Build This MoFo!

If you want a very nice high current, low distortion choke that can provide the measured data shown a few pages above, do a search on eBay for a MOT part number "MD-803AMR-1" - it is a very common low cost item salvaged from dead microwave ovens. Typically under $30 shipping included (in USA).

These measure about 67mH and 0.47ohm DCR. They weigh about 10lbs. The steel appears to be some sort of silicon (non-rusting) steel, e-beam welded at the seam to preserve the airgap.

Your Welcome :)
 
If you want a very nice high current, low distortion choke that can provide the measured data shown a few pages above, do a search on eBay for a MOT part number "MD-803AMR-1" - it is a very common low cost item salvaged from dead microwave ovens. Typically under $30 shipping included (in USA).

These measure about 67mH and 0.47ohm DCR. They weigh about 10lbs. The steel appears to be some sort of silicon (non-rusting) steel, e-beam welded at the seam to preserve the airgap.


Thanks for the tip, I've got some of these on order, going to give them a try. :D
 
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Your Welcome :)

Sorry if I missed your post recommending this model of MOT? Looks like Guangdong Microwave Mfg in China is the leading OEM supplier of MOTs to many microwave oven manufacturers.

Would the 11vac audio on the primary be generating hundreds of volts on the secondaries, so we have to be careful not to touch or short the secondaries for fear of shock? These MOTs when loaded with 120VAC on the primary will smoke/zap you badly, or worse, if you touch the secondaries.
 
Sorry if I missed your post recommending this model of MOT? Looks like Guangdong Microwave Mfg in China is the leading OEM supplier of MOTs to many microwave oven manufacturers.

Would the 11vac audio on the primary be generating hundreds of volts on the secondaries, so we have to be careful not to touch or short the secondaries for fear of shock? These MOTs when loaded with 120VAC on the primary will smoke/zap you badly, or worse, if you touch the secondaries.


The current should divide by the same factor that the voltage multiplies, right? Still don't think I'd be interested in touching a secondary. Could be a couple hundred VAC at 0.1 amps using the 11VAC signal example above......
 
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1r esr
any good for audio?

Afaik class A amps have a very constant current draw. No need for a fast PSU. And I use several. So you get a low effective ESR.

These Nichicons are Vz series. Not very new. I bought some two years ago and a new batch last month. Identical codes....

In my amp they don't heat up what so ever. Seem to behave fine.

I also got the Sikorels from here. Dirt cheap and new.
 
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I hope these are big enough for the MoFo!
 

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Custom made by AE Transformers from Holland . Maybe you can ask Toroidy from Poland too

AE is well known for its tube related transformers. Nice and not very expensive. I didn't think of them as choke suppliers (but I see it is actually their core business).

Regarding Toroidy: on this forum is a topic about this company (tube section). And also on other forums this company can be found. They used to have the issue of providing non-usefull data. The inductance was measured without current and the maximum current had hardly any inductance left. With Hammond you have a rated current and rated inductance....

But I think Toroidy promised to improve this. I don't know the actual status.

A lot of Toroidy stuff can be bought from TME (also from Poland). Good supplier.
 
That's interesting, I never bothered running without the cap Mx. Perhaps the large inductor slows down the startup transient?

I paid some attention while powering up my amps. You can't hear a thing, but you can see.... :D

The woofer cone is moving backwards while powering up and forward powering off (my woofer is out of phase). But this movement is small and slow. So you cannot hear it. Only see.