This is not just another gainclone

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I use the same Conrad case for my brand new Nonoz II DAC...
 

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Bi-Polar Gainclone Suggestion

There has been some discussion lately about the merits of inverting operation VS non-inverting operation for the GainClone circuit, so perhaps it is prudent to show that an opamp circuit can be switched either way as below.
I know the circuit given is configured for X1 gain, but circuit values can be suitably changed.

I did also see a similar circuit in WW/EW circuit years ago that used a pot instead of a switch as the polarity selector.
This gave +1 through 0 through -1 gain and polarity control, and was described as being useful for selecting reverb unit return signal polarity, but alas I forget the finer details - anybody have that circuit to hand ?.

Either of these two circuits implemented correctly may be suitable to give the luxury of choice of GainClone operating mode.
This circuit is of course perfectly suitable for line level polarity control, and could easily be incorporated into a preamp or cdp output stage.

Eric.
 

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does anyone know the exact amount of heat each chip creates at full volume? (a maximum)

i was thinking of using this diagram to bridge and parellel 4 together (4 chips) per channel and tri amp them :devilr:
this would give me 224 watts per channel, per speaker 😎 and then i was going to make a seperate sub woofer driver (posibly with the same chips) and then use 4 car batteries in series to give me +-24v (approx.) and put it in my car (when i get one).

sound cool? 😎
 

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I tested my gainclone today

results: a little hum, and the output level is quite low (I wasn't using a pot, and the volume was a little more loud than a normal listening volume)

I used peter's shematic, with a 220VA 2*18V transformer, and a TDA7294 (10K and 220K resistors)
 
OK, it was the portable cassette player's fault

I tried with a cd player (no adjustable output), and I had the good idea to put noise blocking pads in my ears before 😀

it was a gooood idea 😀 I never saw my woofer moove so much
 
I tried with a cd player (no adjustable output), and I had the good idea to put noise blocking pads in my ears before

A couple of years ago, I bought a cheap 100K pot, put it in a very small box with some wires and phono plugs. I use it when I want to couple source components to a power amp for testing and it's one of my useful tools.
 
some strange things:

with no input, input pin floating: the chip goes hot

same setup, but with the loudspeakers disconnected: cool






with the loudspeakers connected: 4mV DC offset
but when I short input to grount: 100mV !!!




how can I see I have an oscillation problem?
 
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