**********HELP WITH BELLARI rp583**************

[soulrack]

Hi there.

Im from Spain ,First of all thank to de admin for activate my account.

I need help with this unit...and i cant find anydody who can helps me.
My unit has a noise (like a power suply sound ) in channel 2 ,which is near to power supply..
If you turn up the volume on channel two at maximun you can hear that sound...if you do that with channel one,only you hear typical valve and floor noise...

Only happens on channel two,

The unit is new bought on ebay for 500 dollars..The seller says that the warranty do not cover overseas..and if I send the unit back to them, I will lost a lot of money.
So i have decided to repair it...( i like the unit ).

Can you suggest me something?
Its horrible to hear that sound and if i want use it for mastering...that problem must be fixed...

Hope you can help to me.


Bellari guys says the next:
The side nearer the powersupply has more hum than the other side and that is
norman. Warranty only for lower 48 united states.


Well...you can see how they works...and the quality of their components..
well..a better power supply will fix the problem?
or can be the power supply get out from the chassis..and put it on aexternal box?

anybody has this unit..and can hear the hum too?

ANd anybody have the service manual or Schematics?
they have not them...VERY BAD SUPPORT!!!! AND VERY BAD FOR THEM!

please I need help


Thanks AMIGOS


Sorry about my English


GRACIAS!!

[Voodoo Guru]

Howdy Soulrack!
Great to have you on the Forum!!

hmmmm....on your problem it is very very hard to diagnose over internet for sure.
Being that it is only on one channel narrows it down some as the power supply does supply both channels.
First thing I would check would be the Tube.
Remove the tube from the affected channel and see if the humming stops.
If it does then swap the 2 tubes and see if the problem transfers into the other channel.
If it does then it is the tube, if not then it is the circuitry in channel 2.
There are 2ea power supplies in the Bellari, a low voltage supply which makes the +15, -15, & +48 volts for the Phantom power and the Op amp circuitry.
Then a +200 volt supply for the Tubes.
If you removed the tube and the hum stopped, and the hum did not transfer to the other channel when you swapped the tubes, the first thing i would check would be the blocking capacitor for the Tube Plate.
There are so many variables and things that it could be that this is just a shot in the dark.

I have never heard the hum that you describe on my units.

As far as the schematics, they are hard to come by.
They do not give them out at Bellari.

I hope you can find the Problem Soulrack,
Good Luck!

[ECC82]

Was searching the web for for a cure to this problem and ended up at WZ5Q, of course
Got the same phenomena: light hum on channel 2 of the RP 583. Changed the tube, but no improvement. Switched to the second RP583 and same thing. So the service department from Bellari is probably right, channel 2 has hum because it is nearer to the power supply. What surprises me: if Bellari knows of this problem, why not fix this in production?

[ECC82]

PS.
Maybe the problem is bigger in Europe and therefore not solved by USA Rolls: in USA (sissy )voltage is 115 volts and in Europe (real man) voltage is 230 volts. I don't know how Bellari units are made suitable for EU voltage (no switch or anything to simply change the voltage on the unit) but I guess this results in bigger hum problem on that high voltage. Well hum is light and I don't turn the output level way up, we probably have to live with it.

[ECC82]

Answer from Bellari tech support:
In threory 230 volt could make the hum worse but, we don't have a lot of
experience with it so I can't be 100% sure about it. There is not really
much we can do to work around that channel 2 hum.

[ECC82]

Still haven't figured out a way to get rid of the hum. The transformers are already as far from the board as possible. Maybe someone out here has solved the problem in the mean time?