YBA Integre, hum through speakers

[Aracu]

I recently purchased a used 15 year old YBA Integre, the original version with one (not dual) amplifier. It sounds clear, precise and stunning. However, I suspect that the hum of the amplifier through the speakers, the constant sound of the
amplifier when it is turned on, which is not affected by the volume control, is a little louder and more abrasive than it should be, and this sound is distracting during quiet musical passages. I was wondering if anyone could give some insight
into this issue, in terms of how fixable it could be.

 

[Resqueline]

A high-end amp like that shouldn't have any hum or hiss whatsoever.
It has to be fixable, and it could be as simple as dried-out electrolytics.
The challenge with remote-assistance however is finding a schematic diagram of it.
An oscilloscope is a useful instrument for actively locating the culprit.

 

[Aracu]

Thanks for the advice... any recomendations for a New York based repair person?

 

[Resqueline]

I'm sorry but I'm not from around there, nor have I heard about any.

 

[Aracu]

I ended up sending it to YBA in Canada, since there was no schematic available, and since it has some YBA parts. Hope it is not too expensive.

 

[niftynev]

i could be a smart alec & say that it's only humming cause it doesn't know the words, but i won't! lol!

but seriously, there may be an earth loop, via another earthed signal source.

you could try unplugging the tuner, then the cd player, etc & see if the humming disappears.

resqueline is right about the electros - if their electrolyte dries out they won't be able to reduce the 100 (or 120) hertz ripple that is superimposed on the dc power supply line. i've had that problem before. you could look for any electros whose plastic covering has sort-of 'shrunk', or checking their temperature with your finger.

did you end up getting it fixed?

& what's YBA by the way?

 

[computerlen]

It most likely means Yorkville Bass Amp. [I am associated with the company.]

 

[niftynev]

computerlen, i saw the nice valve bass amps you were talking about. i'd love to have a couple o them myself! lol! hand-made ay - beautiful! gotta love that 2nd harmonic valve sound!

but it seems like aracu is talking about a really expensive (nearly $5k!) french-built amp by yves-bernard andre. wow! i've never seen an amp with NO wiring! - well, almost; maybe they've hidden it well.
but definitely one you'd get fixed rather than buyin a new one!

i wanna hear back from aracu as to what was wrong with it though!

 

[biomed]

YBA Integre hum problem

I just found the hum in my YBA Integre Sigma DT to be a bad 470uF 63V cap in the input circuit. Found it with a multimeter after I pulled the board up off the chassis mounts. Just checked all the caps for AC ripple voltage. Any cap reading higher ripple than other similar caps is suspect.

The most difficult part of the job is pulling up the PCB. It is wedged in pretty snug and volume pot will lift up with the board.

Good luck!