potentiometer pass aleph 1.7

[P270]

Hi all

Any it knows sums k it should he is potentiometer for pass aleph 1.7 as me it informs (single function)

Thanks takis
:

[Nelson Pass]

Are you asking for resistor values (switch) or potentiometer
values?

[P270]

Hi mr Pass

I want to try also the two except and if potentiometers one from the two and something still IRF 9610 need heatsink

Best regards Takis

[Nelson Pass]

I having a little problem deciphering the request, but here goes:

There a three places you can put variable resistance in an
Aleph P to alter the gain

1) You can place a dual potentiometer on the inputs as a
voltage divider. (dual pot required for 1 channel balanced)

A good value for this is 10K to 25K

2) You can place a single potentiometer between the Source
pins of the Mosfets, where a good value is about 1 Kohm.

3) You can place a dual potentiometer as a resistive load at
the outputs (again 1 dual for each channel) to load the
current-source output, and here a good value is about 1 Kohm.

And of course any of these pots can be replaced by rotary
switches and resistors (use make-before-break contacts) or
relays and resistors.

And yes, small heat sinks are a good idea.

[P270]

Hi mr Pass

Thanks for your help

takis

[Shaun Perez 2]

So if I were to use the gain control between the source pins of the 610 Mosfets like the original Aleph p 1.7 then just what exactly would be the lowest resistor wattage needed?

I am planning on putting 20 100 ohm resistors in series for 20 gain settings with relays and a multi-position make before break switch to control them in place of the original potentiometer. I can see that there is not a significent dc difference however I am not sure about what the AC is at here.


I was looking at 1/10 watt dales, will these be enough to handle the power at this location?

[wuffwaff]

Hi,

putting 20 100 Ohm resistors in series will make a linear pot wich isn´t really suited for audio. Try something based on a log scale ( X dB per step).

william

[Shaun Perez 2]

Ive got it!
How about I just use one of the original volume controls of the aleph P 1.7 for the 2k gain control! I would just have to take off the first two 8k and 4k resistors and replace them - on the other end - with 30.9 ohms and 15.48 ohms!
I think that this would work.
Then the only problem would be in making them make-before-break to avoid noise pops. I think that would be the ultimate though, 256 steps of precise gain adjustment.