Nelson Pass Aleph J

The chassis they sell are damn nice, and very convenient.

Definitely get a few extra meters for fire up. The Mastech MAS830L are good meters and can be had for ~$30 USD. The Hardbor Freight ones are probably fine for basic measurements, and monitoring. I just ordered another Mastech so I have plenty of meters on hand for biasing, and tweaking. It's nice to be able to have all the critical measurements right in front of you. Especially the first time you fire it up and are nervously checking everything to make sure you didn't wire something wrong.

From listening to Mark's aleph-j while it was here, I'm seriously considering building one.
 

marantzfan

Administrator
Staff member
Are you using it standing on end like that, with a lexan/acrylic cover? That really looks great, but then I love seeing the guts. My wife, on the other hand...🙄

No, i just have it standing on its rack handles while I adjust bias and offset, then I’ll pop the covers on and return it to the horizontal position. :)
 

marantzfan

Administrator
Staff member
Ok, hum has been resolved.

I missed the part about installing a thermistor between the PSU and chassis ground in order to provide a ground lift. Also, I decided in the end to omit the speaker relay board as it was causing a pronounced turn off thump. With it out of circuit, the turn off thump is very subtle now.

So with that, I sat down for about an hour today for some preliminary listening. My first impressions are quite positive, I'm really impressed by how resolving this amplifier is while not being cold or analytical. Interested to see how things develop with more time on it.
 

opa1

Moderator
Staff member
Glad you found it. The Aleph sounds a lot better after it warms up. You and actually tell when it happens. What are you driving with it?
 

marantzfan

Administrator
Staff member
Glad you found it. The Aleph sounds a lot better after it warms up. You and actually tell when it happens. What are you driving with it?

For now I have it in my main system, with the Bottlehead BeePre and driving my Altec 604-8G's.

You're right about the warm up, just like with my old F5 it needs about 30-45 minutes before the magic happens. ;)
 

marantzfan

Administrator
Staff member
So...how does it compare to single-ended DHT amplification when driving your 604-8G's? :)

To be honest, I haven’t gotten a chance to listen since my last update. Just got back home from a two day business trip.

I’m hoping to carve out some time this weekend for more listening.
 

marantzfan

Administrator
Staff member
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.
 
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