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Old 11th March 2002, 09:07 AM   #1
NHul is offline NHul  Croatia
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Default Standby

Hi


If I'm not wrong, Mr Pass "X" series amplifiers are all with standby approach. I'm not familiar with that kind of device. I tried to search for standby on the forum, but I could not find any threads relative to this.
Iwould like to know if anyone has same existing standby circuit.
Would it be possible to built someone, and put it in the Aleph series?

Thanks for any input,


NHul
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Old 11th March 2002, 11:16 AM   #2
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I think the X-series use the same topology as Mark Levinson amplifiers. That means when you switch from 'on' to 'standby' the power stage is switched off while the pre-amplifier stage remains biased.
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Old 11th March 2002, 05:44 PM   #3
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Please do not refer to the topology of X amps as
having any similarity to the Harmon products. I
have schematics of those, and no two types of
amplifiers could be more dissimilar.

The standby in the X amps leaves the supply charged,
but shuts down the bias and front end.
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Old 12th March 2002, 11:31 AM   #4
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Is the reason of leaving the supply charged to prevent the capacitors getting deformed?
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Old 12th March 2002, 06:55 PM   #5
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No, simply to avoid the monster inrush.
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Old 14th March 2002, 04:49 AM   #6
BrianGT is offline BrianGT  United States
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For standby mode, could you simply put a dual pole switch on the + and - voltage lines coming out of your capacitors?

Would that cause problems? Would a 20A switch be enough for this?

--
Brian
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Old 14th March 2002, 09:27 AM   #7
NHul is offline NHul  Croatia
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For shuts down this stage, where exactly in way of bias and frontend put the relays ?

NHul
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Old 14th March 2002, 03:51 PM   #8
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Place a relay between the supply capacitors and the rest of the amplifier. Just make sure the supply for the relay coil is taken from the capacitors of before, otherwise you can switch your amp standby but can never turn it on anymore
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Old 6th October 2005, 07:38 PM   #9
Pboden is offline Pboden  Norway
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Default Stanby on Aleph

Quote:
Originally posted by BrianGT
For standby mode, could you simply put a dual pole switch on the + and - voltage lines coming out of your capacitors?

Would that cause problems? Would a 20A switch be enough for this?

--
Brian
I can't find an answer to Brians question regarding stanby mode on the Aleph. There shouldn't be a problem to place a switch between the capacitors and the main board?
That would stop the massive inrush to the transistors?

As a result, there would be no need for a soft start module, i.m.o.
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Old 7th October 2005, 05:43 AM   #10
Blues is offline Blues  United States
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Default Re: Stanby on Aleph

Quote:
Originally posted by Pboden


I can't find an answer to Brians question regarding stanby mode on the Aleph. There shouldn't be a problem to place a switch between the capacitors and the main board?
That would stop the massive inrush to the transistors?

As a result, there would be no need for a soft start module, i.m.o.
Works like a charm on my Zv4 with 90mF/ch of caps. Requires a main power switch and On-On Standby/Play switch. The latter keeps the caps charged with a standby LED lit orange and in play mode turns blue and plays music. I also don't have to keep replacing 3A fuses every power-on. Initial power on (make sure PSU is ok) requires a bigger fuse. Let it soak for a few minutes then power off and change-out to specified fuse value
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