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What is "Pass A30?" Is it genuine?

Kreshna

Kreshna

...but I have to know.
I found this monoblock amp on Ebay. The description says "Finished Pass A30 Mos Single-ended Class A Power Amplifier Mono 30W HiFi Amp". So, is that a true DIY version of Pass Labs XA30.5? Or is that just a crappy Chinese amp with the name "Pass" and "A30" slapped in to fool people? As far as I knew, DIY versions indeed exist for Nelson Pass amplifier, but they're mostly First Watt equivalents instead of Pass Labs.

This is the picture, by the way.

jKMJHjO.jpg


The innards:

wiDNI9U.jpg
 
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There's not a whole lot that goes into an Aleph circuit. Most of the cost is heatsinking and power supply.

These don't look like they have a huge amount of heatsinking.
 
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That amp says "L Pass", not Pass Labs.

The circuit characteristics of integrated design:
Basically faithful to the classic PassA30 circuit
200W high quality loop cow power supply, the use of 6 fever 10000uf Nover CRC capacitor filter, the total filter capacity of a total of 60000uf, the most important:
Join the upc1237 speaker protection system, switch machine is absolutely no impact sound, execute the midpoint of DC protection at the same time, eliminate the power amplifier circuit and burn your expensive box damaged.
Three pairs of large power field effect transistor parallel flow output, ensure the driving force.
In the differential input link to join a midpoint of the fine-tuning of the circuit, can be a certain degree of correction of the midpoint of the problem.
Finished machine uses about 2KG of the heat sink, while the whole machine is aluminum design, the benefits of doing so is that in addition to the heat sink, the other parts of the machine is also involved in heat, making the total heat radiation area greatly increased.
Pure post mono design, to prevent separation from the more, as long as the fancier, all understand what the benefits of doing so, disadvantages are also obvious, is the high cost.
In addition to the standard lotus audio input, the machine provides a balanced input interface, easy to connect to the front end of the professional.
Click to expand...

It is also a mono block, not a 2 channel amplifier.

https://www.aliexpress.com/store/pr...amplifiers-audio-hifi/936157_32781791211.html

A30 heatsink fins run horizontally.

A "real" Aleph 30 looks like this, and is a stereo(2 channel) amplifier:

607532-pass_aleph_30_volksamp.jpg
 
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Of course it's not a real Pass, that's why it's so cheap.

1. Don't know if it is actually based on any Pass design, or just the thinly veiled implication it is.
2. Even if it is based on Pass design, don't know if the components are sized properly.
3. Quality of components is speculative.
4. If it craps out you are almost certainly on your own to fix it or take the loss.

Just looking at it based on the size relative to the speaker binding posts, I think it is smaller than one might expect. Size doesn't inherently make it a bad amp, but it might if it would otherwise be a Class A design (again, speculative).

On the other hand, even if all that is true, if the price is right it may be worth the risk. Only the perspective buyer can really answer that part...what is your risk tolerance?
 
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It says based on the Aleph circuit. It also has speaker protection but Nelson typically doesnt use it in his designs. If the seller did steal the circuit instead of buying the DIY aleph boards, then IMHO, this is a disservice to a man that has been very generous to the DIY and audio cimmunities.
 
edwyun said:
It says based on the Aleph circuit. It also has speaker protection but Nelson typically doesnt use it in his designs. If the seller did steal the circuit instead of buying the DIY aleph boards, then IMHO, this is a disservice to a man that has been very generous to the DIY and audio cimmunities.
Click to expand...
...if the seller actually went all lengths of stealing the circuits, instead of merely slapping in the words "Pass" and "30" to give false impression that the amp uses Nelson Pass design.
 
This is the second contraband Pass amp you have brought up. Instead of finding the fake amps, and starting threads about them, why don't you spring for a real one? A used Aleph will run $1k to $1.8K, and is a superb amp. His great amps come up every month, the clones every two weeks, and the fake ones almost every day.
 
My apologies, Kreshna. I was wrong assigning the previous thread to you. My main point is please do not get sucked into buying a spurious knockoff, one that is not even close to the design, and deliberately presented to trick unknowing folks.

LPass my p..ass.
 
sheltie dave said:
and deliberately presented to trick unknowing folks.
Click to expand...
.................... and this is the key, they are unknowing and therefore would never pop the coin necessary for the genuine article which means that whether they buy the possibly junk import product or not, it's going to have ZERO effect on Mr Pass' income. IMO, the guys posting on this forum are seeking to be better informed every bit as much as they're seeking to make a purchase.

Interesting that David Theodore Nelson Williamson's designs were/are not defended like this. Instead, some became textbook standards.
 
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