The Signal Chain
The first thing needed is to establish a base line in which to begin our quest. One of the most important
aspects of getting great guitar tone is building the proper signal chain whether the signal flows through
stompboxes, rack gear or a combination the principles are basically the same. Different sound frequencies
have different impacts on the overall guitar sound coming from the amplifier. By manipulating these
frequencies one can make drastic changes in the overall guitar sound. Applying these principles to every
step within the signal chain can have a huge effect on the overall guitar tone.
Through experimenting with the Rockman gear and the advice from
Perfect Sound along with many hours reading AmpTone.com
the ideal signal path is as follows:
Guitar to pre-distortion EQ to pre-amp distortion to EQ power amp
A great illustration is available in the Rockman Sustainor manual which can be see below. The difference
in this signal chain is the patented Rockman compression between the guitar and pre-distortion EQ which is
inserted into the signal chain via the effects loop. Due to the modular setup of the Rockman head adding
EQ after the pre-amp distortion is as simple as adding a Rockman EQ or in my case an old MXR 10 band EQ
after the Sustainor in the signal chain. On a typical amp this can either be the amps EQ section or for
some amps the effects loop is after the pre-amp and before the power amp making the effects loop the
perfect place to insert a EQ.
Why insert an EQ before pre-amp distortion?
In the case of the Rockman gear the main function is to
"de-Bostonize" the sound. The Boston sound relies heavily on mid-range frequencies and by cutting the
500Hz band the Rockman Sustainor becomes much more than a Boston tone replication device. Also depending
on the other frequencies boosted or cut the sound can be changed from a crunchy distortion to a smooth
How does that affect me the non-Rockman user?
The same theory applies, by affecting the sound frequencies that are boosted or cut the distortion
characteristics can be drastically changed.
In the next article we'll explore placing a Boss GE-7 EQ in front of a Tube Screamer before a simple tube
amp, aka Fender Champ, to see what the effect is on the overall sound. The focus will be on what happens
to the distortion when a smile or frown curve is applied to the pre-distortion EQ.
Would like to thank the folks at Perfect Sound Rock Refurbs for all their help.