Author Topic: SF-2 experiments thread (Read 537 times)

hieronymous · « **Reply #15 on:** May 01, 2012, 10:00:43 PM »

Yeah, this sounds like a fun project! I could have sworn I had some pictures of my SF-2 that I took while using it but I just can't find it. Well, that much more incentive to put together something new!

Actually, I found something!

sonicus · « **Reply #16 on:** May 01, 2012, 10:10:48 PM »

Sure , at the next Northern California Alembic Gathering we could do workshops . Gain structure in a rack rig is a good place to start next time . The Alembic SF-2 is an Audio Filter that is very well designed for musical application ( the best In my opinion). There have been others in the State Variable Filter variety that were not as successful in making the cross over from the test equipment classification into the hands of the musician and designed for musical performance .I can mention others but shall refrain from dropping the names of other products that were less successful in this endeavor.

Something to remember when using SF-2 is that all factors of the other components within the signal path are relative to what your will perceive to be the result of your settings . There are such a vast amount of variables from product to product that one can insert in your signal chain that even if you log the settings on the SF-2 and then replicate them on another rig that unless every thing is identical then you as the musician and the listening audience will not have the same experience . Your speakers and amplification will be a large variable in the possible visceral effect that can be produced and experienced with this remarkable product . By visceral I mean vast amounts of gain boost or cut over the audio spectrum that you can really FEEL ! With enough Watts and speakers you can produce sounds like thunder ______ Maybe at a gathering in the future we will do that .

Of course there are certain basics that can be a rules of thumb on the control interface as per the book of instructions to get off the ground and fly right .

jazzyvee · « **Reply #17 on:** May 02, 2012, 01:33:14 AM »

Rusty I had my set wired the same as you, into the send and return loop of my F1-x and it sounded fine and I don't recall getting distortion but then I've never had it up loud.

Mica did suggest that I would be better off putting the SF-2 after the F1-x rather than in the send and return loop of my F1-x. I have a reggae gig next week so really looking forward to getting some serious rich low end in the mix.

Jazzyvee

sonicus · « **Reply #18 on:** May 02, 2012, 04:39:19 AM »

Jazzy , Are you sure ? After the F1-X Not before the F1-X ? The voltage measurement of the output of the F1-X or F-2B can get high . From a perspective of building the gain structure to avoid distortion and not overloading the input stage of the SF-2 , Thus; Alembic SERIES Instrument output FROM DS5R to SF-2 line level inputs , then SF-2 output to FI-X input , OR SF-2 outputs directly to Power Amp inputs.

rustyg61 · « **Reply #19 on:** May 02, 2012, 05:01:15 AM »

Thanks Jazzyvee, I am off the rest of the week so I will be doing LOTS of experimenting! I just wanted to make sure there wasn't a problem with my unit. Has anyone else had loose knobs on their SF-2?

sonicus · « **Reply #20 on:** May 02, 2012, 07:51:28 AM »

Here is a link to past Alembic Club SF-2 threads;

http://club.alembic.com/Images/16271/17596.html?1112538443

jbybj · « **Reply #21 on:** May 03, 2012, 10:14:21 AM »

?Something to remember when using SF-2 is that all factors of the other components within the signal path are relative to what your will perceive to be the result of your settings.?

It?s with these unknown variables in mind that I offer up my SF-2 settings philosophies, no specific settings, just the various ways I have approached the beast.

When I first got my SF-2, I used it as a stand alone preamp, instrument input, mono mode, to a power amp. For the last year or so, I have used it in mono mode, in the fx loop of an F-1X. It gave me the same results sonically in both applications.

1. Using it as an additive EQ. One approach is to start with the direct input as the basis, for me, it?s direct up all the way. Then you can use each filter to add selected frequencies on top of the direct signal.
Add some boom: LP between 80 -200hz, damping between 3 and 8. Add some snap/clack: HP between 1K and 6K, damping between 3 and 8. Mid boost, or any boost at a more targeted frequency: BP at whatever suits your mood.

2. Emulating the on-board Alembic instrument filters. For this you leave the direct down all the way, and use the LP only. Set frequency to taste, and the damping acts like a continuously variable Q. I?ve never played a series instrument, but I think this is the rack version of those filters.

3. Going where only the SF-2 can go. So continuing from, no direct, LP filter only, you can add the HP on the second filter, and have a wide range of scooped sounds to create. Try it with a huge gap in the mid freqs, by lowering the LP frequency and raising the HP freq, vary the damping, you can get some really interesting combinations. From here you can head off in all sorts of directions. In a HP/LP scoop mode, try sneaking in various amounts of the direct, or pairing the LP with a BP. Or all direct with a nice mid boost using the BP. Between the potential variety in the combination of sources and the frequencies and damping settings, the SF-2 is worthy of the praise.

The way I use it, I never actually reference any visual metrics. I don?t start out thinking, I?m gonna boost 80Hz, I just start twisting knobs until I get the desired or unexpected physical response, you know, sternum resonating, lower gums itching, buttocks quivering, I know it when I feel it. Have fun Rusty!

rustyg61 · « **Reply #22 on:** May 06, 2012, 09:57:29 AM »

Thanks Wolf & James! I have played with the SF-2 enough the last few days to get an idea of how it works, but I am still experimenting with different hookups & amp/speaker combinations. I know my ultimate bass sound is in there, I just have to find it! I fixed the loose & free spinning knob problem by putting some stick on felt pads behind the loose knobs. now they don't wiggle when I turn them & have more resistance to turning.

jazzyvee · « **Reply #23 on:** May 08, 2012, 06:24:59 AM »

I've been trying my SF-2 out today with my big rig and also trying to see what kind of use I can get from running the bass on two independent channels.

Maybe I need a bigger space than my living room to judge the sound. But here is what I tried.

(1) - Bridge pickup direct to F1-x and full range out into Channel 1 if QSC, Neck pick direct to SF-2 front jack in mono mode then into Channel 2 of QSC.

This was ok but not great.

(2) - I then tried going mono out of bass into F1-x full range out into SF2 in mono mode then out from there into QSC in parallel mode. This sounded great especially leaving both filters fully open on the bass and controlling the sound from the SF-2 and using the volumes and CVQ on the bass to alter my tone. That worked great and seemed to give me a good full range sound. Crisp and bassy.

More playtime soon.

jazzyvee

elwoodblue · « **Reply #24 on:** May 08, 2012, 09:42:50 AM »

I use mine after my F1-X,
Exploiter ->
F1-X --> high pass ->SF-2 chan.1 (LP /freq >680 /DR 3-5 )
. . . . --> low pass ->SF-2 chan.2 (LP /freq =45 /DR 4-6 )
==> Lexicon MX400 ==> Power amp

I use a 15 JBL 2225 in one cab for the bottom and a 12 for the top.

The F1-x tone settings are usually something like
bass 2-4 /mid 6-8 / treble 2-4 ...My volume is usually relatively low on the F1-X , maybe 3-5.
High freq level on the crossover is set at around +2 to +4 . Crossover freq is 150hz-200 hz .

I open up the power amp around 2/3...a bit more for the low channel .

Setting the filter frequency lower than most of the resonances in the low cab seems to work really well .
There's a nice slope up in volume as I play lower notes but no distracting resonances. Of course you
have to use the damping ratio and filter gain carefully . I rarely have levels (direct or filter) over 6 .

Once I added an MX400 for a little reverb and time based effects it was a Eureka moment.
I haven't had to change anything since then and still love the sound .

hope my ramblings help some,
; )

(Message edited by elwoodblue on May 08, 2012)

rustyg61 · « **Reply #25 on:** May 09, 2012, 06:23:02 AM »

I just got a killer deal on an Eden World Tour 800 amp, & it is set up perfect for my SF-2. It has a stereo effects return loop, so I go effects send to channel A on the SF-2 in stereo mode, then out of channel A to the left effects return on the amp & out of channel B on the SF-2 to the right effects return on the amp. So I have one channel for lows & one channel for highs. I currently have an Eden 4X10 I will use for highs, & am getting a 1X15 this week for the lows. So I don't have any SF-2 settings to pass on yet, but the stereo setup seems to work well with my amp. The rig sounds incredible just going into the 4X10 right now, I can't wait to hear it when I add the 1X15!

jbybj · « **Reply #26 on:** May 09, 2012, 09:29:51 AM »

Looks cool Rusty, now all you need to do is to get rid of that nasty graphic EQ. IMHO, phase coherency between the various combined signals, is where much of the magic lies in an SF-2. That graphic is just one big phase plooker.

David Houck · « **Reply #27 on:** May 09, 2012, 04:17:07 PM »

Here's how mine sits in the signal path ...

rustyg61 · « **Reply #28 on:** May 09, 2012, 04:43:54 PM »

Nice diagram Dave!

David Houck · « **Reply #29 on:** May 09, 2012, 04:47:44 PM »

Thanks! I thought it would be beyond my meager computer skillz, but it worked out ok and didn't take too terribly long.