Original Bee Pre left channel no output [resolved]

[pdxgrampa]

Original Bee Pre with Bee Quiet.
Left Channel no output.C4s A side LEDS lit. B side LEDS not.
Does not follow tube.
Voltages:

11  176 27  0 39  0 D1 NA
12  0 28  0 40  211 D2  0
13  0 29  7.6 41  0 D3  7.6
14  0 30  7.6 42  0 D4  NA
15  184 31  15.2       43  211 D5 NA
16  0.691 32  0 44  00 D6 NA
17  175                 D7  177
18  0                  D8  NA
D9 177                                                                                  D9 177
19  0.691
20  0


Greg
Sorry about the messed up columns

 

[Paul Birkeland]

Can you post the IA, OA, IB, OB, and Kreg voltages on each side of the amp?

 

[pdxgrampa]

Hi Paul,
Here's what i got

      A SIDE
IA 182V
0A 146.8V
IB  146.8V
0B 93.6V
KREG 4.3V

B SIDE
IA 183.7V
IB 167.6V
0B 175.1
KREG 1.93V

Thanks for your help Paul

Greg                     

 

[Paul Birkeland]

On the B side, what are your POS IN and POS OUT voltages?

I don't believe your 300B is conducting, but there are many causes for this particular issue. 

 

[pdxgrampa]

I does not look like the cathode is drawing any current (tube is cold and no glow)

POS in is 15.75 volts

POS out is less than a volt decaying to zero

Greg

 

[Doc B]

Check the socket itself. You may have a loose or oxidized contact on pin 1 or 4 (the bigger holes). That could prevent the tube from glowing, which would keep it from conducting.

 

[Paul Birkeland]

No filament current is being drawn, and nothing is being supplied by the filament regulator board.  This is most likely a faulty solder joint on that PC board.

 

[Doc B]

Oh yup, didn't read the voltages correctly.

 

[pdxgrampa]

Thanks Paul,

Re flowed the board and all is well.

Good call.

Greg