Harman Kardon Citation Eleven Restoration!

[Raccoon1400]

Up for restoration is a harman kardon citation eleven preamp.

Thinking I'll replace electrolytic caps, mylar caps, some carbon comp resistors. Some transistors with lower noise newer parts.

First question. There is a sticker that says "Audio equalizers, volume, and balance controls are silicone loaded. Do not clean with any commercial cleaning solvent" What does this mean? Can I not deoxit it?

-Raccoon

 

[dshoaf]

The slider mechanisms had beads of silicon damping - very thick - to give the sliders a bit of resistance when moved. Today, however, the stuff will have dried up. Pull the front panel and you'll likely find it pooled up in the bottom of the sliders, too.

I'd be frugal with FaderLube - rather than DeOxit on the carbon substrate that makes up the electrical properties of the controls.

Cheers,

David

 

[Raccoon1400]

The slider mechanisms had beads of silicon damping - very thick - to give the sliders a bit of resistance when moved. Today, however, the stuff will have dried up. Pull the front panel and you'll likely find it pooled up in the bottom of the sliders, too.

I'd be frugal with FaderLube - rather than DeOxit on the carbon substrate that makes up the electrical properties of the controls.

Cheers,

David

Would this be that white powder I always find in these old hk units? All over the bottom panel.

I do have faderlube.

 

[patfont]

FYI on Marantz sliding balance controls if you use anything, you loose that nice smooth travel. I would only do it if said control was def noisy and causing problems.

 

[ferninando]

if they all slide smoothly and are not noisy now, I would NOT touch them with any cleaner.
You mite regret it. Just be warned.

 

[Raccoon1400]

I need to choose a new main cap. I think I can fit a 35mm cap if I replace the clamp.
Original is 1000uf, 100V.

Thinking of either
E36D101LPN222TA54M from digikey, 2200uf $12
CG132U100U3C from mouser, 1300uf $35

Any suggestions?

 

[patfont]

What is the original diameter? Is it a snap in or screw terminal?:scratch2:

I need to choose a new main cap. I think I can fit a 35mm cap if I replace the clamp.
Original is 1000uf, 100V.

Thinking of either
E36D101LPN222TA54M from digikey, 2200uf $12
CG132U100U3C from mouser, 1300uf $35

Any suggestions?

 

[dshoaf]

I used a set of paralleled smaller-value caps with diameters to fit under the chassis. Left the old one in place but not connected. There's plenty of space below the chassis and around the can-cap but it is shallow.

Cheers,

David

 

[Raccoon1400]

Would it be okay to increase to 2200uf? I'll be replacing the rectifier diodes too, what current rating to use? Can't find original spec, and I probably want to up it if increasing main cap.

Original diameter is 45mm.

 

[dshoaf]

1N4007 will work with no problem. Wanna hot rod it? Go with Hexfreds - available from the audio boutique suppliers like PartsConxion (sp?).

Cheers,

David

 

[Citation-Fan]

@Raccoon1400:
Is it your Citation Receiver in your Avatar?
Nice gear!

 

[Raccoon1400]

@Raccoon1400:
Is it your Citation Receiver in your Avatar?
Nice gear!

Yes it is. I have two! One in great shape, one a bit challenged. Both getting restored whenever I find time.

 

[Raccoon1400]

1N4007 will work with no problem. Wanna hot rod it? Go with Hexfreds - available from the audio boutique suppliers like PartsConxion (sp?).

Cheers,

David

I've used other fast recovery soft clipping diodes. I don't think I noticed much of a difference, but maybe it was there. I need to be somewhat cost efficient for the customer, but if the sonic difference was major he might go for it.

I'm thinking I'll use the 2200uf chemicon cap, it is cheaper and higher value, the other option I mentioned is much more expensive.

 

[Raccoon1400]

So I think it is done. Converted the entire signal path to film caps. I decreased the 10uf coupling caps in the tone and output board to 4.7uf, and this didn't affect response. I got good response from 10Hz to 20kHz. It started to drop off a bit at 18kHz, but it didn't decrease much before 20kHz.

I hooked it up to a restored sae 2200 power amp and my JBL decade 36.
Here are the pictures.