Apex 460/Peluso CEK-47.......BAD ground problem, need help!!

Yes I just replaced the capsule in my 460 with the Peluso 47 capsule and stripped the wires, soldered and taped them. It shouldn't be that difficult to figure out; there's only one blue wire and two red wires, which correspond to the two red and one silver ground wire on the mic. When listening without the basket on, there is tremendous hum but I can hear that the capsule is working in all polar patterns. If I grab the ground wires the hum disappears for a half second then reappears a little lower in volume. When I assemble the mic case and basket back together, I get no signal and HF hiss.

Anyone had this same problem?
Adam
:?

The head grille needs to be in place to use the mike. Without it, the capsule is an antenna for 60Hz.

The inner clearance on the 460 head grill is tight. It sounds like the grille is making contact with the brass body electrode of the capsule. Stick some electrical tape in there temporarily to verify if this is the problem.

Oh wow! I used masking tape and that seems to be the problem. I guess it makes sense now. There is still some hum but it is only about 10% of what it was. What could be the permanent solution? Some foam inside the top of the basket?

Some mylar (Scotch) tape applied directly to the capsule edges might work. Your capsule diameter is probably a bit larger than the 32mm capsule originally supplied. Make sure the little brass lug on the side of the capsule is insulated too.

As I study this thing I notice that the Pelsuo mount is slightly taller than stock mount and I can see stepping backwards and undoing everything to put the stock mount back on to lower the capsule maybe an 1/8". But hell, that's too much work. I had seen on another forum somewhere that another person had modded an Apex 460 and 435 but swapped the baskets because they were an exact fit on the base just different basket shape on top. Apparently this person had great success with the Peluso capsule fitting the 460 this way. I have a 435 at my studio (30 min. drive...arrggghh... :roll: ) so I guess I'll take an hour and make the round trip to get the other one.

Is there a specific tube that work in place of the 12ax7 that would fit the sound colser to a u47?

I thoguht that they put 12ax7s in because they were cheaper ,
but that the lower gain 12at7 was more appropriate

I have had good results with a 6072a, gain of ~44. The stock Chinese 12AX7 is some kind of a super tube with gain greater than 100. The result is that it overdrives the stock transformer. If you have a tube with a lower gain, 40-70 range, the results will be better.

What about a PF86?

Okay, the hell with swapping the baskets. I just swapped the mounts and went back to the stock one and actually was able to clean up my wiring by shorting the wires. I had to drill to widen 2 screw holes on one side of the mount for the Peluso to fit. Voila! Everything is smooth, working, and hum free. :green:

I would try a triode connected EF86!
But watch out for the earlier Russian pentodes labelled EF86, which weren't.
Very microphonic, mediocre sound.
Try the new EH or JJ ones, or the more expensive Russian made TungSol brand EF806G.
Or a NOS Mullard or Telefunken
I heard a rumor that copies of the EF14 are being made, thats another possibility if you can locate them?
And I have seen new production sockets for them.

Sorr

Sorr you might want to search Tungsol ef806 at Klaus's forum.

Gus, I tried but couldnt seem to find a reference to it.
Do you have a link?
Thanks,

Sorr

http://recforums.prosoundweb.com/index.php/m/238372/18402/?srch=ef806#msg_238372

Matti