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Non-Edcor power transformer options, 6L6 build.

PostPosted: Wed Jan 28, 2015 8:46 pm
by Ludwig
In the beginning stages of sourcing some parts for a 6L6 Clem build and notice that the power transformer recommended is an Edcor.

Unfortunately I've had a terrible experience with their power trannies down here in Oz. The buzz and hum with the 240v (246v to be exact) and 50 Hz requirements. I built a pete Millett amp recently and had to have a power tranny custom made to get rid of the buzz, not cheap! Edcor simply wrote to me and said "it's hard to keep up with all the voltage requirements around the world these days"!

So with that in mind, does anyone have some suggested other power transformers I could try with the Clementine?

Re: Non-Edcor power transformer options, 6L6 build.

PostPosted: Wed Jan 28, 2015 10:31 pm
by Geek
Hammond?

I mount Edcor power trannies on grommets and rubber washers. Quiet as a mouse [:)

Re: Non-Edcor power transformer options, 6L6 build.

PostPosted: Thu Jan 29, 2015 2:30 am
by Ludwig
Yes, the Hammonds seem to be well made - which particular model would be suitable?

Re: Non-Edcor power transformer options, 6L6 build.

PostPosted: Thu Jan 29, 2015 8:41 am
by EWBrown
A toroidal power transformer should be mechanically quiet, much less likely to vibrate at AC power line frequency.
Also, toroids do not "radiate" a magnetic (H) field as strongly as do most "E-I" core transformers (especially the open frame type)
Toroids are best mounted under / inside the chassis, and need only a single drilled hole to mount them.

/ed B

Re: Non-Edcor power transformer options, 6L6 build.

PostPosted: Thu Jan 29, 2015 12:05 pm
by Geek
Closest model to the XPWR005 I can see is 273CZ. Being a Z-mount, you'll have to change your chassis accordingly.

Ed's toroid idea is great as well! You can get toroid covers pretty cheap from fleabay or AliExpress.

Cheers!

Re: Non-Edcor power transformer options, 6L6 build.

PostPosted: Fri Jan 30, 2015 6:43 am
by Ludwig
I like the idea of a toroid as well - I've definitely found them to be less noisy with out high voltage 50hz mains here downunder.

Any manufacturers can recommended for a toroidal tranny that fits the specs of the 6L6 Clem?

Re: Non-Edcor power transformer options, 6L6 build.

PostPosted: Fri Jan 30, 2015 12:55 pm
by Geek
You'll probably need a dropping resistor with this, but seems suitable:
http://www.antekinc.com/as-2t350-200va- ... ansformer/

At 200VA, it's the smallest to allow a tube rect without going half-bridge SS.

A trick with toroids is to put a soft-start, CL-90 or something in the primary as they have way more inrush than a E-I core ;)

Cheers!