100uF Motor Run Caps

[i45one]

I am starting to source parts for my 1st tube amp project. I am looking to construct Porkchop's KT88 se circuit.

Does anyone know where I can find a suitable 100uF motor run cap? It seems as though no one really carries anything that large in the voltage required. Angela carries 50uF, but I would rather not have to parallel two caps if I can help it.

Are there any other alternatives?

Thanks!

 

[88man]

I haven't found any 100uF motor run caps myself, as the largest one I've seen is 60uF. I am building Abdellah/Alexg/Porkchop's SE KT88 too - I am paralleling (2) 50uF caps for my project. Great selection and prices at Alliedelectronics.com.

 

[pjanda1]

Ebay often has cheap big 'uns. There was one seller in particular, but I can't remember who. These guys have some large fellas as well. Don't forget that you can multiple that AC voltage by 1.4 or so for your purposes.

Paul
Wild Burro Audio Labs - DIY Full Range Speakers

 

[rdf]

Some are still available on Ebay. Check out local electrical suppliers to the HVAC industry first.

 

[kevinkr]

midori meadows on eBay used to carry 100uF motor runs, but ran out a while ago, and I have not checked to see whether or not they have restocked.

Edit: Link here to eBay profile: http://myworld.ebay.com/midorimeadowsllc/

Note that she currently is offering 80uF/500VAC motor runs by Eyuda for $13 each...

I've done business with her, and have recommended her as a source of motor runs to a number of friends over the last few years.

 

[tomtt]

heating and cooling shops might have used ones.

 

[alexg]

I find that the ASC, Aerovox and the GE motor run capacitors sounds excellent on my PSUs.

I usually parallel a couple of 45 or 50uf, to get the capacitance that I need.

 

[i45one]

Thanks for all the input! I look forward to working on this project. It's refreshing to know that there are great folks around willing to help as this is my first tube build. I'm sure I will have tons more questions before it is through.

 

[piero7]

MKP caps: CLICK ME

 

[Geek]

MKP caps: CLICK ME

I wonder if it's inductively wound though....

Cheers!

 

[jacco vermeulen]

very small for MKP, even Chinese manufactured CBB60 or CBB61 are larger.

The 400uF/450V caps on offer by that seller are stated to be 50x110mm.
An Epcos MKP pulse cap of that size has 2.5 times the height and almost twice the diameter.

 

[Geek]

Good point Jacco.

Come to think of it, they look the same as those sold in a local hardware store as electrolytic "motor start" caps.

Hey, it's cheap enough... someone should snag one and cut it open

Cheers!

 

[DynacoDave]

You can also shop electric motor repair shops. I picked up a start cap for my dust collector for 6 bucks. They had about 1000 different values, voltages, and manufactures.

 

[kevinkr]

Large motor runs are all somewhat inductive, but then so are most electrolytics.
These are probably ok, and at the price it is hard to imagine you could go wrong.

Odd that the seller who is based in Hong Kong listed them on eBay Italia.. Io penso di comprare qualche pezzi di questo condensatore.

 

[Geek]

Run the auction number through ebay.com or ebay.ca or ebay.co.uk, Kevin, it's just a worldwide auction I think...

Cheers!

 

[piero7]

I've payed the ICAR 90uF motor run here in italy 9 euro and they was 55x116 mm

 

[DynacoDave]

Don't forget motor run caps are ac.

 

[Face]

Why would you use one of these opposed to a standard 100uf film cap?

 

[Zen Mod]

Why would you use one of these opposed to a standard 100uf film cap?

experience and sanity are just two reasons I can think of in this moment

 

[piero7]

Don't forget motor run caps are ac.

huh? A polipropilene cap is a poliprpilene cap anyway

why to use these instead an electrolitic? Give a try, remove your electrolitics from your tube amp and give a chance to these motor run poli caps and hear your music as usually...