Bassguitars and effects

[Halion]

I have a passive bassguitar, which I am going to make active probably next month. I use 2 effects: an EHX Mini-Qtron and an EHX Holy Grail. Both work fine for bassguitar in the way that they work fine through out the entire frequency spectrum (no signal loss at all). However, even with my passive bass, they sometimes clip (when I slap and pop, the Holy Grail crackles). I tried my teachers active bass a few days ago, and they clip a little more often with that bass. Not to the point of uselessness but it's still anoying. And because of the resonance peak that the Mini Q-tron has, the preamp of my amphead clips aswell (this I can fix by setting it real low). Is there any way I can work around this/mod the pedals to be able to handle the higher output?

I don't use a send-return loop, they are in the direct signal path. Would using a send-return loop help?

[black mariah]

Buy or build a compressor. They're pretty much a necessity for slap and pop style playing. Even better would be a compressor/limiter so you can hard limit the volume coming from your bass.

[Halion]

well I don't know about that. A good setup should be able to handle the peaks. A compressor might be a good idea though.

[downweverything]

mod them to run off a higher voltage supply for more headroom.

[mikeb]

Buy or build a compressor. They're pretty much a necessity for slap and pop style playing.

Uh ... only if your technique isn't up to snuff. It's possible to play slap AND fingerstyle at exactly the same volume - with practice. Faster too (lighter touch and all).

The higher-voltage modding gets my vote!

Mike

[dev]

Mod the effects input with a gain reduction pot like the 69 fuzz face, 100k to 1 meg should work.  Use an internal trim pot kind of set and forget.  make sure that this is after the bypass switching going to the effect so you don't lower your straight volume when the effects not on.

good luck

[mikeb]

Mod the effects input with a gain reduction pot like the 69 fuzz face, 100k to 1 meg should work.  Use an internal trim pot kind of set and forget.  make sure that this is after the bypass switching going to the effect so you don't lower your straight volume when the effects not on.

You might as well just turn the bass down then .... not a solution, just a work-around. This will reduce the volume of the notes that *aren't* causing the clipping also.

Consider the MutronIII - no-one *ever* complains about headroom when using it, and a lot of the reason is because of the +/-9V power supply. To maintain full dynamic range and the best signal:noise ratio (ok, unless a compressor / expander setup is used), the *only* way to address the problem is to increase the headroom of the effect in question. Whether or not that is practical for the two boxes mentioned, I don't know.

Mike

[Mark Hammer]

This is the primary reason why I caution people about sticking too much gain in their preamp or "active" instrument.  Effects pedals are designed in anticipation of some range of signal levels, and exceeding that range invites awkwardnesses like this.

That is certainly NOT a reason to not go active, but it is a reason to be very modest in what you ask the active instrument to do.  Personally, unless I was intent on driving a power amp directly, I wouldn't boost more than maybe x4 or x5 on a single-coil equipped instrument, x2 or x3 on an HB-equipped guitar, x1.5 to x2 on anything that purports to be "hot", and about the same on bass.

There ARE a number of effects that don't mind this.  For instance, any effect (usually time-based) that includes a compander will fare okay with a hotter input signal.  And certainly a hotter signal can give a broader range of squish in a compressor, and gobs more overdrive on distortion.

On the other hand, phasers and uncompanded chorus units, flangers and delays, can clip seriously.  Noise gates may not have enough dial-in capacity to set the threshold right.  Compressors or limiters may be unable to provide enough dial-in precision either.  Envelope controlled devices may respond a little too strongly.

It sounds like what you want is a limiter, NOT a compressor.  I know people often use the terms interchangeably, but they are different actions.  A compressor will generally boost input signal, and reduce gain in response to any transients.  The net effect is to have a fairly consistent signal because it is always as boosted as it is allowed to be.  That plays havoc with some things you want bass to do, one of which is keep a beat in an obvious way.  It also robs the bass of any dynamics which will make the Q-Tron wimp out on you.

In contrast, a limiter does NOTHING to the signal when there is nothing special about it, and only reduces gain when the signal crosses over some threshold.  Where compressors set a floor AND ceiling, limiters only set a ceiling and leave all the dynamics below that intact.  I know we think of them as effects, but their original intent was to keep stages in the signal path downstream (including speakers) from exceeding their limits (hence the name - limiter).

The gain of the input stage on the Q-tron can probably be tweaked a bit so that even with a hotter input signal you won't clip or get more envelope signal than the pedal can handle.

[Boofhead]

You might as well just turn the bass down then .... not a solution, just a work-around.

IMHO that is a solution.  The signal is too hot from the bass so just drop it down.  The only side effect is the possible loss of highs with a passive bass with a long cable plugged into the bass.  A better solution is to build a buffer with a divider at the input to reduce the level and place it before the effects chain (after the long cable) - this solution avoids loss of highs.

It's crazy to stuff around with high voltage rails and modding effects when the problem is with the signal at the start of the chain.

Obviously some effects are more prone to the problem than others.

[mikeb]

It's crazy to stuff around with high voltage rails and modding effects when the problem is with the signal at the start of the chain.

You're not a bass player, are you?

Regardless - what problem? Bass is *meant* to be dynamic, it isn't our (surveys collective bass players of the world) fault that most effects are designed to work with the relatively wimpy output and dynamic range of guitars - THAT is what the REAL problem is. Not that I myself would use reverb on bass, but obviously the unit wasn't designed to work with the peaks that most basses can generate; and if it was, they designed it poorly.

Perhaps we should start telling guitarists to 'turn down' when they complain about the distortion in an unmodded Phase 90 then, eh?

If it was me, I would mod the effect or get rid of it. If it doesn't work for my instrument the way I want it to work, it's of no use to me. And +/- 9V isn't exactly 'high voltage'.

Mike

[Boofhead]

Bass is *meant* to be dynamic, it isn't our (surveys collective bass players of the world) fault that most effects are designed to work with the relatively wimpy output and dynamic range of guitars - THAT is what the REAL problem is.

Effects are designed to run off 9V because that is the most practical supply available.  A well designed effect maximises the use of the available dynamic range set by the 9V rail.

Increasing or decreasing the output level has *no effect* on dynamics, both the high and low levels of the signal are simply scaled by the same amount - the tone is generally unaffected.  Jacking up the output until something clips is *asking* for trouble.

I'll admit that effects which clip on a passive bass generally have some kind of design limitation which unnecessarily uses up available dynamic range (which is inevitably set by the 9V supply rail).

Active basses on the other hand are a different issue.  A good deal of active basses have output levels which are set too high.  The high output has little to do with tone, it is often a choice by manufacturers to make an active bass sound louder (to a large extent this is a sales issue and all it does is reinforce the myth that active basses must have higher output than passive ones).  The high output does two things - it often causes the basses internal preamp to clip, and secondly it causes an incompatibility between the active basses and guitars and/or passive basses.  Overall it's a stupid practice which has grown since active basses first hit the market.  Rather than drop the output level so the bass can happily run on a 9v battery there is a tendency to put higher voltage rails on active bass preamps - and that practice only feeds the 18V is better syndrome.  Sure it solves the internal preamp clipping problem but it doesn't solve the compatibility issue between the active bass and the rest of the world.

[mikeb]

The high output does two things - it often causes the basses internal preamp to clip, and secondly it causes an incompatibility between the active basses and guitars and/or passive basses.  Overall it's a stupid practice which has grown since active basses first hit the market.  Rather than drop the output level so the bass can happily run on a 9v battery there is a tendency to put higher voltage rails on active bass preamps - and that practice only feeds the 18V is better syndrome.  Sure it solves the internal preamp clipping problem but it doesn't solve the compatibility issue between the active bass and the rest of the world.

I think you're getting confused a little here - it isn't the internal preamp that clips, rather it is the high output of the bass into a surprised, unprepared and poorly designed preamp that causes clipping in said preamp. Also, there are different types of active basses - those with powered pickups and powered preamps, and thoses with just passive pickups and powered preamps. I don't think it is reasonable to lump all active basses and their manufacturers together in a vague mass of parties conspiring to produce louder and louder basses; it just simply isn't true.

BTW if you have tried changing an EMG system to run from 18V instead of 9V, it *is* 'better' (more headroom etc). IMHO at least, a good preamp and amplification system is all about having enough headroom / power to handle - cleanly WITHOUT clipping - ANY signal that is produced by the bass itself. This *includes* effects units that are placed between the bass and preamp, or preamp and power amp.

Again I say - if the effects don't perform well enough for bass, then change them so they do, or ditch them and get ones that work. A higher output level from any instrument results in a better signal to noise ratio, and is well worth working for.

Mike

[Boofhead]

I think you're getting confused a little here -

No I was just commenting on the more general case of the high output from basses.

There's no problem dropping the output the passive bass with a buffer to get around dodgy effects.  Incidently boosting the effect's rail won't always solve the problem:  For example, a good deal of delay effects have regulators on for the delay chip so this part of the circuit (which is highly likely to be the one which clips) won't benefit from the increased supply rails.  Things like phasers have zener diodes in them for biasing this means the increased supply rails will not give a noticeable increase in dynamic range.  Also, doubling the supply rails will generally change the way the LFO behaves.  Dropping the input level doesn't change the way the effect behave and it has a lot of advantages for the general case - individual effects can always be dealt with on a case by case basis.

[mikeb]

(breaks into Halions' house, steals miniQtron and Holy Grail, takes both pedals to secret location and sets on fire)

And clipping still happens outside an active bass, not inside it. At least on the 10+ I own / have owned.

Mike

[downweverything]

sorry boofhead, being a bass player im going to have to agree with mikeb on this one.  Basses are a way more dynamic instrument than guitar. Especially when playing slap.  Most slap plucks have transients over 9V on most low level passive passive basses even when the normal finger playing is at 1V or less.  Turning the bass down just avoids the headroom the bass already needs not to mention screws the signal to noise ratio.  those less then one volt finger strokes are now going to be in the mV and way too close to the noise floor, goodbye sweet sustain (baaaaaaaaahhhiissssss).  If you look at most pro bass preamps youll notice they run on more than 9V.  Take the aguilar obp-1 and the acoustic 360 for example, 2 of the most popular preamps, 18V and 24V, both transistor units, not tube.  The problem here is the dynamic range of the bass not the output level at all.  Also, a good active preamp is a godsend for a bass player especially one that plays slap, they arent going anywhere anytime soon.

I don't think it is reasonable to lump all active basses and their manufacturers together in a vague mass of parties conspiring to produce louder and louder basses; it just simply isn't true.

yeah ive heard this all too much too...its funny if you just compare output levels, a lot of the passive basses i use are louder than the active ones.  the active ones usually sound a lot clearer though.

[niftydog]

some EH pedals already have a trimpot for input gain.