behringer B-1 schematic and repair

[hooman]

behringer b1 is not expensive mic but good for record problem is main symptom.. .no sound.
what happened ?
first google search for circuit diagram . ..i found circuits for other mics...still cant find circuit .

tow pcbs .
1- main circuit for signal amp
2-60 voltage dc to dc convertor and filter

 

[hooman]

View attachment 691346

 

[hooman]

 

[hooman]

b-1 is not true balance output .just one line signal .if your b-1 mic not working start with dc voltage on output of push pull q3-q2 .normal should be 8 to 11 dc voltage .it mense circuit is ok .

 

[hooman]

 

[hooman]

 

[hooman]

record with tube pre amp big head room no cliping :

 

[hooman]

compare 6j7 from usa and ef804s from w germany 2 of nos tubes in one box

 

[hooman]

fix problem on b-1 mic and send back to customer . there is no schematic of b-1 on internet.but in diyaudio can find this circuit .