Volume knob causing crackle in Cayin Tube Amp.

kib_reddy

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Hi all,

I purchased a Tube amp 2nd hand from the 'For sale by owner' section locally here from a long time member. Cayin T88 Mk2, Absolutely gorgeous amp, at an awesome price. Extricating warm sound. Unfortunately the volume knob gives out a crackle when turned. The dangers of buying equipment without trying it out first. The owner was going abroad literally the day I went to pick it up and I didn't want to impose.

Any idea how this can be fixed? I have expensive speakers and can't afford to have this happen every time I use the volume knob. I live in a modern independent home and there is no possibility of any earthing or voltage issues. Really upset that equipment at this price point can have such basic issues. Please let me know if any of you have dealt with something like this, seems like a simple issue to fix.
 

rrunner

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You need to open up the tube amp and squirt some deoxit or contact cleaner into the volume pot. You need to be extremely careful in not touching any of the capacitors leads to avoid electric shock.
 

dranil

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I had same problem with mu Fatman tube amp.
Sprayed contact cleaner and the problem solved perfectly.
 

venkatcr

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The dangers of buying equipment without trying it out first.

I live in a modern independent home and there is no possibility of any earthing or voltage issues. Really upset that equipment at this price point can have such basic issues.
Couple of points here.

1. Even if you tried it and picked it up, it can always create a snag later. Pots do have wear and tear and can happen to the best of equipment. At all price points.

2. Pots decay because of electro mechanical issues and have nothing to do with voltage or earthing issues.

3. This is a minor issue and can be resolved quickly. Try cleaning the pot as suggested by others. If that does not work, get an good engineer to replace the pot with a high quality one.

Cheers.
 

venkatcr

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Please do not use WD40. That is a lubricating and degreasing oil meant for mechanical equipment. It is not to be used with electronic equipment. There are others such a DetoxIt meant specifically for electronics.

Isopropyl alcohol cleans but does to lubricate.
 

Hiten

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few drops of pure isopropyl alcohol can work. It evaporates and does not leave any residue. WD40 can be used as temporary purpose and residue cleaned in future when time permits and proper cleaning solution is available. Some volume controls has no access or very limited access to the tracks. Making cleaning difficult.
 

rikhav

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What can be done if it's sealed design volume pot?
I think in that case replacement is ly option
 

Hiten

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What can be done if it's sealed design volume pot?
I think in that case replacement is ly option
almost all have tiny hole where one can insert syringe needle and clean the tracks. But I would strictly recommend to skilled technician to do so as he will not damage trackes and avoid cleaning solution reaching metal shaft that holds volume knob. Because the shaft has tiny amount of grease for smooth feeling of turning of volume control. If this is cleaned with cleaning liquid the grease dissolves and the volume control has coarse feeling when turning.
 

djbobby10

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Hi all,

I purchased a Tube amp 2nd hand from the 'For sale by owner' section locally here from a long time member. Cayin T88 Mk2, Absolutely gorgeous amp, at an awesome price. Extricating warm sound. Unfortunately the volume knob gives out a crackle when turned. The dangers of buying equipment without trying it out first. The owner was going abroad literally the day I went to pick it up and I didn't want to impose.

Any idea how this can be fixed? I have expensive speakers and can't afford to have this happen every time I use the volume knob. I live in a modern independent home and there is no possibility of any earthing or voltage issues. Really upset that equipment at this price point can have such basic issues. Please let me know if any of you have dealt with something like this, seems like a simple issue to fix.
Please do not use WD40. It spoils the parts inside. You can use a CRC spray which is also a electrical contact cleaner. It is available on Amazon. Please please do not use WD40. It melts the plastic and the soft parts and then you know what will happen.
 

kib_reddy

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THANKS A TON GUYS!!! So relieved! The Left Right balance also goes out with the crackle which is super annoying. There is this one song with a great center image, I play it to figure out if the L-R balance is correct every time I change the volume. Lol. Will try contact cleaner. This thing weights 35KGs! I will have to get the technician here. Cheers..
 

aljojohn

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Sep 20, 2017
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kerala
Hi all,

I purchased a Tube amp 2nd hand from the 'For sale by owner' section locally here from a long time member. Cayin T88 Mk2, Absolutely gorgeous amp, at an awesome price. Extricating warm sound. Unfortunately the volume knob gives out a crackle when turned. The dangers of buying equipment without trying it out first. The owner was going abroad literally the day I went to pick it up and I didn't want to impose.

Any idea how this can be fixed? I have expensive speakers and can't afford to have this happen every time I use the volume knob. I live in a modern independent home and there is no possibility of any earthing or voltage issues. Really upset that equipment at this price point can have such basic issues. Please let me know if any of you have dealt with something like this, seems like a simple issue to fix.
Maybe dust accumulation in potentiometer, or may be something wrong in preamp section. Minor crack sound will be there for some brands , its not a complaint example prasound, unison research
 

Debojit

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I had a similar problem with my amplifier. The contacts need to be cleaned. In the interim you can try moving the volume knob fully (with out switching on the amplifier) 3/4 times and see if the crackling sound disappear.
 

mbhangui

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Maybe dust accumulation in potentiometer, or may be something wrong in preamp section. Minor crack sound will be there for some brands , its not a complaint example prasound, unison research
This is not a preamp problem. Few carbon particles on the track gets lose and cause the crack sound. Like what @Debojit suggested, move the control clockwise and anticlockwise few times. If that doesn't solve, you can open the case and spray deoxit.
 
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