My WOPL 700 Containment Thread

[mr_rye89]

Did the quick test procedure on the right side of the control board. everything checks out there except Q6 and Q9 get pretty warm. maybe the right backplane is suspect?

 

[Gepetto]

Did the quick test procedure on the right side of the control board. everything checks out there except Q6 and Q9 get pretty warm. maybe the right backplane is suspect?

It is rare but sometimes coincidences do happen...glad you are vectored onto finding where the problem is...

 

[mr_rye89]

Are Q6 and Q9 supposed to get warm during the quick check procedure? I looked over the right back plane and didn't see anything obvious. I'm thinking I made a bad connection somewhere.......

 

[Gepetto]

Are Q6 and Q9 supposed to get warm during the quick check procedure? I looked over the right back plane and didn't see anything obvious. I'm thinking I made a bad connection somewhere.......

You have a full comp setup so I am assuming that your quick check procedure is that of having no devices installed on the backplane boards and testing for bias.Q6 and Q9 typically do not get very warm under any circumstance.

 

[mr_rye89]

You have a full comp setup so I am assuming that your quick check procedure is that of having no devices installed on the backplane boards and testing for bias.Q6 and Q9 typically do not get very warm under any circumstance.

Ok, I'll check Q6/Q9 when I get home. The voltages across the 47 ohm resistors went between .8 an 1 volts when turning the bias pot.

 

[mr_rye89]

Found it. R2 (1 ohm 1/4 watt) not populated on the right channel back plane board. Hiding underneath that emitter resistor. That ties right in to the bias circuit. Soldered that in and I have healthy bias voltage on the right channel. Lol.

 

[Gepetto]

Found it. R2 (1 ohm 1/4 watt) not populated on the right channel back plane board. Hiding underneath that emitter resistor. That ties right in to the bias circuit. Soldered that in and I have healthy bias voltage on the right channel. Lol.

Parts matter Kyle...

 

[mr_rye89]

All transistors in, no kaboom. Final test and first listen will come later. I've gotta meet up with friends for cold snack time (more important)

 

[J!m]

Cold snack trumps hot amp.

 

[mr_rye89]

IT"S ALIVE!

 

[mr_rye89]

 

[mr_rye89]

 

[laatsch55]

Soooo......what do ya think Kyle?

 

[J!m]

He can't hear you...

 

[mr_rye89]

Whaaaat?

 

[mr_rye89]

Soooo......what do ya think Kyle?

First impressions are good. I'm still tweaking the levels/eq cuz I moved the 400 to the tweeters and it has more gain than the 300B

 

[mr_rye89]

It's quieter (lower noise floor) that my 400. I'm thinking about cleaning up the wiring on the 400 and adding that triac power switch.....

 

[laatsch55]

Should be like a black hole for residual....

 

[mr_rye89]

Should be like a black hole for residual....

On the bench hooked to the JBL L15s you couldn't hear any noise, I think the hiss I have is coming from the MiniDSP. I may switch that to a linear power supply.....

 

[Gepetto]

On the bench hooked to the JBL L15s you couldn't hear any noise, I think the hiss I have is coming from the MiniDSP. I may switch that to a linear power supply.....

Amplifiers have a bad habit of amplifying anything that is input to them...