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Vintage threads from the first ten years

Envelope Filters for Bass

3/16/2000 12:13 AM
Troy	Envelope Filters for Bass Any opinions of envelope filters for bass (ala Bootsy)? I'm looking at the EH Bassballs or the Qtron; any experiences with either of these. I think "Bass Player" gave the Bassballs a pretty high mark for "cheap yet cool". I'm just looking for something that will allow Velveeta to ooze from my speaker cabinet (ha ha)! Troy

3/16/2000 12:49 AM
Reid Kneeland	One other thing to check out is from none other than Bob Moog (as in synthesizer). His new company, Big Briar, makes, among other things, a line of effects boxes called MoogerFoogers. One if them is called (modestly) a low-pass filter, but it's an envoloper filter and then some. There's a sound sample at http://www.bigbriar.com/sounds/filtbass.mp2. If I were buying an envelope filter (I'm building one instead), I'd give this serious thought. Reid

3/16/2000 12:49 AM

Reid Kneeland

One other thing to check out is from none other than Bob Moog (as in synthesizer). His new company, Big Briar, makes, among other things, a line of effects boxes called MoogerFoogers. One if them is called (modestly) a low-pass filter, but it's an envoloper filter and then some. There's a sound sample at http://www.bigbriar.com/sounds/filtbass.mp2. If I were buying an envelope filter (I'm building one instead), I'd give this serious thought.

Reid

3/16/2000 10:10 AM
paul perry	One problem with bass envelope followers, is the attack not being naturally sharp on the bass, compared to a normal guitar. (Unless you have really powerful fingers!). So the envelope can be a bit slow & not give a punchy enough effect. A triggered envelope might be more to the point here, or do something with a compressor/expander, buggering about with the envelope shape. I manufactrue an envelope follower (the Frostwave funk.a.duck) and I notice it varies a lot with the person playing it. The (digital) Boss SYB-3 is pretty powerful, but don't expect to get thru more than 3 songs on one battery!!

3/16/2000 10:10 AM

paul perry

One problem with bass envelope followers, is the attack not being naturally sharp on the bass, compared to a normal guitar. (Unless you have really powerful fingers!). So the envelope can be a bit slow & not give a punchy enough effect. A triggered envelope might be more to the point here, or do something with a compressor/expander, buggering about with the envelope shape. I manufactrue an envelope follower (the Frostwave funk.a.duck) and I notice it varies a lot with the person playing it. The (digital) Boss SYB-3 is pretty powerful, but don't expect to get thru more than 3 songs on one battery!!

3/16/2000 3:12 PM
Mark Hammer	Envelope filters for bass need to have: 1) either less sensitivity, or better control over sensitivity, since bass PU output tends to be higher 2) a way of shifting the filter range downward (where the first coupla harmonics are for bass), or a lower range to start 3) a fast attack or way of altering the attack to let bass be as percussive as it can Most available pedals will give you one of these but not necessarily all 3. In many cases, you'll have to mod what you get. I threw together a couple of Dr. Q's recently, from the schematic posted at AMZ (www.muzique.com), and it provides good value for time invested, but would need to be modified for bass. Specifically, the mods would likely involve changing the two .0047 caps that form the filter for .0082 or .01uf caps, and tweaking the sensitivity by either: a) the trimpot setting, b) replacing the 2.2Meg resistor with something a bit smaller (say 1.8meg), or sticking a fixed rsistor in series with the input of the sensitivity control (say 22k). The Qtron+ and Bassballs are optimized for bass, and if you can find an MXR Envelope filter, so is that. I specify the Q-tron+ because it has attack-time control.

3/16/2000 3:12 PM

Mark Hammer

Envelope filters for bass need to have:
1) either less sensitivity, or better control over sensitivity, since bass PU output tends to be higher
2) a way of shifting the filter range downward (where the first coupla harmonics are for bass), or a lower range to start
3) a fast attack or way of altering the attack to let bass be as percussive as it can

Most available pedals will give you one of these but not necessarily all 3. In many cases, you'll have to mod what you get. I threw together a couple of Dr. Q's recently, from the schematic posted at AMZ (www.muzique.com), and it provides good value for time invested, but would need to be modified for bass.

Specifically, the mods would likely involve changing the two .0047 caps that form the filter for .0082 or .01uf caps, and tweaking the sensitivity by either: a) the trimpot setting, b) replacing the 2.2Meg resistor with something a bit smaller (say 1.8meg), or sticking a fixed rsistor in series with the input of the sensitivity control (say 22k).

The Qtron+ and Bassballs are optimized for bass, and if you can find an MXR Envelope filter, so is that. I specify the Q-tron+ because it has attack-time control.

3/16/2000 4:50 PM
Mark Hammer	Oops, almost forgot. One of the common complaints of bass players, when it comes to envelope filters, is that the sound gets too thin. This happens for two reasons. 1) The filters are tuned too high, and sweep upward, so that notes get thin. 2) Most ECF's use bandpass filters, which means that sweeping leaves the bass behind. Several cures are possible: 1) Use a pedal that provides a lowpass filter structure so that only high end is altered, leaving bottom end intact. The Q-Tron/Mutron/Neutron is an example of this, as are some of the BOSS and Ibanez models. The MoogerFooger Lowpass filter is an even better example, since it uses a higher-order filter (4-pole, I think). Instant Mini-Moog. 2) Use a pedal with bandpass filters tuned down especially for bass. The Bassballs is an example of this, although the Q-Tron uses a range switch to accomplish it. Most ECF pedals can be easily modded, if they don't have this feature already. 3) Mixing in some straight signal with the filtered signal, so that there is always some bottom available, regardless of where the filter happens to be sweeping at the moment. You can accomplish this by running your bass into a simple active splitter, with one output going to the filter unit, and the other meeting up with the filter's output, either at a simple post-FX mixer, or at the input jacks of the amp. Running the two signals to different amp channels is even better, since cutting out some of the high end of the straight signal will give you your bottom but make the filter sound more obvious. Lest you be concerned that combining straight and effect inparallel will diminish the tone, let me assure you that parallel effects are VERY groovalicious. The only caveat is that both straight and FX may be of opposite phase, so you may want/need to phase invert one of them to get your desired tone. As a suggestion, the "Retro-Stereo" adaptor that Craig Anderton had in GP magazine many years ago, is posted at various sites (Stellan Lehrberg's is one of them). This is an easy project that will allow you to patch in your pedal to a loop and get two outputs: sum of straight+pedal and difference of straight-pedal. In effect, it has your splitter, mixer, and phase inverter all in one handy unit. Craig made it for just such occasions.

3/16/2000 4:50 PM

Mark Hammer

Oops, almost forgot.

One of the common complaints of bass players, when it comes to envelope filters, is that the sound gets too thin. This happens for two reasons.
1) The filters are tuned too high, and sweep upward, so that notes get thin.
2) Most ECF's use bandpass filters, which means that sweeping leaves the bass behind.

Several cures are possible:
1) Use a pedal that provides a lowpass filter structure so that only high end is altered, leaving bottom end intact. The Q-Tron/Mutron/Neutron is an example of this, as are some of the BOSS and Ibanez models. The MoogerFooger Lowpass filter is an even better example, since it uses a higher-order filter (4-pole, I think). Instant Mini-Moog.
2) Use a pedal with bandpass filters tuned down especially for bass. The Bassballs is an example of this, although the Q-Tron uses a range switch to accomplish it. Most ECF pedals can be easily modded, if they don't have this feature already.
3) Mixing in some straight signal with the filtered signal, so that there is always some bottom available, regardless of where the filter happens to be sweeping at the moment. You can accomplish this by running your bass into a simple active splitter, with one output going to the filter unit, and the other meeting up with the filter's output, either at a simple post-FX mixer, or at the input jacks of the amp. Running the two signals to different amp channels is even better, since cutting out some of the high end of the straight signal will give you your bottom but make the filter sound more obvious. Lest you be concerned that combining straight and effect inparallel will diminish the tone, let me assure you that parallel effects are VERY groovalicious. The only caveat is that both straight and FX may be of opposite phase, so you may want/need to phase invert one of them to get your desired tone.

As a suggestion, the "Retro-Stereo" adaptor that Craig Anderton had in GP magazine many years ago, is posted at various sites (Stellan Lehrberg's is one of them). This is an easy project that will allow you to patch in your pedal to a loop and get two outputs: sum of straight+pedal and difference of straight-pedal. In effect, it has your splitter, mixer, and phase inverter all in one handy unit. Craig made it for just such occasions.

3/16/2000 5:33 PM
Troy	Thanks Guys!! Lots of good info. Troy

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