Patch bay affects tone...

[kvandekrol]

I recently built a patch bay for someone which is used for pedalboard guitar input, output to amp, input from FX loop and output back to the rest of the rig (rack and power amp). He used it and said there was a very slight coloration to the tone when everything passed through it - it sounded just a little bit 'tinnier'. (This is a pretty high-gain setup if it makes a difference.)

Has anyone experienced this with patch bays? This one is pretty well identical to the one Loop-Master makes. I'm wondering if it's just inherent to the design of a patch bay, or if there's anything I could do to remedy this. All the wiring is very neat, 22 gauge stranded, and as short and direct as possible.

(I did later read that there may be some issues with certain amps if all of these jacks are connected to a common ground and not isolated, but I did it the way Loop-Master does it and there are not any ground loop issues with this setup.)

[anchovie]

it sounded just a little bit 'tinnier'

Tell him to turn the treble on his preamp down a little bit!  Or stand in a slightly different place in the room.

By introducing the patch bay you've changed the cabling setup, simple as. It's nothing to do with how you've built it, just something that people with "golden ears" might notice. He should adjust his EQ to taste to compensate for the equipment change.

[joegagan]

interesting, that is the opposite of how it normally goes. if he is actually experiencing less low end as opposed to simply increased highs, this would be my first step in figuring out if something that needs rectifying is truly happening.

if the pedalboard is the last thing before the input side of the patch bay it is no doubt a buffered signal, so i wonder what is going on here.

i have been involved as a builder and tech at my brother's studio since we built it in 02. we use protools to record separate samples to do highly critical AB testing. remove as many variables as possible, make two recordings using as close to the same guitar performance as possible, then listen to the tracks without distraction. we even used this techinque to evaluate the effectiveness of our outside sound isolation methods ( using an ipod/bose setup outside the building, matched vol levels, recording the exact same song on the ipod- mic placed inside the building).

[kvandekrol]

I believe that one of the jack pairs is used for guitar input to the board. I'm guessing the board is split between pedals used before the amp and pedals in the FX loop, so there are two inputs (from guitar and from FX loop) and two outputs (to preamp and to power amp). So the very first jack is likely unbuffered.

[joegagan]

i would definitely  try to assure that everything that hits the patch bay input side is buffered. he's probably getting the signal loaded down.

can you convince him to do a split after an initial buffer stage?

[ayayay!]

so there are two inputs (from guitar and from FX loop) and two outputs (to preamp and to power amp). So the very first jack is likely unbuffered.

I was going to ask that.  Sounds to me like that's a LOT of cable going around.  Since guitar cables (especially the cheaper you get) have inherent capacitance, he's hearing a increase in treble, which often gives the perception of less bass.  

I'm with anchovie:  He'll need to beef up slightly, and cut his treble a little bit.  No shame in it.  

And if it's all true bypass on the board, or maybe only even one buffered pedal at the very front, you're bound to experience some loss.  

Not saying your guy is this way, but it never ceases to amaze me how people basically get an entirely new setup and it "doesn't sound the same on my amp with the knobs the old way."  So?  Turn the knobs then.