Will begin assembly of an Aleph J soon as a stereo amp, so am interested in hearing how they work out for others.
May I ask the details of your reference Class D & AB amps?
Beginning to wonder about getting a more efficient amp for summer use that can rival a Pass Class A for SQ, and it would have to be close, or I'll just pay the AC bill difference.
The AB is the Pink Fish Media Hackernap design which is thought to be better than the Naim NAP250 and the class D is the Connex but I have auditioned a borrowed Hypex in my system with little difference. Look up the Connex, good value for money, cool and small
I would endorse a previous contributor and recommend checking every component before soldering; component removal with plated through holes is a pain. I built mine into the mini dissappente boxes in 3U height and the heatsink gets to 42c after an hour or so
I would endorse a previous contributor and recommend checking every component before soldering; component removal with plated through holes is a pain. I built mine into the mini dissappente boxes in 3U height and the heatsink gets to 42c after an hour or so
Connex website shows several Class D products.
Would you specify the one you're using, please?
Thanks, studying.
Find myself particularly intrigued by the claim of SMPS's with EMI emissions comparable to a good linear power supply.
Another one up! I used my 4U chassis and store boards. I pulled a perfectly good (and great sounding) F4 out of the 4U, and took the plunge into Aleph world.
I found that if one mistakenly reverses the Zeners, that full rail voltage will be present on the outputs, but nothing destructive. Best possible builder error situation with no smoke released.
After an hour of warm up and bias check, I gave it a listen - there's definitely more harmonic 'juice' than the F4 but detail is absolutely still there. Really enjoying it so far, and looking forward to reviewing my music collection with it.
I'm driving a pair of Paul Carmody Carreras with the AJ and an Aikido 5687 pre - this rig is actually louder than my BA3 FE + F4!
Thanks 6L6 for another great build guide.
I found that if one mistakenly reverses the Zeners, that full rail voltage will be present on the outputs, but nothing destructive. Best possible builder error situation with no smoke released.
After an hour of warm up and bias check, I gave it a listen - there's definitely more harmonic 'juice' than the F4 but detail is absolutely still there. Really enjoying it so far, and looking forward to reviewing my music collection with it.
I'm driving a pair of Paul Carmody Carreras with the AJ and an Aikido 5687 pre - this rig is actually louder than my BA3 FE + F4!
Thanks 6L6 for another great build guide.
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Finally had some time to finish my Aleph-J while the turkey was in the oven today. This is my third amp that makes use of my modular power supply.
It runs on +/- 21v rails with ~1.25A bias per mosfet, so the completed amp consumes about 200w out of the wall with a final sink rise of 31c above ambient. I used Keratherm pads for the mosfets and the big silver caps are Russian MBGCh. The CRC power supply has ~70kuF per rail and the amp has another 200kuF inside - 50kuF per rail per channel. The caps are held in place with silicon caulk and wire ties. Final offset is about 3-4mV.
Wood for the chassis is a nice Walnut that I found locally with a few coats of shellac on it. The sinks were a flea market find for $12 total and the metal plate on the bottom came from an old television that I disassembled to recycle. The legs keep the bottom of the sinks about 1.5" above the tabletop for good airflow. Turns out I could have pushed the bias a bit higher, but my pots ran out of room to adjust.
I'm hoping to get it installed tomorrow so I can give it a listen.
It runs on +/- 21v rails with ~1.25A bias per mosfet, so the completed amp consumes about 200w out of the wall with a final sink rise of 31c above ambient. I used Keratherm pads for the mosfets and the big silver caps are Russian MBGCh. The CRC power supply has ~70kuF per rail and the amp has another 200kuF inside - 50kuF per rail per channel. The caps are held in place with silicon caulk and wire ties. Final offset is about 3-4mV.
Wood for the chassis is a nice Walnut that I found locally with a few coats of shellac on it. The sinks were a flea market find for $12 total and the metal plate on the bottom came from an old television that I disassembled to recycle. The legs keep the bottom of the sinks about 1.5" above the tabletop for good airflow. Turns out I could have pushed the bias a bit higher, but my pots ran out of room to adjust.
I'm hoping to get it installed tomorrow so I can give it a listen.
Attachments
Superb cute amplifier Bravo Eric !
Me like a lot Your green resistors
Pio cap is interesting choice as well
me sometimes do the same with russian but bypassed by polyprophylene MKP .
Guess sound fabulous
Kindest regards
I am interested in being advised of further listening impressions comparing F4 and Aleph J as I had an F4 next in line that was usurped by the Aleph J.
Reasons were parts availability and the need for another preamp to drive the F4.
Everybody likes confirmation that they made the right call, yes?
Although what may wind up happening is that you convince me to do the F4 anyway.
BTW, 6L6 recommended the Aikido for use with the F4, but after a look at putting one together, I got a little skittish about trying one at this point in my DIY learning curve.
If you have, or had, occasion to hear both amps in otherwise identical line ups would, of course, be most welcome news.
Glad to hear your project went well.
Just build the Aleph J...don't get stalled by "should I build this or should I build that"...just start building!
I'll second the "just build it". F4 or Aleph J = Ginger or Mary Ann.
My opinion of the F4 is that it's a tight, crisp amp with a special no-feedback openness that sounds great with nearly all of my music.
I liked the F4 so much, that I am considering a 32v complementary output BA-3 as one of my upcoming builds, to see what the F4's more robust half sister sounds like
I'd never really listened closely to a single ended amp. With some good Tung-Sol 5687s in the Aikido teeing up the source, I think the AJ has a lot more flavor than the F4, with a competitive level of detail, and after a few drinks last night, I declared it damn near the end of my amp quest. It's extraordinarily musical.
I've got an M2X on deck to build over Christmas break. No idea what to expect as to how it compares to the F4 or AJ, but I can't wait to hear it.
I will also join the "Just built it" chorus.
The F4 is by design quite neutral and what you will hear is mostly
the characteristics of your preamp. Your preamp also needs
adequate voltage swing and gain, in combination with your source.
In my system, because of gain compatibility issue, with the F4, I
sometimes have lower volume than I desire with certain recordings.
I'm a fan of the Aleph-J (and alephs in general) and it is one I can
always go back to, and simply enjoy.
The F4 is by design quite neutral and what you will hear is mostly
the characteristics of your preamp. Your preamp also needs
adequate voltage swing and gain, in combination with your source.
In my system, because of gain compatibility issue, with the F4, I
sometimes have lower volume than I desire with certain recordings.
I'm a fan of the Aleph-J (and alephs in general) and it is one I can
always go back to, and simply enjoy.
I'll second the "just build it". F4 or Aleph J = Ginger or Mary Ann.
My opinion of the F4 is that it's a tight, crisp amp with a special no-feedback openness that sounds great with nearly all of my music.
I liked the F4 so much, that I am considering a 32v complementary output BA-3 as one of my upcoming builds, to see what the F4's more robust half sister sounds like
I'd never really listened closely to a single ended amp. With some good Tung-Sol 5687s in the Aikido teeing up the source, I think the AJ has a lot more flavor than the F4, with a competitive level of detail, and after a few drinks last night, I declared it damn near the end of my amp quest. It's extraordinarily musical.
I've got an M2X on deck to build over Christmas break. No idea what to expect as to how it compares to the F4 or AJ, but I can't wait to hear it.
You will love the 30 volt rail BA3. One of my favorites of all of them. I have a box of parts for two Balanced mono block versions, some day.
Russellc
I will also join the "Just built it" chorus.
The F4 is by design quite neutral and what you will hear is mostly
the characteristics of your preamp. Your preamp also needs
adequate voltage swing and gain, in combination with your source.
In my system, because of gain compatibility issue, with the F4, I
sometimes have lower volume than I desire with certain recordings.
I'm a fan of the Aleph-J (and alephs in general) and it is one I can
always go back to, and simply enjoy.
So true! That would be my pick if were building just one. Such an enjoyable amp.
Russellc
I'll second the "just build it". F4 or Aleph J = Ginger or Mary Ann.
My opinion of the F4 is that it's a tight, crisp amp with a special no-feedback openness that sounds great with nearly all of my music.
I liked the F4 so much, that I am considering a 32v complementary output BA-3 as one of my upcoming builds, to see what the F4's more robust half sister sounds like
I'd never really listened closely to a single ended amp. With some good Tung-Sol 5687s in the Aikido teeing up the source, I think the AJ has a lot more flavor than the F4, with a competitive level of detail, and after a few drinks last night, I declared it damn near the end of my amp quest. It's extraordinarily musical.
I've got an M2X on deck to build over Christmas break. No idea what to expect as to how it compares to the F4 or AJ, but I can't wait to hear it.
BTW, Mary Ann over ginger, no contest IMHO!
Russellc