speaker "pop" when x150 power-on

[dream]

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]

I'll check on it next week at work.

 

[dream]

thx you nelson

 

[LBHajdu]

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]

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]

Talk about customer service.

 

[dream]

thx nelson

do you think this DC singal will harm the tweeter?

 

[Nelson Pass]

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

 

[jleaman]

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

 

[Nelson Pass]

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

 

[jleaman]

Ok where do we start..!..


Question is.. Is it worth it. ?

im thinking about making a Soft turn on. instead of a huge switch ill use a small micro button with a circuit to turn on the primaries on the transformer..

 

[thylantyr]

Jason;

A cool soft start circuit is 4 giant frankenstien knife switches,
three with progressive lower resistors and the last one
a direct connect..

Throw in a tesla coil for visual effects.


/jk

 

[jleaman]

I wish i had pictures of my dads old tesla coils They were huge and wicked.. he had about 12 of them all different sizes and lenth's..

 

[thylantyr]

Just like the TV show American Chopper where they
make theme bikes, you could build some
"theme amplifiers"..


The Frankenstien amp - tesla coil mounts on top of chassis.

The Mummy - a chassis wrapped in cloth that suffers heat
dissipation.

Creature from the Black Lagoon - a chassis with gills, powder
coat green heatsinks immersed in swamp goo.

Plan 9 From Outer Space - an amplifier without chassis, power
supply and output stage - due to budget contraints.

Dracula - Red heatsinks with teeth. Blood oozing out of
the fins optional.

The House of Wax - heatinks made of wax - not class A friendly.

Night of the Living Dead - Heatsinks made of bone.

Psycho - knife blades for heatsinks.

The Blob - old Bob Carver amp minus chassis.