professional manufactured SSM2044 VCF PCBs are AVAILABLE!!

Mooger5 · Posted: Thu May 17, 2007 6:14 pm Post subject:

I was browsing through the Banzai site and found: http://www.banzaieffects.com/Alpha-24mm-mono-50k-REV-log-pr-17313.html , a true reverse logarithmic pot, for P4. Didn´t know such a thing existed. Sorry if it´s old news.

Correct me if I´m wrong but it may be possible to get the "best feel" for the Q control, as they say in the 2044 datasheet, than with the P4 + R24 arrangement. Good for controlling resonance levels dinamically in a modular set-up, I think.

fonik · Posted: Thu May 17, 2007 10:56 pm Post subject:

great finding! thank you very much.
i never had any log pots anyway. i got used to buying linear only and to mod them if needed. so i have no experience in the different feeling of response...

Mooger5 · Posted: Fri May 18, 2007 5:56 am Post subject:

Me neither. And I still don´t figure much what´s the importance of having a "better Q feel". With me, resonance settings is just a matter of finding the right level and leave it as it is. In the case of the Juno 106, tweaking the reso can be recorded and looped via sys-ex but it rarely or never happens. In a modular set-up however, if you create a patch where Q is controlled by ADSR, LFO, keyboard or whatever, you might get a response curve closer to what the original designers had in mind.

Fernando · Posted: Sat May 19, 2007 4:27 pm Post subject:

fonik · Posted: Sun May 20, 2007 12:16 pm Post subject:

goodrevdoc · Posted: Sun May 20, 2007 4:45 pm Post subject:

Hey put me down for one board + one chip.
-justin

modularkomplex · Joined: Feb 14, 2007 Posts: 11 Location: germany

Hi Matthias,

hope i'm not to late. I'm interested in getting 6 pcbs without the chips. Still possible to join?

cheers,
Mike

fonik · Posted: Mon May 21, 2007 12:25 am Post subject:

you're welcome. put you on the list...

bugbrand · Posted: Mon May 21, 2007 2:15 am Post subject:

Just had a wonder when the Device newsletter was mentioned recently.. Issue 6 has an SSM2040 based VC Filter / Phaser -- is the 2040 similar to the 2044? (I haven't had too much of a look at either this circuit or the 2044 filter..)

Will it be alright to get maybe 1 or 2 pcbs but something like 10 ssm2044s?
That'd be great!

fonik · Posted: Mon May 21, 2007 2:28 am Post subject:

bugbrand · Posted: Mon May 21, 2007 2:46 am Post subject:

Ah-ha.... If I'd gotten around to looking more in depth....!....

Fernando · Posted: Mon May 21, 2007 4:02 am Post subject:

Yes the SSM2040 is extremely interesting because it has separate gain cells to build whatever filter. But it is expensive/rare.

The VCF/Phaser in Device #6 looks great, I was tempted many times in building it.

JH and Rene have a discrete version of it:

http://www.uni-bonn.de/~uzs159/rs2040.html

http://home.debitel.net/user/jhaible/additional_schemos.html
http://jhaible.heim.at/tonline_stuff/jh2040.gif

What I thing would be SUPER is to have a pcb with the discrete cells and free space so one could have a bare discrete equivalent of the chip and be able to build many types of filter (LP/Phaser, HP, BP, weird filters...)

This would be a challenge, but a nice one!

fonik · Posted: Mon May 21, 2007 12:31 pm Post subject:

here we go: i just populated and tested one PCB. they are fine (except for a minor error in the screenprint - i will annotate the documentation tomorrow).

the ICs are sold out but there are still some PCBs left.

tomorrow i will PM everyone who placed an advance order.

Fernando · Posted: Tue May 22, 2007 3:50 am Post subject:

Wooow! what a lovely layout! On-board pots, MOTM and Doepfer connectors... So compact... You are a master!!!

bugbrand · Posted: Wed May 30, 2007 2:41 am Post subject:

I'm looking forward to this!
(by the way, I've ordered two SSM chips from Ebay - think its from a pseudonym of the notorius HongKongSuperSeller so I'll report back as to whether they're recieved ok (..though I've had alright experiences before))

Couple of questions having read a bit through the datasheet

----> Audio input - If the pin1 non-inverting input is used, combined with the output buffer opamp (inverting), surely the output is inverted overall? Maybe I tap across to the inverting input (pin15)

----> mixing a few audio inputs? Ah, maybe I'll add an active mixer (inverting) pre-module --> I quite like having a few inputs into such a device - saves panel space too...
How does the chip sound if pushed too hard? Nice overload distortion?
The 'gain' dial is only a passive attenuator (..ok, you can call it negative gain?!) --- the input resistor values are based on the Analog.synth.de design rather than the datasheet values, right?

fonik · Posted: Wed May 30, 2007 3:47 am Post subject:

sascha neudeck · Joined: Feb 19, 2007 Posts: 10 Location: vienna

Hi fonik,

If you have left PCBs, I would like to order one please.
Also I would like to get an IC for it, but you don´t have any ICs left, don´t you?

cheers
Sascha

fonik · Posted: Thu May 31, 2007 12:18 am Post subject: Re: one more PCB

bugbrand · Posted: Thu May 31, 2007 1:48 am Post subject:

Hey, so two little packages arrived with Mr.Post this morning... 1 PCB from Fonik and 2 SSM chips direct from HongKong. WhoopWhoop!

So, 1st off, thanks Matthias. 2ns - seems like HongKongSuperSeller (or Goodbuy711 --- pseudonym, I think) works out ok - pretty reasonable price and quick delivery. [url=http://search.ebay.co.uk/search/search.dll?sofocus=so&sbrftog=1&from=R10&_trksid=m37&satitle=ssm2044*&sacat=-1%26catref%3DC6&floc=1&sargn=-1%26saslc%3D2&sadis=200&fpos=BS6+5ER&ga10244=10425&ftrt=1&ftrv=1&saprclo=&saprchi=&fsop=1&fsoo=1]Here's a list of the Ebays available[/url]

Going back to the previous posts..

Phase -- I've only just started to worry about keeping things in phase - gets important to set a standard, certainly if you're going to use the modular for effects processing. Still, it looks like a very easy mod on the pcb.

Hehe - crazy Bug design? Probably not! But may add a bit to it -- certainly Q modulation will be good and a couple of cutoff CV attenuators etc... Next week hopefully.

Cheers

fonik · Posted: Thu May 31, 2007 1:52 am Post subject:

Photon · Posted: Thu May 31, 2007 4:51 am Post subject:

softfin · Posted: Thu May 31, 2007 12:55 pm Post subject:

Received the boards today. These seem to be few of the highest quality boards i've seen this far! Great work Fonik!

fonik · Posted: Thu May 31, 2007 1:59 pm Post subject:

Mooger5 · Posted: Thu May 31, 2007 4:09 pm Post subject:

I´m using SSM2044 on a different project and would like to tell all the six chips I bought from HKSS are ok. There´s a sample of the chip being overdriven on my Juno thread http://electro-music.com/forum/download.php?id=8125. It behaves well and sounds quite moogish in the bass department.
What I´m working on now is trying other filter capacitor values. I believe the 820pf and 10nf in the datasheet are for reference only and that we can use other values to tailor the sound. If you look at the Korg Polysix and Mono/Poly schematics you´ll see they used 560pf and 6.8nf. This will make the filter sound brighter, of course. If we increase the capacitance the filter will sound subjectively fatter. I say subjectively since it looks like rising or lowering the cutoff point won´t make the same effect, to my ears.

As 560pf is to 6.8nf what 820pf is to 10nf, we just need to follow the same ratio to experiment with other values...

fluxmonkey · Joined: Jun 24, 2005 Posts: 708 Location: cleve

anyone have a US source for 16mm pcb mount linear alpha pots? i just noticed that the ones i have from mouser are audio/log taper... i have ones w/ terminal lugs, but being able to to mount the board by the pots is handy.

b