Posts Tagged ‘Sequential Circuits’

Sequential Circuits Pro One

On the workbench this time is a Sequential Circuits Pro One. This unit belongs to a famous Swedish musician that’s been in the studio here at Analog Sweden for the past three days. I’m not sure if I’m allowed to mention his name so I won’t.

Anyway the machine had several problems ranging from tuning, crackly potentiometers and keyboard problems. I gave the machine a complete overhaul and now it’s in great shape once again. Quite a bit of work but well worth it for a machine of this calibre.

Instead of using the now hard to obtain rubber bushings we replaced them with our own method using custom cut felt. This works well for all pratt and reed style keyboards, so if you have one that is failing drop us a line. We can also fix and repair faulty J-wires on these keyboards.


05 2010

Sequential Circuits Prophet 5

On the workbench this week is a revision 3 Sequential Circuits Prophet 5. These are still highly revered machines and definately amongst the sought after classic analogs. This unit came in for power supply recapping, it was also very much out of tune. After the recapping it was given a full calibration and tuning back to factory settings. Sure there’s still a little drift in the tuning but that’s to be expected with an old machine. It now sounds as lush as it did when it first left the factory all those years ago, a true classic.


05 2010

Marion Prosynth, Sequential Circuits Prophet 2000 and a Yamaha TX7

We hope you all had a nice holiday, we all had a much needed break here at Analog Sweden. Unfortunately the weather is quite cold here at the moment, but hey we are in Sweden so what should we expect in the winter months. So we have a mixed bag to report on today, some analog, some digital and some digital with analog filters. Quite a mixed bunch.

First up is a stack of Marion Pro Synths, these were designed by Tom Oberheim and the core technology is based very much around his matrix 1000 synths. This are a little better though since you get a nice large LCD for editing. These units are NOS and had been sitting so long that i had to replace all the batteries, originally they were hardwired, but i figured to place holders in there so that the next time the battery needs replacing its a simple job that doesn’t involve any soldering.

Next up was a Yamaha TX7, this needed some general maintenance, i suppose you all know this is basically a DX7 in a small form factor, the less said about this the better, unless we plan to change our name to Digital Sweden…not any time soon thankfully :-)

The current job on the workbench is a Sequential Circuits Prophet 2000. This is an old school sampler, but has nice curtis based analog filters. Three of the eight voices were dead, I’ve since repaired them and have now encountered another problem (this is often the case with vintage gear, fix one thing, find another problem) Thenewly discovered fault is with the sampling input, i can sample but it only samples silence. I’ve traced the input signal and so far I’ve confirmed it up to the input filters. that cuts out quite a large section of the circuit, but there’s still plenty more to debug and so that’s my current quest.

Well I guess its time to get back to it, keep your eyes open over the coming weeks since there will be some major changes around here, including some updates to the site and a new web shop where you’ll be able to browse the goodness we have for sale.


01 2010

The British Empire was Built on Cups of Caps

A slightly mangled version of a quote from a very funny British movie. For those of you who don’t already know I’m actually English and cups of tea are part of my daily routine. Anyway back to the business at hand. All the caps have been removed from the CS70M power supply and I’m waiting for an order of new ones to arrive. Whether that will fix the problem remains to be seen, but as previously mentioned it was a job that needed doing regardless. In the meantime I took the second Prophet VS apart and removed the broken data slider and volume knob. An order for those parts is in progress also, so as soon as that arrives we’ll have two VS’s up and running. I also managed to take an inventory of all the missing knobs/parts of the remaining equipment in the studio, it’s quite some list, but then there’s quite some gear in there after all.


03 2009

Raising the Titantic

After some tests and exploration I was able to repair the broken key. So it was time to give everything a good clean up and put everything back together. Once it was reassembled I twisted Fredriks arm until he agreed to play us a demo. I grabbed the video camera and you can see the results. The next patient is a Yamaha CS70M,  this one might be a bit trickier to fix, time will tell.

Seems we forgot to turn on the gravity generator

Gravity is restored, Fredrik giving us another demo

A test of the internal sequencer


03 2009

The Titanic of the Prophets, the T-8

This synth comes from an era when most manufacturers were moving towards interfaces with buttons and menus, a terrible mistake in my opinion. This has to be the Titanic of the Prophets,  unlike something like the DX7 which could probably be considered the fatal iceberg. This is how synthesisers should be, not a menu in sight and a button or knob for every function. In recent years luckily manufacturers have moved back to tactile interfaces, not a moment too soon in my opinion. Anyway it was in need of a little service since one of the keys had stopped working, so I set to work.


03 2009

Another Completed Job

So the Prophet VS is back together, cleaned and working fine. Here’s a small demonstration video of the beast in action using the arpeggiator.  Fat sounds from the wavetables going through it’s analog filter.


03 2009

One of the Prophets

On the workbench at the moment is one of the Prophet VS that we have. They both need a little attention. First up is this one, cosmetically its in good shape. A few of the buttons aren’t as responsive as they should be. So as usual its time to get it on the operating table for a little exploratory surgery. Once I’d opened it up and had a chance to check out the layout it was a simple task to note down what cables go where before removing the control panel (where the faulty tact switches sit). Once that was out I had to figure out how to remove the switch caps to be able to get access to the switches themselves. This was no small feat, there’s no mention of how to do this in the service notes, and lets face it, you don’t want to force and break them. Eventually I figured out how to remove one, then it was a matter of carefully removing the other fifty of them. I gave them all a good clean and also cleaned the data slider. Next step was to clean the switch caps using my now normal procedure of soapy toohbrushing. Next up will be to reassemble it and check the functionality of the switches.


03 2009