::: Sequential Circuits Max Firmware Upgrade :::

It's a tech kind of weekend! A while back I met a guy named Bob Grieb on the sequential circuits yahoo group who was working on a firmware and memory upgrade for the Sequential Circuits Max.  I am a huge fan of the SCI Multitrak as posted here and the Max is basically the same synth in a smaller package with less programming capability ( no editing grid on the faceplate ), performance features ( arpeggiator and wheels ), and an even less colorful color scheme! ( I'll have one totally 80's football font on grey sparkle please!!! )

As soon as Bob had kits available i had him ship me a set so i could do some tech work on the weekend.  It consisted of a PCB, a new larger ram chip, an eprom with updated OS features, some chip sockets, and a few diodes, resistors, caps, and wires to assemble.  He posted instructions on his site to assist in the process as well.  Its not too complicated but there's several steps that are pretty hard if you are not comfy soldering multi pin chips.

1, First i needed to remove the 2 old non writable ram chips from the mother board.  Thats right, the original OS didn't allow you to rewrite the basic patches, although they could be edited via midi and were remembered while the unit had power.  The same went for the sequence memory: lost at power down.  This was the hardest part of the process.  The memory chips are right next to the CPU and had a very tight space between them for desoldering.  I chose to use a liberal amount of solder wick to pull the solder from the joints.  it took a while but finally the two chips literally fell out without damaging the board!

2, I then assembled the new PCB.  Theres a socket for the new ram and the new OS eprom as well as a set of pins on the bottom that sit in the old eprom socket.  I then added the other components to the board and checked to see if it fit into the socket on the mother board without touching anything.  It looked good and i actually attached a small bit of foam to the bottom of the PCB to relieve the weight of the whole assembly resting on the eprom socket.

3, after attaching the 5 wires for os, ram addressing, and power to the new PCB i was ready to start the Max up!  That wasn't too bad once i got past the chip removal!

At startup the max loads it's basic patches and default sequences from the new ram location on the new chip. Then it goes through the voice tuning routine as it always would.  Pretty smooth actually!

I also did a few other maintenance things while i was inside the max:

1, I gave it a thorough cleaning.  30 years can leave a lot of dust!  I also noticed that the metal supports for the mother board were totally untreated metal and they were corroding.  They were covered in a fine dust of rust and it was gross.  So i scrubbed them in the sink and let the whole bottom plate dry in the sun for a while.  I then used a can of Rust-Oleum clear enamel to coat them.  This will hopefully help keep them from corroding more in the future.

2  I also removed and cleaned the small red window that covers the led display.  I re-taped it on all four sides so it will keep dust out more effectively and look better.

So, the Tauntek SCI Max firmware upgrade adds many features.  Here's a list of them:

1) 100 downloadable programs (Max had 20 that could be downloaded)

2) Storage for ~3200 notes in two songs (Max could store about 500)

3) Unison mode (Max did not support Unison mode)

4) Battery-backed storage of downloadable programs and songs

5) MIDI chan and a few other parameters are also non-volatile

6) Three sets of programs in EPROM, loadable on request:

a) Max orig 80 programs plus Six Trak Unison programs

b) Six Trak orig 100 programs

c) Multitrak orig 100 programs, without chorus and velocity sens parameters

7) Current voice parameters, including any CC changes, can be stored in program #99

8) Program #99 can be copied to any other program.

9) MIDI receive buffer increased from 64 bytes to 128 bytes



Pretty RAD!


::: Hit Designs Dynamic Equalizer :::

Today i have a tech post.  A special one at that! I found this piece of gear in a surplus sale a few years back and i have never seen another.  Its a really special device as few of these types of designs exist in the analog world.

The Hit Designs Dynamic Equalizer is a multi band dynamic equalizer and Limiter.  Each of the 10 bands has a VCA expander and limiter for the left and right channel.  The gain and limit threshold for each band is controlled on the front panel controls to the right.  On the left you can control the input / output gain and look at a real time analysis of the audio spectrum.  Pretty amazing really.

After using this unit for a while I felt like a recap could really help bring the noise floor down a bit and match the response of the left right channels better.  Since i was unable to find the original manufacturer or a schematic i took many pictures so i could double check my capacitor orientation and values.  One stop at Mouser got me the many caps i would need.

And it was a lot!


::: IF :::

::: Roland Jupiter 6 Europa Replacement Power Switch :::

The title says it all!  So i went to turn the JP6E on the other day and i got nothing.  After freaking out and thinking i must be doing something extremely stupid for a few minutes, i decided to get out the volt meter.  To my surprize, the power switch on the JP6E was not working.  How often does that happen>?  Well, At least they are findable on the web thanks to Doug @ Synthparts! And this synth is so well designed you don't even need to heat up the soldering gun to do this work!



Sometimes i need an easy fix so i can get back to the MUSIC!

::: IF :::

::: Roland Filter Comparisons :::

So, there's a lot of confusion around what classic Rolands sound like other Rolands.  And on keeping with my previous post on The History of Roland I figured i would put a concise thread together. First there is a master chart:


There's also a short cheat sheet jpeg for the big boys of Roland fame borrowed from here::


So, in my experience the Jupiter 6 and MKS 80 are very similar in sound ( i've used an MKS80 rev 4 ).  not particularly 'deep' but capable and very useful.

But the Jupiter 8 sounds DEEP.  Like DISCRETE transistor DEEP.  It's beautiful sounding no matter how ugly a sound you make.

This is something the Juno 60 can do too in it's own way. Tight Big Clear Fast.  But it's oscillators aren't as big feeling and they are DCO so they don't drift in any real musical way.

The JX 8P / MKS 70 / JX 10 are in a separate category all together.  They are a bit grungier in sound and vibe and you sometimes have to work harder to get them to sing but it is in there.  It's just not obvious at first or easy to squeak out.

The Juno family is split into two groups.  The Juno 6 and 60 are almost identical.  The Juno 106 / Alpha / and MKS 50 are thinner and less deep than the jupiter 6 and 8.  The Juno 106 kicks ass above the others in this class though because it has all the tactile control and good MIDI implementation ( MKS70/MKS80 have decent implementation, the Jupiter 6 has barely any and the Jupiter 8 had none! )

So, you pick your battles with old hardware i guess.  I happen to love the JP6 Europa because it's more MIDI slick than a Juno 106 and sounds way better.  Plus you can do great interfacing with it!  For instance, you can trigger the arpeggiator from an external analog source and the Europa JP6 will transmit the arpeggios created via MIDI.  this is really fun for creating bass lines and other bouncy 80's bits on multiple instruments rhythmically generated from an 808 for instance...

food for thought...

::: IF :::

::: Synth Pron of the Day :::

In Line with the David Frank interview i posted last week.  Here's Steve Roach's setup from 1987...

OBERHEIM SYSTEM!!!! ( LOL 2 Xpanders!!!! )

and an E-Max...

and an SQ80...

...Steve Roach Setup


borrowed from this flicker stream...


::: David Frank interview from 1986 :::

I Stumbled upon this posted on gearsluts.  Its a great interview with David Frank from 1986! Synths of interest:

Yamaha TX-416

Yamaha DX-1

Moog Minimoog

Emu Emulator

Oberheim Matrix-12



01 david frank keymag1-2002 02 david frank keymag pg 46 03 david frank keymag- pg 47 04 david frank keymag- pg 50 05 david frank keymag- pg 140


PS: I love the discography at the end.  Attitude  is in constant rotation as well as howard johnson

::: IF :::

::: Drum Machines and Swing The Linndrum way :::

I read this article and i had a few thoughts:

Roger Linn Drum machine and timing Interview

Speaking of the old school boxes specifically.  The linndrum is moderately reliable as to sync and very good with internal timing.  It has such a cool pocket to it that i love.  The main problem is that you simply can't record and overdub parts while it's synced to other devices and in context.  Oh sure you can try.  But as soon as you touch any of the drum pads while in record it slips out of sync and gets way out of time with the other instruments.  I often solo the Linndrum or stop everything else to change drum parts because it simply sucks to do this in context.  It's funny because we have an Oberheim DX and DMX here that are basically the same technology as the Linndrum.  They both are 8 bit sample playback systems on a Z80 type processor.  The Oberheim machines NEVER lose sync.  You can overdub, spot erase, and change swing and other parameters on the fly and they stay locked on target.  I asked Bruce Forat about this and he said they were always like that so it wasn't just my specific machine...

The Linndrum feels just slightly more organic though...

It's magic i guess!

I also liked a few other articles on the Attack Magazine site.  There's one 'top ten drum machines' one which is informative.

The Roland TR-808 has quite a tight clock and feel as well.  It is very solid but can feel 'swingy' in a great stand alone way.  I use the swing term loosely because there is no swing built into the TR 808. But the snare on mine is always a little LATE while the hats are tight. This makes this machine feel very bouncy.  There's no adjustment for that either.  It only has Roland TR 808 pocket.  I know the internet says it has no intentional swing.  But something makes that snare late, i mean swing...  Hmmmm...

Nice though.  but it can be hard to get pocketed with other machines.  Luckily it has several trigger outs so you can port it's swing to other sounds in other machines!  As to the Roland TR 808 This page looks great for mods and sync / memory upgrades

PS: I do like Roger Linn's statement about engineering.  The Linndrum was Designed to sound very tight but very specifically swingy when called for.  I suppose this is why they put less priority on staying in time while you input notes.  As long as it sounds great when you hit play again.  You win!


::: IF :::

::: Synth kids in the 80's :::

There's a blog i love called internetkhole. They mostly post family photos from the 80's a la FFFound but with the added twist of generally focussing on music, partying, and all things earnest about cloths, cars, style in the 80's.

Imma post a few of my faves here because i just dug through a few pages and there was some good old synth band shots :


Happy Summer!