• TalkBass has been independent since 1998. Add your voice.
    Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
    Join free Log in
    Want zero display ads or expanded classifieds tools? Compare plans.

MXR M85 clean blend phase issue?

itaisod

itaisod

Jun 21, 2019
9
2
#1
Hi everyone,
after a lot of research here I've finally went today and bought the MXR bass distortion. The wet signal sounds great, but when some dry signal is added the sound suddenly becomes thin, especially on low gain settings. Add more dry signal, and some of the low end returns (but still sounds weird, too much treble).

I've checked, and the wet and the dry signals are simply inverted. To be more accurate, the wet signal is inverted while the dry signal is not. That seems counter-intuitive, assuming the blend controls were meant to restore low-end...

I thought maybe it was made on purpose so I manually blended an inverted dry signal, but no, it sounds great. Have a listen: (see attached files)
Notes: DI recordings. Tracks 1 and 2 were recorded simultaneously. Tracks 3 and 4 are tracks 1 and 2 blended together, in different phases. Track 5 is pure output of the MXR, recorded separately. To my ears tracks 1, 2 and 4 sound good, and tracks 3 and 5 sound thin.

I'd love to hear regarding the Cat Tail by Fuzzrocious, whether it behaves differently. @rratajski, I would much appreciate your input!

Thanks in advance.
 

Attachments

#2
Interesting find! I wonder how hard/expensive it would be to add a phase invert button to the pedal?

I’d assume the Cat Tail doesn’t have this issue when modded with a clean blend but have no experience with one. But from what I remember, Ryan didn’t have much input on the M85’s clean circuit. It was a circuit MXR uses in other products.
 
#4
If you're experiencing a phase issue, please contact MXR directly.
This is the first I am hearing about this, but the blend/mix circuit is MXR's and they would know more about the ins and out of their design, which I would assume is the same blend/mix they use on all of their products that have separate wet/dry controls.

Also, I notice on my instruments that if I roll back volume, the signal always sounds thinner with less bass.
 
  • Like
Reactions: ugly_bassplayer
#5
Thank you, good idea. I'll emphasize that on medium-to-high gain settings this might not be an issue. The wet signal itself sounds great. In fact, as far as I'm aware, the low-end loss is so minimal that many prefer to just use 100% wet signal.
 
#6
Thanks for the recordings and the info, I was considering picking one of these pedals up. What setting did you use for recordings 3, 4, 5? (i.e. dry 12:00, wet 10:00, dist 9:00, etc.)
 
Last edited:
#7
Janforth said:
Thanks for the recordings and the info, I was considering picking one of these pedals up. What setting did you use for recordings 3, 4, 5? (i.e. dry 12:00, wet 10:00, dist 9:00, etc.)
Click to expand...
Tracks 3 and 4 are simulations, with the MXR on 0% dry and a separate clean blend, at the point where the phase cancellation is most extreme.
Track 5 was recorded (if my memory serves right) with around 9:00 drive, 12:00 wet, 9:00 dry, 3:00 tone. The idea was to show it sounds much closer to track 3 than 4.

Also, just watch this:
 
#10
Sorry, I miss the set up, so it only happens with certain parameters not all, that's important info and good to know, I think MXR should state this in the manual or somewhere, thanks again for this video.
 
#14
rratajski said:
Any update from MXR?
Click to expand...
No... I've contacted them via a contact form btw. I'll update if and when something comes up.

And I'll say it again, for anyone stumbling upon this thread: this pedal's distortion signal is fantastic on bass. Minimal low-end loss, and no screechy noise when plucking a string hard. Also, the dry signal can be used to achieve some interesting funky sounds, sounding way less harsh on an amp compared to DI obviously...
Does it restore low-end? yes... but also with a lot of treble since you have to turn the wet signal way up. Simply put, not what I needed.
 
#18
scHism said:
Resesurrecting this thread. I wish I had read this before purchasing the M85.
Any other option or fix instead of returning this? I really like the dirt tone but need the dry blended but it is out of phase and farty.
Click to expand...
No, not really. Many distortions circuits reverse the signal polarity as part of their design, just it would probably require an additional phase invert before the blend circuit. My best guess is that MXR made this for the higher gain tones, leaving the lower gain modes not very usable with the blend. In contrast, I tried some darkglass pedals which had good blend tones, but no rat tone.
My solution was to get another (much cheaper) rat clone. I guess you could add a blend pedal to it for the same total price, just make sure it has an option to invert the phase. Another option is to buy a multi effect pedal which has it all :)
 
#19
I found that keeping the dry volume near unity gain helps to make the overall sound more usable. But a lot of times I also find I just prefer 100% wet. So play with it for a bit and see if you find anything that works for you... otherwise just return it and jump back into the Rat race, err, search ;):thumbsup:

Or if you want to go down the blend pedal route, look at the One Control Mosquite or the Damnation Audio Blender (“bloop”). Both have phase switch control and the Damnation adds a low pass filter on the clean.
 
#20
Thanks for the feedback guys. I find it that running it 100% wet gives me the rat tone I like. Adding any dry signal just makes it farty and thin.
I sold my Acid Pig LM308 just to purchase this since my goal is to get back the bottom end through the blend.
I guess I am back hunting. Narrowing it down to the cat tail or iron pig, both with blend.
 
  • Like
Reactions: rratajski

Latest posts

Top Bottom
Back