Author Topic: Thinking out loud - question about compressors  (Read 173 times)

David Houck

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Thinking out loud - question about compressors
« on: September 16, 2008, 04:58:49 PM »
I have an Alesis 3630 dual channel compressor limiter.  I haven't looked at the manual to see if it addresses this question; I was just thinking of an idea about how to address a problem in my signal chain, and thought I would run it by you guys, in case you may already know the answer.
 
Can I put the two channels in different places in the signal chain?  For instance, can I put one channel in the path between the preamp and the effects unit, and the other channel somewhere after the effects unit and before the power amp?  In other words, are the two channels two completely independent pieces of gear?

lidon2001

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Thinking out loud - question about compressors
« Reply #1 on: September 16, 2008, 06:43:02 PM »
Hi Dave,
 
On the Alesis website it says the unit has a Stereo/Link button, so in stereo mode it should act as two independent units.
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lidon2001

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Thinking out loud - question about compressors
« Reply #2 on: September 16, 2008, 06:43:50 PM »
Hi Dave,
 
On the Alesis website it says the unit has a Stereo/Link button, so in stereo mode it should act as two independent units.
 
T
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lidon2001

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Thinking out loud - question about compressors
« Reply #3 on: September 16, 2008, 06:45:37 PM »
Answered in stereo no less...
 
T
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David Houck

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Thinking out loud - question about compressors
« Reply #4 on: September 16, 2008, 07:11:55 PM »
Stereo!  Hee hee!
 
Thanks; I may give it a try.  It will be a little while before I do, as I have a little preamp issue I need to take care of first.  And I may even be rethinking my whole approach to effects.  I'm having some technical difficulties that seem beyond my limited abilities to solve.  But using the two channels in two different places could be very useful depending on how things shake out.

jbybj

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Thinking out loud - question about compressors
« Reply #5 on: September 16, 2008, 07:35:57 PM »
Typically, two channels of compression, in stereo mode, will make both channels respond identically to either channel's threshold being crossed. In other words, it will maintain the stereo image by riding the gain on both channels simultaneously. With the stereo/link mode off, they should act as independent channels,  just the opposite of what lidon2001 has posted.

David Houck

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Thinking out loud - question about compressors
« Reply #6 on: September 16, 2008, 07:43:40 PM »
Thanks James!  That's what I figured he meant, that the link button meant there was a choice to have them unlinked.

lidon2001

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Thinking out loud - question about compressors
« Reply #7 on: September 16, 2008, 10:12:43 PM »
I stand, actually sitting, corrected.  In the owners manual they say Stereo and Dual Mono modes.
 
T
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mike1762

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Thinking out loud - question about compressors
« Reply #8 on: September 17, 2008, 05:13:33 PM »
I'm not sure why you would want/need compression at 2 points of a signal chain.  Once the signal is squashed at the first point, I'm not sure what would then expand it so that another point of compression would be required.  You would be compressing an already compressed signal; therefore, you might have pumping problems and/or totally lose your dynamics.

David Houck

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Thinking out loud - question about compressors
« Reply #9 on: September 17, 2008, 06:11:28 PM »
I'm using the Ashly that I use now, and I would be using the channels of the Alesis if I went with it, as a limiter rather than a compressor.  I like a wide uncompressed dynamic range.  The Ashly is just there to protect the speakers from a spike.  Past experience has shown this to be a good idea as I have a rather wide dynamic range of techniques, and in the past there have been times I've heard the speakers pop when I've been playing aggressively.  The Ashly also serves as the last gain control before the Elf to get the level of signal going to the power amp where I want it to be to drive the speakers safely and efficiently.  The idea of a second limiter in the chain has come up recently as every once in a while I'm getting a high frequency pop in my signal when I've been playing rather aggressively.  It appears that I may be overdriving my rather sensitive effects unit.  I have reduced the trim pots on my bass, and that seems to be helping.  However, I'm going to be having my preamp looked at for a problem that may or may not be related, so I probably won't do anything else until I get the preamp back.  If I decide that reducing the trim pots on the bass solves the problem, then I might just go with that.  However, as I write this and think through it, I'm now wondering if reducing the output of the bass reduces the degree to which I'm driving the preamp tubes.  Might have to think about that for a while.

David Houck

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Thinking out loud - question about compressors
« Reply #10 on: September 17, 2008, 07:29:06 PM »
I seem to recall that sometime ago there was a thread within which was a discussion about the effect the volume control has on the second tube stage of an F-2B, but I've been looking for the last hour and I can't find it.
 
I think some memory cells are not functioning properly, so please correct me if this isn't correct.  But I seem to recall that if you turn the volume control on the F-2B from 5 to 8, and then reduce the gain control on the power amp so that the overall loudness is the same, the result should be a warmer, less clean, tone.  I even seem to recall having tried this experiment.
 
I think I need an infusion of antioxidants.

elwoodblue

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Thinking out loud - question about compressors
« Reply #11 on: September 17, 2008, 07:44:04 PM »
Dave is this what you were looking for?
(taken from the alembic store description)
The mono output on the rear of the F-2B provides a facility to use a stereo instrument with a mono power amplifier. The mixing resistors associated with the mono jack are only connected together when a plug is inserted, thus preserving maximum stereo isolation when using the separate Channel A and Channel B outputs. Another application is to connect the two channels in cascade, by a cable from the Channel A output jack on the rear to the Channel B input jack on the front. The power amplifier is connected to Channel B's output. The signal from Channel A is high enough to drive the first stage of Channel B into distortion. The tone controls of Channel A are used to emphasize those frequencies which will be most distorted, while the controls of Channel B shape the color of the resulting distortion. Channel A's volume control sets the amount of distortion, while the Volume Control of Channel B sets the output level (Master Volume)
 
 
on a side note, I occasionally use a compressor before my rack gear to tame the signal a slight amount, sort of as a limiter, then one at the end to frame the signal for my recording gear...sometimes before the reverb units so any noise is gated but the reverb sings on.
 
I'm not sure how the pro's do it but I've had success this way without to much pumping or squashing.

David Houck

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Thinking out loud - question about compressors
« Reply #12 on: September 17, 2008, 07:48:42 PM »
Thanks Elwood, but that wasn't it; in fact, I just read that whole page you quoted just a little while ago.

elwoodblue

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Thinking out loud - question about compressors
« Reply #13 on: September 17, 2008, 08:29:03 PM »
ah well...thought I'd give luck a try
 
keep up the tone quest ...it's got to be one of the more interesting sitcheations we put ourselves into.
 
cheers

David Houck

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Thinking out loud - question about compressors
« Reply #14 on: September 17, 2008, 09:13:33 PM »
The ever evolving quest for tone.