You’ve connected top of R34 to Q7 collector? If so, please report voltages at collector of Q7, and base of Q1 and base of Q2.
No i havent connected it, when i connect it. Also i shouldve mentioned it but the divider doesnt connect to anything since i havent added the output transistors yet. I tried adding them into the schematic and i get a huge current flow of 130ma at 10V supply even when the voltage across R19 is less than a volt.
The large current is seen in a breadboard, or in simulation?
If in physical breadboard, try removing Q13 and Q14, and connecting R24 to Q7 collector. Assuming supply current is then reasonable, report test points mentioned earlier.
If in physical breadboard, try removing Q13 and Q14, and connecting R24 to Q7 collector. Assuming supply current is then reasonable, report test points mentioned earlier.
That's great!
Now measure maximum and minumum spreader voltage, i.e. volts across C9. Return pot to minimum voltage.
Now measure maximum and minumum spreader voltage, i.e. volts across C9. Return pot to minimum voltage.
Sounds OK.
You mentioned earlier excessive supply current, so let's populate outputs cautiously. Disconnect R21 and R22 to take Q15 and Q16 out of circuit. Install Q13, Q14, R19, C5, C6.
Apply power and confirm reasonable supply current. There should be no voltage appearing across R12 or R20. If you advance bias current pot, you should see increasing voltage across R19. Don't drive it much above 1.5V. Return pot to minimum.
You mentioned earlier excessive supply current, so let's populate outputs cautiously. Disconnect R21 and R22 to take Q15 and Q16 out of circuit. Install Q13, Q14, R19, C5, C6.
Apply power and confirm reasonable supply current. There should be no voltage appearing across R12 or R20. If you advance bias current pot, you should see increasing voltage across R19. Don't drive it much above 1.5V. Return pot to minimum.
Even when the feedback is connected to the collector of Q7 or the output of Q15 and Q16 its still the same
(The large current flow happens only when i connect the output transistors)
(The large current flow happens only when i connect the output transistors)
Try opening the Q15, Q16 path--- easiest method, eg. R12 or R20. Then recheck supply current.
Also confirm there's no collector-to-collector short through heatsinks.
Also confirm there's no collector-to-collector short through heatsinks.
I oppened it but when i conncet the supply voltage something weird happens. When i connect only the negative rail i get an increase in current flow and after connecting the positive another increase with a total current draw of aboyt 80ma while the voltage across R19 is 1V.
Are R21 and R22 opened to prevent current into output pair? To establish definitively, you could remove R44 to de-power input stages, thus testing only Q15, Q16.
It's possible there's oscillation. It would be good practice to have a 0.1uf cap from Q15 collector to Q16 collector (i.e. ground), with minimal lead length. Also 0.1uF collector-to-collector Q13, Q14. Maybe also 0.1uF shunting R45.
Do you have access to a scope for oscillation check?
It's possible there's oscillation. It would be good practice to have a 0.1uf cap from Q15 collector to Q16 collector (i.e. ground), with minimal lead length. Also 0.1uF collector-to-collector Q13, Q14. Maybe also 0.1uF shunting R45.
Do you have access to a scope for oscillation check?
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