Clean Bitcrusher

[kugelspot]

OK, so I need a pedal to get chiptune/8 bit synth sounds. Relatively clean ones, NES type stuff (like the mario theme or Legend of Zelda theme). The DE Bit and the HEXE Bitcrusher can't seem to clean up enough, at least from the demos I've seen. The only pedal I can find that can do that is the WMD Geiger Counter, which is too expensive (plus, I already have one. I just want a stand alone pedal to free up the Geiger for other stuff). I don't want to spend more than $120 (I'll go to $150 if I absolutely have to). Alternatively, can anyone find me a schematic for building such a pedal?

[Taylor Livingston]

These are all different circuits. The Bit is a type of fuzz, not a bit crusher. The HEXE and Geiger Counter are both digital, so a schem isn't going to do you any good, you'd need the code, and you're not going to get it without writing it yourself.

There are 2 distinct effects that people commonly call bit crushers: real bit crushing, which must always be digital, and sample rate reduction, which can be analog. Real bit crushing sounds like a type of distortion. SRR sounds more like a ring modulator with a square wave carrier (in fact, that's what most "sample rate reducer" pedals actually are).

There are some important components of the NES sound besides bit reduction and sample rate reduction: using a sawtooth or narrow pulse waveform, and the performance characteristics that make chiptune compositions so distinctive - fast arpeggios, portamento, and really fast vibratos. Since you're getting more serious about the sound, you'll need to figure out which of these characteristics you need to achieve the sound you're looking for, before you can figure out the ideal solution.

Here's a true digital bit crusher schematic that requires no programming:

http://experimentalistsanonymous.com...tal%20fuzz.bmp

Here's a waveshaper that turns your signal into a pulse wave with variable duty cycle:

http://experimentalistsanonymous.com...makers/PWM.gif

and here's an analog sample rate reducer (PDF with schem and PCB layout linked on right of page):

http://sites.google.com/site/electro...aliaserproject

[bigchiefbc]

Conical pretty much covered it.

For an analog sample rate reducer in your price range, check out the Copilot Antenna.

For another digital bitcrusher that is in your price range, I ran an Alesis Bitrman for a while. The downside with that one is that it takes 9VAC power, and its bypass switch is a plastic button that makes some people uncomfortable (even though I hit it with my foot hundreds of times and it was fine)

[UncleFluffy]

Originally Posted by conical johnson

Here's a true digital bit crusher schematic that requires no programming:

http://experimentalistsanonymous.com...tal%20fuzz.bmp

Not sure that's quite right. Looks like the switches that set the quantisation level are back-to-front. The way it's drawn has the ADC outputs shorted to ground and the DAC inputs floating.

[gnasher1993]

Originally Posted by conical johnson

here's an analog sample rate reducer (PDF with schem and PCB layout linked on right of page):

http://sites.google.com/site/electro...aliaserproject

That's looks pretty cool! Haven't seen that one before.

Hmm...

[Taylor Livingston]

Originally Posted by UncleFluffy

Not sure that's quite right. Looks like the switches that set the quantisation level are back-to-front. The way it's drawn has the ADC outputs shorted to ground and the DAC inputs floating.

By back to front do you mean the MSB being connected to the LSB? I haven't built the circuit there, but I know some people have. The chips are obsolete, but newer A/D chips don't have the bits on separate pins so messing with quantization requires more hardware and programming.

[Gashaponcito]

The bitcrusher of the champs

[UncleFluffy]

Originally Posted by conical johnson

By back to front do you mean the MSB being connected to the LSB? I haven't built the circuit there, but I know some people have. The chips are obsolete, but newer A/D chips don't have the bits on separate pins so messing with quantization requires more hardware and programming.

Take pin 18 of the ADC for example. It goes into the centre of the switch and can be either connected to pin 12 of the DAC or shorted to ground, leaving DAC pin 12 floating.

Surely it should be DAC pin 12 connected to the switch centre?

If the DAC has pull-down resistors on its inputs it would still work (but then no need for a 2-way switch), but the lifetime of the ADC might be affected.

[Taylor Livingston]

Originally Posted by Gashaponcito

The bitcrusher of the champs

Yep, this is actually a sample rate reducer, not a bit crusher as the name suggests.

Originally Posted by UncleFluffy

Take pin 18 of the ADC for example. It goes into the centre of the switch and can be either connected to pin 12 of the DAC or shorted to ground, leaving DAC pin 12 floating.

Surely it should be DAC pin 12 connected to the switch centre?

If the DAC has pull-down resistors on its inputs it would still work (but then no need for a 2-way switch), but the lifetime of the ADC might be affected.

Yeah, you might be right - I'm fairly certain it works as drawn, but there is some possibility of killing the chips or having erratic behavior with pins left floating. I suspect that these aren't big concerns for most people building it as it's a noise toy.

[kevteop]

I managed to pick up a Bugcrusher at basschat.co.uk this week, took it to rehearsal tonight. Awesome.

When I tried it at home I wasn't sure it would be much use to me, but I experimented more and understood it better and got some better sounds out of it, but I really didn't appreciate what an effective pedal it is until tonight.

If that's the circuit, build one! It does sounds from pitch-dependent vibrato to detuning to in-key ring mod "bell" tones, and adding that computer lo-res vibe to sounds, it's especially effective for this on a bass with few harmonics (my Jazz with flats) or similar sounds (my OC-2).

Ace pedal. Instant keeper.

[kevteop]

I did a few clips today because someone asked for them and it's hard to find examples of this sort of effect on bass, so I thought I'd share them here too.

They were recorded with my Squier Jazz strung with LaBella flats and direct into my soundcard (post-effects obviously!). There are no effects other than those stated, no compression or EQ or anything else.

Each clip starts "clean", then the Bugcrusher goes to 25%, 50%, 75% and 100%.

Clean bass, front pup soloed, tone up -> Bugcrusher

OC-2 with the -1 Oct voice soloed -> Bugcrusher

A fairly heavy fuzz setting from my Chunk OS -> Bugcrusher

A low-pass filtered gated fuzz patch from my Chunk OS -> Bugcrusher

[Gashaponcito]

Originally Posted by kevteop

I did a few clips today because someone asked for them and it's hard to find examples of this sort of effect on bass, so I thought I'd share them here too.

I heard half of the first clip and I was already wanting to buy one! awesome clips I don't know why Bugbrand doesn't make more of this =(

question: which version do you have?

[kevteop]

Originally Posted by Gashaponcito

I heard half of the first clip and I was already wanting to buy one! awesome clips I don't know why Bugbrand doesn't make more of this =(

question: which version do you have?

Mine's the single-knobbed Micro, aka the John Davis signature.

[Albibass]

Just ordered the Hexe Bitcrusher III.
That's the upgraded version of the Bitcrusher II someone on the forum bought.
Talked with the builder a bit and he said that more then half of the Bitcrusher-buyers are bassists.
That's why he tailored his third version more towards bass frequencies.
Hence the input-gain switch for active basses.
It's also 12-bit instead of the usual 8 to make it a bit more usable.
Should arrive end of upcoming week.

[JohnDavisNYC]

got my signature model? nice....

i should make a signature pedal. i guess it would just be a beat up old OC2 with some tape on it, though. boss wouldn't be too excited about that, i don't think.

that hexe thing looks pretty badass.

john

[JohnDavisNYC]

by the way, the clips with the bugcrusher post OS are awesome...

totally squarepusher, circa 'selection sixteen' with that kinda vocal formant filter sound...

john

[Albibass]

Originally Posted by JohnDavisNYC

got my signature model? nice....

Do you mean a bitcrusher?

[AleemRadunzel]

ch-ch-check out the Boss VF1 The alesis bitrman and the "civilan" equivalent, the alesis Bass mutlieffect.. the latter is what i use, its got has 9 presets of prgressively more crushed and the same with the downsampling (refered to within as decimating) an expression out put to go from clean to crushed..

tried it with my bass - no bass loss untill the last two patches. do i care . no i split signal
tried it with the microkorg, same.
tried it with drums

OMG no bad for 40 quid the xpression controlled ring mod is good too .. very mould spore..

[Higgie]

Originally Posted by Gashaponcito

The bitcrusher of the champs

AWESOME! After hearing kevteop's clips earlier today I have been searching high and low for this pedal. Is this an official schem of the Bugbrand Bitcrusher Micro? If so, I could kiss you.

[Gashaponcito]

Originally Posted by Higgie

AWESOME! After hearing kevteop's clips earlier today I have been searching high and low for this pedal. Is this an official schem of the Bugbrand Bitcrusher Micro? If so, I could kiss you.

its not official but Tom (from bugbrand) corrected some values of a previous version of the schem check this out:

http://experimentalistsanonymous.com...hp?topic=794.0