I would use the PCB - you have it, and snap-in caps are many times cheaper than screw terminal, and of equal or better quality. ?Do you already have some screw-terminal caps?
Using chokes is also a good idea. Remember to have capacitors of higher voltage rating, there is a voltage surge at start-up.
As for 2 transformers in one case or not, there is no problem. Except for lifting and moving the amp, it's going to be extremely heavy!! 2 transformer and 4 chokes??
Honestly, consider one transformer, one set of chokes and one of the PCB - it's more than enough for stereo amp.
Or build monoblock... 😀 😀
Using chokes is also a good idea. Remember to have capacitors of higher voltage rating, there is a voltage surge at start-up.
As for 2 transformers in one case or not, there is no problem. Except for lifting and moving the amp, it's going to be extremely heavy!! 2 transformer and 4 chokes??
Honestly, consider one transformer, one set of chokes and one of the PCB - it's more than enough for stereo amp.
Or build monoblock... 😀 😀
Hey I have the EXACT same PS boards, but mine are black. I bought them about 8 years ago from an Ebay seller. IIRC Jims Audio I believe. They are a very good quality pcb. They are large though and take up a lot of real estate inside of the amp. I am getting ready to use mine in another amp I am building, a high bias modified Adcom 5400.
Yes jims audio on ebay. I bought the aleph 3 boards from him. Also a preamp board. The parts list says pass pl20....... if i google it, it says it's a p1.7 .
An externally hosted image should be here but it was not working when we last tested it.
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6L6, no i don't have caps yet. Still deciding on wich to use/buy.
Would 40v be enough considering the start-up surge?
The 4 chokes, bought them for the project, would be a shame not use them. So dual mono or monoblocks. way overkill, i know.
Would 40v be enough considering the start-up surge?
The 4 chokes, bought them for the project, would be a shame not use them. So dual mono or monoblocks. way overkill, i know.
35V caps would be fine for the Aleph 3 rail voltages. 40V or more would be good if you ever think about scaling it up to an Aleph 5.
Interesting that this thread popped up because I just got a second BrianGT PSU board for my aleph mini. Why you ask?! Because I was recently bitten by the bias bug after enjoying the amp for some time in a mild tune. What I wanted was to at least get to 30w/device, which shouldn't be an issue with my 5" x 10.08" heatsinkUSA sinks. They are warm but not hot at 1.5a so I figured there is room to go.. good for A30 at least, right? The problem is after going from 1.1a to 1.5a/device on 18.5v rails, the rectifiers are now screaming hot. I mean, can't even touch them hot. The weather is nice here now, but I'll need this amp when it gets roasting hot here. My rationale for getting another board was bigger to-220 sinks are going cost me $$ anyway from mouser/digikey, PLUS I'd also gain 2X the capacitance from 60 to 120K, and enjoy any possible sonic benefit from a pseudo-dual mono setup. By my reckoning I'll be employing post #53 schematic, but now there's some confusion about this voltage loss/ increased voltage need. Why can't I just take one of the paralleled 15V sec legs from the single PSU in there now and attach to the second board with separate star-grounded leg? Am I missing something here? Isn't that what Zoef was asking from the get go?
edit: nevermind.. I just figured it out. UGH!! I suppose I could go off board with the rectifiers now if I wanted to use the board.. or just use it as excuse to build something else.. second sounds more appealing.
edit: nevermind.. I just figured it out. UGH!! I suppose I could go off board with the rectifiers now if I wanted to use the board.. or just use it as excuse to build something else.. second sounds more appealing.
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Going from a 18V mini (2 devices/channel) to a 25V Aleph 30 (4 devices/channel) will require a ton more heatsink than 5"x10"
Bigger heatsinks on the discrete devices, (if that's what you are using, you said BrianGT PSU, right?) and/or better airflow through chassis.
Or replace with monolithic bridges such as - GBPC3502 Fairchild Semiconductor | Mouser
I just measured mine (amps been on for a couple hours) at 115 (45). It's 68 (20) in my house now.. so I probably am sitting near the threshold already. Oh well, guess I underestimated these things. The amp sounds fabulous now; I wanted more! Whata sick hobby lol
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Well it's not a p1.7 that's for sure.Yes jims audio on ebay. I bought the aleph 3 boards from him. Also a preamp board. The parts list says pass pl20....... if i google it, it says it's a p1.7 .
An externally hosted image should be here but it was not working when we last tested it.
Made screenshot of the schematic, left channel only, image is to big.(pdf file)
not having a bloody schematic with pcbs ?
it's series zenner mosfet follower for reg , two mosfets as gain stage , where one is having small bjt as current governor (read -- CCS with near by mosfet)
so , Aleph L
edit - while I was typing , you got sch
it is
it's series zenner mosfet follower for reg , two mosfets as gain stage , where one is having small bjt as current governor (read -- CCS with near by mosfet)
so , Aleph L
edit - while I was typing , you got sch
it is
Yes have a schematic but it's a pdf file..
Also states cl179.
But thanks zenmod!!!!!!
Also states cl179.
But thanks zenmod!!!!!!
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