[Vincentq]

New to the Circle
Hi everyone.
I leave in France and I am very found of HIFI since very young...I am 54.
I use with great pleasure an Almarro a 318 B to drive my Klipschorn with very good success.
My problem is that my Almarro is since 6 or 8 month making an awful "CRAK" noise when tuning on or off even with the selector and the volume on 0.
I change the general switch but it is still the same.
I check that there is a capacitor stick on parallel to the switch. This can be a "anti noise" capacitor; but there not much information one the cap
Is there anyone that can help me ?
Thank you

[Vincentq]

Hi anyone.....nobodies has any idea to help me ????
thanks

[morganc]

If you added a lot more details you would likely make it easier for someone to help you. 

[Vincentq]

hi Morganc
Thank you for your answer.
Sorry but I do not know what more detail could be of help...
can you please tell me what I should add ?
I do not know much about electronics.....
Thank you

[Tyson]

If you don't know much about electronics STOP working on this amp.  The voltages inside of it are LETHAL.  Take it to a tech and pay them to fix it. 

[NoDisco]

Have you ever replaced the tubes?

[Vincentq]

@Tyson.....thank you for your help.....
I did ask my repair shop and he told me that he did not know.
He told me it could i could not really help but  He told me also  that it could be the general switch.  So I did change it but with still no success.
The only element on the switch i could not change is that thing looking like a capacitor because I do not know what it is ans so what reference to ask to change it.......this is why I am here looking for some help !
I do not know much but I know how to replace a capacitor and soldering.......

[Vincentq]

@Nodisco
It is not a problem of tube but a noise problem when turning the amp off.....that all.

[Dieterle Tool]

Possibly the power supply reservoir caps leaking or failing and causing cracking at on/off operation. Is there any visual damage to the large caps in rear corner of the amp?
Certainly that cap on the switch is a good place to start as well. Wima makes an .01 uF, 630 V cap if that's what I'm reading correctly? Mouser and Digikey would be resources for these parts, not sure if that's convenient for someone living in France however.

Here is a thread discussing some cap "upgrades", it also discusses replacing selector switch, attenuators, etc... https://www.audiocircle.com/index.php?topic=138713.0

-Dieter

[timind]

Is the noise coming through the speakers?

[belle harbor]

I assume you are hearing the noise through the speakers.  The cap in parallel with the switch is for noise and arc reduction.  If you replace it be sure to use a class X or Y type, not a conventional cap.  Hearing the sound at turn on is unusual in a tube amp, but given the extreme sensitivity of your speakers it could be possible.

[Vincentq]

@bell harbor
Yes only a noise in the speakers when turning off the amp.
Thank you for your help. Yes it is what I think; but as the information, on the cap parallel on the switch, is so light I have no idea of what looking for to replace it......
@ timing
 yes
@ Dieterle Tool
yes I am focusing on the cap on the switch. It doe not seems to be damage
Yes I have been to see that thread but I could not get info on the switch cap......

Thank you all
I have added some more pictures on the switch....

[Vincentq]

On the caps parallel on the switch I can read : 630V 871 N

[DWG]

Is the noise coming through both speakers?  If so the source of the problem is common to both channels. 

If the noise is only coming from one channel it is most likely a tube.  Swap the same tube (one at a time) from left channel to right channel and see if the problem moves. If it moves you have found the culprit.

Also, have you reached out to the manufacturer for their advice or recommendation?

[Vincentq]

@DWG
My amp is working very fine no problem at all.
The only little problem is that it is making a kind of CRACK noise only when turning off even with volume at zero and selector to zero......
This is why I am trying to understand the problem.

[FullRangeMan]

Do Its the 6c33 tubes ?
In case the amp no have soft start the big metal plate may made a sound when receive the HV shock.  But it may be other parte from the circuit.
My 2 cents.

[Vincentq]

I know it is not from the tubes.
I am pretty sure it is from the cap on the switch but I need someone to help me to understand what equivalent i should use.
Thank you

[morganc]

Just to be clear, you're not turning the Pre Amp or Source off before the Amp are you?   

[Vincentq]

@ morganc
No it is an integrated amp....no preamp