KA-3020SE diy fix

[Blackdawn]

Dear forum members,

Hope you can help.

I've recently purchased a KA-3020SE amp made by Kenwood. I have a few problems with it.

1st) Should be easy to solve - The Volume pot is noisy, so am going to use contact cleaner.

2nd) The bigger problem - The left channel is great. The right channel is always much lower volume and sometimes crackles. Also when the volume is zero I get some music through the right speaker still (nothing through left - as it should be). So the fault seems to be with the right channel.

Are the two faults linked? e.g. is it just the vol pot needs cleaning or is there something that needs replacing like capacitors?

I have a pdf of the schematics but it seems to miss off the parts list and some of the circuit diagrams. The person that scanned didn't do a very good job! does anyone have a better copy?

Thanks for your help. I'm new to this HiFi DIY!!

 

[Anonymous]

I have recently had the same problem with my KA-3020 (regular edition). It is also the right channel on mine that does not work properly. At first the right channel was only a little quieter and slightly fuzzy but the volume and sound quality deteriorated until the channel was useless.

It seems that the tweeter on my right speaker (KEF Q50's) also blew when this problem started, perhaps due to the distorted signal? I'd recommend not using the amp untill it's fixed (or setting the balance fully to the left) but I have a limited understanding of audio electronics, you sound like you know more

 

[Mooly]

KA3020SE manual,

http://www.hifiengine.com/manuals/kenwood/ka-3020.shtml

The volume control is totally conventional and the wiper takes the power amp input down to ground. If you have breakthrough of audio even with control on minimum then it suggests physical damage perhaps to the pot or surrounding print on PCB.

Is this an amp you have owned from new and it has failed with a genuine fault or is it something like an ebay buy that is faulty ?

 

[Wizzerzak]

Hey sorry for the (massively) necro bump but I noticed Blackdawn is still active on here and couldn't find any PM feature. I have th same amp and and experiencing exactly the same problem with the right channel. Wobbling the Input dial seems to sometimes work but I'm wondering if you ever managed to fix the problem properly?

Thanks.

 

[Blackdawn]

Hi, I'm afraid I didn't fix the Kenwood in the end - even though I had a go. Sorry I have no solution to fix this although I'm sure there is online somewhere. I bought the Kenwood second hand. Even when it was fully working I never really took to the sound- much prefering my Denon PMA250 SE for similar money. The Denon is still working fine, by the way.

If you need a new amp with a modest output - Pioneer A30 is very good indeed, especially with the Dali's

 

[Wizzerzak]

Okay thanks for the quick reply though! Might give open it up and give it a clean anyway, you never know I guess.