Electri-fire's Site | effects, circuitbent stuff,schematics, sounds

Yamaha VSS-200

www.fancygens.com

Bending report in progress. This page is likely of use to VSS-30 benders as well.

The first impressions:

The SK-1 is more mellow, turning both internal sounds and samples into dense washes of ambient soundscapes. The unbent VSS can be sweet sounding and expressive. Best results will yield the effects, electronic and percussive sounds. The static waveforms are a bore to sample. I've found myself absorbed in playing "from samplebank" samples and at the moment I prefer using REVERSE over the U-TURN function as it gives direct control and similar results.

Your sample, when bent, will become a grating rasping noise fest, very upfront and suited for the darkest rock, dance, hiphop, or industrial styles.

Compared to the sk-1 it is relatively crashfree. That's a joy in itself, but....

ISSUES I've encountered....

Using looplenghth, U-turn and reverse combined with held or momentary bends is fun and inspiring , but mostly when used standalone without a fixed metrum to maintain.

Fixed chrystal clock frequency, so no pitchbend. So no tweaking to keep your rythmic samples in line.

All held sample loops will eventually drift out of timing, even with more sophisticated samplers. While this feature has been put to good use with other samplers, with the VSS it´s just not funny anymore. Restarting the sample often is inevitable.

I tried to find work arounds as the VSS imposes it's own peculiar twists.

Sampling an 8 beat loop as I did first doesn't work.

The looplenght is adjustable in ten equal devisions.

Sample LOOP settings are always the same length. With a short sample the VSS will insert silence.

As can bee seen in this Cubase screenshot, looping a single sound is easy. Here I sampled the Marimba sound.

Looping a PHRASE or BEAT chops the sample in these same lenghts regardless of tempo.

I figured if we fill the whole sample memory with EXACTLY a TEN BEAT loop we could make sensible devisions with the LOOP option.

I tried to find the ideal BPM for filling the entire loop memory with one loop.

It is close to 156 BPM , but "close" won't do. Needs working on. With a "proper" sequencer. Too much hassle maybe...

to do:

1 - find out BPM of all tempo settings.

2 - find key / BPM converter or table. example: play C = xx BPM, play C# = ?? BPM. You know? Anyone?

Setting up after sampling

I tend to need some time to set up the sample for use, mostly setting release time and LOOP. This phase is left in the recordings below.

First quick recordings (some with internal drums). Recorded, truncated and compressed in Wavelab. No further edits. I hadn't noticed the timing issues yet. To be updated.

12345

just a bit of sample mangling

another electri-fire sample

and one more

sampled from voicebank: sound 55 marimba.

How to circuitbend the VSS (Aarghh... another of these pretentious electri-fire tutorials. Well...)

The basic bends are at the sample memory. The Sample Memory chip is located above a large chip left to the square CPU.

Some points alter the sample temporarily. Most usefull. Below these are aqua coulored. Combined In/out/Adress pins I guess.

The yellow point inserts the bent sound into the sample and then you can bend that some more. Write enable pin?

The red point always turns the sample into the same harsh noise, making it impossible to return to your previous sounds. Makes any effort into sample recording utterly useless. I suppose his must be the "refresh" pin.

Ground (any ground point or lower left pin) can also be used. I didn't initially, but works fine.

Positive voltage (upper right pin) is best avoided. Crashing and frying danger.

So that's a total of 12 or 13 points for your "basic" bent VSS.

Sample destructive

Using the RAS pin instantly turns my sample into noise.

Yellow, Write Control pin. Can insert noise or bent sounds. But other (multiple) pin combinations also alter sample content, but less often and in a less pedictable way.

So the VSS will surprise you, and self limits the length of your improvisations, often a good thing. After a couple of minutes of frantic playing the sample may be an unregognisable mess. Time for a new start.

Sample altering pins (Write Control and RAS) still connected here. Doesn't look that neat anymore after some resoldering and solder flux smearing the "permanent" markers, does it?

Bending the FM chip

I didn't bend the internal sounds and rhytms yet. I wasn't even sure it did FM. After relentless "Googling" I finally found this entry at OXO-Unlimited, a Sweden based electronic music and arts collective.

There's a link to a compatible FM chip datasheet, here for dead link prevention.

(Still a dead link? Leave a message at the comments, I've saved a backup)

A great FM chip tutorial by Kevin Rees here. For the Yamha pss-270, but works on several FM keyboards like vss-200.

The chip is left of the leftmost connector, near the keys. The data lines can be used for bending the internal sounds.

No trace cutting needed

The VSS-200 has two jumpers for each Data line that connect the FM chip to the CPU.

The best place for a bend is at the lower right corner (opposite the keys).

The jumpers are neatly lined up at the edge of the board, with plenty of space nearby for the switches.

sing FM bends means WRITING settings into the chip's REGISTER. These settings are written each time a preset sound is selected. So you need to select a sound while HOLDING your bends.

Possible strategies

Preset mixing:

1 - Select a preset

2 - switch off your choise of data lines

3 - Select another preset

The settings of the interrupted data lines are kept, the others are overwritten by the settings of the next preset.

RANDOM PATCHER

1 - Connect one or more data lines to some random signal source, digital signals preferrably.

2 - Select a preset

TARGET PARAMETERS (well, sort of...)

Each data line sends data to several functions. As can be seen in the data sheet each data line has it's own group of functions. (tables at page 4 and 5 of the pdf)

example:

D0 targets MULTI , T L (whatever it may be) , FeedBack, Decay, Release, HiHat on/off, Octave and Volume

It is way over my head to target each function seperately. But knowing drum sounds are switched on/off at line D0, D1,D2,D3,D4 and D5 could be fun.

ERROR WARNING , NEXT SECTION UNFINISHED

My VSS200 doesn't completely turn down the volume of the auto bass chord drums. Knowing where the chips output the sounds may come in handy.

First components in the FM lines are 2.2K resistors shunting part of the output to ground. Can they be removed for more volume?

Then through 10K . Maybe replace them with pots for volume?

Next the signal splits two ways. Up through 4700p capacitors to the same pad, this goes down again and connects to ground through a jumper. High off filters. Remove/ replace?

On the other side through 0.1m capacitors. , 22k resistors , Rhytm down > 220k , 47K to chip below pin 8.

Main down 120k, 47k > split to sample in and mixer opamp. near mixer tru 47K split to 47K, ......

Too much filtering and volume pot options. I havn't decided yet.

IVORY: FM synth sounds

RED: FM rhytm sounds

AQUA: Sampler output

to do: replace pic . finish text

END OF UNFINISHED SUBJECT.

Connector to Breakout Box

I connected these points to a DB25 port. As USB makes these near obsolete, ports and cables can be found for next to nothing or free quit easily. As usual I cover all connections with a hefty amount of hotglue.

the "Random" Note glitch

Momentarily shorting a pin at the square CPU crashed the CPU. It restarted instantly with a random waveform. But locks the keyboard, needs a hard reset.

obsolete.

Turned out to be an FM chip pin, (insert pin number) and quickly touching one of the sample memory pins yields more usable bends. Not always completely crashed so it keeps playable.

Warning ! Random volume also, first turn down or use compressor!

Preamp in doesn't really preamp. It's a good input for using memory chip pin signals as audio.

Best interface: Momentary switch matrix. Connect your bends to one side of normaly open momentary switches. Connect the other side of the switches all together. Now by pressing two or more switches any combination or multiple connections can be made very fast.

Pathbays as seen here : http://circuitbenders.co.uk/VSS.html , however inspiring it was to find a VSS in the first place, do not bring the out the best properties as a live instrument.

I connected a DB25 port to use with one of my Breakout boxes to have a choise of options.

Recordings at this page were made with this:

(insert 16x breakout box pic )

Some more circuitboard pics to document your own bends, and for reference.

The VSS200 circuitboard in it's entire wide glory. If it doesn't fit your screen, download so you can scroll.