Found yet another awesome freebie a few days ago. A Vermona synthesizer and electronic piano set. The synth is conveniently named "Vermona Synthesizer" and the piano is called "Vermona Piano Strings"
The piano seems to work fine except the last key on the right seems to get stuck sometimes and feels a bit odd, but other than that it seems to work perfectly. I don't really have a use for it so I'll probably be selling it to buy a new cymbal set 😀
The synth, however, is awesome. It's a classic analog machine from the 80's and has a beautiful old school sound to it, from what I've seen on Youtube. Mine sadly won't play properly. First it wouldn't turn on. I had to replace both fuses on the supply board because they were corroded and wouldn't make contact. Now I got it to work but it sounds very off. I'ts kind of slow and makes weird noises instead of actual tones. Hard to explain but it does NOT sound how it's supposed to 🙁
Where do I begin troubleshooting it? Can't find a schematic for it, so I have no idea what to do, as I have NEVER even used a synthesizer before.
The piano seems to work fine except the last key on the right seems to get stuck sometimes and feels a bit odd, but other than that it seems to work perfectly. I don't really have a use for it so I'll probably be selling it to buy a new cymbal set 😀
The synth, however, is awesome. It's a classic analog machine from the 80's and has a beautiful old school sound to it, from what I've seen on Youtube. Mine sadly won't play properly. First it wouldn't turn on. I had to replace both fuses on the supply board because they were corroded and wouldn't make contact. Now I got it to work but it sounds very off. I'ts kind of slow and makes weird noises instead of actual tones. Hard to explain but it does NOT sound how it's supposed to 🙁
Where do I begin troubleshooting it? Can't find a schematic for it, so I have no idea what to do, as I have NEVER even used a synthesizer before.
Does it have user programmable sounds? In other words, can you edit and save the parameters for a particular patch? Or let me ask another way, is there a battery inside to keep memory alive? If so, is that battery completely discharged?
My first guess is its memory is corrupted and it needs reinitialization - or restore factory settings, in musician speak.
I have no idea how your unit would be reset, on many you press a combination of buttons while powering up. On others it is a function on a menu on the screen.
Always verify power supply voltages, I assume the computer parts run on +5v, while your analog stuff runs on probably +/-15v or maybe only 12v. Since it tries to work, I might assume the voltages are OK, but check.
Is ther a model number on it anywhere other than "Synth"?
VErmona appears to be still in existence, try contacting them directly and asking about it. Don't just look on their web site.
My first guess is its memory is corrupted and it needs reinitialization - or restore factory settings, in musician speak.
I have no idea how your unit would be reset, on many you press a combination of buttons while powering up. On others it is a function on a menu on the screen.
Always verify power supply voltages, I assume the computer parts run on +5v, while your analog stuff runs on probably +/-15v or maybe only 12v. Since it tries to work, I might assume the voltages are OK, but check.
Is ther a model number on it anywhere other than "Synth"?
VErmona appears to be still in existence, try contacting them directly and asking about it. Don't just look on their web site.
See, the thing is, it's model name IS "Synthesizer". There is no memory, like I said, it's a fully analog instrument from the eighties 🙂
This is what were working with: Vermona Synthesizer | Vintage Synth Explorer
Mine kind of works, but sounds... wrong, I guess. I can't seem to get any decent tone out of it, no bass what so ever. I listened to some Youtube videos and tried to set the setting like in the videos, but it's still wrong.
Just thought I'd mention that before we dug it out of our school's storage, It had been sitting there for about 20 years.
Seems like I got a good score for free, considering that the synth seems to sell for about 300-500 bucks and 100-200 for the "Piano Strings"
This is what were working with: Vermona Synthesizer | Vintage Synth Explorer
Mine kind of works, but sounds... wrong, I guess. I can't seem to get any decent tone out of it, no bass what so ever. I listened to some Youtube videos and tried to set the setting like in the videos, but it's still wrong.
Just thought I'd mention that before we dug it out of our school's storage, It had been sitting there for about 20 years.
Seems like I got a good score for free, considering that the synth seems to sell for about 300-500 bucks and 100-200 for the "Piano Strings"
Some analog synths had patch memory, not the same as waveform memory, I had to ask. Have you contacted the company?
It's been about a week since I've had any time to work on the synth. I emailed Vermona and they sent me a schematic, but someone also gave my a direct link to the schematic, it can be found here:
http://tadas.yoyo.lt/wp-content/uplo...ynthesizer.zip
Okay so it's been sitting for about a week in a fairly cold room and has decided to sound a bit more normal. However, it still has a strange problem that I forgot to mention.
When you start playing the keys from left to right, they are supposed to go from low to high, right? Well, on this one, when you start playing from left to right, it starts low and gets higher, but then in the middle of the keyboard it suddenly starts from low again, but with a slightly different, dirtier sound. Doesn't really play any of the higher notes because of that. I'm no expert, but I'm pretty sure it's not supposed to do this? Could anyone please point out what I should check? I've only repaired things like amplifiers, mixers, turntables, speakers, etc... but never synths and keyboards. 😛
http://tadas.yoyo.lt/wp-content/uplo...ynthesizer.zip
Okay so it's been sitting for about a week in a fairly cold room and has decided to sound a bit more normal. However, it still has a strange problem that I forgot to mention.
When you start playing the keys from left to right, they are supposed to go from low to high, right? Well, on this one, when you start playing from left to right, it starts low and gets higher, but then in the middle of the keyboard it suddenly starts from low again, but with a slightly different, dirtier sound. Doesn't really play any of the higher notes because of that. I'm no expert, but I'm pretty sure it's not supposed to do this? Could anyone please point out what I should check? I've only repaired things like amplifiers, mixers, turntables, speakers, etc... but never synths and keyboards. 😛
Two sounds on a "split" keyboard is a fairly normal option for a synth. They frequently have to be programmed to do this, but on a strictly analog synth, who knows how they did it? Permanent memory was hideously expensive before 1980, usually involving networks of iron toroid "cores" strung on grids of wires by ladies. These core memory boards were about $2400 each when I supported testers in a factory that used them. Then about 1978 there came the "dynamic RAM IC's" that forgot everything every hundred milliseconds unless there was a special circuit to "refresh" them.
If you have a split voice control, then that may have something to do with the two different pitch ranges on the one keyboard. The keyboard will have been bought from an organ supply house, probably. The stock organ keyboards were 61 and 44 keys.
If you have more problems than simple power supply sag due to overage electrolytic caps, it might be more fun to take the keyboard and midi-encode it to get music out of a PC or laptop. See virtual organ sites for how to do this. One free organ music software package is called jorgan.
If you have a split voice control, then that may have something to do with the two different pitch ranges on the one keyboard. The keyboard will have been bought from an organ supply house, probably. The stock organ keyboards were 61 and 44 keys.
If you have more problems than simple power supply sag due to overage electrolytic caps, it might be more fun to take the keyboard and midi-encode it to get music out of a PC or laptop. See virtual organ sites for how to do this. One free organ music software package is called jorgan.
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Thanks for the reply, indianajo!
It's hard to explain the inner workings of this thing. Since it's a fully analog synth, there is absolutely no memory or logic controls involved. No coils either. Only op-amps, FETs and transistors. Have a look at the schematic, you'll see what I'm talking about. Basically an adjustable oscillator, is what this thing is.
Overage caps is probably not an issue right now, but I should probably do a full recap for preventative maintenance and better SQ, I guess.
I actually just now figured out what's wrong with it, and I'll try to explain it as best as I can. The first 19 keys work just fine and sound like a synth is supposed to. 20th key somewhat sounds alright. But the rest sound wrong. They have a "dirtier" sound and release/decay just sounds like a low frequency ticking. But when you hold down one of the first 19 keys and then press keys from 20, they sound fine. Might be a connection issue somewhere? I really don't think this is a split keyboard design, since there is one single keyboard "controller".
Have a look at this: https://www.youtube.com/watch?v=o9gL1imQpEs
This is what it's supposed to do when it works. And it has an awesome oldschool sound to it 😀
As for making it into a MIDI keyboard, well, this requires me to tear it into pieces, doesn't it? Because I really don't want to. I'd rather just sell it and buy a digital keyboard, then. This Vermona, when in good working condition, is very rare and quite valuable. Only 500 were ever made and, depending on the condition, a working Synthesizer can fetch up to 400-500$ 😉
It's hard to explain the inner workings of this thing. Since it's a fully analog synth, there is absolutely no memory or logic controls involved. No coils either. Only op-amps, FETs and transistors. Have a look at the schematic, you'll see what I'm talking about. Basically an adjustable oscillator, is what this thing is.
Overage caps is probably not an issue right now, but I should probably do a full recap for preventative maintenance and better SQ, I guess.
I actually just now figured out what's wrong with it, and I'll try to explain it as best as I can. The first 19 keys work just fine and sound like a synth is supposed to. 20th key somewhat sounds alright. But the rest sound wrong. They have a "dirtier" sound and release/decay just sounds like a low frequency ticking. But when you hold down one of the first 19 keys and then press keys from 20, they sound fine. Might be a connection issue somewhere? I really don't think this is a split keyboard design, since there is one single keyboard "controller".
Have a look at this: https://www.youtube.com/watch?v=o9gL1imQpEs
This is what it's supposed to do when it works. And it has an awesome oldschool sound to it 😀
As for making it into a MIDI keyboard, well, this requires me to tear it into pieces, doesn't it? Because I really don't want to. I'd rather just sell it and buy a digital keyboard, then. This Vermona, when in good working condition, is very rare and quite valuable. Only 500 were ever made and, depending on the condition, a working Synthesizer can fetch up to 400-500$ 😉
The 2102 static memory IC chip appeared in 1972. I bought dozens of 21L02's (low power) in 1975 for about $2 each to build my first computer in 1975.
I can't open your schematics, but this sounds like a pretty standard 2 VCO synth. I had an ARP Odyssey in the mid 70's that incorporated "two voice polyphony". The recent Korg reissue has the same feature. It is possible that your synth has this feature as well, and perhaps this is where the problem lies. It is supposed to work like this:
When a single key is pressed at a time (monophonic) the CV is routed to both VCO's which could be tuned to different pitches for two note chords that tracked up and down the keyboard, or the second VCO can be used for other functions (Sync, PWM, or as an LFO). When two keys are pressed at he same time, some diode logic routes the CV for each key to its respective VCO, which are ordinarily tuned to the same pitch. Verify that both VCO's actually work right.
Some of the keyboards of the 80's used conductive elastomers for the key contacts which died or just came apart over time. My Korg DW8000 had this problem. Some keyboards also used wire contacts which corroded, and maybe a good cleaning can fix it.
Thanks, tubelab! Luckily I won't have to dig so deep into this synth, as I already found the problem, and it was a really simple one actually. You see, how the keyboard on this machine works is that there are two metal contact rods and each key has a piece of steel wire attached to it. When you press a key, the wire connects the two signal rods. The roads are made of two identical short rods, which are then soldered together in the middle. Every time you press a key, the rods also flex a little, which over time has caused one of the solder joints to develop a crack just small enough to be unnoticeable, but big enough to screw up the keyboard. I jumped the connection point with wires so I wouldn't break when flexed. The synth works beautifully now. Now that I've played it for a few days, I have absolutely fell in love with synths. I found a buyer for it, and will sell it for now. But when I have spare cash at some point when I've finished my drum kit, I'll probably try to find myself a Formanta Polivoks synth, those sound like beasts :3
A big thank you to everyone who took time to reply! 🙂
A big thank you to everyone who took time to reply! 🙂
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