What makes the Moog fixed filterbank so special?

Rudelius · Post by **Rudelius** » Wed Sep 30, 2009 1:28 pm

Hi,

I have been wondering for a while what makes the Moog fixed filters so
special in comparison to those of some other manufacturers. For
instance, I have a Synthesizers.com fixed filterbank, and I am very
pleased with how it sounds. Some people who know, say they hear
differences, which I don't really hear.

A friend of mine has a modular Moog with an (extended range) fixed
filterbank. Although we never compared the two side by side, I can't say
the Synthesizers.com sounds worse in comparison. It seems that some
manufacturers go to great length to emulate the Moog filterbank in detail,
to mimic the sounds of inductors, or whatever (sorry, I am not at all
technical

), even though it's very expensive.

So it must be that I am missing something. Would some one like to
explain, please? Especially what it does to the sound when you use
inductors, and when using another type of electronics.

Cheers,

Ruud

till · Post by **till** » Wed Sep 30, 2009 1:45 pm

A filter is not only defined or meassured by its slope. There are other things it does to the sound:
- phase shifts,
- slope above the first octave
- distortion of the third harmonic
- non linear things
- interaction with the side bands of the other EQ bands.

And all this is depending on the way the filter is constructed. Doing it by induction is more expensive then using normal RC approaches.

And even if you would rebuild one 1:1, it would not sound 100% alike, due to the toleration of some parts over the years the original Moog module went through.

The easiest way is to trust your ears, and not the marketing of companies.

EricK · Post by **EricK** » Wed Sep 30, 2009 3:04 pm

There was a recent auction of a system that was broken up and sold on ebay. The fixed filter bank sold for 12K!

Here is what CZ rider had to say about it.

CZ Rider wrote:The seller only got $12,356.00 for the 907 FFB.
Time to start rolling my own torridial coils.
What should I charge for a set?
Lets see...20 coils for the 907, and 28 coils for 914. Thats quite a bit of winding.

Im assuming that the answer to your question are those torridial coils. Ill bet that the dotcom system doesn't use them. I will say though that I am talking out of the side of my mouth because my knowlege of electronics is nil.

Ill bet those torridial coils are what makes the difference. That and what till said. This can easily devolve into a MiniMoog vs Voyager debate in the sence that the age of particular componants contributes to the sound just as much as the material of the capicitors. Some argue that if you built a MiniMoog today with the exact same specs as an original Model D that it wouldn't sound the same, due to the fact that there is 30 years difference in the parts.

Eric

MC · Post by MC » Thu Oct 01, 2009 2:12 pm

Bob cut his teeth on winding his own inductor coils when he was learning to build thermins - fifteen years before the FFB appeared. He got pretty good at those things as it was essential to proper operation of the theremin. When I visited the Asheville office (Bob was still around), I found an interesting book on inductors in their library that had more detail than anything in my library. It would not surprise me if the inductors on the FFB were made in house.

cloudhop · Post by **cloudhop** » Thu Oct 01, 2009 3:01 pm

I could be wrong here but I heard it was at the suggestion of Walter Carlos who was quite handy with circuit design, to Bob Moog on the addition of the inductor based fixed filter to the Moog Modular system..
dont quote me on this, its something I believe I picked up a while ago and dont know how genuine the statement was.

Amos · Post by **Amos** » Thu Oct 01, 2009 3:06 pm

cloudhop wrote:I could be wrong here but I heard it was at the suggestion of Walter Carlos who was quite handy with circuit design, to Bob Moog on the addition of the inductor based fixed filter to the Moog Modular system..
dont quote me on this, its something I believe I picked up a while ago and dont know how genuine the statement was.

I could also be wrong, but I believe the relationship was more along the lines of, Carlos suggested functionalities that would be useful from the musician's perspective, and Bob came up with the implementation of those functionalities. I think this is more likely than Carlos actually designing the circuits. There's a lot of this historical info on Wendy's web page, which is well worth a visit.

CZ Rider · Post by **CZ Rider** » Thu Oct 01, 2009 4:34 pm

MC wrote: It would not surprise me if the inductors on the FFB were made in house.

Not sure about all of the torroids ever used in a Moog FFB, but most were outsourced from the Allen Organ Co. in Macungie, PA. The factory is about 20 Min. away from here. I have the original winders from the factory that made them back in the day for Moog. But most important, all of the formulas to wind the different values. I have to get busy making some coils.

Kevin Lightner · Post by **Kevin Lightner** » Thu Oct 01, 2009 7:29 pm

That 907 was relisted and sold for $3000.

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0482617313

Voltor07 · Post by **Voltor07** » Fri Oct 02, 2009 1:43 am

Kevin Lightner wrote:That 907 was relisted and sold for $3000.

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0482617313

Something seemed fishy to me when I saw the previous bid. Nigerian E-Bay scammer, I'll bet.

Rudelius · Post by **Rudelius** » Sun Oct 04, 2009 2:33 pm

Thanks all for the replies. It seems I'm just as happy with the
Synthesizers.com "normal RC approaches" (thanks Till). No way I would put
3000 Dollar on the table for a 907. Not even for a 914, for that matter

Electrong · Post by **Electrong** » Sun Oct 04, 2009 2:47 pm

Probably the only thing you're missing is the fact that the Moog design is the original modular design whereas the Synth.com modular, although excellent, is basically copying the designs that came before it. It's like the difference between an original '62 strat and a new re-issue strat, except that the re-issue strat is made by another manufacturer.

dave500 · Post by **dave500** » Sun Oct 04, 2009 9:56 pm

Twist us up one CZ.

EricK · Post by **EricK** » Mon Oct 05, 2009 12:55 am

CZ Rider wrote:
MC wrote: It would not surprise me if the inductors on the FFB were made in house.
Not sure about all of the torroids ever used in a Moog FFB, but most were outsourced from the Allen Organ Co. in Macungie, PA. The factory is about 20 Min. away from here. I have the original winders from the factory that made them back in the day for Moog. But most important, all of the formulas to wind the different values. I have to get busy making some coils.

CZ,
Did I follow what you meant about the torroidial coils correctly?
Eric

peterkadar · Post by **peterkadar** » Tue Oct 13, 2009 2:36 am

All very interesting stuff indeed. I've always wanted to own instruments that would age and mature - hopefully for the better - with time. Guitarists enjoy this as the instrument grows and matures with the player. So few synths are like that. I dig reading about this stuff, even though I don't fully get all the technical parts.

And... just in case no one has said it today...

CZ Rider has the coolest gear.

There, I feel much better...

jhaible · Post by **jhaible** » Wed Feb 02, 2011 4:32 am

If anybody is interested, and if posting auction links is ok here:
http://cgi.ebay.de/ws/eBayISAPI.dll?Vie ... 0538574862

Selling my 907 emulation prototype. Auction ends today.

JH.

Moog Music Forum

What makes the Moog fixed filterbank so special?

What makes the Moog fixed filterbank so special?

Re: What makes the Moog fixed filterbank so special?

Re: What makes the Moog fixed filterbank so special?