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Here's the specs I submitted:ilya.n wrote:BTW i am getting the range of 40s to 130HZ, is this normal?
Bad diode? it happens. call Synthrotek.wily wrote:I built one of these six months ago from the Synthotek kit and it's a great little LFO. Very useful for OSC FM.
Recently it stopped working (wouldn't oscillate), and I pulled out the multimeter and noticed one of the diodes (D5 IIRC) is no longer functioning. Any ideas why this could occur?
Actually, D5 is one of the reverse voltage protection diodes. It's a 1N914.wily wrote:I built one of these six months ago from the Synthotek kit and it's a great little LFO. Very useful for OSC FM.
Recently it stopped working (wouldn't oscillate), and I pulled out the multimeter and noticed one of the diodes (D5 IIRC) is no longer functioning. Any ideas why this could occur?
Same thing happened to mine , I plugged in another module with a bad power cable and then my MST LFO stopped working. I found out that it was D5 and replaced it and everything was fine.mmm wrote:
Actually, D5 is one of the reverse voltage protection diodes. It's a 1N914.
You can replace it with that or a 1N4148 or any small signal diode with a reverse PIV of 30V or more.
Glad it doubled as a fusesynthetek wrote:Same thing happened to mine , I plugged in another module with a bad power cable and then my MST LFO stopped working. I found out that it was D5 and replaced it and everything was fine.mmm wrote:
Actually, D5 is one of the reverse voltage protection diodes. It's a 1N914.
You can replace it with that or a 1N4148 or any small signal diode with a reverse PIV of 30V or more.
wily wrote:Oops, forgot to watch this thread, I'm bad at foruming.
Just to let you know, I replaced the diode a few weeks ago and it's working great again. Pretty sure I didn't do anything dodgy with PSUs but you never know.
These are really great little LFOs. I should build another one.
Edit: PS, thanks mmm!![]()
dubtoms wrote:That was a lot time ago but I pretty much learned that you need to check pinouts for transistors before substituting them...![]()
I ended up figuring that by myself but I had a lot of support from Mr. Mattson himself, who is very responsive if you contact him via email.
Anyway, it's a great little module, like pretty much everything in the MST line !
I actually ran into that when I designed my VCO. The "stock" pinout for the FETs on the CAD schematic program were a different pinout than the specific FET I was using. I didn't even think about it before ordering the prototype boards. It was "real fun" troubleshooting that...dubtoms wrote:That was a lot time ago but I pretty much learned that you need to check pinouts for transistors before substituting them...![]()
I ended up figuring that by myself but I had a lot of support from Mr. Mattson himself, who is very responsive if you contact him via email.
Anyway, it's a great little module, like pretty much everything in the MST line !