ZEN Amps
Well-known member
The Friedman Plexi thread got me thinking - essentially I don't fully agree with the 'loop in a plexi' is pointless argument. Although it's well known that the PI/power tubes provides most of the drive in a NMV Marshall, the preamp does contribute - especially if you're slamming the input with a boost.
A while back I built a 1959 clone with loop and PPIMV for a client who's a big FX (verb/delay) user. We ran some controlled tests with and without a boost using three setups:
1. FX upfront
2. FX in the loop (Metro board)
3. FX post amp (similar to a power station setup)
With a good loop setup properly for unity gain, and with outboard FX that don't screw with the return level or have other issues, 2 wasn't amazing but still objectively better than 1. Of course 3 was far superior to both.
Two other factors - with a clean boost upfront, the difference between 1 and 2 widened as expected. Also not surprisingly, dialling back the PPIMV helped (output tubes running cleaner). This, and other tests have led me to believe that a loop in a Plexi style amp with a PPIMV (like Suhr and now Friedman) isn't ideal, but can be of some benefit. If done well of course.
End of the day, an ordinary loop with a dodgy pedal will affect overall tone quite negatively. A good line-level loop with quality rack gear can sound decent. Most guys will live in between, but I suspect the former happens enough to turn many off - including builders.
Experiences / thoughts?
A while back I built a 1959 clone with loop and PPIMV for a client who's a big FX (verb/delay) user. We ran some controlled tests with and without a boost using three setups:
1. FX upfront
2. FX in the loop (Metro board)
3. FX post amp (similar to a power station setup)
With a good loop setup properly for unity gain, and with outboard FX that don't screw with the return level or have other issues, 2 wasn't amazing but still objectively better than 1. Of course 3 was far superior to both.
Two other factors - with a clean boost upfront, the difference between 1 and 2 widened as expected. Also not surprisingly, dialling back the PPIMV helped (output tubes running cleaner). This, and other tests have led me to believe that a loop in a Plexi style amp with a PPIMV (like Suhr and now Friedman) isn't ideal, but can be of some benefit. If done well of course.
End of the day, an ordinary loop with a dodgy pedal will affect overall tone quite negatively. A good line-level loop with quality rack gear can sound decent. Most guys will live in between, but I suspect the former happens enough to turn many off - including builders.
Experiences / thoughts?