I will say… I don’t like it as much as my old analog tektronix scope.
Yeah, digital scopes are like modern cars…
Slim, efficient, but not as much fun as the old way…
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I have exactly the same problems with mine.
@CTorp torp did you manage to solve this? im a little bit stumped to be honest. the status led on the front panel is wired straight to 12v via the switch im not sure why it would be doing such a thing apart from solder joints. which valves are you both us9ing??? maybe they are the same? and we could go from there?
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Not yet, but I haven’t messed with it. It’s an ECC83S.
Like I said before, I could never get the stripboard schem to work with it either, so I have a feeling it just won’t work with this tube. Don’t see where I could have really messed up this build haha
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It works when you touch the tube leads? My tiny imagination can only think of 2 reasons for this:
- Something bad happened when you soldered to the tube leads (like something came loose inside and you’re wiggling it to touch
(In the laser cutting world when you go to replace a CO2 laser tube they have all kinds of warnings about not soldering to the tube lead)
OR
- Is it a grounding issue?
12AX7/ECC83 is just supposed to be a US/Rest of the World name thing.
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my tube is a JJ valves EEC83s , so they do work.
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I got mine working, the signal from my kosmo modules needed amplifying (probs around 3-5x is best) before going through the safety valve.
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thats rather odd. so in order for it to work you have to boost the signal of the oscillators etc? as in if you plugged in an oscillator straight in it would not work?
rather odd im trying to figure out why this might be the case, in normal function you plug in anything from a contact mic up to an oscillator it will make it louder, I dont think there would be an instance it would make it quieter as the boost circuit way beyond the headroom of the synth so im trying to work out why yours is not doing that
Just to add in mine, I’m not getting anything at all unless I fiddle with the valve pins, here’s my valve.
thats the same tube as in mine
hmm maybe there is another variable at play here. what power supplies are you all using?
is there a possibility the jacks have been soldered on the wrong side of the jack board?
I had that problem before cyroS it turned out to be a dry joint on the valve to the circuit board.
Yes, my external synths like microbrute, ms-20 have noticeable distortion and the led behind the tube lights up. With my kosmo stuff there is no distortion and the led doesn’t light, until I boost the signal. My diy valve distorting vca also doesn’t have this problem.
how extremely odd. what are you plugging into it? from the Kosmo modules
So I just bypassed the 27r, working good for me now, definitely louder on the output now?
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mad. with the 27r in or out do you notice any other modules doing anything different?
I think maybe just maybe the 27r in some systems are causing the heater filaments not to heat up sufficiently. because it does run pretty cold already. what is the power supply you are using?
I have not, but I haven’t racked it. Didn’t affect the two oscillators and filter tho
I’m using frequency centrals
By bypass do you mean you ran a wire between the pads, or just stripped out the resistor completely?
Ran a wire, I just left the resistor
Okay have also just done that and still getting absolutely nothing, valve feels warm to the touch so it’s definitely getting heated up.
Reflowed the valve pins again and still getting absolutely nothing coming out with it switched to on, oscilloscope turned up but I need to look up how to actually use this thing!!!
Still getting a very very very faint signal if I whack all the levels to max.
I plug into 3 kosmo oscillators even with complex waveforms + high resonance and flicking the valve on made the signal quieter unless I amplified the signal first. It works now anyway so if no one else has the problem then we can assume I’m an anomaly.