Line driver for parallel FX-loop

Started by VPIF, November 16, 2009, 04:01:09 PM

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VPIF

Are any of the GGG buffer circuits suitable as a line driver to buffer the "send" of my amps FX-loop? I am going to split the signal in 10(!) to make four stereo parallel FX-loops + a stereo channel for the dry signal. I imagine I would need a line driver for each line after the signal is split - total of ten line drivers. Is this correct?

GGG buffers:
http://www.generalguitargadgets.com/index.php?option=com_content&task=view&id=74&Itemid=26
http://www.generalguitargadgets.com/index.php?option=com_content&task=view&id=75&Itemid=26

sean k

I personnally wouldn't go that far and simply use 10 transistors as emitter followers but it might be an idea to have a couple of output buffers using a TL072 to drive what would be a quite low impedance driving 10 transistor bases then again even 2 fets, alike the ruby fet, as source followers might be enough as well.

I think thats your only real problem, as such, is converting the output impedance of your amp into 2 x 5 outputs of about the same impedance.

So this is just about, this post, a lower parts count and less space used  to acheive essentially the same thing.
Monkey see, monkey do.
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Ben N

There's more information you need to gather to figure this out intelligently. Such as: what is the Z-out of the fx-send, how hot is the signal, what kind of inputs, in terms of Z-in and expected signal level, are you going to be feeding. At the other end, depending on the output level of your effects, you may need to bring your levels back up before going back into your fx-return (if you are indeed bringing the signal back).
Presumably, your amp's send is mono, meaning that although you are feeding stereo imputs, there is only one signal going to them. So, if your buffer has a low enough Z-out and your fx have a high enough Z-in, you wont need a separate buffer for each channel, just one per effect. Of course if you are paralleling a lot of buffers that don't have really high Z-in (like bipolar transistors), you have to be concerned that your total impedance will be low enough to cause a mismatch with the fx-send.
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