KLD JMC Amplifier with METRO FX loop kit REV 4

[stagam]

Hello, New on the list and have a question about an install I did on a KLD JMC 25 amplifier with METRO FX loop kit rev 4.
There does not seem to be enought gain when using pedals in the effect loop even using -20 db switch. I tested the two with an Alesis Quadraverb which has alot more gain to drive back into the phase inverter. Here is the schematic and I installed loop after the master volume. http://www.kldguitar.com/Home/Product/JCM25 Thanks Stan Gamble