Marshall DSL40CR effects loop weirdness

[Snags]

Is this a "just me" thing, or is it a known issue? If the latter, hopefully with an easy and non-invasive solution.

I've got a DSL40CR paired with the (correct) 6-button footswitch.

Initially I used it all in the front, but latterly I've been playing with using the loop, so there's a small board in the loop. Contents vary but generally something like Mooer Baby Tuner, Boss CE-5, a flanger (Boss or TC), Source Audio Collider, and either a Boss RV-6 or a Boss DD-6.

When first powered up the amp is remembering the settings correctly, as indicated by all the lights. Engaging the tuner on the board shows the board in the loop is receiving signal, because I can tune. However, in terms of the actual effects, it appears that the board is bypassed - I get no change with them engaged or otherwise.

Toggling the FX loop off/on from the footswitch generally brings the loop to life properly.

The bit that's freaking me out is that the tuner sees signal, and I thought the loop was series not parallel, so if there's signal going in to the tuner, and if the amp makes noise, how is it cunningly bypassing all of the actual effects until I kick its arse a bit?

 

[Orvillain]

That makes little sense to me tbh. Unless those amps have a general bug that you're now discovering?

BTW, apropos of nothing, I wouldn't have the tuner in the loop of the amp. You might accidentally try to tune using a distorted sound from the amp, which could throw the tuner off perhaps?

 

[Snags]

Yeah, the tuner is only there because I'm a lazy shit. It's a board that I sometimes use with the acoustic (hence all time-based stuff) and I sometimes shove in the front and I'm just too lazy to take it on and off. It's not really there for utility so much as "ah, sod it, whatever", a bit like the old rules are for the obedience of fools and the guidance of the wise. Not that I'm that wise. Maybe I should take it off

The loop behaviour makes no sense to me either, though. Hurts my brainy, so it does.

 

[Baba]

Would you be able to make a video of this phenomenon? I can't make sense of it either.

 

[Snags]

Sure. Let's see if I can work out how to embed video ...

Extra info to go with it:

• forgive the mess, it's combination music room and home office and there is just too much going on so it's a total tip at the moment
• pedal power supply is a Cioks DC5
• each pedal is on an appropriate outlet in terms of ma
• at the end when the FX engage, you hear some "shitty signal", as though there's a bad patch cable or interconnect, or something isn't getting enough juice:
  • this clears up after a few seconds
  • I've checked and swapped all the patch leads and interconnects, and they're sound
  • I haven't actually stuck a multi-meter on the Cioks to check each outlet, maybe I should
  • the Collider is on the current firmware
  • I'm vaguely suspicious that the Collider might have "issues", but that doesn't explain how none of the other FX get applied to the chain initially, and how the tuner isn't blocking the signal when it should be

What you'll see is the FX loop engaged, and the tuner engaged. The tuner should mute the signal when engaged. It doesn't, and no FX are applied to the signal, it's as though the loop is bypassed but the tuner registers signal, so it isn't. Then I toggle the FX loop on the foot controller, and lo, the tuner does mute the signal, and FX are applied when engaged (with, initially, shitty signal quality)

It's like the loop is both active and bypassed at the same time, which is ... just very strange.

 

[laxu]

I'd try simply paring it down to a bare minimum, like only the Collider or only the tuner and see what happens then. Just to figure out if it's the board or the amp.

I don't know if there's maybe some issue with the amp where a bit of signal is leaking into the pedalboard even with the fx loop off.

 

[TravisG406]

I know I had to use some contact cleaner with my DSL40CRC footswitch because it was not responding to me pushing buttons. Try that too...

 

[Snags]

Quick update on this. Haven't had much opportunity to test and faff about for various reasons, but some further experimentation means I can exclude the footswitch and I'm pretty sure it's something iffy at the amp end.

Next job is going to be to shove some contact cleaner up the send/return jacks for the loop, and if that doesn't cure it either just go straight in the front all the time, or take it to a grown-up for a service and once-over.

 

[Blix]

I would say there's no mystery,I will bet the send is always active and there's a switch or relay at the return for bringing it in or out of the signal path.

 

[Snags]

Quick update on this. I think I might have sussed out what's going on, although more play testing required before I'm completely sure.

Prompted by an apparently unrelated issue (intermittent and unpredictable loss of signal to amp, even going in the front, and some behavioural weirdness on a Source Audio Collider which culminated in me having a mid-song pedalboard reconfigure earlier this week, throwing pedals and patch leads hither and thither in a bad mood) I think the problem is actually the Collider.

Either it's got some weird intermittent fault, or it's possible it's not getting quite enough juice which is making it behave unpredictably. Like 98% of the time it's fine, but 2% it freaks out to some degree.

This morning I took the Collider off the board, and ran the board in the FX loop, and it was perfect. I then added the Collider back in, but with a dedicated power supply with way more juice than required, and it was still fine. Not conclusive so I'll be trying different combos and attempting to "play it until it fails" over the next week or so.

Assuming it all behaves during that time, I'll be getting a current doubler cable for the PSU. Or a new PSU, but that's a somewhat more expensive option.

For info, the Collider was being powered by a 300ma out from a Cioks DC5, and all the docs I could find for the Collider said it needs "at least 300ma". So perhaps it needs a bit more, or perhaps the Cioks is being a bit stingy (although I thought that Cioks PSUs would deliver more than the nominal rating from any one outlet if there was enough spare in the tank, as it were, and the other pedals are all pretty low draw; maybe not).

In case anyone cares or it helps someone else down the line I'll report back when a definitive conclusion is reached.

 

[Snags]

Another update - I am an utter front bottom. The weird pedalboard issues all appear to actually relate to the sockets on a BF-2 coming loose. Hasn't cured the FX loop oddness, suspect that's still down to a socket on the amp, or the PCB, but it has caused the periodic silence, glitches and farts. Muppet.

 

[6CA7-A]

Sure. Let's see if I can work out how to embed video ...

Extra info to go with it:

• forgive the mess, it's combination music room and home office and there is just too much going on so it's a total tip at the moment
• pedal power supply is a Cioks DC5
• each pedal is on an appropriate outlet in terms of ma
• at the end when the FX engage, you hear some "shitty signal", as though there's a bad patch cable or interconnect, or something isn't getting enough juice:
  • this clears up after a few seconds
  • I've checked and swapped all the patch leads and interconnects, and they're sound
  • I haven't actually stuck a multi-meter on the Cioks to check each outlet, maybe I should
  • the Collider is on the current firmware
  • I'm vaguely suspicious that the Collider might have "issues", but that doesn't explain how none of the other FX get applied to the chain initially, and how the tuner isn't blocking the signal when it should be

What you'll see is the FX loop engaged, and the tuner engaged. The tuner should mute the signal when engaged. It doesn't, and no FX are applied to the signal, it's as though the loop is bypassed but the tuner registers signal, so it isn't. Then I toggle the FX loop on the foot controller, and lo, the tuner does mute the signal, and FX are applied when engaged (with, initially, shitty signal quality)

It's like the loop is both active and bypassed at the same time, which is ... just very strange.

Bad cord / connection somewhere.