My last post (until I can try one) on this subject less anyone think I am TOO interested, but I got into the idea of a tube preamp in the first place partly because cats like Dave Holland use them...He uses the Retrospec which IS a preamp compressor (a limiter compressor which is what we are talking about here anyway not the noisy country guitar kind of compressor) Not that Dave always has the greatest sound, but he DOES have the greatest technique and plays with loud drummers effortlessly.
I think that running a Keeley Bassist AFTER the Sarno V8 would be the way, so that you get the mojo of the Piezo/tube impedance and the wideness of that, but also like a belt on a fat man the compressor could keep the sound focused and directional after being plumped.
It seems like from listening to what the sound does to electric basses on youtube it brings your sound forward some. It does not seem like a transparent limiter compressor is going to mess up a piezo sound too much or kill your ability to play dynamics.
Also then there is the limiter which personally I could use ( I occasionally bonk my speaker and the MAS16 I had, which was stolen, would bonk more frequently and THAT speaker could really use a well placed limiter.I miss the 16 and would get one again, if I ever get to play more gigs.)
A compressor does not bring your sound forward. It narrows the dynamic range. A compressed signal can then be placed a bit more forward in the mix, and still lay where it is supposed to.
In the FM radio wars multi-band peak limiters, like the Aphex Dominator, where used to create the perception that different radio stations had a louder signal. What was going on is there are limits to how modulated the radio signal can be, and the station would get fined for over modulating. Note. The audio level and level of modulation are directly proportional. So peak limiting was used to lop off the peaks of the music so it could be turned up, without exceeding modulation limits. This reduced dynamic range and increased the nominal level of the audio.
As a performer, compression can make you overplay. When you hit the compressor, the bass no longer responds to your inputs in a linear way. Essentially you thump harder and don't get the response you are looking for, so you thump even harder. As an example, it's generally a bad idea to use heavy compression on vocal monitors as this will tend to cause the singers to blow out their voices. Some vocalists can't even stand light compression because it makes them feel disconnected from their voice.
Another problem is compression reduces gain before feedback, which can be a serious factor with amplified upright bass, especially if you want to use a mic. The issue here is the gain is variable. When you thump hard the compressor clamps down and limits gain. When you play softer or stop playing, the compressor releases and opens up to max gain.
The next thing to understand is when you use a compressor there is an associated reduction in gain when you are above the compression threshold. In order to maintain a nominal output level, you must apply make up gain to boost the signal back up to where it was.
Here is where the problem comes in and reduces gain before feedback. When you stop playing and the compressor releases, this makeup gain is added to the gain you already had before you applied the compressor. This is what I mean when I say a compressor adds gain to the signal path between transients. This increased gain can make it challenging to play softer passages with the proper sensitivity. Even without a compressor, I sometimes find that playing pianissimo passages can be challenging with the amp cranked up to the level I need to carry a loud band. Compression will exacerbate this problem.
Think of it this way. Compressors bring the high SPLs down and low SPLs up. Pop music has a very limited dynamic range so compressors can be wonderful tools. If you play music with a wide dynamic range, about all you will likely do is apply compression to the loudest passages.
The exception might be if you have a compressor that adapts in real time. Or you could use two compress set to different thresholds and different compression ratios. One compressor kicks in early with a very low ratio; the second kicks in with a higher ration.
Don't think I am trying to discourage you from experimenting, because I am not. If you do experiment, I think you will have a better understanding of what I am staying. Also you may find compression is extremely useful in certain circumstances, so by all means have some fun and learn something.
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