Any effect pedal mimicking the DBX 165 compressor?
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There is a Pumpernickel wishlist topic here on the forum.
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For me what matters is the Auto Release/Attack setting and the Overeasy function from the DBX 165. This one linked reminds me of the Carl Martin Compressor/Limiter, another VCA with the THAT chip, that has such a summarized Attack/Release knob called Response, but I didn't find it useful for my needs. The Carl Martin compressor suffers from very serious breathing effect, knocking effect on transients, very difficult to set up properly, never could. So I have a suspicion it is very far from the real DBX compressor behavior. IF the linked one is a Carl Martin variant, one warning sign in that as the manual says the DBX uses 3ms Attack in certain situations, the Carl Martin cannot go lower than 12ms. If this applies to the Becos, then it won't get me closer to what I need.
I appreciate that you are trying to help though.
Erik S
Well-known member
Have you considered trying some 19 inch DBX gear?
The vintage 165 you like is way out of my budget, but I've got a lowly 166xl in my rack that has those auto and overeasy settings. Looks like they're well under $100 at the usual used gear sites.
Apart from the pedal, that's what I am planning to do if no other way. Recently it seems the 166XS and the 560A is available. The 560A is smaller but double the price of the 166, I wonder what's the reason for that?
Erik S
Well-known member
I'm not familiar with the 560a, but it looks like it's a 500 series module - in case you're not familiar with the format, that means it needs to be installed in a 500 series case to be useful. The modules don't have their own power supplies or in/ out jacks.
Are you satisfied with the performance of the 166xl. It seems in the recent situation it s the 166xs that would be available for me. I wonder how these perform compared to old ones, or compared to the 160A, that is the normal rack version of the 560A.
Thanks for the clarification about the type of the latter, I had no idea it can be installed in other manner than the rack.
Erik S
Well-known member
I’ve been satisfied with mine, but I can’t say whether it could meet your requirements. I read most of your first compressor thread and I know you’re looking for some very specific results. I mostly wanted to point out that they’re inexpensive and have those two features you mentioned (over easy and auto modes).
Another thing to consider is that the DBX is a line level device, so your instrument level signal would need to be raised up with a preamp, DI, or effects loop before it hit the DBX, making it inconvenient to use in a typical “first in chain” pedal board arrangement.
At least you didn't write the new ones are garbage, that is already a useful info
As I remember the back input on the Audient iD4 interface is Line-in. If my guitar worked there, it can work with the DBX rack as well, can't it?
Erik S
Well-known member
I expect sound would pass through at instrument level, but the compressor wouldn't perform the same.
Compressors react to the strength of the signal that hits them - in other words the voltage of the signal. So if a rack compressor circuit is designed to respond to a signal at line level voltage, and you feed it instrument level at around 10x less I'm not sure what you'd get.
Very approximate numbers for ease of math:
1mV - Mic Level
100mV - Instrument Level
1000mV - Line Level
10,000mV - Speaker Level
No DBX 165 but a real nice compressor:
www.hagamps.com
12AU7 Compressor - Tube Pedal
The 12AU7 COMPRESSOR is a boutique all-analog vacuum tube pedal designed to offer the most transparent compression available, providing sustain without sacrificing articulation. Its feed-forward side-chain and custom opto-resistive attenuation produces a soft knee, as opposed to hard limiting...
www.hagamps.com
No DBX 165 but a real nice compressor:
12AU7 Compressor - Tube Pedal
The 12AU7 COMPRESSOR is a boutique all-analog vacuum tube pedal designed to offer the most transparent compression available, providing sustain without sacrificing articulation. Its feed-forward side-chain and custom opto-resistive attenuation produces a soft knee, as opposed to hard limiting...
I have a similar one already, but it distorts with my guitar. Intermodulation happens. It is not related the the opto design but something else. Because I have a Carl Martin Optical compressor, that is clean. But that one suffers from breathing and treble loss. These and what you linked sounds the nicest to me, but haven't found one yet with minimal artifacts. The Carl Martin is the best I found so far, I dissembled its circuit, I am in the middle of drawing the schematic, once ready I want to modify it to get rid of the breathing somehow. Originally the Attack/Release shares a common knob. I want to separate them.
Erik S
Well-known member
That's a hot signal! I've never had a guitar with active pickups, so I'm not familiar with if that's a normal level, or how that effects other things in the chain.
What does the pad knock the voltage down to?
I wonder if/ how your voltage level is contributing to your experiences with compressors. Maybe you would have better luck with a line level compressor.
It is passive. But the problem is not the hot signal in case of many compressors. I have an active pad, so I can decrease the gain to any value, the bigger problem for compressors is that in the style I play, you mostly use the notes between frets 12-24, and especially around 24 the intermodulation occurs. You can influence it with input gain setting, but only to a limited amount. So for example you set it to an ideal level, notes around fret 12 do not distort, but at the same or even lower volume (you pick more lightly) the higher notes distort, if the compressor has non-linearity problems. If you lower the input volume more, the IMD disappears but then the noisefloor will be very high. This happens like that with OTA and some other designs like the one I linked. FET is okay, and also VCA and some opto like the Carl Martin. The Gurus I linked produces IMD however, and also the Demeter Compulator behaved strangely. The latter was a strange exception though, that was distorting on the decay.
In case there is no IMD, I have no problems setting the compressor. I just put the pad after the guitar, set the reduction to 50-20%,depending on what comes after it. But, for comparison: if the pedal is problematic because of IMD, i need to decrease even more, I have no idea how much exactly, but to 10% or maybe more (usually that extra attenuation happens on some of my pedal outputs). This final extra attenuation you cannot do on the pad or the guitar, because you have to decrease so much that you would need a multi turn trimmer to do it. With normal pot or small trimmer you are decreasing, and at one moment the IMD is still there, while in the next moment the sound is gone. Not sensitive enough. But this correlates to the specs of the ICs in the problematic pedals, their linear operation window is that small indeed as I read. That's why when being a beginner I did not understand how the pedals can still distort when I turned the pot back to almost 0. If I'd play below the 18th fret or so most of the time, I would have never noticed this problem.
However the challenges to set compressor comes from the operation of the circuit most of the time. That is an even bigger problem for me. We play at fast tempo, sometimes around 127 BPM, many 16th notes, this challenges the compressor to do Attack/Release on tempo. But yet the DBX rendition in Logic seems to keep up with the situation and is surprisingly good. Very likely because of the dynamic timings.
In case there is no IMD, I have no problems setting the compressor. I just put the pad after the guitar, set the reduction to 50-20%,depending on what comes after it. But, for comparison: if the pedal is problematic because of IMD, i need to decrease even more, I have no idea how much exactly, but to 10% or maybe more (usually that extra attenuation happens on some of my pedal outputs). This final extra attenuation you cannot do on the pad or the guitar, because you have to decrease so much that you would need a multi turn trimmer to do it. With normal pot or small trimmer you are decreasing, and at one moment the IMD is still there, while in the next moment the sound is gone. Not sensitive enough. But this correlates to the specs of the ICs in the problematic pedals, their linear operation window is that small indeed as I read. That's why when being a beginner I did not understand how the pedals can still distort when I turned the pot back to almost 0. If I'd play below the 18th fret or so most of the time, I would have never noticed this problem.
However the challenges to set compressor comes from the operation of the circuit most of the time. That is an even bigger problem for me. We play at fast tempo, sometimes around 127 BPM, many 16th notes, this challenges the compressor to do Attack/Release on tempo. But yet the DBX rendition in Logic seems to keep up with the situation and is surprisingly good. Very likely because of the dynamic timings.
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Erik S
Well-known member
Is the active pad a commercial device? Or something you built?
Those requirements are way out of my wheelhouse, so I've got no relevant advice, but I do think it could be interesting to measure your signal voltage at different stages and consider how that might factor into your results.
I kinda studied how the signal affects the pedals. And I tried other guitars that are high gain as well, they behave similarly, though there are slight differences, some are better. Like the Schecter Omen Extreme (Diamond Plus Pickups), has more even dynamics, less high amplitude peaks, but similar result from problematic pedals though its signal characteristics allow for a lower noisefloor at less IMD.
I tried many compressors options during the years to find good results for my needs. There are some that were close but still a bit problematic (not distortionwise but compressionwise), the DBX however seem to be a totally different "player". That's why I am so interested about it. Fits quite well to my playing style at my recent EQ settings. The Demeter worked as well but with adjusted EQ settings, I figured this out right before I sold it, could not test what happens in case I need to readjust after the compressor. So in the future I may give it another go when building a DIY one. But it is definately better if you can just use the compressor as a drop-in addition, not changing anything else.
The active pad idea was brought up by someone I contacted for advice to avoid treble loss in the guitar signal. I was assisted to create the buffer as a standalone element based on the Boss MT pedal. That has an initial buffer stage, it is the copy of that, reinterpreted for a standalone form. I had better results with treble bleed on the guitar volume pot, the truth is however that it changes the character. The active pad is better if one wants to preserve the character of the signal. But the treble bleed just shifts things to the direction that I prefer. At the moment it is desoldered. If that is on, I skip the active pad.
