Ross Compressor for Bass Guitar

[astley]

any one can tell me how to mod my Tonepad Ross Compressor to Bass Guitar use , and also want add SPDT to control input -10db and 0db , because i want Bass and guitar both can use this compressor.
thx~

[astley]

any one can help me ??

[Mark Hammer]

There are many posts about this if you do a search through the archives.  Typically, shortening the recovery time by making the 150k resistor lower in value will help.  This is the resistor connected to the 10uf cap and the two transistors.  The normal circuit is set up for longer recovery times.  This is good for strumming chords, but not so good for bass.  Try something between 10k and 47k.

The 3080 chip can not take high input levels without distorting so the input to the chip is attenuated already.  You probably don't want to attenuate it more.  However, strong input signals from a bass can cause too much compression.  You can change this in on or both of two possible ways:

• Change the .01uf capacitors after the 2nd transistor to something a bit lower, like 2200pf or 1000pf.  This will reduce the compressor's sensitivity to signals under 150hz or so.
• Increase the compression pot from 500k to 1M.  This will still allow you to get maximum compression, but will let you reduce the overall sensitivity of the compressor more.

[astley]

thx~~~ but by the way . How to add SPDT to control input -10db and 0db

[Mark Hammer]

No idea.