Amp powers up and produces both - and + rail.. I get -15 volts on both pins 4 and 8 of all op-amps ..
Amp produces no sound any ideas where to check??
Amp produces no sound any ideas where to check??
I'm assuming that you've checked all switches and pots.
With the black probe on leg 1 of Q504 and the red probe alternately on each end of R516. What is the DC voltage on each end of R516?
With the black probe on leg 1 of Q504 and the red probe alternately on each end of R516. What is the DC voltage on each end of R516?
Drive a strong signal into the amp. Set the gain to the highest point and set the crossover off.
Which op-amps have signal on their output pins?
Which op-amps have signal on their output pins?
At the top of the page, I assumed it was a typo but I may have been mistaken. Do you really have -15v on pin 8 of the op-amps?
If so, you need to find that fault first.
If it was a typo and you have +15 on pin 8, do you have signal on pin 5 of IC101 and IC102?
If so, you need to find that fault first.
If it was a typo and you have +15 on pin 8, do you have signal on pin 5 of IC101 and IC102?
You should be able to identify the regulators by now. You've been doing this for quite a while. The positive regulator output is taken from Q605.
Back to this amp again I set it aside due to thr fsct that the guy had no money at the time..
They are using a C2690 for the positive regulator can i use a 7815 for testing??
They are using a C2690 for the positive regulator can i use a 7815 for testing??
No... well, it's not a drop in substitute. The 2690 is a transistor. The 7815 is an IC. The circuit would have to be reconfigured to use the 7815.
Virtually any NPN transistor rated for more than 1w will work. If you have a 2N6488 or an MJE15030, you can use those but you will have install them reversed because the pin configuration is reversed.
I understand that .. I wanted to know if there was a sub i could use for right now for testing before i order parts for this amp Since i dont have a 2690 on hand