U47 fet pics

Hiya Chaps,

just checked over a 47fet for a mate - no signal !, and diagphram was a 'little bit' dirty :wink:

traced problem down to the O/P pad switch ( cleaned up, and reset the contacts) working o.k. Also the output connections, were a little bit ropey !

While I was in there, cleaned up the capsule , as per previous posts

http://www.groupdiy.com/index.php?topic=697
http://www.groupdiy.com/index.php?topic=22287&highlight=u87+capsule+cleaning

anyway, here's the pics - bigger res at http://www.twin-x.com/groupdiy/thumbnails.php?album=172








Steve :thumb:

Just uploaded rest of pics, http://www.twin-x.com/groupdiy/thumbnails.php?album=172

if you click on the individual picture, you should get them supersize !
Max, there's some pics of the transformer, but not on it's own :sad:

you can see the lam pattern, and some of the windings.

Enjoy :grin:

Thanks for sharing, Steve!! I will probably never see one of these up close like this!

Charlie

cheers - very nice pictures!
you can see the secondary (low-z) side as the inner (fatter wire) layer, the feebackwinding in between and the secondary on the outside.

http://www.twin-x.com/groupdiy/albums/userpics/IMG_3391.JPG

No worries Charlie, :grin:

Max, I'm glad they were O.K., are you going to be making you own soon :wink: Let me know, as I'd love to have a go at doing my own 47 fet !
On another note - my G7's are nearly done, a sneak pic for you



Steve :thumb:

wow - looking forward to see the finished mic very nice work so far!
what capsule, tube, transformer?

i´m collecting data of different mic-out transformers, i started winding some variations with different coil structures which accomodates the impedances of the ef 86 & ef 12 in triode mode - pics of some experiments can be seen in the dissection thread.

-max

Nice one Max,

I'm using a Peluso capsule - can't remember the model, but it's the dual capsule.
For the valve, i'm using a pair of n.o.s. Telefunken EF86's, and at the moment, I'm using a Lundahl 1538, but I'm going to try the 1538XL out as well. ( Got to finish of the wiring tho :shock: )
I'd be well up for testing some of your transformers, if you ever need some extra hands :wink:

I'm at the start of a very big hill with regard to transformer winding, but I'm starting to get my head around it a bit more, where have you been getting your supplies from ?
Also, just remembering, there's some telfunken transformer data around here somewhere. can't seem to find the post tho.

Steve :thumb:

hey Steve, I have a G7 with a Peluso capsule and NOS EF86. I did vocal tracking this weekend through a DIY 1272 > DIY LA-2A.

Fantastic results, honestly. I've recorded this particular singer several times. I've always had some troubles softening the midrange in his voice. This combination worked great.