Eventide H9 Coloring Tone in FX Loop

I wonder if anyone has any advice or insight to offer about an H9 in my FX Loop that is slightly coloring the tone when engaged.
First here is a demo of the difference in sound with some comments posted for when the effect is turned on and off. If I had to describe it I would almost say it is a little "nasal" like maybe a wah or talk box got turned on with the pedal in a fixed position. Maybe it is losing a little bit of the low end or mid-to-low frequencies?
Tone Coloring Demo
Some specifics...
I have the pedal in the FX loop of my MKV and I am using an EQ algorithm on the H9 with EVERYTHING zero'd out. I have also tried a delay algorithm with the MIX at zero and get the same effect. I have tried the H9 in front of the amp and can not tell a difference between bypass and engaged (again using an algorithm with the mix at zero or everything zero'd out). The H9 does have a choice for True Bypass and DSP Buffered bypass. I tested these different options out. With the DSP buffered bypass selected, I can hear the difference when switching on and off the FX loop of the amp, even with the H9 in "Bypass". With the "True Bypass" (they call it "Relay") mode selected, I don't hear the difference until I activate the H9 (again, even if I use an algorithm with zero mix or the effect zero'd out). So that tells me (I think) that the sound difference is happening in the DSP (the H9 in fully DSP, there is no analog pass-through except in True Bypass mode with the pedal not engaged). As I mentioned, it doesn't seem to be an issue in front of the amp and I get it that the gain hasn't been introduced yet. But another interesting thing is that, in the FX loop, CH3 modes don't seem to be affected, at least much less noticeably. Maybe since high gain modes (CH3) probably filter out more lows and maybe mids before the gain and CH2 modes tend to be more medium gain and actually come out a little more "beefy" could that explain why "crunch" mode seems the hardest hit by the DSP in the H9? Another thing I should mention is that I also experimented with the send level on the MKV. I did notice that with the send relatively low, the difference seemed more noticeable. If I crank the send, the difference seems less noticeable but still evident.

Is this just the facts of life about a true DSP pedal? Or is there something else I might try? I guess I can live with the coloring when I want to use the pedal. The harmonizer, reverbs, and delays, are great and I tend to prefer modulation effects in front of the amp anyway.
I also thought that if I could use the CH2 tone controls to remove the frequency that is getting cut or raised in the DSP (if that is even what is actually happening) then I could add it back using the 5 band. But that is assuming the change is, in fact, an EQ shift and not something else.

I did have another thought...
The DSP will introduce a VERY slight delay. I know from previous experiments that some of the pre FX loop signal bleeds through to the power amp (if I unplug the fx loop cables and engage the FX loop, I can still hear a quieter signal getting though. So maybe the mixing of a slightly delayed signal with the original produces a very mild chorus or phasing type of sound. This is at bedroom levels so I could test that theory by cranking up the amp. Then the bleeding through pre FX loop signal would be more negligible and produce less of the effect.

Anyway, I am interested to hears other's thoughts....

Does the H9 accept line level signal? Silly question probably but thought I'd ask.

Wayno said:

Does the H9 accept line level signal? Silly question probably but thought I'd ask.

Click to expand...

Hi and thanks for the reply. It does accept line level signals or instrument levels. Probably one of the reasons for it being fully DSP. It analyzes the signal and adjusts for appropriate levels. The control app even allows the user to see the levels at the inputs and outputs and adjust input or output gain if necessary. But, it claims to handle that on its own without user interaction.

The more I have been playing around with it, the more I think it is just the nature of it. I also have a Marshall JVM and it seems to have a similar effect on the "Crunch" modes. I have noticed that it seems to be more noticeable on "crunch" type modes in both amps which tend to have a "thicker" more boosted midrange type of tone. The "high gain" type modes (CH3 in the MKV and OD1,OD2 in the JVM don't seem to be affected as much and those modes, to me, sound more scooped with less midrange, even without the 5 band EQ. On my MKV, if I take all the midrange and bass out (with the ch2 EQ knobs, not the sliders) it seems to be a less noticeable change. So maybe the H9's DSP just doesn't handle the boosted midrange signals as well.

Hi,
One thing you didn't mention is the cabling to and from the H9-- if you are using the shortest possible high quality cables then this wouldn't be a factor. Also, even though true bypass would hopefully mean what it implies, with a DSP your signal is most likely still going into and out of a printed circuit board, so there's that. I have a beloved Boss CE1 chorus from the 70's that really messes with the tone, and it was suggested once that I build a true bypass box with a double-pole/double-throw switch and route the chorus through that, so I could totally remove it from my signal path when not in use. Food for thought. Good luck to you!

jaslan said:

Wayno said:

Does the H9 accept line level signal? Silly question probably but thought I'd ask.

Click to expand...

Hi and thanks for the reply. It does accept line level signals or instrument levels. Probably one of the reasons for it being fully DSP. It analyzes the signal and adjusts for appropriate levels. The control app even allows the user to see the levels at the inputs and outputs and adjust input or output gain if necessary. But, it claims to handle that on its own without user interaction.

The more I have been playing around with it, the more I think it is just the nature of it. I also have a Marshall JVM and it seems to have a similar effect on the "Crunch" modes. I have noticed that it seems to be more noticeable on "crunch" type modes in both amps which tend to have a "thicker" more boosted midrange type of tone. The "high gain" type modes (CH3 in the MKV and OD1,OD2 in the JVM don't seem to be affected as much and those modes, to me, sound more scooped with less midrange, even without the 5 band EQ. On my MKV, if I take all the midrange and bass out (with the ch2 EQ knobs, not the sliders) it seems to be a less noticeable change. So maybe the H9's DSP just doesn't handle the boosted midrange signals as well.

Click to expand...

Hmm, dunno, strange one. You ever find a reason / solution?