speaker "pop" when x150 power-on

dream · 19th July 2003, 09:18 AM

i turn on the system in the following order:
1. mute x2.5 pre-amp (x2.5 is always on)
2. push the "STAND-BY" button on the front panel of x150. x150 goes into operation

however in step 2, my x150 always makes the speakers (b&w m801) a pop, although not very loud.

is this a normal case or my x150 need to be repaired?

thx in advance

Nelson Pass · 19th July 2003, 11:18 PM

I'll check on it next week at work.

dream · 20th July 2003, 04:29 PM

thx you nelson

LBHajdu · 20th July 2003, 11:27 PM

If it’s not too much to ask could you post the stand by circuit Mr. Pass. Some people may want to implement it in some of our diy amps. I’ll even draw it up for you if you send me something ruff.

Levente Hajdu

Nelson Pass · 21st July 2003, 06:19 PM

If you have an early X150, then the direct coupled inputs will
experience a slight difference in turn-on thump when the
circut is activated because the relay shorted outputs of the
muted X2.5 present a low impedance DC source. If you
capacitor couple the inputs of an X150, which was done on
later models for just this reason, you do not experience the noise.

All this is normal, and the thump itself is minor. You can confirm
this by trying your ordinary turn on procedure but with the
volume control set at "1" instead of "0".

The standby circuit varies by model, according to the needs of
each amp. Publishing any particular one of them is not likely
to be helpful in general.

tiroth · 21st July 2003, 06:29 PM

Talk about customer service.

dream · 22nd July 2003, 07:26 AM

thx nelson

do you think this DC singal will harm the tweeter?

Nelson Pass · 22nd July 2003, 10:21 PM

No. Something like this is usually a large fraction of a volt
in the 1 Hz range.

jleaman · 22nd July 2003, 10:27 PM

could you post the stand by circuit for a aleph 2 ?

Nelson Pass · 22nd July 2003, 10:38 PM

There has never been a standby circuit for the Alephs. I would
have to create one...

19th July 2003, 09:18 AM	#1
dream diyAudio Member Join Date: Jun 2003 Location: taiwan	speaker "pop" when x150 power-on i turn on the system in the following order: 1. mute x2.5 pre-amp (x2.5 is always on) 2. push the "STAND-BY" button on the front panel of x150. x150 goes into operation however in step 2, my x150 always makes the speakers (b&w m801) a pop, although not very loud. is this a normal case or my x150 need to be repaired? thx in advance

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19th July 2003, 11:18 PM	#2
Nelson Pass The one and only Join Date: Mar 2001	I'll check on it next week at work.

20th July 2003, 04:29 PM	#3
dream diyAudio Member Join Date: Jun 2003 Location: taiwan	thx you nelson

20th July 2003, 11:27 PM	#4
LBHajdu diyAudio Member Join Date: Feb 2002 Location: NY, USA	If it’s not too much to ask could you post the stand by circuit Mr. Pass. Some people may want to implement it in some of our diy amps. I’ll even draw it up for you if you send me something ruff. Levente Hajdu

21st July 2003, 06:19 PM	#5
Nelson Pass The one and only Join Date: Mar 2001	If you have an early X150, then the direct coupled inputs will experience a slight difference in turn-on thump when the circut is activated because the relay shorted outputs of the muted X2.5 present a low impedance DC source. If you capacitor couple the inputs of an X150, which was done on later models for just this reason, you do not experience the noise. All this is normal, and the thump itself is minor. You can confirm this by trying your ordinary turn on procedure but with the volume control set at "1" instead of "0". The standby circuit varies by model, according to the needs of each amp. Publishing any particular one of them is not likely to be helpful in general.

21st July 2003, 06:29 PM	#6
tiroth diyAudio Member Join Date: Dec 2001 Location: Pittsburgh, PA, USA	Talk about customer service.

22nd July 2003, 07:26 AM	#7
dream diyAudio Member Join Date: Jun 2003 Location: taiwan	thx nelson do you think this DC singal will harm the tweeter?

22nd July 2003, 10:21 PM	#8
Nelson Pass The one and only Join Date: Mar 2001	No. Something like this is usually a large fraction of a volt in the 1 Hz range.

22nd July 2003, 10:27 PM	#9
jleaman Banned Join Date: Apr 2002	could you post the stand by circuit for a aleph 2 ?

22nd July 2003, 10:38 PM	#10
Nelson Pass The one and only Join Date: Mar 2001	There has never been a standby circuit for the Alephs. I would have to create one...

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