Hi Scott,if you are there I have a question regarding the compander in the PT80.
What would I have to do to use ONLY the compander from the PT80?.
Can you tell me what to take out to use as a stand alone for a guitar signal about 70mV.
What I want to do is clean it up before I amplify it.
Thanks a million
Aharon :?:
BTTT
Aharon
Ok,I've isolated what I think should be working compressor/expander bits of circuit.
Now I need to know what the transistor after the delay chip does and is it needed if I just want a compander,is that buffering the delay chip's output?.
Thanks
Aharon
Not exactly sure what you are doing, but a little background.
Companding is a double ended system used to reduce noise buildup in a portion of a circuit or storage media. Like for instance for delay pedals (noise buildup through the BBD) or cassette tape recording (Dolby, dbx are both companding systems).
It cannot remove noise present in the source, like from a buzzy pickup.
You would need a single ended noise reduction system like the Rocktron hush to do that.
The transistor on the PT-80 is part of the post delay filter, but also provides a low output impedance to drive the expander input. Actually both the compressor and expander of the SA571/NE570 inputs need to be driven from a buffer.
Thanks Scott.So if I have nothing between the compressor part and the expander portion any noise present will not be removed?.
In other words I have to place some portion of the circuit between them,right?
Thanks
Aharon