Forum upgraded to SMF 2.1.2!
Started by benzer, September 15, 2007, 10:34:16 AM
Quote from: benzer on September 15, 2007, 07:51:38 PMwell thanks man for being concerned in the design
Quotesecond about the circuit ,,i havnt built the circuit but i simulated it over proteus. it works fine there .
Quoteabout the diodes .... in the proteus software when using only 2 or 3 diodes the provide only around 0.5 voltage drop between the two bases .....is that enough to open up the 2 transistor base-emitter junctions to create some quiescent current?
Quotewhat are the vaules of the emitters resistors should be?
Quote,,and about the unity gain stage. it is just to offset the signal by -0.5 volts,and i chose the 5 M cuz i didnt know that it would cause that much noise ,,thnx for the information..
Quoteagain about the resistors to the collector of the transistor pairs ,ive seen schematics that include them and some they dont,, still not sure what s the main benefit of them.
Quotethanks again for the schematic u included and do u know any source that explains that feedback u told me about? to include the output transistors in the feedback loop of the opamp?
QuoteAccording to datasheet, 1N4007 should have a forward voltage of about 600 mV at 10 mA (my sim shows 7 mA through diodes at idle).
QuoteI wouldn't build a unity gain power amp - or even a discrete power amp for less than 30 W of (RMS) output power.
QuoteI have been dealing with amplifier circuitry (researching & developing, repairing, building etc.) for few years. I'm for the most part self-educated in electronics
QuoteI can't really recommend you a schematic since I hardly know what type of music you play, what features you need, how much complexity in the circuit you "tolerate"
QuoteI suggest you make the preamp versatile and nice sounding, then build the power amp section based on a chip.
QuoteTIP142/147 (output devices). This of course depends a lot on the circuit you are intending to build. Those are pretty good for a 60 W amp but overkill for 10 - 20 watts.