ARGH! Where can I get .1uf 200V electrolytics?

[putrefusion]

I'm restoring a Kay 703 for a vintage nerd, and I cannot for the life of me find .1uf 200V electrolytics anywhere.

While were at it, where do you guys find your weird and obsolete components?

[Peter Snowberg]

0.1uF @ 200V???

That is an odd value.

I would replace it with a film cap. You could even use a vintage one.

[vfr800fiman]

I'm restoring a Kay 703 for a vintage nerd, and I cannot for the life of me find .1uf 200V electrolytics anywhere.

While were at it, where do you guys find your weird and obsolete components?

Doug has a .1uF 400V as well as 600V.
http://www.hoffmanamps.com/

Glenn

[vfr800fiman]

OOOPS!, just saw the electrolytic part  :oops:

[birt]

i've got a couple 250v .1uf tropical fish caps

[vfr800fiman]

I'm restoring a Kay 703 for a vintage nerd, and I cannot for the life of me find .1uf 200V electrolytics anywhere.

I don't mean to question you, but you're sure these are electrolytic?
Glenn

[vfr800fiman]

Is this a Kay 703, 703 2nd version, or a 703-C? Like this:
https://schematicheavencom.secure.powweb.com/bargainbin/kay703c.pdf

[putrefusion]

yes, it is definately electrolytic.  the parts list on the amp chassis specifies this.  

The caps I'm replacing are labeled A, B, and C on the 703 schematic as follows:  

https://schematicheavencom.secure.powweb.com/bargainbin/kay703.pdf

later versions of this amp look to use the same preamp, but have different filter caps values, ones that make sense... (2) 40ufs, and a 20uf.

I guess what I can do is replace all the weird cap values in there now and update it to model the last 703 revision, as here:

https://schematicheavencom.secure.powweb.com/bargainbin/kay703c.pdf

[vfr800fiman]

You'r right!
So this looks like a multi-section electrolytic.
What are the values on the rest of the sections?
Glenn

[putrefusion]

You'r right!
So this looks like a multi-section electrolytic.
What are the values on the rest of the sections?
Glenn

Its not multi-section, its 3 caps precariously piggy-backed upon one another.  Just for my own amusement, I may take some pics of the inside of this thing.  Its ridiculously simple inside, just a handful of components... very compact and cheap to make, I assume.

[vfr800fiman]

Yes, it looks like a simple design from the schematic.
I've never heard of an electrolytic at that low of a value.
I'll keep looking though.
Glenn

[putrefusion]

Could I replace this .1uf with a 1uf, without freaking the circuit out?  I'm not good enought at this yet to know if its OK to do that in this case.

[Sir H C]

I can not imagine that .1uF are the correct values here.  You need 10+uF for those three positions.  I would go with the later values of 30uF and 40uF.  Those make sense.  Maybe someone changed them a long time ago with the wrong values.

[putrefusion]

The schematic and parts list are glued to the chassis, and I know for a fact that it states that its a .1uf 200V electrolytic.  In addition, this cap is in the amp, and it states in plainly on the cap. This amp also looks to have never been serviced before, having all original parts.  

Just because, I'll take some pictures of this thing.

[Sir H C]

Does it state .1mF?  Sometimes that meant millifarad.

[Fret Wire]

A, B, & C were originally a three section multi-electro (paper cased, radial lead). 30uf @25v, 40uf @150v, and 40uf @150v. Every original 703 & 803 I've seen had the paper cased multi-cap.

The .1uf @200v can be replaced with a Mallory 150 type. Most of the Kay's and the Harmony's used cheap caps (usually white) like this with a band on one end. When you check one with a DMM, you find they are not polarized.

Along with Hoffman's, Antique Electronics has a good selection of amp components, and a decent selection of wha parts too.
http://www.tubesandmore.com/

[putrefusion]

Thanks fret wire!  Now to order some mallory 150s...  :lol:

[Fret Wire]

C1-C5 can be replaced with Mallory 150's or other film caps. Use original or higher (better choice) voltage ratings for each cap. C6 (a,b,c) is the multi-electro. You'll probably have to make your own out of three separate electro's.

I'd replace R9 (56 ohm) with a 5 or 10 watt resistor, and R10 with a 2 watt resistor. Many of those schematics are incorrect, however. Before you start, take good photos of all components and make good notes. Check each resistor with a DMM as you remove it and note it. Even if the schematic is correct, they are notoriously hard to read! Also, make a drawing of the chassis layout, you'll be glad you did.

Remember, this amp doesn't have a power transformer. The ckt runs on AC, those type of amps are nicknamed "death amps". The last thing you want is component failure so your chassis goes live with 120v ac. So make sure your wiring is straight, grounds are good, use a three prong plug, and don't plug it into any wall outlet that you haven't personally checked with a polarity tester.

On many original vintage amps, the service advice is to replace all electro's, highly stressed resistors, bad caps or resistors, and leave all other components original. These non-pt amps have so few parts, it's wise to replace all components for safety's sake and piece of mind.

[Sir H C]

Often too people will use an isolation transformer with them to help keep the death trap at bay.

[vfr800fiman]

Remember, this amp doesn't have a power transformer. The ckt runs on AC, those type of amps are nicknamed "death amps". The last thing you want is component failure so your chassis goes live with 120v ac. So make sure your wiring is straight, grounds are good, use a three prong plug, and don't plug it into any wall outlet that you haven't personally checked with a polarity tester.

I'm curious, what do you do with the ground wire on the three prong plug :?:

My other hobby is restoring antique radios. I've done a lot of old 50's tabletop radios that are built this way, no transformer.
Usually the neutral goes to the chassis, and the hot goes to a dropping resistor, filtercap, etc.
What would one do with the ground wire?

BTW: I always use an isolation transformer when working on these units.

Glenn