Listened some more with my new build last night. First I have many SE tube amplifiers and I love the sound. To me the Aleph needed something to get to the level of my SE tube amplifiers. Then I decided to hook up one of my Tube linestages and boy did it make a difference. In NP's description of this amplifier he noted how this amp with it's high input impedance was excellent for a tube linestage. One must remember that this amplifier was introduced almost 20 years ago. Excellent sounding with my tube linestage.
I do not want members to get the wrong idea. On it's own with just my B1 buffer the amp sounds really good, if not excellent depending on your taste in amplifiers and music. To me the tube linestage took it to another level.
I relegated my B1 in preference to the P1.7.
I built the Aleph J as it is supposed to be as close to tube sound as a semiconductor amplifier can be.
Unfortunately my Impasse pre-amp has a hum problem that I haven't been able to solve.
I built the Aleph J as it is supposed to be as close to tube sound as a semiconductor amplifier can be.
Unfortunately my Impasse pre-amp has a hum problem that I haven't been able to solve.
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Maybe but then NP designed the SIT amplifiers. Many reviewers considered the SIT-1 sounding much like the SE 300B amplifier. Being that mosfets have the same curves as a pentode amplifier and NP designed simple circuits for them they have a lot in common with a tube amp. All the tube amplifiers I have built have a different sound compared to each other as well. There are no culls in the FW designs. A lot comes down to customers favoring SS over tubes.
Just want to mention, the Nutube linestage should have the same results. My Nutube has developed a nasty oscillation that I need to dig in and find.
I could not get to the root of the hum in the Impasse.
The HT was rock solid and regulated.
I played with the GND but that didn't seem to make any difference.
Heaters were isolated and twisted pairs.
The HT was rock solid and regulated.
I played with the GND but that didn't seem to make any difference.
Heaters were isolated and twisted pairs.
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I finally had the chance to test my build for the source of transformer hum (new baby {5/23} =no free time) Without the amplification boards connected to the power supply the transformer is still humming quite loudly. I will next try to dis- and re-connect the transformer and the other power supply elements and remount the transformer. Then I’ll remeasure the voltages and listen for hum. The current voltages are consistently 24.8V in both channels which I believe is about right for the amp based on NP’s article for the amp. I also measured the temp of the thermistors. Right after power up they reach 114F,which, surprisingly, is only slightly higher than my M2x with the same power supply. Not what I was expecting. Any suggestions on what to check with the power supply, in particular, is appreciated. Thanks
Desolder the secondary wiring from the power supply board, let the secondary wiring hang in the air, and see if the transformer still buzzes when you apply the mains voltage.
I first listened to my new amplifier with the B1 version2 and stated in a previous post I thought it would sound better with a tube pre and it did. Last night I listened to it with Wayne's linestage and the sound was much the same as with the tube pre and possibly better. The linestage given to diy'ers by Wayne who designs linestages for Passlabs is a blessing. Everyone needs to build at least one. This Aleph J is a keeper.
EB, do you mean disconnect the secondaries from the rectifiers or disconnect the rectifiers from the board? I assume the former, but I thought I’d ask. Thanks
You should start by disconnecting the secondaries. See if the transformer buzzes. If it does, then remove the transformer completely from the amplifier and try again.
That’s not one of Nelson’s designs, that I’m aware of, but looks to be some omitted parts and other notes on a schematic. It will probably work.
Concerning the question I asked it appears that only R3 and C1 are eliminated. Just briefly comparing the 2 schematics nothing other than a few values has changed.
And the output limiter is removed. This won’t effect operation.
I must admit, in my experience Black Gate caps are awful (YMMV) and anytime I see them specifically called for I twitch a little... that said there’s no reason why the changes won’t work. I personally, however, would not omit C1. I want no possibility of DC on that side of the diff pair.
I must admit, in my experience Black Gate caps are awful (YMMV) and anytime I see them specifically called for I twitch a little... that said there’s no reason why the changes won’t work. I personally, however, would not omit C1. I want no possibility of DC on that side of the diff pair.
black gate in Aleph CCS modulation route is recipe for 3 months of pain
been there,done that
black gate as filtering cap in LTP CCS is plain Audiophoolery
been there,done that
black gate as filtering cap in LTP CCS is plain Audiophoolery