Nelson Pass Aleph J


Staff member
Good assessment of the Aleph. I concur. This is the first amp I've owned that I didn't want to move on to something else. That's SS and tubes included. Now I just need the 604's back. LOL


Next Round Is On Me
I got to spend a few hours of quality time with the Aleph J in my system this last weekend.

I’ll just start by saying that i continue to be impressed by this amplifier. Hands down, this is the best solid state amplifier I’ve ever had in my home.

I won’t say that it sounds like a SET amp, because it doesn’t. It also doesn’t sound like a ballsy push pull tube amp nor a typical solid state amplifier.

In my opinion, the Aleph J kind of skirts the line among all of them, incorporating some of the best qualities of each design.

It’s detailed like the best solid state amplifiers but not analytical. It’s got presence like a good SET amplifier, but not quite to the same degree. It has drive like a ballsy push pull tube amplifier when the program material calls for it.

What was supposed to be a quick one hour listening session turned into more like three hours with every member of the family joining me for at least a few songs at some point. I didn’t want to turn off the music and to me that is the litmus test.

At this point I may have 7-10 hours on it, so likely there’s still plenty of burn in to go. I cannot wait to see what’s in store and cannot imagine how one could better spend the $700-800 it costs to build one of these.

Very highly recommended.
This build is looking mighty attractive at the moment!
Any completed pics? (Front/back/sides/top, please and thank you!) looks like rack handles on yours?
Have any of you guys compared your home builds with the genuine Aleph J by Nelson Pass. I need to be assured that the DIY amps are not missing out a bit.


AARP Member
Case was a repurposed unit I built for SE amp. I built 4 of those in total. The heatsinks just happened to kind of fit and I didn't feel like spending $400 for a metal enclosure. Wood was sourced from a black walnut tree in our property. Nothing special. The top has a 1/4" rabat where the heatsink rests. The gut's are a mess I'm embarrassed to say. I worked on this 3 12 hr. days in a row, made lot's of mistakes. I'll clean it up when I get more wire.

Amps keeps up with the music effortlessly. Excels with all the acoustic stuff we like. Yea I know, acoustic music has no dynamic range but, been there done that. We like mellow.


Staff member
Interesting, always wanted to hear one in my system. Didn't you build 45 (or maybe 2A3) SET amps in the past? Would love to hear you take on the comparison.


AARP Member
45's and 2A3's. This amp has the warmth of a good tube amp and really sparkles up top. It's been a while since I've plugged in the 45's and I'll get to that soon. For the time being I'm doing a Citation II/Aleph J comparison.


AARP Member
the Aleph J's really dig's in the mids compared to the Citation. My impression is there very different. Granted the Citation's not hot yet but it seems thin in comparison.

Listening to Nat King Cole on vinyl.
A great thread, I have not built the Aleph J but I did build the M2X, brilliant amplifier. I use an Elekit TU8500 valve pre amp kit to drive it and a Pair of DIY Lenehan LK1 kit speakers which are 86dB 1w1m.
Plenty loud enough.


AARP Member
Aleph J's a very easy build compared to a tube amp build once you understand how to properly hook up a bi-polar power supply. With off the shelve parts it could be done in 2 sittings especially if you start drinking during the first.

It sounds thin at first as warm up takes quite a while. The difference between hot and cold is readily apparent and you hear it come in.
Delicacy, depth, articulation is excellent so much so I can actually comprehend what the artist is singing. I thing it's strong suit is unamplified music. Piano, acoustic. Nice piece and I have $500 invested +/- $50.


AARP Member
5 hours run time. Very very nice sound's coming through here. It's got speed, dynamics and clarity. Is it better than the Aleph J. That's hard to say. It doesn't take a back seat to it though. Today I will bias some real 45's and pull these overgrown EML's out. This amp reminds me of the Citation II in some ways. Very accurate. Some could be fooled. It must be the iron. I have another unit like this with Edcor Iron I'll dust off soon.