Aleph J illustrated build guide

The Aleph J on Harbeth may be my new favorite amp combination. I was using a Pass xa25 over my M2x and Amp camp Dual monoblocks before.

I have a 4U 400mm chassis with dual mono AS-2220s, 54000uf per rail, and 28V rails.

Not shown in the pictures as I did it later, I added rca inputs with an On On switch for each side to tie pins 1 and 3 together. Kind of the same concept as the new amp camp wiring for parallel. Not sure why I waited so long to build this amp.

The imaging and Mid range are very nice and the top end is just enough.
 

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Isn't that a really smooth, fairly conservately powered single ended First Watt amp made of pure unobtanium?

❄️🎄🎷🎅🎸🎄❄️
:santa:

The F2J is with unobtanium. Smooth clean positive phase 2hd.
 

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I don't have that scope, but unless the time scale / axis of the blue and yellow traces are different (I don't see that on-screen anywhere), then that's not showing a 2nd harmonic. It's showing a lower-level signal at very close to the same frequency as the fundamental and slightly phase shifted (if the traces are time-aligned). I can see the period / frequency of Trace 1, but not 2.

Not second guessing anything, but from what I can see in the picture by itself, I'm not seeing a clean visual of a 2nd harmonic distortion.

Cheers!
 
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I don't have that scope, but unless the time scale / axis of the blue and yellow traces are different (I don't see that on-screen anywhere), then that's not showing a 2nd harmonic. It's showing a lower-level signal at very close to the same frequency as the fundamental and slightly phase shifted (if the traces are time-aligned). I can see the period / frequency of Trace 1, but not 2.

Not second guessing anything, but from what I can see in the picture by itself, I'm not seeing a clean visual of a 2nd harmonic distortion.

Cheers!
Maybe my 334 is broken. Will do some digging. But I did manage to adjust the amp for minimum thd using it, but what it is showing - I agree, looks off.
 
Nooooooooooooo. I hope not.


Christmas wishes for a perfectly functioning 344, AJ, and Andy. :joker:
Haha! What I build seems to always work. Me myself, however, tagging along and working like an Alfa Romeo: keeping up appearances :rofl:

Forgot to say I did do some zooming and adjustments of the residual, but with this 334 I have always experienced this phase shifting, and what is shown always looks like a lower level version of the fundamental. But I have been able to read the seemingly correct thd off the meter, and affect the visual residual by adjustments. Hmmmm. Will check it out, maybe I’ll have some time this Christmas. The unit was tested in 2010. But of course, in these sorts of measurements, there is always a huge room for F40 errors (error being 40 cm from the unit) :rofl:
 
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I’m sorry everyone, I think I wasted your time last night. The fuse hadn’t blown, the smps had tripped out. The tiny thing can’t handle 200w continuous for more than 10 minutes. I even put it in a larger enclosure this morning and that did not help, the Heatsink still gets too hot. However I have managed to test the amp and I am impressed, absolutely totally silent with better bass, mid and treble than my 405-2. I’m sure it would continue to get better after a couple of hours of being on.
I still want to use an external smps so I have found a 1000w ±24v that should cope with an AJ. It’s LLC soft switching.
1000w smps
What is the lowest I can set the bias? Maybe I can run the amp on less power for a bit until I sort out a better smps.
Hi I am currently using 2 of these 24V 9A PSUs https://pl.aliexpress.com/item/1005003394055957.html
 
Hi guys, i'm working on this Amp and actually i'm building it as reported in the blogspot guide: https://diyalephj.blogspot.com/

I'm planning to use it with my .FLAC audio library and i've two main doubts about DAC and/or preamplifier: You guys have some recommendations about which USB DAC (with balanced XLR output) i can buy and use with this amplifier?

Also, using a good quality DAC, it's necessary to also add a preamplifier?

BTW, Sorry for the dumb questions! :)
 
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Joined 2016
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Hi guys, i'm working on this Amp and actually i'm building it as reported in the blogspot guide: https://diyalephj.blogspot.com/

I'm planning to use it with my .FLAC audio library and i've two main doubts about DAC and/or preamplifier: You guys have some recommendations about which USB DAC (with balanced XLR output) i can buy and use with this amplifier?

Also, using a good quality DAC, it's necessary to also add a preamplifier?

BTW, Sorry for the dumb questions! :)
Hello,

I’d say if the DAC you buy has a variable output/volume control built in there would be no need for a pre amp. Others may have different suggestions though.

Enjoy the Aleph J, it’s been my main amplifier since I’ve built it.
 
Hello,

I’d say if the DAC you buy has a variable output/volume control built in there would be no need for a pre amp. Others may have different suggestions though.

Enjoy the Aleph J, it’s been my main amplifier since I’ve built it.
Thanks mate, which DAC you suggest?

I've looked at this model on Amazon: SMSL DO100, you think that will be okay or it's a crap?
 
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Thanks mate, which DAC you suggest?

I've looked at this model on Amazon: SMSL DO100, you think that will be okay or it's a crap?
Thanks mate, which DAC you suggest?

I've looked at this model on Amazon: SMSL DO100, you think that will be okay or it's a crap?
I honestly don’t have a useful opinion on that dac because I’ve never used it or any of the SMSL dac’s. If that dac looks of possible interest to you I’d search the web for reviews from as many sites as possible to absorb opinions from users and testers to see if the features fall in line with what you’d like.

You may also consider reading and post a question regarding a dac recommendation with volume control in the following link that was started by another member of the Pass Forum. Be sure to mention your price point so others may be able to offer a suggestion.

https://www.diyaudio.com/community/threads/dac-recommendation.376015/page-8#post-7222911