Alembic filter EQ?

Stuggi · #1 12-07-2007, 07:48 AM

I've heard all kinds of stuff about 'em filterbased EQ's Alembic uses. So I wonder if someone here's sitting on any schematics for a Alembic Preamp/EQ or a similar circuit?

Hoover · #2 12-07-2007, 08:26 AM

Do a search (either TalkBass or Google) for "SF-2", that's the outboard Alembic preamp/equalizer that uses the same parallel filters as their Series II basses. I've posted some explanations about how these work (or how they differ from conventional parametric equalizers) that might help.

I think you can download the owner's manual from Alembic's website, which might contain schematics...I know at the very least it contains block diagrams.

MPU · #3 12-07-2007, 12:14 PM

So far I haven't been able to find any schematics for Alembic Superfilter. All I have found is explanation of how they work. That alone does not help much if you (like me) would like to make one. So. if anyone have schematics for Superfilter I'd be interested too.
Marko

DavidRavenMoon · #4 12-07-2007, 12:32 PM

I'm looking for the schematic for the onboard filters as well. I did find a place to buy them from.

DavidRavenMoon · #5 12-07-2007, 08:48 PM

I just ordered them...

MPU · #6 12-08-2007, 06:24 AM

Which one of those did you order? Was it really SF schematics? I have Alembic tube preamp schematics already so I don't need F-2B schematics.
Marko

A9X · #7 12-08-2007, 09:14 AM

Quote:

Originally Posted by MPU

Which one of those did you order? Was it really SF schematics? I have Alembic tube preamp schematics already so I don't need F-2B schematics.
Marko

The PF6 schematics listed are he older Series insrtrument onboard diagrams. The SF2 isn't listed, but it's a 2ch SVF with selectable outputs (HP, LP, BP) and a mixer. The hard part about building one is the low tolerance, excellent tracking pots required for the F controls. Everything else is textbook.

Stuggi · #8 12-08-2007, 09:18 AM

Well, it's the on-board electronics that I'm after, and those sure look good to me.

DavidRavenMoon · #9 12-08-2007, 05:40 PM

Quote:

Originally Posted by MPU

Which one of those did you order? Was it really SF schematics? I have Alembic tube preamp schematics already so I don't need F-2B schematics.
Marko

I got the Series I and Series II guitar and bass circuits, which contain the low pass filters. I believe the Series I had a three way Q switch, and the Series II has a continuously adjustable Q.

A9X, did I get that right?

DavidRavenMoon · #10 12-08-2007, 05:53 PM

Quote:

Originally Posted by A9X

The hard part about building one is the low tolerance, excellent tracking pots required for the F controls. Everything else is textbook.

Yeah, you can get a similar operating filter (LP/BP/LP) in the book Electronics Projects for Musicians, by Craig Anderton. (I know you know this... it's for everyone else).

I used to use one of those in a box I kept on top of my amp. A 2 channel version would have been cool!

MPU · #11 12-10-2007, 02:32 AM

David, have you received your schematics? I ordered mine on Saturday and now I can't find the site using your link.
Marko

Stuggi · #12 12-10-2007, 04:54 AM

Lol, what am I going to do now?

DavidRavenMoon · #13 12-10-2007, 05:21 AM

Well isn't that interesting... no, I didn't receive them yet.

I did see that the guy had some health issues, but the site had been up for a while. He must have let his domain expire!

I did pay with PayPal, so I should be able to get my money back if I don't get them. I did get a receipt and stuff.

I just went to archive.org and got the last update to the site from August, so I got his phone number just in case...

I also did a whois, so I have his name and address as well.... His domain expired on December 8th.

I ordered them on the 7th, so I'll give it a few days and see if they get here.

I know of another site that has them, but he wanted to charge me more than double!

MPU · #14 12-10-2007, 07:15 AM

David,
please let me know if you find out anything about the schematics.
Marko

edwinhurwitz · #15 12-11-2007, 11:15 PM

Quote:

Originally Posted by Hoover

Do a search (either TalkBass or Google) for "SF-2", that's the outboard Alembic preamp/equalizer that uses the same parallel filters as their Series II basses. I've posted some explanations about how these work (or how they differ from conventional parametric equalizers) that might help.

I think you can download the owner's manual from Alembic's website, which might contain schematics...I know at the very least it contains block diagrams.

The Series II differs from the SF-2 in 2 significant ways. 1) It can be high, low or bandpass. 2) The frequency range is larger, 40-6khz instead of 350-6khz. I have a SF-2 and I am considering taking it out of the case putting it into my Starfire!

Hoover · #16 12-12-2007, 08:39 AM

Quote:

Originally Posted by edwinhurwitz

The Series II differs from the SF-2 in 2 significant ways. 1) It can be high, low or bandpass. 2) The frequency range is larger, 40-6khz instead of 350-6khz.

I stand corrected, thanks for the update. (Presumably you mean the SF-2 has those features listed, that the Series II does not.)

Yeah, putting a complete SF-2 into your bass would be awesome!

A9X · #17 12-12-2007, 04:44 PM

Quote:

Originally Posted by edwinhurwitz

I have a SF-2 and I am considering taking it out of the case putting it into my Starfire!

Have you opened the lid and looked at the PCB? This transplant ain't gonna happen without a huge amount of work.

synaesthesia · #18 12-12-2007, 04:58 PM

I built Anderton's filter circuit in '81 and blew up some Celestion speakers.

It would seem to me that you could run some readily available electronic crossovers and feed the outputs to a mixer, this might simulate some of the SF2's possibilities.

A9X · #19 12-12-2007, 05:08 PM

Quote:

Originally Posted by synaesthesia

I built Anderton's filter circuit in '81 and blew up some Celestion speakers.

It would seem to me that you could run some readily available electronic crossovers and feed the outputs to a mixer, this might simulate some of the SF2's possibilities.

To destroy speakers, you did something wrong.

Xovers won't emulate an SF2 for a few reasons; no Q control, no switchable LP/HP/BP function, no mixer.

abngourmet · #20 12-12-2007, 05:15 PM

Alembic sells replacement pickups in J and P Bass configuration, but to my knowledge aren't the low pass filters and Q switch setups you find in their Basses from the Essence and up. They're bass/treble/volume/pan, which is pretty much what they have in the Epic, Excel, etc., which is the lower end of their line.

If you want the low pass filter with Q, you'll probably have to find it used, or buy an Alembic, which, IMHO, is a good thing.

I have an SF-2 in my Rig, along with an F1-X, and I can tell you with that combination I can dial in just about any tone I want. You might want to consider buying a used SF-2 - I swear to God, it makes any bass sound better, whether Alembic or not.

My two cents,

Alan