Friday, 18 April 2014


Just found this pic that Belle made of me working on the Machinebeats :)

Sunday, 6 May 2012

New general synth stuff blog

As I've finished the Introspectiv 9090 (909 clone), the blog will not be updated any more. It's also about time I moved to a more general blog, as the latest posts are not related to the 909.

To continue following my company and my projects, check out A to Synth!

Tuesday, 3 April 2012

Decoding the PG-200

Just did something cool - I used a logic probe and decoded the PG-200 protocol :) I've identified the address of every switch, button and potmeter. However, since two of the rotary switch shafts on my PG-200 are loose, I have to get the multimeter out and do some measuring of the various position to verify that some of the logic measurements are correct.

So far I can tell the following about the PG-200 (partially from the service manual, partially from my research.

The manual says that the dataformat is asyncronous serial start-and-stop. The PG uses a 0 as a start bit and 1 as a stop bit (or stop period, as it runs untill a new start bit is encountered).

The data format is 9 data bits, no parity. The 8 first bits are address or data bits, the 9th selects either data or address. 1 is address, 0 is data.

Each potmeter sends two frames, one with the address and the second with the value
Switches are sent as three frames and are grouped as they only require 1 bit per state (or two for up to four states as is the case with the rotary switches). The first frame is the address of the group, the second is a bitmask saying which bits in the third frame to look at, the third frame is the state of all switches within that group.

From experimenting I've figured out the following:
The output from the PG is inverted, 0 is high and 1 is low
The bitrate is 31.5kb/s, which makes sense since the transfer line is connected to the same data RX line as the MIDI in (which of course is also 31.5kb/s

There are three switch groups, with addresses 1-3
There are 18 potmeters with addresses from 16 to 33

I will add the addresses and bits in groups for all controllers as soon as I have decoded the last rotary switches.

Sunday, 25 March 2012

Updated synths list

Time to adjust the synths list. Some new ones have entered the "has" list, some drop out of the want-list (I don't really need both the OB-Xa and the OB-8, or the Juno 6 AND 60) and a few new arrive.


Elka Synthex (new march 2012)
Oberheim matrix-12
Oberheim DMX (new march 2012)
Roland JP-8000 (got it, sept 2013)
Roland JD-800
Roland SH-101 (new march 2012)
Roland Juno-60
Roland sh-2
Roland vp-330
Linn drum
Moog memorymoog
Moog minimoog
Korg polysix
Korg ms-20
Korg DW-8000 (new march 2012)
Korg Wavestation (new march 2012)
Kawai K5000/K5000r (new january 2014)

E-mu SP-12 (new march 2012)
Technics SX-K100/200 (new october 2012)

Synths I now HAVE:
Oberheim OBXa (march 2012)
Clavia Nord Lead 2 (february 2012)
E-mu Emulator II+ HD
Roland JP-8000 (september 2013)
Roland Jupiter 8
Roland Juno 106
Roland JX-3P (march 2012)
Roland JX-8P
Roland D-50
Roland TR-808
Roland MC-303
Sequential Circuits Prophet 5
Sequential circuits Drumtraks (february 2012)
Yamaha DX7-IIs
Yamaha DX7-IID
Yamaha MU-10
Yamaha SY-77 (spring 2012)
Korg M1
Korg DS-10 (softsynth for Nintendo DS)
Korg Micro-Preset MP500
Korg mono/poly (march 2012)
Crumar BitOne
Moog Little Phatty Australian Redback Edition
Casio CT-101 (october 2012)
Casio MT-400
Casio VL-1 Lost :-(
Novation KS-Rack
Oakley Sound Systems TB-3031
Introspectiv 9090 (with custom sequencer/controller by me)
Technics SX-K250
Yusynth modular system (work in progress)
Xonik Devices M8 polyphonic modular (work in progress) (new january 2014)

Wednesday, 15 February 2012

Saturday, 4 February 2012

Circuit boards for modular

From now on I will probably not post much about the Machinebeats. Instead, I will post the progress of the modular. A lot has happened that has not been documented, but the current state is:

- most circuit boards have been populated
- 200 Dave Smith instruments Prophet'08 have been bought
- loads of different toggle switches have been bought
- I have decided which jack sockets to use
- Most pots have been bought

Right now I am working on the small circuit boards that will hold the pots and various front panel parts. Tonight the pots circuit boards, measuring 20 * 22 mm, are finished.

Saturday, 31 December 2011

BREAKING NEWS: Mad scientist finishes project after 7 years

Oslo, December 31st 2011

Eccentric engineer and inventor J. Tysseng announced today the completion of his long awaited project, the Machinebeats drum synthesizer.

"I'd almost lost hope that it would ever be finished" the exhausted project manager told, mere hours before the end of the year. "It's already one year late, as the engravings on the bottom says '2010', so it HAD to be completed today".

The drum machine, which is a clone of the classic Roland TR-909 synthesizer, is built on top of the circuit boards adapted by Trevor Page from the original Roland schematics. Putting it all together in such a small box, and designing everything from the control circuitry to the display and input system, as well as doing all the necessary programming, has proven way more time consuming than expected. Indeed, when asked in 2004 when the Machinebeats would be finished, the answer was "maybe next year". This became the standard answer for the next half a decade. "That just makes it even better to publicly announce that it will indeed NOT be next year after all!" says Joakim, before diving back into making cool grooves on his beat machine.

So what is the secret behind success in a project like this? "Dedication, curiosity, fun and most importantly, sticking with the plan" says the proud constructor. "Everything - aluminum panels, display window, the powder coated steel box etc - is based on an initial 3D drawing made way back in 2004. Without that detailed plan, getting everything to match up would have been a nightmare". And indeed, looking at the sketch today, it looks remarkably similar to the end result.

And what about the final cost, you may ask. Will taking this route be cheaper than buying the original, which with its price of more than NOK 10000 is out of reach for many a poor musician? "Unfortunately not", mr. Tysseng says, refusing to tell us the real total, "not even if you exclude the cost of the countless hours it has taken. It is more likely that you could buy at least two of the original for the price of this one. But where's the fun in that?"

As his biggest project so far has finally reached its end, what will the DIY artist do in the future? "Oh, it's not like I will have any problems filling my spare time. I have at least two new projects going on, and an even bigger one in the planning stages" he replies, blinking.

With this in mind we leave the inventor, and will certainly keep our eyes open for cool new stuff from the amazing little lab in the small house on top of the bigger house.