Aleph J illustrated build guide

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Joined 2003
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I also like this idea. Would you suggest using IEC power inlets and matching power cable to unplug it from one amp to another or something else?

Thanks

Originally, from tube days, I have some plugs that are basically like the bottom of an octal tube. I was going then put octal tube sockets on backs of amps. Then I saw Eric's separate power supplies and decided to copy his idea. I think it was neutrik or something similar?

I suppose IEC could work as well, does fine bringing it in from wall....but might be easy to plug regular power cord into amp with no power supply....that wouldn't work out well....


Russellc
 
I paid about what 6L6 suggested for my build - maybe closer to $750 with shipping costs, taxes, etc.

Toroidal transformer from Antek, as far as I know, is the best bang for the buck. Deluxe 4U chassis may cost more than a homebrew solution, but it does save in frustration since the PCB / output device holes are pre-drilled/tapped.

The other expense that comes to mind- where I save a few $$$ and spent a few $$$ more are the bevy of .47ohm / 3W resistors. Ordering from Mouser I went with KOAs which were cheaper than the recommended Panasonic. But for the power supply caps, I went with "Audio Grade" Nichicons which aren't the least expensive but not exotic either. And the caps are gold!! Gold!!! ;)

Aleph_J_1.jpg
 
I also like this idea. Would you suggest using IEC power inlets and matching power cable to unplug it from one amp to another or something else?

Thanks

I wouldn’t recommend IEC connectors for transfer of low voltage ac or dc between power supply and the amplifier. It’s just too easy for someone to plug the amp directly into the wall and put 120 or 240vac into it.
On my F5 monoblock build I used Neutrik speakon connectors. You could always just use a terminal strip as long as you were careful with polarity.
 
Hi,
I hope that I'm hot bothering you. Again on fins size.
On page Aleph J – diyAudio Store a 60cm2 of finned heatsink per output transistor, that is for each channel.
On the other side a 3U/300 Pesante dissipante has approx 2,500 of finned heatsink for each channel.
Let me guess that's enough.
On the other side a 3U/300 is large just enough:
An externally hosted image should be here but it was not working when we last tested it.

I tried to better understand how it works using an LTSpice simulation:
An externally hosted image should be here but it was not working when we last tested it.

but I've got unreliable results.
I hope I have made some stupid mistake, but I fear that I'm using ureliable transistor models.
Anyboy tried this?
Thanks
 
Member
Joined 2003
Paid Member
Hi,
I hope that I'm hot bothering you. Again on fins size.
On page Aleph J – diyAudio Store a 60cm2 of finned heatsink per output transistor, that is for each channel.
On the other side a 3U/300 Pesante dissipante has approx 2,500 of finned heatsink for each channel.
Let me guess that's enough.
On the other side a 3U/300 is large just enough:
An externally hosted image should be here but it was not working when we last tested it.

I tried to better understand how it works using an LTSpice simulation:
An externally hosted image should be here but it was not working when we last tested it.

but I've got unreliable results.
I hope I have made some stupid mistake, but I fear that I'm using ureliable transistor models.
Anyboy tried this?
Thanks

No bother, no question no learn. I have Deluxe 4 and find it fine, even in summer but it does stay in A/C house. Anything smaller is going to get hot.

How hot? Wont know until you try. Most everyone here is 4U minimum. Look at Zenmods "Babysitter" if yours gets to warm, i.e., cant hold hands on over 5 second rule. A fan like in Babysitter can make up for a lot of sink.

Seems to me heatsink height plays more important role than heatsink length. Speaking of length, make sure those small sinks will at least accommodate the Aleph J boards.

I figure it may work with a Babysitter arrangement, but if too hot, get larger chassis and use that one for something else. Definitely plan on Babysitter.

Russellc
 
I've ordered a 5U Deluxe.

My thinking was:
- I've got the space
- Marginal cost increase so no big financial drama
- Never hurts to have a bit of performance margin when it comes to cooling

On that last point, I'm not a fan of fans. My thoughts are that reliability and moving parts aren't great friends. And yes I know fans are generally pretty good but as Henry Ford is reported to have said, "What you don't fit, can't break."
 
Today I finished an Aleph J. I had read the thread front to back before building. Thanks to the great info and tips, everything went well. I bought matched 2SJ74s from Punkydawgs. The other devices came from the DIY Audio Store Aleph transistor kit. (Beware, they are still shipping the F6 zeners instead of the Aleph J zeners).

I did way too much DIY over the past six months. I started with a pair of ACA 1.6, and was so impressed with them I decided to build an M2. I was so impressed with the M2 I decided to build an Aleph J. Now I am going on the wagon - no more amps for me.

However, I would like to build a good solid state preamp that would work well with these amps, if anyone has suggestions.
 

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