Like something that would essentially have the same effect as turning your guitar down with the push of a switch? Or are you looking for something that gives you the clarity of a full volume guitar with less volume?
I built something similar for a client. He wanted something like the Signal Pad as well without the tone loss.
What we ended up with was essentially a footswitchable volume pedal which is controlled by a knob. He sets the ideal volume drop on the pedal and is able to switch between dimed volume and his lowered volume setting when he engages the pedal. No complaints on tone loss.
You can refer to GGG's schematic here. To wire it up into a pedal with a footswitch google you can refer to a guide on offboard wiring, or something like this.
The signal pad and other "pots in a box" suck tone, but you can fix that. If you are handy with a soldering iron, or have a friend who is handy with one, you can make a pedal like that for 10-15 bucks.
I built a box with a 1M Log pot in it (basically a volume control) but I soldered a treble bleed capacitor (470 pF I think, I need to check) across the top and middle lugs of the pot to let more high end through (less tone suck). I used a 3PDT stomp switch because I wanted an LED indicator. If you omit the LED, you can use a cheaper DPDT switch and no 9V power supply jack or battery. It's simple, you set the volume control to how much signal you want to cut, and then stomp on it when you need it. No other effects necessary and it's a nice way to have a foot switchable, reproducible volume cut.
I can send you a schematic if you're interested, but it's really that simple. The signal pad does the same thing, but I am guessing without the treble bleed cap. I haven't looked inside of one, but it may be possible to solder a treble bleed cap on the signal pad PCB.
Thanks for all the help, the Dmb volumizer and the minus booster look good so gonna look into them more. Also Mufftastic if you could send over the schematic that would be great, the others look great just slightly out of my price range unfortunately.
Would something like a Barber Tone Press with volume rolled below unity work for you? I only suggest this because the TP sits around 2 o'clock for unity so there's plenty of wiggle room for volume reduction.
So it has nothing to do with line level effects loop overpowering pedals (because THAT can be very tricky), but just lower volume.
Then I really don't get it. A volume pedal at the end of the (at least dirt end of) the chain would let you adjust volume.
Again, I may be missing some point here, but volume is volume...turning down ALL of it can be done at the amp. It doesn't get "cleaner" than clean. If there is no desire to drive the amp into OD, but instead just want clean, then amp volume will do it. I'm really puzzled by what you are going for that you cannot do just with amp volume control, and/or guitar volume.
The same principles apply for lowering the level as for boosting. If you do it before distortion, you'll mainly change the amount of distortion, while the overall volume doesn't change as much. If you do it after distortion, you'll change the overall volume while the amount of distortion stays the same. To change the level after distortion while using the amp's distortion channel, you'll need to use the amp's (series) effects loop.
An EQ pedal will be able to both boost and cut, and will also allow you to tailor the sound a little while you're at it. The Detox EQ and Mad Professor Underdrive are specifically designed to sit in front of a distorting amp and create a pseudo-clean tone. But those may be too specialized if you're simply out to reduce the amount of distortion a bit.