The Gainclone amp I built from two kit amps just used a 22uF polarised cap in that part of the circuit;
http://www.romanblack.com/gainamp.htm
http://www.romanblack.com/gainamp.htm
How accurate does the capacitance value have to be?@ RB,
Does it work perfectly?
I'm extremely happy with its sound quality, and it has never missed a beat in terms of reliability.@ RB,
Does it work perfectly?
IIRC from a sim there's possibly ~1V below ~10Hz when the amp is being driven to the clipping point.Alec_T said earlier it should only get "a few mV swing" which sounds reasonable at audio frequencies. At very low frequencies there could be a couple of volts there?
Ran a sim at 1Hz. No measured difference in THD for various polarised/non-polarised cap models.I'm curious to see if the polarised electro causes distortion on the bottom half of a sine waveform at very low frequencies.
Thank you very much!Ran a sim at 1Hz. No measured difference in THD for various polarised/non-polarised cap models.
Yes. Clipping seemed symmetrical.Did you check the waveform across the cap when running at 1Hz and large output waveform?
Distortion was primarily odd harmonics. Very little 2nd harmonic.Of course the THD test you did probably confirms the cap is charging equally to + and -, or there would have been significant 2nd harmonic distortion?
I believe you. I'm not convinced that the cap models are completely accurate regarding asymmetric effects with polarised types.A PSPICE type circuit simulator will not care about which type of capacitor that is used.
I dare say it will follow ok; the question is will it damage (de-polarise) the cap in the long term?I can easily connect a sine generator through a resistor to a polarised cap and see what voltages it will follow.
Tantalum capacitors are very vulnerable to going leaky if reversed - even small signal!!!@RB
I dare say it will follow ok; the question is will it damage (de-polarise) the cap in the long term?
Tantalum capacitors are very vulnerable to going leaky if reversed - even small signal!!!
Aluminium electrolytics are a little more resilient, but may need re-forming after mild reversing.
Its a procedure that's sometimes required on aluminium caps that have been in storage a long time.I have to ask, what is meant by re-forming a cap?
That's an excellent question! I always assumed the damage occurs when the reverse current rises, making heat/electrolysis etc.@RB
I dare say it will follow ok; the question is will it damage (de-polarise) the cap in the long term?
I was looking at ur Regulator circuit tht u build. I like to use it and need ur permission. so Can I ? pretty please.The Gainclone amp I built from two kit amps just used a 22uF polarised cap in that part of the circuit;
http://www.romanblack.com/gainamp.htm