#4710 safety valve

hello! sorry about missing January in module a month, I had a couple of emails asking where the fudge January is. Truth be told I got a bit bogged down in jan so back up again for the next one in feb which is one to be honest should have been done earlier! but its been spurred on by a situation a few weeks ago where I needed more safety valves for a build just plain simple safety valves.

so this is basically a rehousing of the original but with a bypass switch.

Why no cv? well in my opinion. the niceness from the safety valve comes from what you plug into it. it can change the sound in all manner of ways from slight to pretty crunchy all depending what is plugged in, and on these grounds I figured keep it simple. its by far the lowest component count and can still be put together in under half an hour if you were so inclined.

I will elaborate on more modules as they come but last year the series was the bread and butter this year is the filling! numerous oddities.


Powered by windows 3.1 ? :stuck_out_tongue:


why of course!!! haha


also a couple of things I should add about the safety valve which I have done in this new design.

sockets or soldered valves? I have gone for soldered valves. why?

  • because in this design they are running below recommended operating temperatures and voltages which means they are going to last longer, even though valves are incredibly robust when it comes to longevity compared to capacitors for instance. This means there is as much chance of the valve dieing as other components, so swapping it out doesn’t seem to justify a socket.
  • it simplifies the build process, because there are no sockets the valve wont stick out as much meaning it can go on the same pcb as potentiometers etc. This means less circuit boards and less faff
  • over time especially in a touring synth valve sockets on the front of modules get looser and looser. This causes a bit of a temperamental module where valves sometimes wriggle themselves to a loose connection.

also another thing I thought worth mentioning is handling valves with your fingers. In the application of the safety valve it doesnt really matter, even in most household applications of valves it doesn’t really matter handling these with your hands. purely because they aren’t on all the time and most importantly they don’t get hot enough. handling with your fingers is more an issue in valves in places like radio studios and power stations of old where operating temperatures were a lot closer to the crunch point in glass and over such a long amount of time that yes oils and such could pose a corroding issue.

In the safety valve because the 12ax7 is a pretty darn robust valve and the fact that the safety valve operates below recommended temperature of the 12ax7 its fine its the same as holding a glass with mulled wine in it :smiley:

If someone manages to rupture a safety valve with oils from their fingers let us know! cus that is a super power:D haha.


Awesome!!! I’ve had two tubes sitting around since the 1222


Just skimming this. Will there be cv to control the volume of mulled wine it holds?


hello! alas for this module no its not going to act like a vca just distortion and boosting. I have found the most interesting use of valves within a volume circuit is a vca before the valve. but this is a mk1! version just to get a nice simple one down :slight_smile:
also! it has a self oscillation mode at least haha


feb’s module, tiny bit more fiddling, I have decided to go pretty much completely back to the mk1 of this module. Its the one in my opinion sounds best, its different to the GMSN module, which is actually a chunk different to the strip board version. so yeah keep an eye out! its a nice quick and easy module for tone :). a mk2 will likely come which will be larger but this is to tick the flick on and sound Nice and chunky boxes!


Love it! This turned out very well!


also the LED behind the valve reacts to the signal. which I think is a neat touch, as these things never get hot enough to properly glow visibly, (it does a tiny tiny bit but not much)


I’m assuming with recent projects this has been postponed a bit! Is there any news on when this is coming to the shop? Only ask because there’s a few other modules I’m wanting and it’s sod’s law that I’ll hit purchase and 5 minutes later this will go live :grinning_face_with_smiling_eyes:

hey up sorry for the delay this past few months it was quite a backlog. good news it tonight im packing all of them up and sending them. so expect it I recon on Wednesday!!! and we will then be back to 1 a month. it had just been an unfortunate couple of months!


No Worries, can’t wait to build another :slight_smile:

No worries whatsoever! I’ll hold off till then, thanks for the update

I am working on the page right now you can see here !

They should be available within the next 24 hours as well as some more mega drones. Amongst others :slight_smile:

Not much to say about it except it sounds exactly the same as the first 4710 that I was trying to replace in my modular ha. Which was harder than I thought, each bit of fancy I tried to add to the circuit messed with the sound hence its just a straight up safety valve module.


Booom :- Order is in!

Likewise! Looking forward to this!

Woop woop! Mine has shipped! (Along with another VCO, 'cos who has enough of those)

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yep shipped too, should realy order a valve…

I ended up picking up a nice-ish one from Tung-Sol over on HotRox UK, didn’t want to spend a fortune on it, but when I ordered it I hadn’t seen the link to that super cheap one on RS. We’ll see how it sounds.