Sorry Tom, you are my only source of home-brew 901s. I’m sure there are some more in the moog-o-sphere though!
The current semi-commercial 901 clones are not ‘true’ clones in the way yours is. I guess we use the word ’clone’ to include some minor changes in the design and not ‘exact copy’ which would be the true meaning of the word. But even yours has those minor changes to allow for easier servicing and reliability - but it sure hasn’t affect the sound!
Another 901 video from you? Yes please
I love your story! I can’t imagine what it must have been like 45 years ago gigging with a large Moog modular. Maybe the audiences were so in awe of a synth sound that you could get away with any ‘ify’ modules, bad tuning and thought that the hairdryers were for were for personal grooming! Having experience with a cantankerous synth only increases my appreciation of the guys (and girls) that would do the modular thing in live shows. When is your Oz tour? - would love to see you live…
Cheers,
Keith
noddyspuncture wrote:
Do you know of any other home-brew 901 demos...? I'd like to see them if you have any links...!
When you say "within my own builds" - I only actually built one 901b and then later a 901a. So I can only compare them to my original R.A.Moog ones. I have four original 901b's and two original 901a's. The R.A. 901b's all sound very similar, as you would expect - but you know the saying no two Minimoogs sound alike... even Hammond organs have subtle differences... well I think module to module each have their own "personality". It could be a calibration anomaly... but it's definitely there...!
The comparison video of mine was shot by a friend on his mobile phone... so the picture quality is great... but it has the 'room sound'. I am thinking maybe I should do another one - recording the sound direct onto my Zoom - but my only video camera is an old Hi-8 one and it leaves a bit to be desired picture quality wise. I suppose it's the sound that's the most important thing here. Also, I could then include my 901a controller which wasn't ready when that comparison video was shot...
The 901a worked first time as well. I was really surprised, haha!
The reason they sound good I suppose is because I didn't change anything - except for performing a few minor 'upgrades' which I also performed on all of my R.A a's & b's when I got them and serviced them originally.
Basically they are calibration modifications. I brought all the adjusters to the rear slot - visible because I changed the old 22 way connector to the newer 'D type' - which are much more reliable. The adjusters that I then brought to the rear are "multi-turn" and I also changed a couple of resistors 'feeding' the (901a) calibration presets, to board mounted presets so I can set the multi-turns to the centre position - then roughly calibrate the module with what would been fixed value resistors before - and then work from there. That way there is no danger of end-stopping. Also the modules never need pulling out to calibrate - I can do that just from looking into the back of the case.
When I made these modules I actually cloned the circuit boards using copper board and etchant and I sourced all the original components... such as the germanium diodes, the CA3019 diode arrays and even the CL-1 diodes..! I don't think any of the clone manufacturers do that - they all have quite marked differences form the original Moog design..!?
Anyway I have a story for you now...
Recently I was asked to take the Modular out to a seminar type thing to display it - which I did. It was a mid-week event so I needed help getting it into my van before hand. That was at the weekend when friends were free... so the Modular stayed in my van in the garage for a few days. It was raining heavily during that time so there was a lot of moisture. When I took the Moog to the seminar during the afternoon and set it up - it was really bad. I had actually never seen it like that. One of the original R.A. controllers was playing up big style... as was my own home-brew 901a In exactly the same way..! The other R.A. 901a was not at all bad. I had to wait until they put the heating and air-con on and it all settled and acclimatised after a while - and then it was perfect. I have gigged this thing a lot and it has never been like that when setting up, which would be a nightmare. But it was a good exercise seeing it that way, as now i know what to do and expect. So I have got myself a couple of small hairdryers to point into it which I shall carry to future gigs so I can dry it out quickly...
Cheers,
Tom
