Starting to stretch my knowledge here, but would perhaps, buffering the input potentially help?
Iāve had 2 from the time of the first publication by Sam and they always worked fine. No need for any amplification of the input signal, quite the contrary. If you turn mine up and then try to additionally increase the volume of the signal put into them you can really hear the limiting effect / saturation effect the circuit has. There is no need to lower the 27 Ohm resistor in my case to maybe increase the amplification factor. It keeps the current surge preceding the PTC-effect of the filament at bay when I switch it on. Note, my bypass switch also switches off the filament to lessen the load on the power supply.
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This is where some oscilloscope readings would be interestingā¦ (Iād expect the brute and MS-20 to have lower signal levels since theyāre line outputs, but donāt know how you connected things).
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Ok It seems my problem is actually the #1114 filter. Its most likely I soldered it up wrong, if I send anything through it then into the distortion then turning on the distortion lowers the volume. Bypassing the #1114 filter everything works as normal.
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Do you have a buffered multiple or some other neutral module that you can place between them, to see if that changes anything?
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That is a good idea to concur with my thinkingā¦ I think?
right so just did a test with the 1114 going into the safety valve, and it seems all setting I do the safety valve (if volume on max) does boost it in one way or another.
the 1114 already does clip the signal so it will have a lesser effect in its highest settings over others but it seems to still do it
a couple of things to maybe check maybe a short on or around C7 r47 of the 1114??? its just a wild guess but it may be down to the fact the 1114 does its distorting weirdery by offsetting the signal like crazy and making it saturate unsymmetrically, possibly its going in already offset to the safety valve which is pushing it beyond its headroom and causing it to get quieter.
that is just a wild guess
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So I havenāt read all the previous posts, but i ran into an similar issue other people seemed to have.
I finished the module yesterday but didnt solder the tube in. It worked but the tube wiggled out of place when pluggin in stuff, so i decided to solder it on. Now it is dead and I already tried to reflow the joints. Tube is getting warm but no signial comes out of it
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hey aaah thats a different problem it seems, how long did you spend on the legs when soldering? however they arenāt very susceptible to heat. is the valve heating up at all??? or isi it cold? leave it on for half an hour and it should be a little warm is that happening?
i tried to solder them as quick as possible. the valve is getting warm after a few minutes
can you send a picture of the joints? just a closeup?. or even of the board in general
well there is a problem, i ruined the module completley yesterday after trying to get the valve desoldered :lā¦so i guess better luck with the next pcb.
what country are you based?
an update I will be addressing on a video on Sunday on the safety valve! everyone with a low volume problem its all good its an easy fix!
so I built one on a builders livestream just now and it happenned to me! volume was low or similar to what went into it. and I figured out the problem, the only thing differing between my other ones and this one was the type of 27R resistor, which makes zero sense, I had a pile of tiny tiny 27r probably 1/8 watt micro resistors and thats what I had been putting in all of the safety valves and they were working,
this week I ordered some standard ones just 1/4 watt metal film resistors same as the rest and boom! it was quiet because it was not warming up enough.
the easiest fix to this is swap the 27R with a 10R the same as the other ones on the board. or if you are feeling fruity just bypass the resistor completely! if you notice a hum anywhere just put in a 10R.
good luck
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Were they still 27 ohm after that adventure, or did you short them out or something? As weāve noted here and there, 27 ohm in series with the heater corresponds to 1/3 W, which is a bit more than 1/8 W 
Iām based in Austria
sorry typo they were 1/4. they are 27r I measured them after to make sure as thats what I first thought, I took one out of the old one./ā¦ and yeah 10r or these magical small 27r ones donāt get hot, so yeah 1/3 is a tad higher but seems all fine and dandy as long as it isnāt more its not gunne burn up in a frenzy. ill cover it in the vid on Sunday! butyeahmaybe a higher watt could work mad these small ones are fine/. the 27r ones that are the micro ones have been sat in these modules for a number of years. who knows.
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What time is the stream today 
will probably miss it as I am at the Virtual Pub
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very unsure im afraid!!! I need to get it setup and stuff. 
itll be a long one tho so likely ill still be at it hahaha. it will be afternoon I think
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Ahh cool, may be able to dip in and out whilst doing other stuff, sunny out there so got to make the best of it
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