Anyway you have some idea but the photos do not do justice to the effort.
The idea of design was to use a MDF base initally to build and model the construction, enabling scaling of the amp along with more heatsinks as required. Using aluminum seemed unwarranted at this stage.
I also wanted to maintain a distinct diy theme and flavour rather than a cloned re engineered outcome. I think a diy mentality is a more relaxed way of approaching the home built task, particularly as Mr Pass has commented the exact specifications and tolerances are really there to met the manufacturers advertised claims. So why bust your boiler over a few millivolts.
I put the driver board up on a centrally mounted perspex platform for several reasons, to enable easy adjustment, access for assemble / re assemble via the screw in terminal blocks, and the board is central to the box for future heatsinks.
The output stage as you may be able to see is point to point for similar reasons, so I can easily mix and match and scale the amp at this early stage. But it is delicate and I will improve on this with terminal strips to provide strain relief for the wiring.
The final tesing is done an it is completely stable, offset both absolute and Dc are only a few millivolts after 1/2 hour warm up.
Technically matching the negative drive side and the input pair seem to cure the offset ills without issue here
The DC bias is as per Greys original design at 4 1/2 amps per side
In fact I rebuilt the output with 2 pairs per side for best practice minimising wattage per device @ 14 watts each ie there are 8 output fets per channel.
Soon I will up the anti with 2 x 300 va tranni per channel for +- 25 VDC and add 2 more heatsinks for box for 300-400 watts disippation.
I expect this will be a fair comparison for the mighty Aleph 2 and will then report on the subjective outcome.
Again sorry for the poor images, there will be better ones soon
macka
The idea of design was to use a MDF base initally to build and model the construction, enabling scaling of the amp along with more heatsinks as required. Using aluminum seemed unwarranted at this stage.
I also wanted to maintain a distinct diy theme and flavour rather than a cloned re engineered outcome. I think a diy mentality is a more relaxed way of approaching the home built task, particularly as Mr Pass has commented the exact specifications and tolerances are really there to met the manufacturers advertised claims. So why bust your boiler over a few millivolts.
I put the driver board up on a centrally mounted perspex platform for several reasons, to enable easy adjustment, access for assemble / re assemble via the screw in terminal blocks, and the board is central to the box for future heatsinks.
The output stage as you may be able to see is point to point for similar reasons, so I can easily mix and match and scale the amp at this early stage. But it is delicate and I will improve on this with terminal strips to provide strain relief for the wiring.
The final tesing is done an it is completely stable, offset both absolute and Dc are only a few millivolts after 1/2 hour warm up.
Technically matching the negative drive side and the input pair seem to cure the offset ills without issue here
The DC bias is as per Greys original design at 4 1/2 amps per side
In fact I rebuilt the output with 2 pairs per side for best practice minimising wattage per device @ 14 watts each ie there are 8 output fets per channel.
Soon I will up the anti with 2 x 300 va tranni per channel for +- 25 VDC and add 2 more heatsinks for box for 300-400 watts disippation.
I expect this will be a fair comparison for the mighty Aleph 2 and will then report on the subjective outcome.
Again sorry for the poor images, there will be better ones soon
macka
Hello everyone,
Okay following a very busy working week I finally found the time to do some more evaluation of the X Aleph vs Aleph.
Despite not being apples for apples (in terms of power)I could not wait for the decision on resourcing a 100 X Aleph, so here are my impressions. My speakers are about 96dba so most of the time I'm using just a few watts anyway.
I used the BOSOZ with ccs (Aleph fet type) in X mode as retrofitting back to the original design is a tedious process, and I felt it would give the best performance with unbalanced inputs.(and the rails on the X Aleph are closer to 15 vdc now and current share tweeked for 50/50% ~ 1.0k...its helps).
Playing the Aleph first, I could hear the familiar engaging sound, the mids appear accentuated, lusty and warm, and the top end warm and a tad slightly recessed. The bass has plenty of ommp.
Smooth, mellow with nice imaging and a sound that can be played all day long.
Switching to the X Aleph, its hard to descibe, but the presentation is less forward in the mids, perhaps because the tops are more crisp and decisive, with a nice hint of warmth and the bass is firm and articulate.
The presentation appears to have more drive and dynamics, less oozing and more snap and bite on those transients than the Aleph.
The surprise is an marked improvement in spatial imaging and staging of instruments and solist vocals to the point where they can be quite visible. The drive, snap transparency appears to replace the warm & romantic engagement of the Aleph, and creates a new kind of excitement (of being there) that is still quite sweet.
Is it better , well if absolute realism is what your lookin for, to my ears yes.
macka
Okay following a very busy working week I finally found the time to do some more evaluation of the X Aleph vs Aleph.
Despite not being apples for apples (in terms of power)I could not wait for the decision on resourcing a 100 X Aleph, so here are my impressions. My speakers are about 96dba so most of the time I'm using just a few watts anyway.
I used the BOSOZ with ccs (Aleph fet type) in X mode as retrofitting back to the original design is a tedious process, and I felt it would give the best performance with unbalanced inputs.(and the rails on the X Aleph are closer to 15 vdc now and current share tweeked for 50/50% ~ 1.0k...its helps).
Playing the Aleph first, I could hear the familiar engaging sound, the mids appear accentuated, lusty and warm, and the top end warm and a tad slightly recessed. The bass has plenty of ommp.
Smooth, mellow with nice imaging and a sound that can be played all day long.
Switching to the X Aleph, its hard to descibe, but the presentation is less forward in the mids, perhaps because the tops are more crisp and decisive, with a nice hint of warmth and the bass is firm and articulate.
The presentation appears to have more drive and dynamics, less oozing and more snap and bite on those transients than the Aleph.
The surprise is an marked improvement in spatial imaging and staging of instruments and solist vocals to the point where they can be quite visible. The drive, snap transparency appears to replace the warm & romantic engagement of the Aleph, and creates a new kind of excitement (of being there) that is still quite sweet.
Is it better , well if absolute realism is what your lookin for, to my ears yes.
macka
macka said:Hello everyone,
The surprise is an marked improvement in spatial imaging and staging of instruments and solist vocals to the point where they can be quite visible. The drive, snap transparency appears to replace the warm & romantic engagement of the Aleph, and creates a new kind of excitement (of being there) that is still quite sweet.
Is it better , well if absolute realism is what your lookin for, to my ears yes.
macka
I agree with you! I also found the bass has more slamm, and oompf in a nice way, it comes from nowhere and disappears as quick as it came, very spooky in a nice way... (at least with my 130W version!) ...
Edwin
Heck,
What will I do with the Aleph 2, the mind's ticking over already!!
The problem is if I grow to like the X Aleph more and more, the Aleph 2 will not get played often.
Could the Aleph 2 be rehashed and molded into a X 180 Aleph?
Yes.
With a bit of re organising the chassis of the Aleph 2 to could be made wider, with new top and bottom plates and I could add two more big heatsinks to the front an rear like a super Aleph cube for 600 watts capacity.
I figure my surplus matched 24 IRF 244 should not go to waste and +-29 volts @ 1200 VA from the Snowy Mountains would keep the winter blues at bay.
Who needs Pot Belly stove with two of those....Muhahahahaha
This would also be the most practical and cost effective solution.
I'll sleep on it.
macka
What will I do with the Aleph 2, the mind's ticking over already!!
The problem is if I grow to like the X Aleph more and more, the Aleph 2 will not get played often.
Could the Aleph 2 be rehashed and molded into a X 180 Aleph?
Yes.
With a bit of re organising the chassis of the Aleph 2 to could be made wider, with new top and bottom plates and I could add two more big heatsinks to the front an rear like a super Aleph cube for 600 watts capacity.
I figure my surplus matched 24 IRF 244 should not go to waste and +-29 volts @ 1200 VA from the Snowy Mountains would keep the winter blues at bay.
Who needs Pot Belly stove with two of those....Muhahahahaha
This would also be the most practical and cost effective solution.
I'll sleep on it.
macka
Attachments
Also the top panel complete with 23 position switch attentuators.
I should point out the switches were generously supplied by Mr Pass. Special thanks to Mr Pass.
The soldering of the mini boards (vero board strips was a work of art...I have ordered Dale resistors up an upgrade now I am satisfied the attentuation is correct (scaled from the Pass L)
macka
I should point out the switches were generously supplied by Mr Pass. Special thanks to Mr Pass.
The soldering of the mini boards (vero board strips was a work of art...I have ordered Dale resistors up an upgrade now I am satisfied the attentuation is correct (scaled from the Pass L)
macka
Attachments
And the rear panel with balanced and unbalanced connectors.
The top panel and rear were made from 3 mm perspex.
I am very pleased with the sonic qualities and the construction of both projects.
Special thanks to Karen the Pass Diva and Mr Pass for their friendly & expert assistance.
macka
The top panel and rear were made from 3 mm perspex.
I am very pleased with the sonic qualities and the construction of both projects.
Special thanks to Karen the Pass Diva and Mr Pass for their friendly & expert assistance.
macka
Attachments
Hugo,
Sometimes words fail me,
But on this occassion I knew I was falling in love with the sound.
Very shortly I will be revising the Aleph 2 box for X Aleph
I recall you have the big one already....
I have to say this amp is a real sweetie...I think Mr Pass desription is the one that sums it up best...Like Peanut Butter & Chocolate.....
I am sure there are more than a few tooth aches among the crew at Passlabs hey Karen, she's just the best.
macka
Sometimes words fail me,
But on this occassion I knew I was falling in love with the sound.
Very shortly I will be revising the Aleph 2 box for X Aleph
I recall you have the big one already....
I have to say this amp is a real sweetie...I think Mr Pass desription is the one that sums it up best...Like Peanut Butter & Chocolate.....
I am sure there are more than a few tooth aches among the crew at Passlabs hey Karen, she's just the best.
macka
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