filter based preamp vs whatever the others are

[Clark Dark]

I know Passinwind but we're only talking about three examples (as of now) in Alembic, ACG, and Wal whereas when talking about "non filter" eq's theres a laundry list which seems to grow every six months. I think using the term filter narrows it down and excludes the one type from the other.

 

[khutch]

Should we as consumers get riled because the descriptions aren't empirical?

Yes, because the use of a generic term to indicate a specific product type opens the door to the possibility that sometime in the future you will buy a "filter" preamp and find that it does not do what you expected it to do. Every preamp ever made is a filter preamp.

 

[Clark Dark]

I appreciate your explanation but we bassists love our candy and don't mind paying for it. Unless someone is a newbie and hasen't been exposed to buying and sampling different eq's and being somewhat up-to-date on circuit enhancements that are available to us as bassists then I could see where it may be confusing. But if I were to ask 'you' directly you would know exactly what I meant if I said "man for my next pre I think I'm going for a filter. I think khutch would know I'm talking ACG or Alembic or Wal and not EMG or Taurus or Noll (using these as examples) because of our exposure to these things as buyers and users.

 

[khutch]

The curious thing is that we engineers are often regarded as dull, unimaginative creatures yet we have more names for filters than Eskimos have words for snow and of course all the technology that everyone relies on today and for the last century or two is the product of our imaginations. We have names for both the filter passband shapes and the circuit topologies that are used to create them. Yet the best name a group of creatively gifted musicians can come up with for this kind of preamp is "filter"? Do you all name your dogs "Dog"? Your songs "Song"? As it turns out engineers typically find this particular filter response a little too generic to have given it anything but a dry, technical name so if nothing else do what the early electrical engineers did and name it after the designer who first recognized its utility in a bass preamp. Filter based preamp is just about the lamest name I can think of, Wickersham preamp would be HUGELY better and a nice way to honor him, if he is the one who first used them.

Sheesh, do you need me to help you write some bass lines now?

 

[Passinwind]

I know Passinwind but we're only talking about three examples (as of now) in Alembic, ACG, and Wal whereas when talking about "non filter" eq's theres a laundry list which seems to grow every six months. I think using the term filter narrows it down and excludes the one type from the other.

No worries, the market has pretty much already voted and I have plenty of other windmills to knock down. But personally, "non-filter EQ" as a term applied to things that are more or less universally filter-based circuits is never going to fly with me...Link Removed

 

[RobbieK]

what the early electrical engineers did and name it after the designer

You obviously havent heard of Dr Frank P. State-Variable (1912-1994) and his pioneering work in the 1970's searching for the perfect wah-wah pedal for the porn sound-track industry.

Wickersham preamp

A great suggestion. Ron is a bit of a hero to me...

This forum always goes off on tangents about language matters like this. With respect to the well-meaning engineers who hang around here, there are literally billions of people around the world who know exactly what you are talking about when you refer to "football". But this game was called soccer when I was a kid. And here in Australia we have three other football codes (two of which are called "rugby"!). And these days they call soccer "football" here as well! Welcome to the english language. Full of inconsistancies. A rudderless ship. I wouldn't be surprised to find "yolo" in the dictionary these days...

So, back to the re-poster.

Hi guys, how long battery life Boogieman low pass filter vs. Bart, Aggie and others?

Anyone know the current draw specs on the boogie man? Personally I would assume it to be a little more thirsty that a typical preamp, as it takes 4 opamps to make a state-variable filter, but audio opamps vary enormously, as do regular cut/boost-type preamps. Some have just a couple of fets and others have 3-4 opamps...

Perhaps you could email the actual boogieman guy and ask him/her what the current draw is. Or maybe a shout out to someone who has one, plus owns a multimeter to help out...

 

[khutch]

This isn't a trivial language matter. There are times when language can be as sloppy as can be and it will serve perfectly fine. And there are times when more precision is called for. I once had to attend a business meeting in San Jose. Luckily we discovered just in the nick of time that our travel assistant had us all going to Puerto Rico instead of California. And we only discovered that because she happened to mention to me when I picked up my tickets that she had always wanted to visit Puerto Rico! If you are going to call your preamp a filter you are opening yourself and your customers to a lot of confusion and you are handing your competition an easy way to capitalize on that confusion. I am taken aback that you consumers aren't more interested in fixing the problem before it burns you. I am astounded that the preamp manufacturers seem to have no more concern than you do.

By the way, here is what you can do with four capacitors, a 25k pot, and a rotary switch:

Is this also a "filter based" "preamp" then? People on TB tend to call this a "ToneStyler" which is actually a StellarTone trademark and incorrect anyway because StellarTone's response curves show a critically damped, "mids preserving", response rather than the underdamped response shown above that you get from the typical DIY versions. I have a version of this in one of my basses that gives the curves shown on the right but it does not have a series pot to give the peaking control shown on the left and I like it. So I am biased and I think the active version we have been discussing above is a fine addition to the world of active bass guitar electronics. Fine enough that it deserves something better than a lame generic name. I'd much rather call what I have in my bass a passive Wickersham (if he is the guy that deserves the honor in this case) than a ToneStyler. But even ToneStyler is better than passive "filter based" tone control! And as you can see the active and passive versions of the same filter response will forever have completely different names if we continue to stick with "filter based" and "ToneStyler".

 

[wisconsindead]

khutch, could you link me to a diagram for that set up you have above? It looks very intriguing. I could use that for a passive bass correct?

 

[Jon Clegg]

By the way, here is what you can do with four capacitors, a 25k pot, and a rotary switch:

View attachment 593738

I take it you went with 25k to get a sharper resonant peak?

 

[khutch]

I take it you went with 25k to get a sharper resonant peak?

No, I went with 25k because if the pot is more than that you will overdamp the filter and get the traditional tone control response. In practice you might want to be able to do that, why not have both, so there is nothing wrong with using a traditional 250k pot, but for the sake of illustration I limited the resistance to 25k. And I misspoke, you obviously need five capacitors, not four, to get five different peak frequencies. To be sure the active version is better behaved, the peaks are the same height as you change the peak frequency for example, but the passive circuit will do the same thing to an extent and its modest popularity is an indication that the active version is laboring in an undeserved obscurity.

 

[wisconsindead]

No, I went with 25k because if the pot is more than that you will overdamp the filter and get the traditional tone control response. In practice you might want to be able to do that, why not have both, so there is nothing wrong with using a traditional 250k pot, but for the sake of illustration I limited the resistance to 25k. And I misspoke, you obviously need five capacitors, not four, to get five different peak frequencies. To be sure the active version is better behaved, the peaks are the same height as you change the peak frequency for example, but the passive circuit will do the same thing to an extent and its modest popularity is an indication that the active version is laboring in an undeserved obscurity.

Khutch, could you share the diagram for this? I'm interested in making one.

 

[bholder]

I had an allergic error....alembic ....... onboard preamp I have not been able to replicate the sound of. I have read it has to do with filters. What exactly is the difference? Also there was a switch and knob on my set up, when you threw the switch the knob acted just like a wha pedal. Sound familiar to anyone? I don't know what it was, but I know it cost 850$to replace just that one part of the circuit, (or would have).

"sounds like a wah pedal" means "sweepable mids control".

 

[LowB-ing]

The long and the short of it is, at some point "filter" became bass community slang for resonant lowpass filter, becasue "resonant lowpass filter" is such a cumbersome word to pronounce. Well according to some at least

Then the slang became the accepted use of therm. I don't like it either.

It really isn't deceptive marketing from any one company, though. The bass community have themselves to blame.

By the way, here is what you can do with four capacitors, a 25k pot, and a rotary switch:

You can't do it to each pickup individually though. Alembic, Wal and ACG do offer models that can.

Is this also a "filter based" "preamp" then? People on TB tend to call this a "ToneStyler" which is actually a StellarTone trademark...

The tonestyler is a lowpass filter (in context), but it's not a preamp. So no, it's not a filter based preamp.

 

[khutch]

Khutch, could you share the diagram for this? I'm interested in making one.

There really is not much to it. If you put a rotary switch between the pot and the capacitor on a regular passive tone control so that you can select one of several (doesn't have to be five) different capacitors you have it. If you want to limit the action to the underdamped regime then you would use a 25k pot, but if you want to be able to run in normal tone control mode too then you can use the traditional 250k pot. That's it. If you do a search on tonestyler you should turn up several threads where people discuss building their own version. A normal tone control already gives you this mode when you turn the pot down to the vicinity of zero but you cannot select the frequency of the peak unless you put in multiple capacitors selected with a switch.

In passive versions the resonant frequency is determined by the tone capacitor and the pickup inductance. So it is going to vary from bass to bass to bass and it will vary depending on whether you have one pickup selected or both and from pickup to pickup. And in VVT or BVT multiple pickup basses the volume and or blend settings can affect the amount of peaking you can get. So for many reasons the active version is a more robust choice but if you experiment with the capacitor values on your particular bass you can get the sounds you want, mostly. Probably many people who like the passive version would like the active version better if the terminology we used to describe them let them know that they are close to the same thing.

Of course you won't sell very many at $850 a pop but tell you what I'll make you one for $600 and if you act in the next 20 minutes I will make you two for that price! Free shipping!!

And for the sake of the humor impaired, that was a joke, I'm not in the business of making bass guitar preamps and have no intentions of doing that at the moment.

 

[Jon Clegg]

Search for a thread called "a simple varitone for bass" here on TB. OK its not a notch producing circuit like the Gibson circuit of that name, but it yields the type of response khutch is talking about.

 

[wisconsindead]

Of course you won't sell very many at $850 a pop but tell you what I'll make you one for $600 and if you act in the next 20 minutes I will make you two for that price! Free shipping

But wait. There's more!

Thanks guys.

 

[nashvillebill]

I'm surprised Randall Smith hasn't patented the "filter based preamp"

 

[Passinwind]

I'm surprised Randall Smith hasn't patented the "filter based preamp"

Link Removed

 

[wcriley]

I call that knob on a Precision Bass a tone control. But I could just as accurately call it a filter based tone control and if I made it with fine vintage CTS pots and Orange Drop caps and cloth wire I could get rich selling my filter based tone controls here on TB!

Thanks!...I've been looking for a way to supplement my pension checks...
Hmm...maybe add a little block of black epoxy to hide a "secret circuit"...

 

[CrashClint]

I put one of these filters on my bass and it add 30% more volume flow.