Chinese Pass amp clone

[john65b]

Little late to this thread...

The Accuphase will have a higher inherent value, once fixed, than the DIY A30 or amp from Aliexpress.
The DIY A30 will give you sonic satisfaction, perhaps more than the Accuphase, and added Builder appreciation...

I preferred my F5 over my A3, and I never listened to anything from Accuphase, but heard many good things...

I also have a pair of unused BrianGT Aleph 5 boards as well as the power supply boards, somewhere too...

But if fixated on the A30, buy the Ali amp, strip it of the amps / power supply assemblies and put in the advised PCB / Parts. The Chassis, sinks, transformers are possibly fine...

 

[Mike Gergen]

FYI
Be careful buying from Ali, back in the DIYHIFI days we would post circuits with errors, on purpose.
Then watch the design show up on Ali for sale, errors and all.

 

[TheSoundMann]

The Ali amp has only 2 output transistors per channel, indicating that it is a hodgepodge of Pass designs.

 

[TheSoundMann]

Edit: I noticed the predrilled UMS store heatsinks were mentioned earlier. Note these PD boards most likely do not fit the UMS pattern since I believe they pre-dated that standard.

So the boards won't mount to them?

 

[TheSoundMann]

The Chassis, sinks, transformers are possibly fine...

If this is true, then I can buy the actual case for less. But everyone keeps telling me that it is insufficient. What is the truth?

No one currently stocks an 18+18 300va transformer, and buying the whole amp would be an expensive way to get them.

 

[Demonkleaner]

500va Too large?
https://www.ebay.com/itm/3733371716...+VGFvlVUFAqxjKPbRBqlPf5fJX|tkp:Bk9SR6TD1qqJYg

 

[TheSoundMann]

This case should be suitable? 150mm tall, but 400mm long heatsink/internally.

I can fit everything plus a preamp in it.

https://m.aliexpress.us/item/225183...lgo_pvid=91daaba2-bd9e-4442-8bbb-7344cfd7bc22

 

[TheSoundMann]

I can buy 20+20v transformers in either 300 or 400v from Antec for $57.

 

[von Ah]

This may suffice. Other more experienced builders could confirm.
https://www.digikey.com/en/products/detail/triad-magnetics/VPT36-6940/2090092

 

[Ben Mah]

20V secondaries should work. The original Aleph 30 had 25V rails so 20V secondaries should get you there. Be sure to use 35V capacitors, not 25V.

 

[tonyEE]

I have been debating whether or not to purchase a clone I found on Aliexpress.

They call it an A30, but it looks like an Aleph3/Zen project.

Here is the link to it.

https://m.aliexpress.us/item/3256805025011655.html?spm=a2g0n.productlist.0.0.14bedd4dAhdl6Q&browser_id=fb02a597949f4b549926b0d23314af5d&aff_platform=msite&m_page_id=oqrohktrpnqcaaqa1881c941a1d1806dc301185287&gclid=&pdp_npi=3@dis!USD!522.37!339.54!!!!!@211bf31716841069979266590d07e4!12000032191927464!sea!US!3328241714&algo_pvid=bf60a4f9-f6a2-434f-b749-23b32348ef1b

Is that thing even legal in the US?

 

[TheSoundMann]

Did the original Aleph 30 have a 300v transformer? And Nelson mentioned that it had bigger caps. So 33000uF?

 

[tonyEE]

Want I really want is a used Aleph 3/30 at a reasonable price, even though they would likely need to be serviced soon.

...

Jeez... and to think how I got flamed when I first bought the Rawson A5 monos and found that one wasn't working right.... So I posted for schematics on this forum.... I must say Nelson was a gentleman that evening... but I got flamed ( I mean, I needed asbestos underwear that night ).

And, heck, it was because I couldn't find a used Pass A5.... ( I fixed it.. it was a cold solder that I found on inspection ).

No, no, no.... as an engineer, I have taken MANY courses about Intellectual Property. This stuff should be held up at US Customs!

 

[Ben Mah]

Did the original Aleph 30 have a 300v transformer? And Nelson mentioned that it had bigger caps. So 33000uF?

Don't know what transformer but the power consumption was 200W so 400VA is probably the better fit.

Manual says 120,000uF total.

 

[TheSoundMann]

All of my fake Cardas cables sailed right through customs.

 

[tonyEE]

Peppe - if you can’t find a power board I’ll chip in one.

I will supply matched input and output MOSFETs if this will get built.

I do have those spare A5s..... but those are the ones that got me flamed to start with.... so I'm sort of attached to them.

I honestly don't understand how those people get away with posting that stuff on the Internet. It is patently (pun) an illegal theft of IP.

 

[Pars]

I can buy 20+20v transformers in either 300 or 400v from Antec for $57.

Antek are good transformers IMO. Never had any problems with them if they have what I need.

 

[TheSoundMann]

I was thinking of using a 400v 20+20 with 33000uF caps @35v, but I will wait and see what 6L6 has for me.

 

[TheSoundMann]

You guys are going to love this one!

https://m.aliexpress.us/item/325680...lgo_pvid=947cf0cf-a12b-429a-8f66-4cc47051bba0

 

[6L6]

Bigger capacitors are not automatically better. Phase angle of conductance becomes an issue when they get big.



The Chinese clone chassis cease being interesting once the shipping cost is factored in. (And that’s aside from the dubious implications of the copy of the trademark/brand…)