Amps and effects
This set of rare equipment arrived the other day for service. I’m told it will not interact with a synteziser.
Here’s a picture of the Ampeg pedal hooked up for testing and calibration.
I could not find anything wrong with the Ampeg pedal, though it did need a new calibration. The old electrolytic capacitors will also be replaced.
/Krister
So it was time to get the power supply mounted in the enclosure for the Steiner Microcon Syntheziser. Power inlet, transformer, rectifier and so on. A pretty tight fit but it all went well.
My main concern was that due to the tight fit, I would have transformer hum picked up in the audio path. I must admit it felt god firing it up and realizing there was no interfearence from the powersupply.
Chassie with transformer and PSU electronics. As seen I mounted a fused powerinlet with built in main switch and a poweroutlet for the Ampeg Patch 2000 pedal.
A picture of the unit mounted
Here’s the complete setup all hooked up for testing
And a video
/Krister
Since the units started working together in my Hagström Patch 2000 project it was now time to get a propper chassie for the syntheziser.
The choice fell on a Rolec-Hammond enclosure, here’s a few pics with the electronics and faceplate mounted.
Next step is to fit a power connector, transformer and the PSU card, it will be a tight fit but it should be possible.
/Krister
A both intresting and a challenging project.
The guitar is Hagström Patch2000 from the late 1970:s. It is the first guitar/synthesizer hybrid made by Hagström in collaboration with Ampeg.
The interface between the guitar and the synth is an Ampeg Patch2000 pedal. It’s got three controls, Pitch, glide and 5th.
So what’s needed from me is to build the syntheziser. The choise fell on the Steiner Microcon. Synthcube carries a full kit for the build.Here’s the circuitboard, started to get populated.
Populated and mounted on the faceplate. The offboard wiring is a challenge on this thing.
Worth knowing is that synthcubes “full kit” did not include the powersupply.
A gutshot of the Ampeg pedal. It has by now got new electrolytic capacitors and a calibration.
Here’s a picture of both the synth and the ampeg pedal together.
Once I finally got things hooked up together and could try it out it was clear that it is not fully functional.
First thing I did was check was the offboard wiring on the microcon. There’s eleven pots and a few switches and I had got some wires mixed. After sorting that out the synth now seems to work properly.
Second thing was that the guitars electroninc always had the high E string set as active, therefore the Ampeg pedals Gate got blocked. I found nothing wrong with the guitars harware and measuring indicated that U7 (string monitor) was defect. Schematic for the guitar
So the 74LS151 got replaced with a new one and suddenly things started to interact as it supposed to.
Here’s a pic of the guitars circuitboard U7 is located on the low left
Here’s a short video of the tryout, my son Markus is playing the guitar wich is connected both to the synth and as a normal guitar to an amp. This videoclip also appeared in my earlier post Mystery circuit….
So what’s left for now is to check the Pitch pedal on the Ampeg, it does not always work, there’s some problem with the 7 pin DIN cable from time to time. The Microcon will get a new chassie and a calibration.
I just need to find the time for everything.
/Krister
Trying out a work in progress circuit. I wonder if anyone can take a guess on what it is? Sorry about the orientation on the video.
/Krister
