The very first version of BrianGT's was blue and about 2.4mm thick, 2nd version was red. The red and blue version had a silkscreen error for one of the 220uF caps. That black board Boywonder put up is corrected and matches the attached schematic. I have a stack as well that I've been hoarding for some reason, I'll let a bunch go free..just pay shipping.
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Not correct, one board = one channel. I've built (blown up) about 15 amps using these boards over the years.
Well it looks like I will have to take an offer from the other side of the pond...
I may bring this thread back to life, have a few projects that were started and never finished so why not start with this one already have the chassis done with with transformer/rectifiers and cap bank.
I may bring this thread back to life, have a few projects that were started and never finished so why not start with this one already have the chassis done with with transformer/rectifiers and cap bank.
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I just assembled one channel of those black boards a couple of days ago. 10 years too late, but better late than never I guess... The schematic is correct but it is missing some values (listed as TBD). The TBD is is in another file, attaching it now.
Thanks
Going to dig out (literally) the chassis from my shed to give it a clean a start with the preparation for the boards.
Going to dig out (literally) the chassis from my shed to give it a clean a start with the preparation for the boards.
Stupid question :
What are the dimensions of the black boards (don't have then yet) without the "wings" just want to be sure 100mm tall heatsinks are big enough.
What are the dimensions of the black boards (don't have then yet) without the "wings" just want to be sure 100mm tall heatsinks are big enough.
The amazing sound quality of the Aleph's low noise floor and wide bandwidth is often overlooked with the wave of FirstWatt products available in recent years. Hopefully there is a resurgence of interest.
Much has been written about them. For me, I enjoy the sweetness of tube type quality with clarity and speed of solid state. Running the amp with balanced sources is something special. For all the amazing amp's Nelson has built, the Aleph is legendary. Very hard to find someone who is critical of the Aleph when built properly.
I agree with your sentiment.
If an easy to find PCB is available I think this again will be a popular project.
And no unobtainium parts either. 🙂
Thanks
I don't use "boutique" components but I have some nice ones
Had a look and found the pictures from the case I build for this little fellow
( Can't believe 10 years gone by)
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Hope this will help using BrianGT board and Official Schema
I found a hard copy of this but couldn't find the original file that it came from, likely a Excel spreadsheet. However, I found this quite useful when using he BrianGT black board and the official Aleph schema..
I hope someone has the original spreadsheet and will post it. Until then, use this if you have question of "what is this parts in the Pass schema".
Thanks,
I found a hard copy of this but couldn't find the original file that it came from, likely a Excel spreadsheet. However, I found this quite useful when using he BrianGT black board and the official Aleph schema..
I hope someone has the original spreadsheet and will post it. Until then, use this if you have question of "what is this parts in the Pass schema".
Thanks,
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Mini-A uses a single pair of output FETs.
In my build I use IRFP150 which has a much higher transconductance than IRFP240, but also higher capacitance. IRFP044 might be a bit too much in that respect.
If you do an Aleph 30 build (3 pairs of output FETs) then IRFP240 is just fine IMHO.
Disclaimer: I like the sound of high Gm devices. Perfectly suited for SE amps like Zen, Aleph, ACA, etc.
In my build I use IRFP150 which has a much higher transconductance than IRFP240, but also higher capacitance. IRFP044 might be a bit too much in that respect.
If you do an Aleph 30 build (3 pairs of output FETs) then IRFP240 is just fine IMHO.
Disclaimer: I like the sound of high Gm devices. Perfectly suited for SE amps like Zen, Aleph, ACA, etc.
This is fun but this "conversation" has a load of lag, States -6 hours, Australia +11.
Going to start with the one on the parts list and go from there I may even try the IRFP450 just because.
I never listened to an Aleph so can't comment on that.
Just realized that I'm going to need a pre amp... so where did I put that unfinished 1.7 ?
Going to start with the one on the parts list and go from there I may even try the IRFP450 just because.
I never listened to an Aleph so can't comment on that.
Just realized that I'm going to need a pre amp... so where did I put that unfinished 1.7 ?
"Going to start with the one on the parts list and go from there I may even try the IRFP450 just because."
Yeah, why not.
Just keep in mind you are not gaining anything with IRFP450 apart from high voltage capability. I would think this FET is best suited as a series device in a CapMx for a tube amp.
Gm almost the same as IRFP240.
Qg is double, therefore needs twice the current to get the same bandwidth.
Input capacitance double to what is with IRFP240.
Your call, but the end result is not looking very promising (with IRFP450), better stay with the one on the parts list.
Yeah, why not.
Just keep in mind you are not gaining anything with IRFP450 apart from high voltage capability. I would think this FET is best suited as a series device in a CapMx for a tube amp.
Gm almost the same as IRFP240.
Qg is double, therefore needs twice the current to get the same bandwidth.
Input capacitance double to what is with IRFP240.
Your call, but the end result is not looking very promising (with IRFP450), better stay with the one on the parts list.