My kenny ka-801 progress

jpdylon

non-active member...
Following up from this thread...

WHen i picked this up, it was in sad shape. The outside looked ok, but the insides looked terrible. Upon complete disassembly there was a nest of some klind, lots of spider webbing with a dead black widow and tons of what looked to be dirt, as if this was pitched out in the back yard! :yikes:

Most of the solder joints on this amp are long gone. I had to re-solder almost the entire pre-amp board, and the front pannel tone board. This unit is also a victim of that nasty corrosive glue. i scraped off a bunch of it on the tone board that was beginning to eat away at components. I haven't even gotten to the driver board yet, but I'm sure it wil need resoldering as well.

It also appears that this was repaired at one time by a company called "Stereo Lab" THe driver transistors on the left channel board are not original.

The faceplate was in nasty shape, full of smoke stains, old tape that people had used as labels. Some idiot also seems to have tagged up the face with permenant marker labling his appropriate inputs as TV and something else. I was able to get 99% of the ink off, but a slight bit remains that is barely visable. If anybody has recomendations on getting permenant marker off, i would really like to know.

I hope to get this working properly again and give its beafy 110WPC a spin. I'll post more as I make progress.

Some descriptive pics...
 

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first power up

I've put everything back together tonight. I cut out new foam to put over the switches and the top where the cover rests. I also put the new meter lamps in (thanks Dave). I powered up the amp and the reelay clicked after about 10 seconds. THe offset was now at 150(left) and 48mv(right) I managed to get it down to 2mv on both channels.

Upon checking bias, There is a problem. The left channel starts at 22mv andslowly climbs to 55mv. The manual specifies 18mv, but even at the lowest setting possible I still have 55. The right channel starts at 18.5 and slowly climbs to about 25mv. I may start another post and the VSS fourms, because I don't think this will arise much attention here.

Pics:
left: chassis filally all cleaned up
middle: front pannel re-assembeled with new foam around the switches.
right: my glowing meters thanks to dgwojo!
 

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All finished

After some troubleshooting suggestions from dr*audio, i was able to cure the bias problem. I put everything back together, and the below pictures are the end result.

I must say this is the second "high speed" integrated I've owned. The first was a Denon PMA-777. Both of simply do not suit my taste. The kenwood is like the denon: loud and clear, but seems to be lacking in the bottom end. I zero'ed out the pre-amp DC offset and amp DC offset as specified in the manual, but I guess that's just how it sounds. Maybe my other stuff is muddy, who knows. All I know is that I like my other stuff better.

The important thing here was that it didn't go to the dump, get stripped for parts, and I learned a few things along the way. This was also the first kenwood I've worked on.
 

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Looks great! :yes:

Where'd ya get the foam for the switches?

Scott
 
Not sure if this will affect the lettering but you can remove permanent marker with either brake or hydraulic fluid. Amp looks great though, wonderful job :banana:

Yank
 
SPL db said:
Looks great! :yes:

Where'd ya get the foam for the switches?

Scott
UFO
Upholstery Fabric Outlet. There's two here in so-Cal, and they sell tons of different kinds of foam, thick and thin. I also get badding for cabinet dampening and speaker cloth there. Fairly inexpensive too.

Bigyank : I'll give that brake fluid a try in a place without the silkscreen, and see what happens.
 
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