I've been taking a break from analogue circuits to investigate the world of DSP using an ESP32 microcontroller and the Faust DSP librares. This has been quite an adventure involving building my first dedicated Linux computer with PlatformIO running in Microsoft VS Code. So far I've got it running three sawtooth oscillators, a noise source, triangle LFO, amplitude and pitch envelopes and a simulated Moog resonant filter. The I2S interface produces impressive 24-bit sound quality at 48kHz sampling rate. Unfortunately the Faust delays and reverbs seem to make the processor brown out and it goes into a reboot cycle. More work required. Or possibly just a lot more memory. That couldn't hurt. The crackling noises are due to having the record level turned up too far rather than any problem with the synth.
Well, we're all confined to our homes while the COVID menace stalks the streets so here's a good old blast of insanely resonating modular synth with some 808 drums from Native Instruments Battery.
What to do, what to do. I just can't decide.
I know. I'll make strage noises on the modular.
Yes, it's another new (old) guitar. This one has been a "Holy Grail" guitar for me for a long time. I used one back in the 1990s in a studio in Newcastle and I always remembered it being a great guitar. Turns out they were built for Casio in the Japanese Fuji-gen Gakki plant that made the Japanese Fenders of the 1980s and the neck contour is exactly the same as my E-series MIJ Stratocaster.
Unfortunately, someone's done amateur repairs to this and soldered it up with jam and a hot spoon so the MIDI circuit is dead as a doornail and not coming back. No matter, I may even retrofit a Roland GK kit into this and have the world's coolest 90s tech guitar.
I stumbled across a video demo of a clone of the Buchla LPG on Youtube and was phenomenally impressed. So much so that I knew I had to build one. It's an ancient type of filter using Vactrols, a combination of an LED and a light-dependent resistor to effect a frequency response change. And it sounds wonderful.
The first PCBs aren't quite right, I managed to omit the two voltage tracks to the ICs so this first version is patched up with a couple of bodge wires to make it work. Only smoked one opamp making it, a new record.
Just arrived this week, an eBay special. The Novation Supernova has always been on my list of interesting virtual analogue synths so when I was looking for a Roland JP8080 and this popped up instead I didn't hesitate.
And it sounds bloody great. Absolutely pisses on the old MS2000, the filters sound really good (for digital filters that is) and it's got a really nasty clanky edge to it. Not figured out the arpeggiators yet but I've managed to get the LFO to sync to MIDI clock already. So that's good. And it would appear to be eight-part multitimbral. So I can can eight different programs playing in each performance patch. All with their own arpeggiator. No built-in sequencer but I never use those anyway. Brilliant piece of kit. genuinely dirty-sounding filter which reacts in a pleasantly surprising way as you crank the cutoff up.
To assist in my electronic endeavours I have treated myself to the very wonderful Rigol DS1054Z digital storage oscilloscope and BLIMEY, it is good. This machine does everything from FFT analysis to SPI bus decoding in realtime (almost). It's a four-channel scope, brilliant for watching the channels of something like an SPI or I2C bus.
So naturally the first thing I'd want to connect up was my modular synth. Here's the MakeNoise DPO oscillator outputs running in hard sync mode. FFT shows the harmonics and already I can see that I need to turn up the sweep extent trimpots for the pulse width modulation on two of my other oscillators.
The scope has LAN connectivity, PNG waveform saving to USB memory stick, hundreds of features you might normally expect to pay twice the asking price for.
And by illicitly googling "RIGLOL" you can find a page that lets you enable the paid performances for free.
Not that I condone such behaviour.
I've had endless problems trying to get an M-Audio MIDISport 4x4 interface working under Windows. Half a day of googling, driver updates, registry edits, reboots and nothing was working but there was a clue in a post from (of all people) Microsoft tech support. Apparently some MIDI interfaces don't like the identifier requests sent out by USB 3.0 hubs. The solution? Use a USB 2.0 hub. Simple as that. Works first time. Posting this so the internet can share in the secret.
This is an interesting Fender oddity, a Mexican Stratocaster body with a USA made neck and incorporating Roland's GK hex pickup to drive guitar synths and processors like the GP-10 or the VG-99.
The GC-1 had a fairly short production run in the early 2000s and is out of production now, probably due to the apparent reluctance of guitar players to fully embrace hex pickup technology. This is a pity as it is capable of stunning effects that can't be achieved on any other guitar such as baritone guitar, 12-string simulation and programmable pitch shift per string which allows for alternate tunings at the press of a button. The GP-10 also lets you do string bends from a footpedal, creating impossible multi-string bends and pedal steel effects.
Here's the GP-10 and GC-1 doing some of that stuff. First off, the GP-10 is set to play an open E minor chord and the expression pedal bends strings up and down to make an open A minor chord. Hit a few harmonics and the thing warbles into a sound vaguely reminiscent of a pedal steel but with a far more modern edge to it.
It does straight tuning transpose too, here's a baritone guitar effect.
And it's handy for recording demos if you can't be bothered to pull more than one guitar off the stand. This is the GC-1 standard magnetic pickups mixed with the modelled sounds to provide electric, acoustic and 12-string sounds as well as an open G slide part.
Currently on the production line is another kit from Rick Holt at Frequency Central. This one is the fabulous Meth Amp, effectively a clone of the EHX Big Muff in Eurorack format for those insanely distorted TB-303 squelches. Should be ready within a week if the Alpha pots arrive soon.