fosgate g250_a2 bias problem

[toobnoob]

ok,

down to a problem with getting the right channel to bias correctly. currently, the base of q212 will only adjust 1.7 to 2.0 volts.

any suggestions?

p.s.

perry, did you get my email?

 

[Perry Babin]

Does the channel work properly otherwise?

When did you email me?

What was in the subject line?

 

[toobnoob]

hey perry,

alright, the right channel is the problem child.

i have a 1v p-p signal being applied.

the first pic is the left channel output, 10v p-p.

the second pic is the right channel with same input applied but at 2 volts per division.

i have 4 ohm resistors on the output.

i'm a little baffled right at the moment.

 

[Perry Babin]

Lift D204. Does that allow the bottom half to swing below 0v?

If not, what have you replaced in the right channel so far?

 

[toobnoob]

hey perry,

lifted D204, and have a full sine wave on the output, but with a 5.2v p-p value with same input conditions as listed above.

also have not replaced anything yet.

 

[toobnoob]

perry,

replaced q216 as it was shorted base to collector. resoldered d204 and now have a full 5v-pp sine on the output.

 

[toobnoob]

belay that last post about the 5v p-p output, i apparently had the left channel gain set up higher than the right channel.

both outputs look good. now to adjust the bias.

got the bias adjusted.

eta:

pic is the left and right output at 5v per div.

 

[Perry Babin]

What do you think this is, a self-service forum? You're supposed to make us feel like you need our help.

 

[toobnoob]

What do you think this is, a self-service forum? You're supposed to make us feel like you need our help.

lol...

hey perry, thanks so much for the assistance.

trust me, i am sure i will asking for more help!