DIY Audio General - stuff you're making, tips, advice sought, etc

This was more of a bargain.

Chopped out all of the nasty Lm3886 crap. Earthed it properly as it was dangerous. It is now about to be a Pass B1 remote controlled pre. The relay volume control seems quite nice.
Gave him a pound as I was feeling generous.
Got a better built SKA GB150 amp off him for £41. Needed a couple of fets and it is all good.

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I need to give the transformers on my amps a bit of a spruce up. The black bits are looking less black and a bit scruffy.

Any recommendations for black transformer paint?

Once used fireplace paint on a naim amp, worked very well

Yes, but is it sufficiently tough for an NVA amp? :laughing:

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Are the tiles from the space shuttle available now?

If you mean the lamination stack then Leak used to wrap some of theirs in sticky-backed plastic (aka Fablon). It could look quite neat

VB

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Sticky back plastic and valve heat?:scream:

Well Leak’s Stereo 20’s and TL/12 Pluses have been running like that for more than 60 years now.

I think if your transformer laminations are getting hot enough on their surface to melt plastic then maybe there’s a more serious problem to worry about …

VB

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Although probably not for very long before vapourised polyester fumes fill the room and at least one fuse somewhere blows

Years ago at AI, we’d buy transformers from Hinchley who supplied Leak but also Savage (also in Devizes). The laminations on the Savage ones were often covered in a black woven fabric which always seemed to convey a bit of class. There was another supplier who also did that whose name escapes me. I’d need to ask PQ.

My OTX and ITs from SP Wound had black fabric tape wrapped around the lams back in 90s.
That was so any rusting on the end of the lams wouldn’t show after I stopped having them impregnated.

It’s not the plastic but the adhesive of regular sticky back that would be of concern.
I’m guessing the adhesive used originally was something better?

Stephen Spicer in his history of Leak Firsts in High Fidelity says

“Damaged or worn black tape on Leak transformers can be removed and replaced with a self-adhesive plastic cut from a roll as shown on this Stereo 50 power transformer.”

And there’s a picture of an un-taped transformer alongside a roll of what looks like Fablon, although he doesn’t mention it by name. The original tape looks a lot like plain black electrical insulating tape. I assumed the adhesive on that wasn’t very different from Fablon. Farnell’s bog standard stuff is good for use up to 50C (just about the hottest thing you can keep your hand on) http://www.farnell.com/datasheets/2921902.pdf. 3M-branded posher stuff (but still under two quid a roll) is good for 80C http://www.farnell.com/datasheets/1923355.pdf.

VB

bloody foo merchants

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The foo is everywhere …

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Putting a P10 and an A10 in one box.

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Are you prototyping an integrated with MM stage?

Does the phono stage behave itself with all those transformers in the case?