Anybody else using DigiTech GSP1101 + MKV? Tone EQ issues.

[Jiveman]

I don't know if I haven't noticed this before (likely), if it's somehow more noticeable at quiet bedroom levels that I'm playing at nowadays (unlikely), or if something's goofed up with either the MKV or the GSP1101 ( :!: ), but there seems to be a fairly drastic tone EQ shift that occurs when the MKV signal goes through GSP1101.

I used to think that this FX processor has overall good build and low tone suction, but now I'm not so sure.

Does anybody else have GSP1101 with their MKV that can try this for me and tell me how your experience is? I would really appreciate it.

Let me explain further. Here's how things are configured:

1. GSP1101 is attached either via 4CM or just in FX loop of MKV (doesn't matter, both ways exhibit the problem), and the corresponding GSP setup wizard configuration has been performed to let GSP know which way to operate.
2. A "blank" custom patch is used that has each and every option (OD, compressor, delay, reverb, EQ, etc... EVERYTHING in the patch itself) turned OFF. But the GSP is NOT in bypass mode--it's just passing the signal through the patch without applying any effects whatsoever.
3. The global EQ in GSP1101 is zeroed out.
4. The volume levels have been calibrated so that they don't [noticeably] change if you were to turn on and off the FX loop on the MKV (with the footswitch or with the loop assign knob in the back), thereby alternating between passing the signal through GSP and NOT passing it through GSP. The point is that the GSP1101 doesn't make the signal quieter or louder when compared to just the MKV, with all else being equal.

Now, here's what's happening... When I put the GSP1101 in BYPASS mode (by pressing the BYPASS button on the GSP itself), the tone sounds natural and completely unprocessed (as if there were no FX processor in the loop). If I disengage the bypass mode, the tone sounds like it gets a pretty horrific EQ shape, sort of scooped but kinda honky too. Almost like a stuck wah pedal sound. It's barely noticeable on CH1 on clean unbroken-up type stuff, and it's moderately noticeable on CH3 although somewhat manageable. But on CH2 it just destroys the tone. Just bad.

Here are my channel settings for reference:

CH2
Mark I mode
Any wattage (let's say 45, diodes)
EQ = ON, PRESET, 12 o'clock
GAIN = 2 o'clock
VOLUME = 10 o'clock
TREBLE = 1 o'clock
MID = 10 o'clock
BASS = OFF
PRESENCE = 2:30
THICK = OFF

I can try and do a recording to show you what I mean... But what I most need right now is somebody to check if this is happening for them too (if I'm lucky enough to find someone here who also has a MKV and a GSP1101). If not, I would be interested to see if you can do a test through a G-Major or something similar, if you have it.

 

[SteveO]

You're going to find tonal changes through the "target amp" settings, as they have different EQ curves to them. That's where you want to mess around. When I get a chance I'll mess with mine and see what I come up with, but I had it dialed in pretty transparently with my Mark V.

 

[Jiveman]

Hmm... I don't seem to notice any difference switching among the different target amp settings. :?: Definite difference switching between Amp In, Amp Return, and Mixer, but nothing on Target Amp. I wonder if that's because I'm at low volume levels and the difference is too subtle? Hmmm...

Also... I'm using the beta vC63 firmware on the GSP1101. I wonder if I should try going back to original and seeing if it makes a difference.

But, SteveO, if you could just a few minutes and create a patch with all options turned off in it, then try alternating the BYPASS on and off on the GSP (while playing), and report the differences. Use Mark I mode if possible, because it seems to be most noticeable. I would really appreciate it.

 

[SteveO]

I'll do that as soon as I can, but right now the Digitech is racked up with my home studio stuff so I'll have to do some rewiring.

 

[Jiveman]

It's not an emergency, but I'd like to solve this sooner rather than later. Sometime in the next couple of weeks would be great, if possible. :mrgreen:

If it makes it any easier, you don't have to do 4CM. Just connect it in the effects loop of MKV, and choose the appropriate configuration in the wizard.

 

[unclechopchop]

Hi,

I'm experiencing the exact same issue and this is the only post on the web I could find that mentions it. Basically i'm using the GSP1101 in the fx loop of my Kustom Double Cross Head using option 5 in the setup wizard. The amp fx loop is a serial tube buffered loop that can be adjusted for +4/-10 level using the send/return level controls. Both amp and GSP are connected with high quality 1' mogami cables using +4dB option.

In bypass mode the GSP is very transparent and allows the true sound of the amp to shine through but activating an empty patch (all preset options turned off and flat global eq) effects the sound significantly in a bad way. The sound becomes thin and loses all the earthiness particularly in the lower frequencies, almost as if there is a high pass filter in the signal somewhere.

Just wondering if you've had any luck resolving this issue as I can't work out what's going wrong. I'm hoping it is a configuration issue and not a design flaw as it really is unacceptable for an otherwise great unit.

Thanks.

 

[Jiveman]

Unfortunately, I haven't been able to resolve this issue. I haven't invested much more time into it, but I'm afraid that it might be that GSP1101 is the problem. One thing I thought about is to try and restore the factory firmware (instead of the latest beta firmware I have on there now), and see if the problem is still present. But that takes time and effort, and I haven't had it.

If you find anything, please post here, for the benefit of me or anybody else who might be searching the web for this.

 

[unclechopchop]

I just worked out what the problem is...

As stated I have my amp and gsp setup with option 5 (fx loop only) which basically gives you no further selections in the setup wizard and therefore I assumed turns everything off (ie amp/cab modelling etc as it is not relevant). However when i looked at the "1/4 Line Output Setup" the option "Cabinet to Amp" was set to ON. Once I turned this off the true sound of the amp came through again.

I must say that now I have that option turned off the GSP is completely transparent and i'm loving it!!!

 

[Jiveman]

Glad you solved your issue. I'm pretty sure I tried that for me without success. My gear is all packed up now, so I won't get a chance to try it again any time soon. But I think my problem is more subtle. On 2 of the 3 channels of the Mark V it's barely noticeable, but on 1 channel in particular (Channel 2), it's very noticeable. The channel sounds fine without the GSP (or with GSP in bypass mode).

Just out of curiosity, are you running the beta firmware on the GSP1101 or the factory one?

 

[unclechopchop]

i'm running C63 firmware. my amp too was ok on the clean/crunch channels with the gsp but switching to the dist/lead channels the tone change was obvious and awful. once i turned off the cab to amp setting the channel sounded the same in both gsp and bypass mode.

 

[Jiveman]

EDIT:

OK, I think I've figured this out. It's due to the fact I'm playing at an EXTREMELY low volume level. Something happens when the MKV output knob is so low that you get this sort of a inverted phase / super scooped type sound. When you dial the volume a little louder, even if it's only say 8 - 8:30 o clock, the sounds starts to open up. The weird thing is, this doesn't happen when GSP1101 is out of the picture.

So, to recap:

• MKV + GSP1101 + super low volume = PROBLEM :!:
• MKV alone (no GSP1101 in FX loop) + super low volume = no problem
• MKV + GSP1101 (bypass engaged on GSP) = no problem
• MKV + GSP1101 + moderate volume = no problem

CONCLUSION: do not play at super low volume levels with FX.