My little Nelson Pass Aleph J rackmount

[myfirstamplifier]

I really like Nelson Pass designs and I just finished a "mini" version of his aleph J.. I see so many people building to print but I set out on another way to build the Aleph J amp. I'd like for anyone to submit improvements and I posted a show and tell here:

https://www.youtube.com/watch?v=zOrmEaV5xvg

This is sort of an opportunity for me other Aleph J builders or just people who appreicate the tonality of this amp!

25 watts per channel is definately enough to fill my room for both audio and video sound with this amp. You can bring it to 10 and it will not fall apart. No adverse distortion detected audibly at full tilt. Lol what a great deisgn. Thanks Nelson!

 

[Zen Mod]

ask Mods to move your thread in Pass subforum

what's temp on heatsinks , when lid is closed ?

 

[myfirstamplifier]

ask Mods to move your thread in Pass subforum

what's temp on heatsinks , when lid is closed ?

Right now after running it for 2 hours @ 23 degree C indooir temp the backplane temp is reading 89 degree C.

If i use a higher cfm fan in the chassis I can get it down to 60 with the lid on... tho i haven't put the lid on yet... I will try that tomorrow.


Thanks.

Eager Beaver. My first amp.

 

[myfirstamplifier]

Just testing -- but i don't think i can even get a word to you wityhout it being moderated.. sorry -- I AM A NEWB.

 

[AudioSan]

it takes some time to get the posts out when you are new. this will change soon.
89C is way too high. the ideel temp is about 55C

 

[myfirstamplifier]

it takes some time to get the posts out when you are new. this will change soon.
89C is way too high. the ideel temp is about 55C

Nelson has mentioned to me in email that even 100 degrees C is fine to operate at. I couldn't really get a stright answer out of him about how high the mosfets can operate in terms of temperature.

If you see my Aleph J build here:
https://www.youtube.com/watch?v=zOrmEaV5xvg

It tends to run at a high ambient temperature... but i have asked NP several times if 100 degrees is too much for these FETS. I am uncertain and maybe he is too about the longevity running them at these temperatures. It seems my amp runs very well for hours and days at 80 degrees C heatsink temp. I can bring this temperature down but in the video is what you see is what you get.

-Jeff

 

[myfirstamplifier]

The sound quality does not seem to change much from warmup (20 Degrees C) to max temp (85 Degrees C)... I am surprised to see this. There is no audiable difference to me.

 

[AudioSan]

ooh. i was thinking of the heatsink temp
80C on heatsink is way over what i would be comfortable with

 

[Zen Mod]

next time try to stay away from NP's personal email

try first with forum

he's feeding too much mouths around

 

[AudioSan]

ZM. yes nelson have many hungry (diy) birds to feed

 

[billyk]

Mmmm But so much food for thought!

 

[AudioSan]

yes. but then again. one can be over worked by making and serve all that food

 

[Boscoe]

Your problem with temperature is with those heatsinks. They need fans directly blowing air through them or he hot air will just sit in them. The fan you have in the back will just move air from the chassis but the heatsinks a will just get hotter and hotter.

 

[sakellogg]

are those studio 20's or S2's?

lucky dog so close to paradigm...

 

[myfirstamplifier]

are those studio 20's or S2's?

lucky dog so close to paradigm...

S2 signature reference.

Paradigm has nice stuff but I find them overpriced.

 

[sakellogg]

S2 signature reference.

Paradigm has nice stuff but I find them overpriced.

I enjoy them also. I thought you might be close enough to get the b stock from the factory.