Recently had to fully test and evaluate an rare old modular synth. Splendid , I thought, a chance to try out another interesting old synth that I hadn’t seen before. Got to the current resting place to find it was an old PPG analogue modular that appeared to be a fair copy of and old Moog modular. Here’s the tough bit, all the controls were labeled in German!
Everything…
Started off by identifying the oscillators (only three – shame). Then had a brainwave, step back until the writing couldn’t be read and bingo everything became recognisable. Reason – it was such a good copy of a modular Moog that the knob layouts started to look familiar so various modules could be identified. From that observation I worked out the EIN and AUS were the inputs and outputs so with a fistful of patch cables the old beast was soon making some great sounds.
One major difference (improvement) was that most module had several control voltage inputs.
The sequencer was such a close copy of a Moog that I ended up operating it without reading anything. But all in all a very nice machine with a very classy filter, capable of some very nice sounds.
One of the strangest thing I’ve looked at recently is a Yamaha Silent Piano. On paper it sounds a bit weird but here is the idea.
Take a perfectly good upright piano (actually a very good one) and then add a digital piano as well. The clever bit is that you can mechanically disable the normal piano so that the hammers do not strike the strings but a series of optical sensors under the keys still determine which notes have been played. You then plug in a pair of stereo headphones and practice away without disturbing anyone – genius…
As a bit of a nerd I was quite impressed by the optical detector system that determines which notes have been played and at what velocity. This is done by two beams per key (2 x 88). As a wired system would need two wires per beam this has been reduced by using optical fibres. This allows multiple beams to be derived from a single transmitter and that multiple beams can be received by a single receiver, thus reducing the electronics. The whole lot is arranged as a matrix that is being scanned at regular intervals fast enough to be able determine which of the keys have been pressed.
As each key has to cut two beams then it is possible to calculate the speed the key is travelling by measuring the time taken between the beams being cut. On the one I looked at there was a small brass vane on the bottom of each key positioned so it cuts both beams.
The bit that got me was that with headphones on and the piano in silent mode the brain links the clunk of the disabled hammer with the sound in the phones and projects the sound “into” the piano making the experience of playing very realistic indeed.
Recent repair job was an old Gibson lap steel with an open circuit pickup. Closer inspection showed that the copper wire in the pickup was suffering from a terminal wire rot where there were patches of green oxide resulting in many breaks in the coil.
Only solution was a rewind…
Not having any equipment to do this I thought “it can’t be too hard to rewind a pickup by hand can it”. So I sourced some nice old 42AWG formvar coated copper wire, cut the old useless wire off and started winding.
It took six hours in total! About 9000 turns of wire you can barely see – never again…
But the results were worth it. I was never quite sure about the claims for hand wound pickups but the sound of this one was superb, warmth and clarity in equal strength and a tone control that made a difference (as it matches the pickup very well).
Why should this be, well the theory goes that a hand wound pickup there is less stray capacitance as the wires are not in neat layers that act as plates. I can see that makes sense.
Trouble is I’m now hooked so I am now designing a pickup winder to speed up the process so I can experiment with winding a few pickups for myself to see if the “hand-wound is best” claim is actually true.
The jury is out…
You must have done it – sell something that you think is redundant and then years later regret it, I know I have…
Leaving the USA hard-tail Strat aside (as this isn’t a guitar related blog thingy), the one I really regret selling was an Oberheim OB-1 number 00036.
The OB-1 was the first commercially produced monophonic synth with memories. Only eight, but that was eight more than anyone else! A truly stunning feat as there was no microprocessor in there it was all done with discrete digital logic. Same principle as later programmables such as the Prophet V, scan all the pots in quick succession, digitise the voltages on each and store the values in RAM. Use a synth voice where every parameter is voltage controlled and derive all these voltages from the previously stored values to be able to recall sounds at will.
However it isn’t the programability that I now miss, it is the truly glorious sound of a synth with the smooth Oberheim filter that is quite different to the MiniMoog that replaced it.
Ho hum…
Had a reminder recently that some instruments deserve the reputation that they have. I was asked to sort out a very unwell set of Moog Taurus Pedals (the original version).
Freshly revived Taurus Pedals
I approached the task with a “whats all the fuss about” especially when the instrument was powered up and a very sick weedy sound was the result. A bit of investigation traced the fault to the power supply where the rail for the discrete logic would measure 5V under no load conditions but collapse when everything was connected up.
Regulator duly replaced the pedals were powered up and the result was a deep deep trouser-flapping bass that makes even a Mini-Moog sound a bit thin. How do they do that…
Note that MoogMusic (www.moogmusic.com) are advertising that they are going to do a re-issue, that should be interesting
Well most of the info from “members.aol.com/tronpage” is now available again, next job is to make sure that the search engines can find it. Meanwhile nothing else exiting to report on the synth front as most of the recent repairs have been amplifiers. Must have a rummage through my archives to find some interesting synth related stuff.
Oh and Happy New Year if you’ve got this far…