20 November 2011

say it ain't so - kenwood ka-6100

...put... the...phone... down...

That is what I need to say to myself now,
along with a good rubberband snap to the wrist.


I had seen the craigslist ad late that night before.
The guy had relisted it from way too high to just the amount that was in my pocket.
Something about 70's stereos with the VU or Watts meters and I go crazy.

He lived in Fallbrook almost an hour away,
but he made it easier by meeting me at his work 10 minutes away.
So when I got the text,
I jammed out there to check it out.
Obviously I couldn't resist.

Without even hooking up speakers first,
I had to see inside.
Holy Chit,
these guys with there cat's or dogs.
The inside had a decent fur coat.

kenwood ka-6100 guts

This is a '77 or '78 Kenwood ka-6100 integrated amplifier.
At 50 watts per channel it's a mid-powered machine,
perfect for a house or garage
Since there is no tuner,
it is really simple inside.
After hooking it all up,
I found out one of the meters was dead.
It did sound equal though on both sides at least,
although it was really scratchy when playing with the controls.

not so secret weapons

With some kid time over the weekend,
this was a good garage project to fiddle with.
Let's break out some chemicals.

I sprayed the heck out of it with the contact cleaner,
 all over the board,
than scrubbed around each resistor/cap with the little acid brush,
than more spray to wash it down.

I've been way more careful with the other stereos,
just cause I have no idea what I am doing.
This was a good experiment to see what they could take.
Obviously I was a little careful.
but this thing looks like new inside now.

After using the lubricant spray to clean the pots,
(volume type controllers)
I let it dry for a while before hooking it up.

custom voltmeter

Well the thing sounded about the same,
but at least it wasn't scratchy when moving the controls.
Couldn't fix that meter though,
oh well.

After letting it play overnight with the CD player,
I tested out the DC offset using this links guidelines.

Amplifier Distortion, DC-Offset, and You! - AudioKarma.org Home Audio Stereo Discussion Forums

dc offset check left

Surprisingly both sides weren't too out of control,
both steady around 18 (+/-) each side.

dc offset check right

So now we've got another good running 1978 vintage stereo.
Just what we needed!
The dead meter is a bummer,
but it's not like i've got time to watch the meters bounce around,
 for too long anyway.
(If you're reading this and have a replacement,
email me!)

if you think I'm crazy,
check out this link.

Kenwood KA-6100 restoration

There's a bunch of guys that think its fun to take off all the  capacitors (caps)
and solder new ones in!

I'll just stick to the rattlecan rebuild!


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