Front end boards and daughter boards. Randy also provided me with the matched mosfets, matched 313s and answered many of my texts and emails as I figured things out and worked through the usual start up issues. A true Diyaudio member and gentleman.
I disassembled the non-working amp down to the chassis. I think I only kept the donut, switch and jacks, (for the moment). I got proficient at drilling and tapping 3mm threaded holes for the 24 mosfets that the two chassis use. I made a rookie builder mistake when I could not get my dimbulb tester to dim when I fired up the first amp. It turned out that my 150 watt bulb was not going to dim when your amp sucks down 300 watts. Once #1 was finished, #2 went much quicker except for that cold solder joint on the power supply.
My goal was to build a pair of amps for my vintage ADS 910 speakers. 6 ohm and not Maggies but not the easiest, either. I figured the Aleph 2 would pair nicely with the 910s. Plus, it would be nice to give a bit of love to the Aleph line and get these orphans working and set up properly.
How do they sound? First weekend impressions- they are authoritative. Neutral in color, not sweet or dry with my B1R2. Bass and pace are strong. They wake up the speakers in a way I haven’t heard them before. I’m guessing this is what the speakers must have sounded like to the ADS crew during the Design process.
Many thanks to Papa for his skill, support and generosity! And of course thanks to Randy for his skill, knowledge and patience supporting my windmill tilting Aleph 2 quest!
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Hi, I would like to build 2 mono blocks of Aleph 2.
Please tell me where did you buy PCB's and what PSU/TRansformer have you used. Also how big or what weight are the heatsinks for each mono block ?
Please tell me where did you buy PCB's and what PSU/TRansformer have you used. Also how big or what weight are the heatsinks for each mono block ?
https://www.surplussales.com//item/_tp/600239.htmlRead post #1. Username - rhthatcher did the boards.
Heatsinks look to be ~5U or 4U / 400 ish. Dissipation is noted in user manual of Aleph 2 and also estimated in post #1. Choose accordingly.
OP can confirm / correct.
Mainly posting b/c I don't know how I missed this thread. @wg45 Sweeeeeeeeeeet!
Heatsinks look to be ~5U or 4U / 400 ish. Dissipation is noted in user manual of Aleph 2 and also estimated in post #1. Choose accordingly.
OP can confirm / correct.
Mainly posting b/c I don't know how I missed this thread. @wg45 Sweeeeeeeeeeet!
I did those boards custom for that chassis. I think that donut WG45 is using was originally in the amp chassis, so it is likely 10-20 years old. You could use a 600VA 35+35V Antek or Toroidy.
You could consider using boards for Classic Aleph for UMS chassis (see Group Buys) and change a few values to go from Aleph 60 to Aleph 2. I can send a BOM for that configuration. You'll need to spread a total of 12 MOSFETs across your heatsinks.
You could consider using boards for Classic Aleph for UMS chassis (see Group Buys) and change a few values to go from Aleph 60 to Aleph 2. I can send a BOM for that configuration. You'll need to spread a total of 12 MOSFETs across your heatsinks.
Thanks, IAIMH and rhthatcher for adding updates!
Yes, please contact rhthatcher for boards and advice. Aside from Papa and ZM, he's the authority on the current Alephs that he has prototyped and fabbed with help from 6L6. He's linked his GB for the boards above.
Comments-
I measured my heat sinks and they are about 430mm by 120mm, in total. 2 sinks make up each side, with 3 devices per sink. My sinks are not too hot; moderate on the Papa scale. If I was to use my same pcb's I think I could get away with (2) 3U/400 chassis. But to be safe 4U/400 would probably be better. You'll have to check with rhthatcher to see what chassis would work best with the current Aleph 60 boards that would update to Aleph 2.
There is also news of monoblock chassis being available from the Diyaudio store- Diyaudio Monoblocks
Obviously, there are a few drawbacks to owning monoblocks- it's basically the cost, energy and work of two amplifiers for performance of a really good sounding amplifier. I think it's worth it, but I can be a bit of a kook. I do think this will be my only pair of monoblocks.
Yes, please contact rhthatcher for boards and advice. Aside from Papa and ZM, he's the authority on the current Alephs that he has prototyped and fabbed with help from 6L6. He's linked his GB for the boards above.
Comments-
I measured my heat sinks and they are about 430mm by 120mm, in total. 2 sinks make up each side, with 3 devices per sink. My sinks are not too hot; moderate on the Papa scale. If I was to use my same pcb's I think I could get away with (2) 3U/400 chassis. But to be safe 4U/400 would probably be better. You'll have to check with rhthatcher to see what chassis would work best with the current Aleph 60 boards that would update to Aleph 2.
There is also news of monoblock chassis being available from the Diyaudio store- Diyaudio Monoblocks
Obviously, there are a few drawbacks to owning monoblocks- it's basically the cost, energy and work of two amplifiers for performance of a really good sounding amplifier. I think it's worth it, but I can be a bit of a kook. I do think this will be my only pair of monoblocks.
