Aleph-X builder's thread.

[Zen Mod]

Originally posted by Phill
hello



i'm winemaker
nobody is perfect !

thanks !
Phill

ya need to know way to became perfect?

send few bottles of your finest to Papa

[Nelson Pass]

I just received three bottles from Austria, and I have to say that
the Bordeaux was excellent this evening.

It goes very well with the new DVD: Apostrophe / Overnite Sensation

:zappa icon:



(Sorry, I just couldn't wait for the wine to mature...)



I think I'll go out to the shop and work on some DIY project now.

[Blues]

Please send more Bordeaux to Mr. Pass...he just posted about 8x on 8 different threads...and he's in his shop (kitchen table) brewing something for DIY.

[Manu]

Glad to hear that the Côtes de Bourg makes you hyperactive, Mr. Pass.
Cheers

manuel

[noisefree]

Cheers to all and hello!!!

I am new here on this forum and it is my first post.

First of I want to thank Mr. Pass for sharing his knowledge with us and spending so many projects to the world.
Really great!!! Thanks a lot!!!
Please excuse my poorly English. I read this forum since 3 or 4 years but never have registered me because of this reason. Forgive me...
I have all German test-magazines to Passlabs X-series products and sometimes I could see good pictures of product details. For this reason it was possible to reconstruct some circuits but often with one or more questions left over.
Unfortunately I have no time to build something but when I am ready with a lot of other work and study I will start. I have bought many parts the last time mostly by ebay and all goodies are waiting for their adoption...(for example: 4x heat sink à 0,125K/W (two XA100?) and 2x 0,15K/W (X250.5?))
O.K. ......here are few of the questions which I have collected the last two years . I hope someone can answer them (perhaps Mr. Pass personally?) and it is the right thread for them!?

1. XA160 :
What is the resistor on the Aleph-CS for which is attached from collector to emitter on the ZTX450 transistor? Current limiting on the positive half or DC-offset stabilisation?
Which value should be used?
Does every bridge side uses one heat sink or the Aleph-CS one side and the gain devices the other?

2. XA60.5/XA100.5 :
Does each bridge side uses FOUR parallel N-ch. mosfets as CCS?
(+ eight N-ch. and P-ch complementary pairs?)
I count 32x 3W-resistors an 20 mosfets on each side in the Japanese manual. But with 20 mosfets each a resistor on its source there are 12 to much. What are these power-resistors for? Output to ground - helping to stabilize the DC-offset like the XA-series does? When it is so, why does a X.5-amplifier not need this feature?

3. XA350.5 :
The SE-CCS is made of a power-pnp-transistor and a high-power-resistor (20W/ 50W with heat sinking) attached between output and emitter. For this kind of CCS you need a reference voltage between base and output for turning it on. Which value has this voltage and how can I generate it?
When this reference is half the negative supply voltage, the dissipation on the transistor and on the resistor are nearly equal which makes sense by a whole dissipation of perhaps 30W or 40W. But what will happen when the negative output-voltage swings more than half the negative supply - than there is not enough for the reference-base-output-voltage left over!? When using only a small reference voltage for example a Vbe-reference there is no need for such a power-resistor? Unfortunately I cannot see the value of this resistor on the magazine-picture and so I cannot find the solution.
Last questions: Am I right that there is no separate transformer or windings for the front-end and for what is the BR+ connection on the mainboard?

I know…..a lot of questions for the first time been locked in!

Hopefully and with best regards from Germany

Dirk

[steenoe]

Dirk, look around and see for yourself what we are doing (or trying to do) here Noone expects Mr Pass to hand over the details of his newest creations. After all its what he makes a living from. We mainly use the service manuals published by Mr Pass covering older models together with the Firstwatt and PassDIY papers. There has also been some second guessed circuits (Mainly the Aleph-X by Grey Rollins and also some work on the .5 XA's by McMillan, together with some other amps) I suggest you take a look at those subjects
How was that, for being diplomatic?

Steen

[Magura]

Originally posted by steenoe

How was that, for being diplomatic?

Steen

Dygtig


Magura

[steenoe]

Originally posted by Magura



Dygtig


Magura

Thanks, I knew I had it in me somewhere

Me

[Zen Mod]

Originally posted by steenoe


Thanks, I knew I had it in me somewhere

Me

what's dygtig?

[steenoe]

Originally posted by Zen Mod



what's dygtig?

What is your best guess?? Me doin' mindgame on you ZM