Hi! You're reading this because you're having an issue with noise and your Reverberator. I'm sorry to hear it! Please read through this and I promise you'll come to an understanding of the situation and we can take it from there. *Scroll to the bottom for noise solutions in a nutshell!*
Condition 1: We shall assume that you have a normal, quiet, properly grounded guitar with normal, quiet, properly grounded cables and a normal, quiet, properly grounded amp. All of these parts of your signal chain can contribute noise, sometimes intermittently, so make sure you start the trouble-shooting process with all your tools in proper condition so they can be eliminated from suspicion. Also take note of the natural background noise of your rig, just guitar into amp. It's there and many people tune it out subconsciously and then are surprised when it's made louder.
Condition 2: We shall assume you have a proper power supply that's designed to be used with effect pedals. For the Reverberator this adapter shall be rated 9VDC, centre negative, and it shall be regulated and filtered and provide at least 60mA of current, more is fine and won't hurt anything. This excludes any and every adapter from Radio Shack/Maplin/random electronics shop/random adapter for synths/rack gear/other electronics etc, even if it says it's regulated, it more than likely won't be filtered enough and it will cause hum. Guitar pedals, especially digital ones, need very clean, very well filtered power supplies, it's critical.
The first step in trouble-shooting is to isolate the problem. Remove everything else from the signal chain and power supply except the Reverberator. Just plug your guitar into the pedal into your amp, nothing else. One power supply with only the Reverberator being powered. Now you've isolated the pedal and can see how it's behaving on its own.
Now let's talk about the two kinds of noise that can happen if your Reverberator isn't happy: hum and hiss. Hum is a low frequency sound, it's like the 60Hz hum you frequently hear with single coil guitars. It's a deep sound, a low drone, and it's associated with your power supply and/or ground of your system and/or interference between two pedals.
If you have hum with a Reverberator there's a few ways it can happen. First, what are you using for a power supply? Digital pedals are picky about their power and you can't just use anything that's rated for 9VDC... if it's not specifically designed for guitar pedals then it's almost a 100% guarantee it will be noisy. You might find one laying around that's 9VDC and quiet with simple analog pedals like overdrives etc, that doesn't mean it will be quiet with the Reverberator.
Note about switch-mode power supplies like the Visual Sound One-Spot or the Godlyke Power-All or the BOSS PSA-120T: These are great power supplies. I have all three and they're all quiet with all my pedals, no hum at all, I use them all the time with 3 different amps and several guitars and they're great. BUT! They generate their output by running internally at a very high frequency... sometimes, and this is rare, but sometimes digital pedals or analog pedals that have timing signals like delay, chorus, flange, will not get along with a switch-mode power supply. Their timing signals will fight each other and make for some weird noise. This frequently is a hum noise although it can also be weird high pitched squeaks and squeals too.
Another way to get hum with the Reverberator is to daisy chain your power supply or share your power supply outlets with multiple pedals. Digital pedals and analog pedals with timing signals don't generally like to be daisy chained although it works fine for many many people. It's unpredictable.. it depends on the pedals involved, the current they need, and the electrical situation of your setting. Live in a building from 1910 with original wiring and ground? You'll probably have hum if you daisy chain or share outputs. You might even have hum just with a switch-mode supply alone and might require a transformer isolated supply if it's really bad.
Hum can happen with transformer isolated supplies too though, like the Voodoo Labs Pedal Power 2+, one of the best supplies for pedals that you can get. I use one regularly with all my pedals, it's top notch. BUT! Supplies like this use a fancy transformer with many taps coming off it for the outlets, then they're regulated and filtered, and this is a great way to power pedals. It's still a system though with ground in common and parts of the system can affect each other if they aren't happy or are over-worked. If you have pedals that are drawing too much current from one tap, it can cause other pedals on other taps to hum. Same with digital pedals or analog pedals with timing signals, in the right bad luck situation they can interfere with each other and cause hum. You can try moving the outputs around, sometimes if you put some space between the taps of offenders they'll be quiet.
Some power supplies have individually regulated outputs from one transformer, like the T-REX and Dunlop supplies.. this is ok most of the time but is more of a cause of hum than the transformer isolated style of the PP2+. Regulator isolated supplies will be more prone to timing signal interference and/or current sharing problems between high current users like digital pedals.
On to hiss! Hiss is a much higher pitched sound than hum, it sounds like the white noise between radio stations or a big waterfall. Hiss is inherent in all active devices, anything that touches your signal and does something to it electrically will impart a small hiss to the signal, adding to the over-all noise floor.
There are ways that hiss can be exaggerated or made more prominent/obvious. One is raising the signal level a lot as it brings up the noise floor and makes the hiss more audible. Another is running into the front of a high gain amp, all the gain and compression will make the noise floor much more prominent. Plus it's important to remember that anytime you're able to hear the 100% wet output of any audio processor, especially analog or old-ish digital, there's gonna be hiss.
Hiss with the Reverberator is never due to the power supply, I can't think of a single situation where that caused hiss, but there definitely is a noise floor to the circuit. With the Mix and Level knobs all the way down there's very little additional noise in the signal path, just a simple op amp buffer stage and a simple op amp boost stage. Keep the Mix down and raise the Level knob and you'll hear the noise floor increase as the boost raises your signal level. This noise was already there, now you're just making it louder.
The wet signal of the Reverberator has a higher noise floor. The more you turn the Mix knob towards fully wet the more you bring this noise floor into the fold. It's a perfectly reasonable amount of hiss for mid-90s digital processing, but it's there. When you hear the fully wet output of basically every processor, there's a noise floor, a hiss down there somewhere. So if you're using the Reverberator set very wet and you're experiencing hiss make sure you have the Level knob no higher than you need it to be, or expect to be boosting some hiss.
When you run pedals into the front end of an amp with a lot of gain you make the noise floor really jump up... so if you're using the Reverberator with a lot of amp gain you'll want to keep the Level knob all the way down and expect to hear hiss the wetter you set the Mix. This is a perfect situation for an effects loop as the Reverberator can be placed after the high gain pre-amp stage where the hiss gets amplified so much.
Ok, that covers all the common ways that Reverberator users encounter noise, thank you for reading!
TL;DR: Got hum? It's probably related to your power supply, start there! Got hiss? Turn down the Level knob or don't run it into your dimed 5150 or don't set it so wet!