MXR Super Comp ODD harmonics feedback even on mild settings? :O

[thrashingbass]

I recently acquired a MXR Super Comp. I was actually surprised how excellent it is, how little, if any loss of lows (bear in mind, I do use 4 string bass on standard tuning) and how clear it makes my playing, while evening out dynamics...

...until I played through my amp 1x15 speaker. I was using it with my headphones!

Is this normal behaviour? I am playing through my Carvin BN615Neo (identical to the discontinued BR615N combo.) Everything is flat, no drive (overdrive) settings, no special effects, and not using any of the two equalizers. All flat.

I discovered the problem while attempting to lpay semi loud. If my amp is very low volume, the problem does not occur. when the volume know is in the 9 position (which usually it is still quite low volume) I start getting feed back. At 12, horrible feedback, of course I haven't even tried to crank the amp. Obviously, it goes away when silencing my strings. But open strings feedback like crazy. G harmonic feedback, on both the G and E strings, obviously.

Bear in mind that I understand what compression is, and what I need it for. It's not a matter of having my tone distorted, or squashing it. That's not my problem. This feedback occurs with even very mild settings on the compressor. I can only avoid it by having extremely low output on the compressor, which makes the final output extremely puny and unusable.

My pickups are moderate output, Delano passive, a vintage P and a bridge soapbar. I don't think the problem is the pickups. They are VERY silent, even if I crank the highs. So that you have an idea, even with heavy compression, the noise on the headphones ONLY is very, very low. On the speaker is almost unusable unless I am touching the strings at all times.

I am not using any other pedal, by the way. Bass, compressor, amp. I used to use the optical compressor on my amp on max, but it offers only very mild compression, mainly to avoid clipping the amp. I wanted some heavier compression, but again, this problem happens even with rather mild settings. The ground noise brings out the string harmonics and sustains them forever, much as feedback (unless I block string vibration.)

Might the problem be my amp? Or should I expect this from this particular compressor? In no review (and I read a ton of them) I read about this particular problem. Even bass players had good experiences with it on many reviews, and the negative reviews usually were "user error," as it were.

I understand many of you have had this particular compressor, but this problem seems odd to me. Note that I am not asking which compressor you prefer, or why the Super Comp is a "piece of trash" because you didn't like it. Something must be wrong if it works with my headphones and not with my amp's speaker. My current wattage is 400 watts at 4 ohms for the 1x15 (but note I am not even cranking the amp) although it is a expandable 600 watt combo.

Any thoughts on this? Any suggestions or advice are welcome. Thank you!

[thrashingbass]

Just in case somebody thinks about mentioning "do a search," I did, and didn't find anybody with my problem. Wish I had.

It seems as if my pedal is overdriving the amp unless I have the compressor output set to extremely low settings (which is unusable for all practical purposes... but since nobody else has this problem, how can this be?) The best output setting (the most similar to bypassed output) is between 1 and 2. Even lower than that is giving me problems (about 9 it already does the harmonic noise, but below the tone is too feeble!)

[thrashingbass]

I'll experiment more on my day off. This thing can be too loud, but even though it still does the harmonic feedback on thing past twelve on the output, I figured out the stupidest thing:

my fan was activating all sort of additional harmonics as well. :P Turned it off, and the problems were considerably less.

There is still the need for me to use no more than 12 gain output, which might be normal. I will probably report my findings when I can play loud soon, probably tomorrow. An E harmonic still activates frequently, but it's not ear screeching as a very high G harmonic that pops out when the gain output is after 12.

The pedal seems to be great though. Hopefully I can figure out this soon.

[thrashingbass]

Thanks to Bongomania, I think I figured out a bit a better way to use my Super Comp. I read his "good settings" article again (I have read it multiple times, but noticed something that was of big help.) The caveat is that I managed to make it work beautifully, but when engaged the output is a bit lower than when bypassed. But no more harsh, overdriven high G harmonics are coming from my amp for now.

It works fine, though, because I can just turn up my amp a bit louder, and it had watts to spare. Also, since I have a push/pull volume switch to have both pickups in series, it works well (as when series is engaged, my bass no longer overdrives the amp when the Super Comp is engaged.)

My problem also was that I require lots of clean compression. Meaning, lots of compression, but without a distorted tone (not used as an effect, but to even out my dynamics... this is not used as a "technique" fix, it's just that my fast finger picking is too soft compared to my banging of the strings, and I bang the strings for a SPECIFIC sound I want to achieve. And no, I don't bang them all the time. I like to play relaxed more than anything, but sometimes one needs a bit of energy for your music!)

I have to conclude that the Super Comp is NOT the best compressor ever, but works excellent for me, noting that I do use only four stringers tuned EADG (your mileage might vary). I don't listen to any noticeable or annoying loss of lows, and the clarity is excellent (it opens up the sound nicely, but in a very nice, "organic" way that doesn't seem forced, which gives the illusion of transparency. I don't believe it IS totally transparent, but the bass does sound like my bass; the pickups sound like they usually do, with a bit more "character" to them, but in a very "natural" way, at least with the settings I chose.)

My final experimental settings for the Super Comp for the night:

Output: 11
Attack Level: 11
Sensitivity: Cranked to the max

Any more attack distorts the tone on the other knobs settings. Anymore output risks overdriving the amp with that nasty high G harmonic. Any less sensitivity widens too much that dynamic range I need at the moment (I need a little dynamic range, but not too much, as you can notice from these settings!) I lose some output, but I achieve what I want from the Super Comp. This is of course, always bound to change a bit, a work in progress. Not a bad pedal at all, though, sounds very good and natural, and it's very, very low noise. Grabs every nuance of your playing without hissing much at all.

Thanks, Bongomania, for putting up with so many reviews and guides for so many years. You must really love your compressor loving hobby, but we love you for doing so much for the bass playing community. Since using this particular pedal compressor, I realized that it is not only useful, but almost necessary for what I aim to do with my bass. Before purchasing this Super Comp, I read most of your reviews about the Ross circuit compressors, including the Biyang, the Keeley, Dynacomp, etc. I am glad I got this Super Comp, because the attack knob makes the bass sound much more natural that when the attack is fully congested (although I found that even that sound is not bad, but chords do sound better with a less congested attack.)

Thanks again, Mr. Bongomania, and good luck in everything!

[bongomania]

Glad to help. Just out of curiosity, what specific idea in the FAQ helped you solve the problem?

[thrashingbass]

Sure, it was mostly a combination of this paragraph:

"If your compressor has just two knobs, typically labeled "comp" or "sustain", and "level" or "gain", then just set both knobs at 12:00, their midpoint. Then adjust to taste. If the result is too noisy or extreme, then turn the comp/sustain knob down to a much lower setting."

With this:

"When setting input level and threshold, remember that raising the input level is the same as lowering the threshold. Also note that the threshold knob on some comps may be "backwards", so that turning it clockwise lowers the threshold, increasing the amount the signal is compressed."

"The next parameter to consider is the ratio. Of course the usual thinking is that a low ratio (under 5:1) is for gentle compression and a high ratio (above 10:1) is for peak limiting; but even those ideas are dependent on the threshold and the results you want. For example a low ratio and a very low threshold can result in a lot of extra sustain, while retaining fairly natural dynamics. A high ratio and a low threshold results in a super-squashed signal."

All "obvious" facts that I wasn't taking into consideration wisely! I went with less gain and more ratio to get rid of the "problem." With the output higher (1 to 2, as I mentioned before) and a lower ratio I was getting more dynamics, but the output gain was "reading" too much noise (not as in hiss or hum, but as in too much harmonic content being brought up to the amp, similar to overdrive). I am sure I still can get some much more useful tones, and a beautiful less compressed signal as well (the MXR Super Comp, as many other compressors, is not ugly sounding unless you force it to be, IMHO), but that did work for me.

Thanks again!