Aleph1.7

[RSQ8P]

nobody?

 

[AudioSan]

this is a 7year old forgotten tread🙂

 

[RSQ8P]

So?
People still build these amps. I could have opened a new thread, but this seemed more economical.
So still nobody ;-)

 

[mat1976]

indeed, people do still make this pre-amp.
i just started building mine to work with my aleph 5 mono blocks (not completed).

my biggest problem seems to be the fact that i lost my original PDF file of the aleph 1.7
can anybody help me out?

 

[Itsmee]

i lost my original PDF file of the aleph 1.7
can anybody help me out?

You can find it at http://www.kk-pcb.com/

 

[Gyuri]

Maybe this is what you need:

 

[mat1976]

Gyuri.

many, many thanks.
it is axectly what i need. 🙂

 

[3drickie]

Resistor question

I' ve ordered almost all the stuf I need for my Aleph 1.7 project. This week I received some resistors that I bought on Ebay. They are: DALE RLR05C2210FS 221R 1% 1/8 (0,125) watt. Normally the 1/4 (0,25)watt resistors are used. Can I use these ?

Thanks for your time.

 

[3drickie]

Resistor question

Here is the data sheet.

http://www.vishay.com/docs/31023/erl.pdf

 

[Danger Mouse]

looking at a Zener diode can drive some circuits into oscillation

Hello

I`ve also build an Aleph P1.7 a time ago.
It had hum with PC worser than with CD Player.
Seems that this are oscillations.
Put in a 221Ohm resistor at the input like in BOSOZ R18/19
solved the problem.

In the BOSOZ article is this:

Also note that if you do not use Zener diodes for input protection, you
will not need R18 and R19, and they may be replaced by wire. Their
function is to ensure stability for the circuit driving the input, since
directly looking at a Zener diode can drive some circuits into oscillation.​

This is also why we use R7 and R8, and R9 and R10.

The input at BOSOZ and ALPEH P looks similar
But Aleph P dosn`t have 221Ohm input resistors but the problem is the same-> circut looks at input directly at Zener and maybe drive crazy???

Is it possible that Pass use this resistors but they are not in schematics?
or is that problem solved at another way?
(Used friendly Zeners that dont annoy other circuts😀)

Maybe Pass himself can give a hint😉 he must know it best😀😀😀


(For fun i tested my Bosoz without R18/19 an problem is the same i had hum/oscillations with R18/19 hum was gone)

 

[nrg2009]

Post some photos if you can. Im thinking of building one of these..

 

[AudioSan]

i have no hum what so ever with my aleph P1.7🙂 and here it is🙂

 

[nrg2009]

Very nice photo. What do the additional boards do? Is that your remote controlled volume control?
What type of 10pF caps did you use right in the middle of the board?
Seems like a shielded toroid? Very nice!

 

[AudioSan]

it is dantimax input board, control2 board, front control board, remote PSU for the boards (wich also activate the preamp with remote control) and volume control board🙂
the 10uF caps are panasonic. and the transformer is shelded 160VA 2x30V🙂

 

[sakellogg]

Post some photos if you can. Im thinking of building one of these..

i like mine. sounds good to me.

 

[impuls]

Hello, I want to ask one question. Two years ago I started making Aleph P1.7 with some changes in the configuration. I put the relay shunt type attenuator at the input and output goes directly from output capacitors. Did I made ​​a worse solution knowing that the preamp sensitive to the impedance next level if it is not loaded symmetrically?

I didnt found a common theme for P1.7 so I asked the question here.