you can get a reasonable approximation of the money for nothing sound by using a whawha
set to a fixed position with a bit of overdrive. depending on your guitar it even be sufficient
to roll off the treble of the bridge pickup. and, naturally: fingerpicking.

http://www.gyraf.dk/ good stuff.

there may still be some merit to using a dual opamp, under certain circumstances, for example if you decided that you wanted an arrangement similar to the PI of a tube amp in order to reproduce certain characteristics like voicing etc.

yes, i guess it would have to work, although you could omit the noninverting system- it doesn't amplify anything and the phase is the same as at the input.
you need to suplly power to the opamp though, ptherwise it won't do a thing.

you need speakers rated for the right performance, rating does indeed not depend on the size of the speaker. a new jensen10" 25W one should probably cost some 40-50 bucks.

if you can find a defective combo (preferably w/ a working speaker) you should get that and gut it- it can save you the bother of building the cab and the chassis (12 hours of work)and you can concentrate on the electronics. furthermore you get the switches, knobs, etc almost for free, possibly even a suitable transformer.

QuoteRunning the input into one op-amp's + inupt and to the other op-amp's - input will put the signals out of phase, correct?

-basically  yes, but the op-amp needs to be biased slightly differently, depending on whether the+ or -input is used. so the regular approach is to use a phase-inverter to make the
actual halves of the bridge as identical as possible.

well, the gimmick is that, as far as i know, you can't bridge two amps that have partial current
feedback implemented. so i was wondering if it could work like this.( the obvious method would be paralleling them, i guess )

hi,
it's a bit of a joke, more a sort of thought-experiment, but it should work in theory, no?

maybe: http://en.wikipedia.org/wiki/Bridged_amplifier

hi,
very late and completely unrelated to the last postings- but: would it work to "tap" the output of the small peavey by using a small transformer and just feed that signal into any large
ss-poweramp?
basically the interaction of rage-amp and speaker should be preserved like this and you can simply plug it into any cheap PA and drive a marshall cab (good for rock'n roll).

yes, THAT is right:)
if i'm not mistaken the 2nd tl072 doesn't need any extra connection to vb because these stages don't produce any gain and the two opamps at the input have already brought the signal to the right potential.

hi,
"vb" should be half of your supply voltage, or, if you're using a symmetric supply, 0.
to get the actual power in there, connect the supply to the designated pins of the opamp, in
case of a tl074 it's nr. 4 for positive and nr.11 for negative. the data sheet can be found at
http://www.tldp.org/linuxfocus/common/src/article251/TL071.pdf

hi,
using a pot or a voltage divider would be very nice for sure   if you can't see anything that makes this thing completely unuseable for guitar i'll just try it out when have some free time.

aah, yes the application would be good to know. in this case it's a limiter in front of a PA ( probably tda 2030) as i'm planning to build a small practice amp.
the preamp is going to be something with 2 jfet- stages with moderate gain.
what i found interesting was that the article mentions methods of controling harmonic distortion in that type
of circuit  -so i  wonder if someone has explored that before?

hi,
i suppose that many of you have seen this limiter design  http://sound.westhost.com/project67.htm  - does
anybody have any experience with this circuit?
thanks in advance
el mo.