Metro Loop problem?

[Rogue]

Hey guys. I have a 68 plexi clone that I installed a metro effects loop on. I have also installed a normal master volume (like a 2203) as well, and the loop is installed before the MV pot.

I'm not certain it is functioning properly. I only use it for a delay and using an El Capistan.

I'm having two issues. The first is that at higher frequencies (not sure why it would be limited to highs), I get a nasty sound as the delays repeat, or on the first repeat anyways. It almost sounds as though it's overloading something and getting distorted. This is with the mix around 35%, it only gets worse as you approach 50%.

The other issue (although maybe not an issue) is that I've never felt it "wet" enough. It reminds me more of a delay in front of the amp as opposed to a delay in a loop. Not sure if that makes any sense to anyone. Just not quite what I expected from past experience with other loops.

I don't remember the voltages I measured when assembling it, but all the measurements when done was well within the values posted in the installation instructions. I think I used the 10k resistor.

I tried another delay over the weekend just to see if it was the delay and I had the same issues. I used a Glab smooth delay with an input gain adjsutment figuring I could eliminate a potential overloading problem if that was the case. Same thing. A "rough" top end during delays and a feeling of a in front of amp delay as opposed to in the loop.

So, my next step is to start over with the install and make sure everything is correct again. However, I did read on another forum that some people used a different "component" for better results. "Component" perhaps meaning a different B+ resistor value. I asked about it but was ignored, so that is the only info I have.

Anyone have any issues similar to these or any thoughts on what I might could look at that might cause any issues like these?

[51N15T3R]

Is the trim pot on the loop board set for unity gain (i.e. no volume difference between loop switched in and loop switched out)?

[SDM]

Is the trim pot on the loop board set for unity gain (i.e. no volume difference between loop switched in and loop switched out)?

Indeed the correct thing to check first. In your particular case (assuming the amp is stock aside from added master), best way to check if the trimmer is properly adjusted would be to crank the master full, but set the regular volume/s low so that the amp is still clean/cleanish. This way you can most easily hear if there's any change in actual volume when switching the loop in or out.

If the amp is cranked way up/well overdriven all around, may be hard to tell how well the trimmer is adjusted as (unless the loop trimmer is set way too low), you may only note more or less distortion possibly. Thus much harder to dial in the trimmer with a cranked amp, set it up clean instead to check.

Also sent you a PM in this for further follow up.

[Rogue]

Steve, thanks a bunch. I sent you some info.

51N15T3R, thanks for the reply. Yeah, it was the same and I also did it the way Steve suggested and it was still the same volume. Even looking at the level within the DAW. It's very close.

[Deric]

Different situation but.....I put a Metro Loop in a homebrew Daisycutter. Very high gain and VERY small chassis. Loop sounded great with everything but delay. Delay sounded OK unless I cranked the repeats...then it sounded like what you described. At first thought maybe I had a bad loop....so, pulled the loop out of another amp and it did exactly the same thing. After staring at (ie: trouble shooting) the amp for a while I realized just how close the loop board was to the pre-amp tubes.

Carefully crafted a "shield" out of tin foil and cardboard. Placed the shield between the loop board and the tubes....no change...until I grounded the tin foil. As soon as it was grounded...problem solved.

Ended up making a nice shield out of a piece of copper clad board and mounting it permanently.

Anyways...if the board is REALLY close to the tubes or other signal wires, it may be something to try.

Good luck!!

[Rogue]

Thanks for the thoughts Deric. My board is right above ( or below rather) v3 and partially v2. I pulled the board out, but left it connected, and fashioned a shield. However, I still have the same problem.

I have looked at all the connections and it all looks fine. I haven't checked voltages though. I did remove the return chord and ran it straight into the daw and used a cab simulator. They delay sounds like I would expect to. So, something appears to be going on after the signal is returned to the amp. I did have to run the input on my audio interface with a -20 db pad, and pretty low on the gain. Not sure what to expect from there though.

[Deric]

The shield thing was just a thought. The amp I used it in was VERY cramped and very high gain. I have the same loop in a 2204/Mod 5-ish amp that's pretty cramped too but the loop works perfect without any extra shielding.

Hope you figure it out!!

[Will.Simmons63]

The strymon "el capistan" is to hot for most FX loops you need a line level pedal and that should solve your problem.

[Will.Simmons63]

The strymon "el capistan" is to hot for most FX loops you need a line level pedal and that should solve your problem And as far as the wet sound you are wanting get something like a Suhr Mini Mix to make your FX loop parallel instead of series that way you have no dry signal going in your fx loop only your wet.

[Mcewen4444]

Hey guys. I have a 68 plexi clone that I installed a metro effects loop on. I have also installed a normal master volume (like a 2203) as well, and the loop is installed before the MV pot.

Correct me if I am wrong, but the loop should be installed after the MV pot. Perhaps you are hitting the delay with too much signal. I have put this loop in a 2203 style amp and it worked perfectly.



Edit....Sorry, did not see this was a necro post from November.