Bottlehead Forum

Bottlehead Kits => BeePre => Topic started by: pdxgrampa on May 27, 2025, 11:29:37 AM

Title: Original Bee Pre left channel no output [resolved]
Post by: pdxgrampa on May 27, 2025, 11:29:37 AM

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

Title: Re: Original Bee Pre left channel no output
Post by: Paul Birkeland on May 27, 2025, 02:42:35 PM

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

Title: Re: Original Bee Pre left channel no output
Post by: pdxgrampa on May 28, 2025, 10:58:36 AM

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                       

Title: Re: Original Bee Pre left channel no output
Post by: Paul Birkeland on May 28, 2025, 01:41:29 PM

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. 

Title: Re: Original Bee Pre left channel no output
Post by: pdxgrampa on May 29, 2025, 07:11:54 AM

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

Title: Re: Original Bee Pre left channel no output
Post by: Doc B. on May 29, 2025, 08:30:28 AM

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.

Title: Re: Original Bee Pre left channel no output
Post by: Paul Birkeland on May 29, 2025, 08:31:53 AM

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.

Title: Re: Original Bee Pre left channel no output
Post by: Doc B. on May 29, 2025, 09:35:25 AM

Oh yup, didn't read the voltages correctly.

Title: Re: Original Bee Pre left channel no output
Post by: pdxgrampa on June 01, 2025, 06:48:16 AM

Thanks Paul,

Re flowed the board and all is well.

Good call.

Greg