Classic Aleph Amplifier for Modern UMS Chassis Builder's Thread

[starcat]

For mono A30 with the Antek AS-2218 you'll run 1 donut per channel, 1 bridge per secondary pair into a mono (V8) PCB. Easy.
But I think you have a stereo board... Did you want to try mono boards?
I have never heard of a single donut per rail (parallel secondaries into each bridge). Has anyone tried this? Can it work?

Old post but maybe of interest to others.

Yes, it can be done, paralleling transformers, look up here:
https://www.diyaudio.com/community/...rated-build-guide.254056/page-87#post-7354510

 

[rockies914]

I have two big Yamaha +24vdc power supplies handy that originally came from a pro recording console setup. They do not reference ground to wall outlet ground, so they are floating. I've successfully used them as a bipolar 24v power supply for other projects, when I needed some serious amps

Would that work with an Aleph 30?

 

[TungstenAudio]

The power needs of a pro recording console are different from an Aleph 30. Total bias current of the Aleph 30 could be as high as 2.0 Amps, class A.
The Yamaha power supplies probably have excellent line noise rejection, but perhaps not good for 2A continuous.

 

[e_fortier]

Here you go, 2.2A continuous

 

[rockies914]

I've used them at a little over 10A per rail without issues so far 3u & 22lb rack mounted units, each drawing 1000w from the mains at full tilt. I have had them both on a single 15A house circuit without blowing the breaker, but I don't think I'm pushing them much. They seem efficient and pretty quiet.

https://www.markertek.com/product/ymh-pw800w/yamaha-pw800w-cl-series-power-supply

They've been in production for some time and are for the Yamaha CL line, PM5D and a few others. They can be regularly found used for $500 apiece fwiw; sometimes lower depending upon cosmetics.

(edit: these might be overkill, haha! I'm just looking for a head start & to be able to get going promply, if I somehow luck out with the current giveaway/raffle )

 

[tonyEE]

At that price point, why not just get lab supplies?

 

[Vunce]

Probably not a problem for the Aleph30

 

[rockies914]

Yep, for certain. I have them handy, that's all. I would build the proper power supply while listening to them

 

[Vunce]

You have them, might as well use them

 

[e_fortier]

Yep, for certain. I have them handy, that's all. I would build the proper power supply while listening to them

I’ve just downloaded the service manual, Yamaha is simply using a Cosel 24Vdc, 1000W switching mode power supply inside that unit. Perfect for a class A if you ask me.

 

[rockies914]

Thanks, that explains a lot Btw those Cosel SMPS are not exactly cheap! https://www.digikey.com/en/products/detail/cosel-usa-inc/PBA1000F-24/7044555

 

[e_fortier]

Yep, very pricey.
In the service manual they show the following model
ADA1000F-24-YMH

 

[rockies914]

The current rating on the ADA1000F-24 when supplied by 100v at the wall and using forced air cooling: 33A (Peak 63A)

The PM5D boards that these came with draw 600w or 660w depending upon the model, which is a little less than 28A.

Thanks for all the info. Perfect for an Aleph based Atmos setup (and combination sauna/equipment room)!

 

[wdavis009]

Finished the Aleph 60 build after a couple set backs due to my own carelessness. A big thank you to Randy for supplying me with a replacement set of MOSFETs for one channel after I toasted a few. I still have some wire organizing to do but was eager to listen to it tonight. The amp sounds really nice. Excellent drive and bottom end authority with my speakers. The Aleph 30 drove the speakers quite well but the 60 takes it even further. Really happy I decided to do this build. A huge "thank you" to Randy for creating these excellent boards and build guide.

 

[rhthatcher]

That’s a super clean build! Very nice job!!

What chassis and donut(s?) are you using?

For those who want to know - that power supply is my W12 dual mono CRCRC on one board.

 

[dantwomey]

Chassis used?

Regards,
Dan

 

[poseidonsvoice]

Likely 500mm deep given how well organized it looks…

Best,
Anand.

 

[wdavis009]

What chassis and donut(s?) are you using?

For those who want to know - that power supply is my W12 dual mono CRCRC on one board.

Transformer is the ANTEK AN-10425. Chassis is the 4U 500mm.

 

[Vunce]

I’ve been on the Antek site countless times buying trafos but never came across 4X secondaries all at the same output voltage, great find! Much easier to deal with a single trafo for dual mono psu.

Very nice Aleph60, well done!

 

[ItsAllInMyHead]

I finally took a bit of time to stuff some boards for the Aleph 60.

Once I get the external PSU all sorted out... I'll make some music. At the moment... subject to change at any moment... the PSU is planned to be...

Two of the V8 boards in a separate chassis with one set of resistors subbed out for the 'standard' Hammond 159ZJ. So, it will be a CLCRC... or a CRCLC. I'll have 33kuF electrolytics and motor-run caps in the amp chassis. Still trying to understand local decoupling etc.

I'm also determining what to use for a soft start. I'll likely just use thermistors for the time being, but I've got boards and a stack of parts for Mark's H9KPXG. I need to do some reading to see how to implement it with dual mono, dual rail. If anyone has already done so... or just knows how to do it, and could point me in the right direction, I'd be grateful. I plan on re-reading the thread again, but any help is appreciated.

Then, I'm trying to decide on speaker protection... I haven't done it yet for any builds, but...

Most importantly - Fantastic boards and guide, @rhthatcher!