Aleph P 1.7 output muting relay...

Freddie · 20th March 2002, 05:20 PM

I've read in the service manual that the output muting relay is controlled by the circuits of Q21 and Q22. But where is the output relay? I can't find it anywhere on the schematics, I can't find it on the component placement diagram either. I suppose it is directly after the 10uF caps, and simply shorts to ground so there are no turn on transients, am I right?

Thanks in advance

/Freddie

fcel · 20th March 2002, 07:50 PM

I don't mean to bug in here but has anybody installed/design a turn on muting circuit for BOSOZ? Nelson Pass has indicated in the BOSOZ article as a exercise for the reader.

Helix · 20th March 2002, 11:52 PM

i guess it justs attenuates the output to the full, by using it's volume control relays

GRollins · 9th April 2002, 12:55 AM

The mute relay runs off of the Mute + and Mute - coming from Q21 & Q22. Q21 switches on and off more or less instantly once the rail comes up or drops. Q22 provides the delay on turn-on via the cap at the gate. The relay itself is not shown (at least not on the power supply schematic with the rest of the circuit--I didn't bother looking for it elsewhere), but it's not too hard to hook up a relay to Q21 & 22, then apply ground to the outputs. The IRF610 and IRF9610 have sufficient current capability to drive any reasonable relay coil for this application.
The circuit tickles me, because it's such an elegant way to use up out-of-spec parts from the gain stages.

Grey

Klaus · 23rd October 2002, 02:43 PM

Hi,

I do not understand all details of the voltage losses of this damned FET´s...

Could anyone please tell my the Voltage rating of the mute relay coil, thanks!

Klaus

Jens · 23rd October 2002, 07:41 PM

I believe 48V types, but both output relays serial - like the input relays.

20th March 2002, 05:20 PM	#1
Freddie diyAudio Member Join Date: Oct 2000 Location: Sweden	Aleph P 1.7 output muting relay... I've read in the service manual that the output muting relay is controlled by the circuits of Q21 and Q22. But where is the output relay? I can't find it anywhere on the schematics, I can't find it on the component placement diagram either. I suppose it is directly after the 10uF caps, and simply shorts to ground so there are no turn on transients, am I right? Thanks in advance /Freddie

23rd October 2002, 02:43 PM	#5
Klaus diyAudio Member Join Date: May 2002 Location: Germany, Frankfurt/Main	Voltage of mute relaiy? Hi, I do not understand all details of the voltage losses of this damned FET´s... Could anyone please tell my the Voltage rating of the mute relay coil, thanks! Klaus

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20th March 2002, 07:50 PM	#2
fcel diyAudio Member Join Date: Sep 2001 Location: LA County	I don't mean to bug in here but has anybody installed/design a turn on muting circuit for BOSOZ? Nelson Pass has indicated in the BOSOZ article as a exercise for the reader.

20th March 2002, 11:52 PM	#3
Helix diyAudio Member Join Date: Jul 2001 Location: UK	i guess it justs attenuates the output to the full, by using it's volume control relays

9th April 2002, 12:55 AM	#4
GRollins diyAudio Member Join Date: Feb 2001 Location: Columbia, SC	The mute relay runs off of the Mute + and Mute - coming from Q21 & Q22. Q21 switches on and off more or less instantly once the rail comes up or drops. Q22 provides the delay on turn-on via the cap at the gate. The relay itself is not shown (at least not on the power supply schematic with the rest of the circuit--I didn't bother looking for it elsewhere), but it's not too hard to hook up a relay to Q21 & 22, then apply ground to the outputs. The IRF610 and IRF9610 have sufficient current capability to drive any reasonable relay coil for this application. The circuit tickles me, because it's such an elegant way to use up out-of-spec parts from the gain stages. Grey

23rd October 2002, 07:41 PM	#6
Jens diyAudio Member Join Date: Feb 2001 Location: Germany - Taunusstein	I believe 48V types, but both output relays serial - like the input relays.

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