MATRIXSYNTH: Search results for Harry Axten

Showing posts sorted by date for query Harry Axten. Sort by relevance Show all posts
Showing posts sorted by date for query Harry Axten. Sort by relevance Show all posts

Sunday, May 19, 2024

TR-909 Firmware Version 5 Demos

See this post for details.


// The most wonderful thing that could have ever happened for Roland TR-909 owners and lovers has actually happened.
2. TR-909 FIRMWARE V.5 - Demonstration 1 - MIDI SYNC CORRECTION
// I’ve installed one of the first Revolution 909 firmware upgrades from Addictive Instruments into my own personal Roland TR-909 and I released a little enthusiastic clip about how delighted I am to have 33 year old serious problems resolved. This is the first of a few posts planned for today to show you why it’s so amazing to me.
// This is something that I’ve been thinking about since 1991 when I first got my own TR-909: The ability to switch between pattern play and pattern write without having to stop the sequencer.

The TR-909 in pattern write mode allows us to do some clever things. We can change the length of the pattern using last step, and we can add and subtract notes and accents (internal and external) to develop our pattern. However, we can only do this in write mode.
So in order to do these things in performance we have to A ) stop, change modes, and start again B ) stay in write mode always (can’t change patterns in write mode) C ) program our drums from another device entirely D ) add all the chaos, and then use the level knobs to bring sounds in and out (the way maestro Jeff Mills makes magic!) or E ) make a ton of patterns ahead of time and switch between them as our performance.
We can do mutes on a mixer, use a midi controller. There are options, but when I’m playing live it’s just me. I have stuff happening. It’s a lot to navigate and keep track of. Changing mixer settings, dealing with midi controllers, or even flipping through preset patterns can be distracting and a bummer. Adding the ability to just get into write mode and change the length for a fill, or a sidetrack, or a totally new in the moment idea is fantastic!
4. TR-909 FIRMWARE VERSION 5- Demonstration 3 - MUTES
// This is something which I didn’t anticipate being so amazing. I use mutes on the mixer as a fundamental part of how I perform live, but I don’t tend to reach for instrument mute functions on the actual devices. This is not a personal bias, but rather a point of clarity. I’m doing like 25 things at once in any given performance (and singing) so it’s pretty easy to forget what I’ve muted or un muted unless it’s in central place (like on the mixer), but after all I just explored in demonstration clip 2 about ways to add and subtract sounds live, mutes are a marvelous and really powerful addition to this list of ways to address patten complexity in a live performance.
// Ok, this is really simple, but it’s so super extra totally bad ass.

The thing about the TR-909 is that it doesn’t instantly change patterns. You have to wait for the end, and then it starts the next selected pattern. To get around this you can do some stuff:
• make some really complicated patterns
• make one big complex pattern and then use the mixer to bring things in and out (fun!)
But this is fantastic! Just hold down shift and start instantly jumping between patterns. Add a crash from a crashy pattern, start a fill, and switch to just a kick drum, mix and match patterns and really get something heavy going - THEN get involved with the mixer, and it’s a gorgeous avalanche of TR-909 awesome!

In my example here I’m just showing you that it’s possible now. The rest is up to you.

Addictive Instruments have released firmware version 5 for the Roland TR-909 and the RE-909. It’s a real upgrade which requires soldering and while it isn’t easily reversible, the upgrade also includes firmware v1 and v4 so you can revert by choosing another firmware and booting it that way (no one would ever know).

Find out more at
This first batch is limited to 100 so if you’re as happy about this as I am, hurry up!
That said, I believe in these guys and totally hope that this all goes well, and this will continue to be available (and more!) until all the TR/RE-909’s have one inside.

This was demo 4, one more and I’ll leave the rest to you.
// I’ve been using the EXT INST function of the Roland TR-909 since the day I got it. I love triggering samples, basslines, and other drum machines from the stately TR-909’s main panel. The hassle has always been that the notes it generates can’t be changed. So you get an octave or so of fixed notes and that’s all. I’ve spent a lot of time messing with samplers and getting the sounds I want to trigger from the notes I have to offer, and while it’s fun, and useful, it can be a drag. Fact is, a lot of people never even explored it.

The TR-727 doesn’t allow us to control its midi notes either, but the Addictive Instruments firmware v.5 update has presets and it has a user mode (fig.2). So we can play any note we want on any channel we want at any velocity we want now.
My 727 is upgraded with Harry Axten‘s perfect sound rom upgrade, and this is my own custom rom, and here it is being beautifully programmed by my beloved TR-909!

This is an example of using the user template to create a chromatic keyboard and programming a bassline which is saved with my drums, and subject to all the new and original functions of the 909.
So much fun!

Clearly I was already in love with my TR-909, but I’ve fallen all over again here.

The external instrument mode is expanded, and it much more powerful now, it’s also nicely documented (at last) in the manual. It is more complicated than plug it in and go if you want to make the most of it, and it’s worth it. This is something wonderful.

Thursday, April 18, 2024

TR-707 with ROM Expansion and Cymbals Board

video upload by Harry Axten

"Realised I haven't done a video showing the current version of the TR-707 ROM Expansion modification - it now allows switching kits at any time while the machine is running, done by holding down the enter button and pressing one of the first 8 step buttons. This TR-707 also has the optional cymbals board installed, which allows the last two sounds (crash & ride cymbal) to change as well. More information here -"

Thursday, August 03, 2023

That one time that MXR made a Drum Machine

video upload by Alex Ball

"In 1983, effects giants MXR made a drum machine.

Huge thanks to Harry Axten for the loan.

0:00 Intro Jam
1:05 The MXR Drum Computer
1:37 Face Review
2:08 What is it +Harry Axten Midi
3:47 Demo 1: Know what I mean 'arry?
4:46 The tuning problem
6:04 Demo 2: Drum Computer
7:00 A later success
7:47 Sample Pack
8:27 Outro Jam"

Tuesday, June 20, 2023

MPC Electronics MPC-1 with Tubbutec uniPulse MIDI retrofit

video upload by Harry Axten

"Pretty rare British-made drum machine from 1981, originally intended to interface with the Sinclair ZX81 computer. I’ve installed Tubbutec’s excellent uniPulse MIDI retrofit in this, using the existing sync socket for the MIDI input. The drum voices are very responsive to playing dynamics, which I was pleased to find works great with the uniPulse’s velocity-sensitive outputs.

The sequencer board in this one was wrecked by a battery leak, which is sadly very common in these. The leakage also got onto the main analogue board, although fortunately not as badly. It ate up three of the potentiometers for the Tom 4 voice, and I haven't yet located suitable replacements, hence those controls being missing and blanked off; but everything else is now working as it should, having cleaned up corroded board traces and replaced a number of damaged components."

Saturday, March 25, 2023

Doobie Rhythmini FR-112 preset rhythm drum machine

video upload by Harry Axten

Note this is the first post to feature Doobie and the Rhythmini. If you know more about either, feel free to leave a comment at the bottom of this post.

"Thought I'd record a brief demo of what this somewhat rare machine sounds like prior to selling it - not that it's anything particularly special. It's based around the Sanyo LM8972, so will have the same patterns as every other rhythm machine that uses this IC.

Not much known about the company other than it was made in Japan, presumably in the late 1970s. Possibly related to the Newport Rhythm Sound, which looks visually similar."

Thursday, September 22, 2022

Korg KPR-77 MIDI Retrofit Kit

demo video upload by Harry Axten

"Updated version of my MIDI kit for the KPR-77. More info at"

Wednesday, March 31, 2021

E-mu E-drum demo

video by Harry Axten

"Couldn't resist pulling the trigger when I found one of these for sale online. It plays back 8-bit samples stored on cartridges, with velocity routed to amplitude and optionally pitch. Mine only came with the 'ROTOTOM1' cartridge, but I was able to scan in and copy the cartridge PCB to produce my own; which in this case have the TR-909 cymbals on them.

It's basically a rebadged Clavia unit, with a different paint job. I think the cartridges are also compatible with the original Clavia DDrum rack system (but not the later 'Sound Pac' ones)."

Monday, December 28, 2020

Sequential Circuits TOM 'Classics Cart'

Harry Axten

"Replacing my previous set of 3 mini cartridges for the TOM. This multi catridge has 8 banks, full of classic EPROM drum machine sounds, which are cycled through with the button. Housed in a proper case this time too! Coming soon."

Update: now available here:

Thursday, July 09, 2020

Roland TR-707 ROM Expansion Kit

Harry Axten

"Coming soon for the Roland TR-707 and TR-727..."


"You asked for it, now here it is – a ROM expansion kit for the Roland TR-707 and TR-727. It gives the machine 8 banks of sounds you can select, including the stock sounds from both the TR-707 and TR-727, so you can turn one into the other (to an extent – more on this later).

Changing between 8 banks would be a bit cumbersome using toggle switches, and I didn’t want to spoil the machine’s futuristic looks either, so this time the bank switching is done by holding down one of the first 8 step keys while turning the machine on. The setting is remembered and will be recalled the next time it’s turned on. There are no modifications to the outside of the machine, and the installation is easily reversible.

Apart from having different sounds, a modified TR-707 / TR-727 behaves exactly the same as a stock unit, no functions are lost. The machine should also be compatible with any other modifications or circuit bends you may have fitted, such as voice tuning, hi-hat decay mods etc.

I’d like to extend a huge thank you to Sunshine Jones, who donated the TR-727 which I used to develop the modification, and who also provided the excellent TR-808 and TR-909 samples which were used in the expansion banks.

The 8 banks included are :


TR-707 + TR-727 mix (handy for those who don’t own both machines)
The ROM expansion kit will switch out all of the sounds (referred to as a bank) apart from the last two sounds (crash + ride / quijada + chime), which will remain the same across banks, as they are stored on their own ROMs in a different part of the machine. I may produce an optional add-on board that can switch these as well if there’s sufficient interest."

Sunday, December 29, 2019

Crumar Bit One MIDI Upgrade demo

Published on Dec 29, 2019 Harry Axten

"This is a modification I developed for the Crumar Bit One, a fairly rare Italian-made polysynth from the mid 1980's, that improves its MIDI capability. The upgrade takes the form of a small daughterboard that installs neatly inside the synth. More information can be found at"

Sunday, July 21, 2019

HKA Design Digitizer Bitcrusher Pedal

Published on Jul 21, 2019 Harry Axten

"This is a digital sampling bitcrusher pedal I've been working on recently. It samples at 8/6/4 bit resolution and is based around an ATmega328P microcontroller.

The project is open hardware - all of the design files, code and construction details can be found on my website:"

Demo with the Sequential Prophet-6.

Tuesday, January 01, 2019

HKA Design Roland TR-626 ROM expansion

Published on Jan 1, 2019 dothkoi

"refer to the following pages"

Be sure to check out HKA Design's other DIY projects. HKA Design is run by Harry Axten whose work has been featured here on MATRIXSYNTH.

"My TR-505 ROM Expansion has proven itself to be a popular kit, but I was regularly asked if it would work with the TR-505’s big brother, the Roland TR-626. The answer was no, as even though the two machines look and sound quite similar, the electronics inside are incompatible. Eventually, somebody very generously offered to send me a TR-626 to keep if I could produce an expansion kit for it. Naturally I accepted.

Sample ROM address map / encoding

The TR-626, although it has more sounds than the TR-505, fundamentally works in exactly the same way. Samples are played back at 25.0 kHz, and once again some are stored in sequential order, while others are interleaved in pairs. Cymbals are stored in 8K blocks, with a byte being read from each block in cyclical order.

The TR-626 even uses a standard JEDEC-type ROM pinout for its sound ROM; unlike the 505’s which had a horrible custom pinout, requiring a complicated adapter board. The kit I designed for the TR-626 does still use a board, but this time it’s to allow for two ROM chips to be switched. The only real catch with the TR-626 sound ROM is that address lines 6 & 8 are swapped (in the data). It’s easy enough to swap them back using an EPROM pin swapper utility.

For the new sounds, I reused all of the classic sounds from my TR-505 version, although there’s also some TR-707 sounds in there as well, thanks to the TR-626’s larger ROM size. The new sounds are spread across two banks, with LM-1 and LinnDrum sounds in one, and DMX and TR-707 sounds in the other. There's also a socket to install the TR-626's original sound ROM, so you can keep using those sounds as well.

The TR-626 has several strange quirks. One is the way polyphony is assigned across the 8 drum voices. Despite the fact that some sounds share the same key, they don’t necessarily share the same voice. For this reason, some of the key assignments for my new sounds may seem a bit odd, but the reasoning is so that you can play certain sounds together - i.e. the LM-1 hi-hats and snare drum. A full list of the sounds can be found in the manual (see below). As the TR-626 lacks an individual output for claps, I duplicated these sounds into the china cymbal and cup memory locations, so they can come out of the crash / ride cymbal outputs."

See HKA Design for additional details.

Monday, May 28, 2018

Super modified Korg Monotron keyboard demo

Published on May 28, 2018 Harry Axten

"This synth was a work in progress from mid-2012 until last year when I finally got around to finishing it. It's based on a heavily modified Korg Monotron; giving it a full-size two octave keyboard with mod wheel, a sub-oscillator, a variable pulse wave and more. The digital side is running on Arduino code and supports MIDI, although that functionality isn't shown here. The case is laser-cut MDF with an aluminium panel and the keyboard mechanism was re-purposed from a dead M-Audio MIDI controller.

Photos, code and schematics can be found here:"

Sunday, May 13, 2018

Sequential Circuits TOM custom cartridges

Published on May 13, 2018 Harry Axten

"Showing off some sounds and famous patterns demo for these bare-bones cartridges for the Sequential Circuits TOM drum machine."

Sunday, August 28, 2016

Roland TR-505 ROM Expansion demo (new LM-1, DMX & LinnDrum kits)

Published on Aug 28, 2016 Harry Axten

"The latest version of my Roland TR-505 custom ROM project. Now uses a 512K EEPROM so it can store 4 kits, including the original stock sounds. Kits will be for sale shortly."

Sunday, July 24, 2016

KORG KPR-77 Retrofit MIDI Interface (work in progress)

Published on Jul 24, 2016 Harry Axten

"This is a project I'm currently working on. It adds MIDI to the KORG KPR-77 analogue drum machine from 1983. It installs internally; requiring no case mods to fit it, as it fits in the battery compartment and re-uses the DINSYNC connector for the MIDI input.

There are still things to be done, such as redesign the printed circuit board and add the final feature set to the firmware, but I aim to have a kit for sale this year."

Sunday, October 11, 2015

PAiA Fatman Analogue Synthesizer Demo [Keyboard Version]

Published on Oct 11, 2015 Harry Axten

"A quick demonstration of some of the sounds the PAiA Fatman synth can produce. Although I housed mine in a custom built keyboard, it's a vanilla unmodified kit. Recorded with no effects."

Monday, September 28, 2015

mCKENIC Linn DMX 505 rom

Published on Sep 28, 2015 mCKENIC

"Quick play after installing Harry Axten's WONDERFUL Linn/DMX rom for the Roland 505... makes the 505 a whole new beast :-)"

Sunday, August 16, 2015

Roland TR-505 EEPROM Adapter / New Sounds

Published on Aug 16, 2015 Harry Axten

"The PCBs for my EEPROM adapter finally arrived so here's a demo of the two new kits, based on the LinnDrum and Oberheim DMX. The board installs directly in place of the original sound ROM."

Saturday, August 01, 2015

Roland TR-505 modified with custom LinnDrum ROM

Published on Jul 19, 2015 Harry Axten

"A quick demo of what I've spent the last week or so tinkering with. I've gotten the fairly bland Roland TR-505 from 1986 playing back custom sounds from an EEPROM. I chose to use sounds from the LinnDrum, my favourite drum machine. Full writeup can be found at"

Patch n Tweak
Switched On Make Synthesizer Evolution Vintage Synthesizers Creating Sound Fundlementals of Synthesizer Programming Kraftwerk

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