Beautiful build. Inspiring really. Did you go with 5U because of the dual mono power supply design? I'm currently thinking over my choices. I want 3U, but I'm hitting 28C in my living room right now in the summer with just an Aegir on duty. In the winter I wouldn't mind the extra heat source at all. I'm torn between dual mono and mono blocks. I prefer the low profile and 5U won't fit in my rack. Even 3U blocks would look cool beside each stand. I'm really really torn.
Nicely done jmpyoung! I am liking the 5U chassis, made my NPXP build much easier to configure.
Enjoy,
Anand.
Enjoy,
Anand.
NightFlight,
With the amount of heat dissipation from the 4 MOSFETS/ch in the Aleph J, you will at a bare minimum, need a heatsink the size of a 4U/300 or 0.3 degC/watt. As such, a 3U won't work unless you drop the bias considerably which would be suboptimal for the Aleph J design.
I currently have 3U/300 monoblocks that I built as Mofo monos and they run warm to hot, the heatsinks are about 50-55 deg C with 2.5A bias @ 24V DC or ~ 60 watts dissipation. The 3U/300 is 0.4 deg C/watt. And that's with the 10mm thick front panel helping it out.
Best,
Anand.
Pass DIY Addict
Joined 2000
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Very nice work! I like the clean chassis floor by mounting the caps on the front plate. My bench gets banged around quite a bit, though I never thought of lining it with that endless stream of cardboard that we seem to have as well…
I originally built my Aleph J as a stereo amp, and I also had built an M2 as a stereo amp. I decided to make them both mono blocks by putting a channel from each amp in each box, then wiring up a heavy duty switch so that the power supply would power only to one board at a time depending on the switch position.
When I moved to monoblocks I noticed three positive effects.
- Better oomph
- Increased stereo separation
- No residual hum even with my ears right on the speaker drivers.
I think the move to monoblocks was a nice increase in overall performance.
Alan
When I moved to monoblocks I noticed three positive effects.
- Better oomph
- Increased stereo separation
- No residual hum even with my ears right on the speaker drivers.
I think the move to monoblocks was a nice increase in overall performance.
Alan
I went with the 5U based off of what others suggested. Min 4U for the Aleph J and 400mm deep to accommodate a dual mono set up. Frankly, I was already having to learn a ton through this process, and I didn't feel like adding having to learn how to tap holes to the list. Only the 5U had a 400mm deep option with pre-tapped homes. I'll drill and tap the holes on my next project. The added bonus, of course, is that the additional heat sink surface area allows for more bias.
The 5U chassis was great. Definitely made things very easy. The only thing you have to be careful of is that since the 400mm heat sinks are split into two pieces, alignment issues can crop up with the pre-tapped holes and the amp boards. It took a little bit of fiddling to get everything to align properly, which is nerve-racking when the amp boards are already mounted. My suggestion (which seems obvious in retrospect) is that you should completely assemble the chassis sans boards to make sure everything goes together well and then try to fit the boards to see if anything needs to be bent or whatever to get everything to fit properly. Once everything is good, then disassemble and proceed normally with your build.
The 5U chassis was great. Definitely made things very easy. The only thing you have to be careful of is that since the 400mm heat sinks are split into two pieces, alignment issues can crop up with the pre-tapped holes and the amp boards. It took a little bit of fiddling to get everything to align properly, which is nerve-racking when the amp boards are already mounted. My suggestion (which seems obvious in retrospect) is that you should completely assemble the chassis sans boards to make sure everything goes together well and then try to fit the boards to see if anything needs to be bent or whatever to get everything to fit properly. Once everything is good, then disassemble and proceed normally with your build.
jmpyoung,
If you have a source that is balanced or differential output I would encourage you try the Aleph J completely wired for balanced. I think at this point, you have the (-) input connected to ground and are running it unbalanced which I am assuming is because your source is unbalanced/RCA as well.
I just checked up on the price of the ARC Ref 110, it was a $11K amplifier at the time! Wow! The pics look pretty cool in the ARC database.
Enjoy!
Best,
Anand.
My balanced cables are only about 4ft long. When I pull the ARC out of the rack, I will be able to connect the Aleph J balanced to the Brooklyn DAC.
I bought the ARC used, so I definitely did not pay that much for it!
I bought the ARC used, so I definitely did not pay that much for it!
He means pin 3, which is the negative leg: When running unbalanced input, that typically gets connected to signal ground.
My J is also working!
Hi All,
this email is just to tell all of you "thanks". Finally, with your guide and help, my Aleph J is also working and what a music.
I did not realize how the amp is important. Indeed the differences between my commercial YBA Integrè and my self-made Gainclone were subtle, but the improvement in sound quality with the Aleph J on the contrary are incredible.
First aspect I noted is that now I am able to listen to the reverb of the recording hall, I never noted it before.
In addition, separation of instruments is much better, I think now I realized what hi-fi reviewers call "air".
Finally the energy of drums is such I can almost feel their presence in my room.
Thank you again
renato
Hi All,
this email is just to tell all of you "thanks". Finally, with your guide and help, my Aleph J is also working and what a music.
I did not realize how the amp is important. Indeed the differences between my commercial YBA Integrè and my self-made Gainclone were subtle, but the improvement in sound quality with the Aleph J on the contrary are incredible.
First aspect I noted is that now I am able to listen to the reverb of the recording hall, I never noted it before.
In addition, separation of instruments is much better, I think now I realized what hi-fi reviewers call "air".
Finally the energy of drums is such I can almost feel their presence in my room.
Thank you again
renato
Attachments
You are right. I think I got the definitive nirvana with the amplification, nutube + aleph j (I know never say never with this hobby) and now I am looking for the definitive speakers. I am in the search of a two way open baffle I can copy and build Mr Pass active crossover that gently shared with the community
(I could use my gainclone monoblocks for the subs).
The problem is the need of a reasonably sized ob, otherwise the speakers are in and I am out of home (waf factor as usual).
Renato
(I could use my gainclone monoblocks for the subs).
The problem is the need of a reasonably sized ob, otherwise the speakers are in and I am out of home (waf factor as usual).
Renato
if not horn or OB (reason - size), next logical thing is TL
already with proper 10" driver you're in Big League
already with proper 10" driver you're in Big League
Yes, a cheaper possibility I have is to throw away the cabinets of my Jimmy Griffin minimonitors (never painted in more of ten years) and replace them with the TL cabinet already published here also saving ther crossover.
It could be a kind of strategic approach to the OBs 🙂
renato
It could be a kind of strategic approach to the OBs 🙂
renato
Well done! I have owned most of the Aleph amps, and they are special beasts.
Mini-monitors like those have their own sound. The imaging in particular can be wonderful. I built a pair of SEAS Curv speakers last year for my daughter, and they were amazing. Not a lot of bass, but what they did they did well. So don't underestimate little speakers!
Mini-monitors like those have their own sound. The imaging in particular can be wonderful. I built a pair of SEAS Curv speakers last year for my daughter, and they were amazing. Not a lot of bass, but what they did they did well. So don't underestimate little speakers!