B1 Buffer Preamp

Hi all.
I am using a computer brick to power up my b1!
Only 19vdc goes to the box , no grounding!
I was testing it with a ACA today,
If I power up the b1 first ! This is all good!
But if I power up the ACA first , then I have a pop noise on the speaker and the brick goes to some kind of safety mode ! So it does not deliver anymore tension until I unplug it from socket and back,
What could help to prevent this pop?
Caps at power switch? Inrush limiter? Do I need to put grounding?
Thanks in advance for you advises
 

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care to clarify?

you're feeding both B1 and ACA with same switching supply?

are both B1 and ACA made without any change in schematic?
try , ofr test , disconnecting B1's first smoothing cap ( 15000uF in schematic in article)

maybe it's too much of surge current when ACA is already connected

in that case , increase 1R resistor (in front of mentioned cap) to , say , 10R
 
...if you're sure in your build...

Heh, heh. I was sure of my build... until I wasn't.

After looking more closely at my wiring I noticed that I had + - input leads backwards. The twisted CAT5 were hard to see which one was solid and which was striped. 😱

After correcting that, the B1 is now as quiet as an undiscovered mummy's tomb. The Mean Well GS06U-6P1J works perfectly and only cost US$12.00. 😀
 
No, ACA has onboard Smps sypply, and b1 its own brick!
Yes both amp and pre are sticking to schematics! No changes!

I have same feeling that too much current comes in when aca is on already,
When b1 is on , I can turn it off and on without any pop as long as there is still something in the capacitors
 
writing in a hurry is becoming your habit .........:rofl:

so , let me guess here what's really happening :

case A: you power up B1 first , then you power ACA and everything is good

case B: you power up ACA first , then you power B1 , there is POP! and ACA's supply goes to protection mode ?

well , if I guessed right ,and if you're doing it as case B ....... that's the same as throwing a brick on gas pedal of your car , before you lay your ar$$e in driving seat

in other words , same as leaving your head at home and going to school


always power up power amp last and power off power amp first

:devilr:
 
Hi zen mod and mjf,

Thank you for you message.
Zen, what you were guessing is correct...
Case A : no problem
Case b :""""" you power up ACA first , then you power B1 , there is POP! ....."""". and B1 supply goes to protection mode ! Not ACA!
But I understand your point! That make sense! Still I will try to get rid of this pop by increasing the 1r to a 10r!

MJF: yes the polarity of c1 is correct,!
And you are right there is quite mush wires, I brought the components before the box, and I wanted to have it in small format, but the caps height did fit, so I decided to install them horizontally using these extra wires!
 
He/She is using an external wall wart PSU...the PSU internal protection is shutting down the power supply.

It's not exactly a wall wart. Syl20m posted, "I am using a computer brick to power up my b1!"

Some laptop power supplies have under/over voltage protection built in to protect the computer's battery. This could be the culprit.

I found a link to someone who disabled theirs.

As I said a few posts back, my $12.00 wall wart works perfectly!
 
Hi all,
Some of you are wondering about what PSU I am using !
So please see the model on the picture !
This laptop charger goes indeed in some protection mode when a pop occurs if powering the ACA first and then the B1!
I must unplug the charger from wall socket to make it work again.
Thanks
 

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I just replace the R1 1r to a 10r and now quite no pop and charger does not go
To safety state!
Then I have tried 20r , but it does not help further more!
I have to try now to take out C1 15000u out as Zen mode suggested, or replace it by a smaller one?!

Anyway this is already quite alright, as b1 should be power up first , which in that case does not produce any pop!

Thanks