The first one is a 6-postion switch with a variety of capacitors. The second is a rotary variable capacitor, and the capacitance is continuously variable.
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Empress Compressor side chain variable HPF idea
- Thread starter labeledbass
- Start date
The first one is a 6-postion switch with a variety of capacitors. The second is a rotary variable capacitor, and the capacitance is continuously variable.
Yes. I soldered a 3,9 nF cap first in the stereo plug, and put it in the side chain jack. Then eventually I soldered the cap straight to the side chain jack inside (tip-ring) the compressor.
I didn't read through all of the posts, so forgive me if this has already been stated, but putting an HPF though the sidechain of the Empress is not going to actually work like a HPF like a broughton. The sidechain function on the Empress simply adjusts the frequency that triggers the compressor. It doesn't actually effect the EQ of the signal being output through the pedal. For instance, a bass guitar generates a lot of low frequencies which can cause a compressor to trigger more so than say an electric guitar, specifically when playing on the E and A strings. Using the sidechain function, you can dial out the lowend frequencies which allows the compressor to trigger at a more neutral frequency.
okcrum
in your chest
Yep. You can get them up to 2-3 nf or so, but it will cost, and they are large, because they're generally made for high power RF applications.
2000 pf, 3 KV Peak, Jennings CVCA-2000-3S
I was thinking of using this in the side chain of my Empress comp... a Cave Pedals Tighter Arse passive variable HPF... but I ended up putting it to a different use in an fx loop taming the low sweep of a phaser. I think it's exactly what you're looking for but I don't know anything about how it's wired up, sorry.
We've been begging Heath to make more of these for over a year now.... no such luck if anyone is interested.
I just have a regular Tightarse myself, works great.
I have the Empress compressor. It and the Mesa Subway DI are the only two things on my pedal board I currently use.
The whole sidechain thing stymies me.
The Mesa DI has a high pass filter in it but that does not stop the compressor from engaging prematurely.
What kind of EQ could you put in the side chain?
The whole sidechain thing stymies me.
The Mesa DI has a high pass filter in it but that does not stop the compressor from engaging prematurely.
What kind of EQ could you put in the side chain?
I think the OP understands this, and is just trying to use the sidechain + HPF combo to replicate what the Cali Compact Bass does.
I don't know enough to say if the proposed schematic would work, but the idea in principle is a good one, a lot of people love that HPF on the Cali (it too doesn't affect the sound, just how the comp is triggered).
THIS^^ - I understand I'm not effecting the output signal, just trying to figure a way to 1. consolidate a current HPF to reside ON the pedal to adjust the capacitance, in turn manipulating what the compressor "triggers" (hell no one has even mentioned a low pass and what it might do if adjusted high enough) and/or 2. at least make a plugin, device of sorts, that myself and anyone else wondering EXACTLY what capacitor makes their particular rig do. I know this application could benefit in a recording situation.
But in the end its just a thought, I may get a few and check them out, see what others use and try to make it smaller. I've also noticed that every one I've see (stand alone HPF) requires power as well.
And to the others talking about the variable CAPS being large, I've looked them up and understand but I could have sworn there was smaller ones years ago. Way back in the early 90s I modded a lot of cable boxes that way, maybe things have changed.
I think this is going to be the simplest approach. Get a stereo plug, a pair of alligator clips, and a handfull of different caps and get to experimenting.
Yeah, probably, but wouldn't it be convenient to just plug something it, play it for a few weeks in different settings, and in a month know exactly what or which ones to go for, then pass it to another Empress owner.
Your right though, its not like they are expensive. My mind wanders, and typically tries to reinvent the wheel.. less think, more play
This guy made a rotary switch with a different capacitor in each position. That should only cost a few bucks. I made a few different of the pancake jack with different capacitors and settled on the 3.9nf for 100Hz as my favorite. Especially with the parallel dry control, I don't hear any compression artifacts and I hit it pretty hard.
The sound quality going into the compressor sidechain doesn't matter, so I agree with not spending $100 for someting fancy. I do have a Broughton HPF in my signal path, and it's great, but overkill for this purpose.
That's a nice filter but doesn't show you any capacitance values to create your own, I'll figure this out. Talking with my local vintage repair shop this weekend for some ideas.Yeah, wouldn't it be convenient if there was something out there that would allow you to do that.
Agreed that it's overkill for a sidechain, but it would allow you to easily experiment with different settings (as requested). If you find some that you like, then you could back-calculate the required value of capacitor and make a jack-plug capacitor filter for your favorites, and then sell or repurpose the HPF into your actual signal chain.
I'd say 100 Hz is a good place to start. I have a Broughton Apex compressor which has a built-in variable HPF sidechain, which I'd guess I typically set anywhere between 60-150 Hz depending on the bass, application, and intended result.
Keep in mind that a simple capacitor high pass is a first order filter, and cuts low frequencies at 6 dB/octave below the cutoff frequency. The Broughton HPF (for example) is a second order filter with a slope of 12 dB/octave, meaning low frequencies are more effectively reduced below the cutoff frequency. All this to say that setting the cutoff frequency of the filter (by choosing a particular cap value) is not the only factor that will affect the response.
- Apr 20, 2009
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You're creating a first-order passive RC couple. The value of the cut-off frequency will be determined by both the value of the capacitor and the value of the resistor.
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All of this is predicated on AC signals. It's the very basis by which capacitors block low frequencies.
Think of a sin wave... The lower the frequency, the longer the wave length is between peaks. So as your audio frequency gets lower and lower, the AC signal starts to look more and more like DC voltage. Capacitors only pass AC, thus the blocking of low frequencies.
Think of a sin wave... The lower the frequency, the longer the wave length is between peaks. So as your audio frequency gets lower and lower, the AC signal starts to look more and more like DC voltage. Capacitors only pass AC, thus the blocking of low frequencies.
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