what the heck IS this part?

[sjaltenb]

Ok this picture has already been posted elsewhere on the site and is also up on 4x12, but if it needs to be removed thats fine. I'm not trying to copy a design or anything like that I just cant figure out what it is? it is used on all the Send or Output buffers (some are just outputs, others are variable) either way it doesnt matter im just curious as to what the part actually is!

I really just can't figure out what it would be...I'm talking about the little grey cubes in the bottom of the picture...labeled tuner out, delay send, harmonizer send, preamp send...etc. the circuits are all a little different based on the application but the cube is always there.



thanks.

[aziltz]

my first guess would be that its just covering something.  to protect from shorts or static?

[Boogdish]

transformers to isolate the different outputs?

[sjaltenb]

yeah my guess was transformer too...but..doesn't look like one. I've seen it in almost all his designs, this one was in 1996 but i've seen the exact same in his new boards.... very curious!

[Nitefly182]

Gooped box of secret parts?

[aziltz]

british engineering heat sink?

[sjaltenb]

well i dont think its meant to hide anything...cause this is way before he ever started gooping. I"ve seen these same output circuits with the silver box with the goop over them more recently...

[Auke Haarsma]

my guess would be that it is indeed a small 1:1 transformer. The metal box is to shield it.

[sjaltenb]

yes...and after taking a closer look...the parts count looks *remarkably* similar to R.G.'s  A/B Amp splitter  ....so, basically, those circuits are probably either unity or variable gain output or send buffers with transformer isolation...

neat.

[MartyMart]

They are indeed transformers, look like OEP's in screening cans to me like this :
http://uk.farnell.com/jsp/search/browse.jsp?N=500006+1001637&Ntk=gensearch_001&Ntt=OEP&Ntx=
This is how they look without the "can"

About £10 a pop plus £3 for the screening can.

= Balanced line outputs

Marty.

[sjaltenb]

ah ha! Cool. thanks for the insight Marty.

[MikeH]

I'm more curious as to what that big doughnut of an inductor is for.  Or it that some kind of power transformer?

[sjaltenb]

dual output toroidal transformer. it feeds two power supplies, one you can see, and one on the other side. 32Vdc and 27Vdc if i remember correctly....its dual primaries (240/120) so maybe that contributes to the size

[Mick Bailey]

I go with transformers with Mu-metal screens. Probably to impedance match, isolate and offer balanced inputs/outputs.