Mic, Line, EQ... Preamps

ML3 with gain, unbalance input...
 

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Sir Mile,

My mains power transformer had a +/-18vac secondary winding. I would like to use it for this preamp psu design, will it maintain the +/-15vdc regulated output supply?
Can I also use TIP41C for the power regulators? and any other substitute for the TO-92 fets?

Thanks!:)
 

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Sir Mile,

Do you still have the foil pattern for toner transfer on this fan control circuit? I tried to do it manually using pen type cutter over masking tape but the result was so bad :no: Sorry I posted it in this thread ...can't remember though to which thread I got the file.

Regards!
 

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Just had the time to finish my DIY -/+15vdc pre-amp power supply...I have tested it to power an op-amp driven dc-protect works fine, only that -rail measures 15.51v and +rail measures 15.18v but I guess I placed different made TIP (transistor) devices. The other was from fairchild and the other one from ST(?)..:) Anyway it was the device I have in hand.

Thank You! Sir Mile!
 

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Just had the time to finish my DIY -/+15vdc pre-amp power supply...I have tested it to power an op-amp driven dc-protect works fine, only that -rail measures 15.51v and +rail measures 15.18v but I guess I placed different made TIP (transistor) devices. The other was from fairchild and the other one from ST(?)..:) Anyway it was the device I have in hand.

Thank You! Sir Mile!

Nice job Sir,
what do you use TIP for this PSU?
 
MC4558 in place ofTL072

I have tried 50K pots but no improvement.. Even replaced the TL IC with two new ones, both purchsed from different vender... Still bass is not low as with the Lowpass circuit.

If any one else can try it.. may be all TL ICs can be faulty..

Waiting for reply from members...

Rakesh Sharma

hi sir. the filter which you are regarding is been tested by you?? how is the sound?? can we use MC4558 ic instead of TL072?? plz reply
 
Hello APEX .
I made your auto range VU and i have a question about the clipping indicator led. i tested it with a power supply of +33V and the input of the VU connected at a voltage divider. i was expecting that the red led would turn on when the voltage at the input was equal to the supply voltage of 33V,but it turned on quite lower at 26V. Why is that?
 

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Hello APEX .
I made your auto range VU and i have a question about the clipping indicator led. i tested it with a power supply of +33V and the input of the VU connected at a voltage divider. i was expecting that the red led would turn on when the voltage at the input was equal to the supply voltage of 33V,but it turned on quite lower at 26V. Why is that?

Most amps have cliping level when output voltage is about 6V under rail voltage.
 
APEX TUBE preamp files for pcb done by viktor1986,thanks Mile and thanks Viktor! :)
 

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