aleph L preamp

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nope!

Well I already have built the aleph-L (the second version) and I do not think there is a mistake as it works perfectly for me. Only mistake I found is the values of the various test points in volts which are essentially the values of the first version.
If u think there is a mistake though i would be glad to hear from u.

Regards,

Panos
 
preamp aleph L

In the schematic of the service manual, the intput impedance is near to 1 or 2 KOhm only.
More, if the volume selector is on the RV6 value, when the relay is
on, the outstage of the input is short-circuiting.
I speak about version 1.2.
If anyboby want to show the problem on the schematic, give me your @mail adress.
 
L-aleph

Dear SDF,

Let me try to explain things a bit for u.
first of all lets clear the relay part which is there just to mute any poping sound when u first turn on the preamp. Meaning that the relay is shortcircuiting the input to ground only for a few seconds after turn on and emmediately again when u turn off the preamp.

About the volume control is a very smart setup since until vr6 it only controls the volume directly from the input to output without using the active circuitry, working as a passive preamp, after vr6 the preamp becomes an active peamplifier.

The preamp works very well and I have it working for a years or so but without this volume control, i use the electronic volume control from aleph p. If u like to built it I can post also the pcb I am using designed by muself, not that R115 and R106 should be 2W resistors.

Moreover since I am coming to Paris in 2 weeks I would very thankfull if u could provide me with some info concerning any shops selling quality audio components as resistors from vishay-holco, capacitors etc and if u know of any shop selling used equipment for testing as, osciloscopes signal generators etc

Regards,

Panos
 
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