dsPIC FPGA board

A new DIY FPGA project by Eric Brombaugh. Click here for full details.

"Potential applications include:
* Wavetable oscillators
* Field upgradable MCU firmware
* Flash-based FPGA configuration
* Voltage Controlled digital hardware
* Granular Synthesis
* etc"

FPGA 8 Voice 2 Operator FM MIDI Polysynth

"Description:
8vFM-2x4 is an 8 voice two operator FM MIDI polysynth. Each voice is comprised of 4 FM sound generators which can be individually tuned, configured and modulated.

The main reason I wanted to do this project was for bells and chimes. I had heard that FM is good for them. I had tried doing them with a linear arithmetic synth design (GateManPoly/8), but bells and chimes were lackluster in that synth."

You can find more details and samples at the FPGA Synth Wiki.

ARM FPGA Audio board

LINK
via Eric on the SDIY list:
"Basically it's a MIDI controlled 2-op FM synthesizer with an ADSR and a regenerative feedback delay. The ARM processor is responsible for configuring the FPGA and parsing the MIDI data into parameter settings for the synth design.

I've made a few audio samples to demonstrate some of the sounds. Find them here.

Descriptions:
fm.mp3 - this is playing around with the 2-op FM waveshaping. You can hear changes in the mod/carrier ratio as well as the mod index. Note the rather strong clicking as the mod/carrier ratio is changed, while sweeping the index is much smoother.

gong.mp3 - this is a high and low gong sound to illustrate the exponential release.

delay.mp3 - this is playing around with the regenerative delay / feedback feature.

Let me know what you think!

Eric"

ScottG FPGA MIDI Synthesizer Information and Source Files

http://home1.gte.net/res0658s/FPGA_synth/

Another FPGA project.

You'll find the following:
# Avnet Board PolyDaWG/8 Synth Details and Source
8 voice Polyphonic Karplus-Strong string physical model synth redesigned for the small Avnet Spartan-3A development board.

# GateMan I FPGA MIDI Monosynth
Linear Arithmetic Subtractive Monosynth, 4 NCOs with 4 waveforms each. This is the first version of the GateMan synths.

# GateMan II & GateMan III FPGA MIDI Monosynths
Linear Arithmetic Subtractive Monosynth, 4 NCOs with 4 waveforms each. GateMan II contains a state variable filter which replaces the simple IIR filter in GateMan I. GateMan III is also described, the major difference being better use of RAM and fewer flip flops in the design.

# Digital Waveguide Information
General digital waveguide information plus 8 voice Polyphonic Karplus-Strong string physical model synth for Spartan-3E Starter Kit development board

# GateManPoly
Linear Arithmetic Subtractive Polysynth (8 voice), 4 NCOs per voice, each NCO supports 4 waveforms.

# PolyDaWG8 on Spartan-3A DSP.html
Test port of PolyDaWG8 on Spartan-3A DSP 1800 Development Board.

# Xarp-56
Xarp-56 (pronounced 'harp fiftysix') is a 56 voice physical model using the Karplus-Strong string model. Each of the 56 strings is implemented as an individual digital waveguide and not multiplexed/reused as in the PolyDaWG synths.

ARM FPGA Audio board

"This is a development system for audio applications of FPGAs and Microcontrollers. It provides the following features:

* NXP LPC2144 ARM Microcontroller with 128kB Flash, 16kB SRAM, USB, 2 ADCs, DAC, etc.
o Pin-compatible with LPC2146/LPC2148 for more SRAM and Flash
* MicroSD Flash card socket for on-board program, FPGA bitstream and data table storage.
* Xilinx XC3S250EVQ100-4 FPGA with ~250kgate capacity, 12 multipliers, 216kb RAM and 66 I/O
o Pin-compatible with XC3S500EVQ100-4 or -5 for more gates, BRAM, multipliers and speed
* ISSI IS61WV25616 SRAM with 4Mb (256k x 16) and 10ns access time.
o Pin-compatible with IS61WV51216 8Mb (512k x 16) for 2x capacity.
* Cirrus Logic CS4270 stereo audio CODEC with up to 200kHz / 24-bit sampling.
* 24.576MHz Oscillator
o Optional VCXO and simple PLL for sychronization to external sources.
* USB 2.2 full-speed port in Mini-B format.
* MIDI physical interface.
* Hitachi-standard character LCD drive signals.
* Off board analog/digital expansion port with 8 MCU I/O.
o Up to 6x 10-bit ADC inputs.
o 1x 10-bit DAC output.
o Up to 8x GPIO (4 with pullups for switches / encoders)
o 2nd UART
o Up to 3 PWM
* One Digilent-compatible 6-pin peripheral module connector for direct FPGA interfacing.
* JTAG ports for MCU and FPGA development and debugging
* USB or external 5V power.
* SMA Clock In/Out
* Uncommitted FPGA testpoints

I envision this being used for development of unique digital synthesis systems based on a hybrid of 32-bit ARM MCU acting as a powerful command interpreter and realtime scheduler, along with the FPGA/SRAM/CODEC which combine to provide a powerful audio synthesis and effects engine.

Potential applications include:
* MIDI-controlled digital synthesis
* Delay effects (more than 5 seconds of storage at 48kHz)
* Real-time spectral analysis with Xilinx FFT cores
* AES/EBU and SP/DIF interfacing (via Digilent port and VCXO)
* Vocoders
* Granular Synthesis
* etc"

schematics and more at ARM FPGA Audio. Be sure to see the FPGA label below for other projects.

PolyDaWG/8 for Low Cost Avnet FPGA Development Board

"PolyDaWG/8 is an 8 voice polyphonic physical model synthesizer. It implements 8 Karplus-Strong string models in a harp that supports variable string length. String vibrational behavior is one dimensional due to RAM size limitations.

The source code provided here implements the PolyDaWG/8 synth on an inexpensive FPGA development board marketed by Avnet. This synth is functionally identical to the original version written for the Spartan-3E Starter Kit. The sound samples are from a Spartan-3E Starter Kit which has a 12 bit DAC. "

more info including samples here. vie this thread on electro-music.com where you will find more info as well. You can find more info on the FPGA Synth here.

FPGA Music Synthesizer

YouTube via lcircuit
"a 32 polyphony fm Synthesizer implemented on FPGA"

Digital Waveguide phLUTe

"This project is an FPGA based MIDI monophonic synthesizer implementing a digital waveguide physical model of an open ended cylindrical bore excited by a jet of air. The design is based on Perry Cook's slide-flute model. This model changes pitch by changing the length of the waveguides (making sure that the bore delay line is always twice the length of the jet delay line). The state machine to perform the functions required currently uses 14 clocks (50 MHz) and one for init. The output sample rate of the synth is 100 KHz."

click here for more info including samples on the FPGA Synth Wiki.

Inside the Alesis Micron

via Lyle: 

"Here’s a few pictures inside my Alesis Micron. I was expecting to find a Freescale(Motorola) or Analog Sharc DSP but instead I found these low cost Wavefront AL3101CG DSP’s. Nine of them to be exact, 8 for voices and 1 for effects. These are interfaced to a Freescale Coldfire micro via some FPGA glue logic. Some time ago Alesis sold semiconductors for audio and ADAT applications but has since ceased doing that. I wonder if Wavefront is the same group? Perhaps someone else knows."

If anyone knows more, feel free to comment.

Pochi Crafts DIY DKI Synergy

Remember the DKI Synergy? Title link takes you to Pochi Crafts' DIY Synergy page. Make sure to check out the rest of the site while there.

"SynclonOne is the DKI SYNERGY II+ compatible DIY digital synthesizer. SynclonOne main PCB is very small(140mm x 95mm), but it contains almost all SYNERGY II+ circuit, include Z80 CPU, 32 digital oscillators, panel scan processor, MIDI and serial interface port, DA converter interface. They are integrated into single Altera Cyclone FPGA chip on the SynclonOne PCB." [Previous posts on FPGA]

This one via Mikael.

Airbourne (Airböurne) AVS04 - Updated Info

Remember the AVS04? Click here for a post on sequencer.de with more info in German.

The following is the Google translated version:

"The second part of the Synths is now also available. Thus it has thus all 4 Voices and 8 filters as well as 8 envelope generators. Also those Noise generators, random CV and the Mehrphasen LFO is ready.

If it is enough to me, I will still adapt the Midiinterface that it also with two pressed keys correctly functions; -/Default-moderately that stands Interface for the moment on mono mode.

The wildest things are written over my VCF. BPF are and were never intended. At present the LPF with 12, 18 functions and 24 railways. I worked to the HPF for a long time and am not not to the goal come with my technology. I assume that the 80 bits Computational accuracy are not sufficient for a HPF. Around the project not still more to retard, I have at present only times the LPF built in that Hope, by reprogramming the filter modules medium-term also HPF realize to be able. I do not have a schedule in addition however.

The Midiinterface is not in the back and takes away from anybody place. The difference between the two Synthteilen AVS-04A and B is in that the right five columns:

CLICK FOR MORE »

FPGA - Martin Hollingers Airböurne AVS04A Synth

Another shot from the Swiss Synth Meeting. Check out this post on sequencer.de for more shots of this particular synth.

What's funny is not too long ago Moogulator of sequencer.de told me about how we were lucky in the US because of all the synth gatherings, and the images that come back from the events. Then we see stuff like this. : ) Hmm...

Update via sendling: "oh yes, and btw the rest is here."

Swiss Synth Meeting Pics

Pic from sequencer.de, from a synth gathering in Switzerland. FPGA modular pictured.

Update via Moogulator in the comments:
"it is completely new, made by martin hollinger.. it is not ready today, but almost closed.. check for "FPGA".. digital based tech, really cool in sound..

I will put a post up somewhere later, but there are ppl that can tell more on the forum.. but since it is very new and somewhat limited to synth geeks, he brought it .. we will do some more on it when it is ready .. some german words can be found in our synthesizer-magazin "dummy" zero-issue which is just an excerpt..

well, there will be more in the next months.. (aka s.o.o.n)"

Update via swissdoc in the comments:
"It is a voltage controlled synth, but the VCO and VCF are internally digitally created and based on FPGAs, so you have an oscillator or filter done in real hardware with very high precission and clock rate. All ins and outs are analog voltages, as well as the pots, but they are digitized at high rates and then used to controll the algorithms in the FPGAs. The envelopes are done in SW by a PICT, the VCAs are modern SSM chips compensated for temp drift. The patching is done with real pro cables, small they are, indeed. Front panel is from special multi-layer paper, not conductive.

It is a no compromise design, stable, no trimmers internally, well 2 for the whole synth.

I was impressed by the concept and the build quality for a DIY synth.

Well, Martin is a PRO, working on this kind of things on a daily basis in his professional life.

Georg."

FPGA Synth

Interesting project from Chris Strellis. I asked him what an FPGA was and he said the following:

"Field Programmable Gate Array - programmable logic. You write C like software that when compiled produces a binary file you load into the FPGA. The software describes what you want the output pins to do with given input pin signals. For instance with a clock signal going in - you could make 8 output pins go high in sequence according to your code and these outputs could drive LEDs and you'd have Knight Rider lights! Of course more complex things can me done. It is very different to DSP though. DSP can achieve the same things but it's more of an emulation. Programmable logic is the real deal :)"

Title link takes you to his page on the FPGA which includes more shots and some samples. It has a really nice tone to it. Thanks Chris!