Oberheim Matrix 1000 EPROM chip, operating system version 1.16. The last official version released by Oberheim was 1.11; this version corrects some MIDI SysEx control issues that Oberheim overlooked, such as a really slow response to filter cutoff frequency settings. This replaces chip U804 on the main board (it is socketed, so no soldering is required). Took about 30min. – Bug fixes made by Nordcore. – MIDI NRPN parameters editing fix. – Faster processing of parameter changes that need a modulation matrix rebuild, there’s still a small lag but it’s…read more
This one was suffering from juno cancer on one voice. Uncoating the 80017 chip did partially not work (no resonance). Put a replacement chip on a socket and recalibrated all of the 6 voices. Took 2-3h For the chorus there was used a test-point on the board as input and a new pot was installed for chorus speed. Very useful! 1-2h
Recapped power supply and old tantalum caps. Nice stereo expander!
Those great sounding 70’s preamps from the former GDR broadcasting with discrete design and transformers were found on a local fleamarket. Now they needed recycled wooden housings (dia boxes) powersupplies und XLR inputs/outputs. Not the most versatile preamp (no low cut,48V) but perfect for dynamic mics. Really pleased with the coloured tone and the huge amplification of 70dB!! V740 schematic:
Modified this little beast of distortion with some new clipping diodes that change the pedal into the Turbo Rat. You can select the stock diodes or disable the whole clipping. 3pedals in one!!! The filter circuit was enhanced by the Ruetz poti that changes the tonal quality a lot. Duration: 1.5h
Duration 2h for Mod: 100€ + postage (german clients +19% tax) Fairly simple modification to my favourite chorus device. Its possible to use the depth of the vibrato section for the chorus as well now (or switch it back to original). I can perform this mod for your pedal as well! Please contact me here: www.jacobkorn.de/contact The sound is a dx7 string patch btw. Input impedance mod: Replace the 50k volume pot with a 500k log and for R11 ( 470k) 1M in parallel (=319k). Duration: 2h
Replaced the internal sound eproms of the cheesy sounding machine from 1987. The new roms include 2*48 sounds of Classic drummachines like TR-707, TR-727, 909, Linndrum, DMX, RZ-1 etc. Still needs the overall pitch adjustment mod. Thanks to Alex Erlewein for burning the eproms and the help! more info here: http://www.burnkit2600.com/hr-16/ http://www.vintagesynth.com/misc/hr16.php