# Reverb from a Delay Pedal?



## Greg Ellis (Oct 1, 2007)

I'm a bit equipment challenged at the moment (financially challenged too).

I'm contemplating buying an amp that doesn't have any reverb built in.

I do like a bit of reverb, especially for some of the styles I'm working on at the moment (clean-ish blues and whatever).

Will it be possible for me to get a decent reverb effect from a delay pedal?

I have the Visual Sound H2O (chorus/echo in one box) to work with.

What settings should I try?

Thanks!


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## traynor_garnet (Feb 22, 2006)

I use my analog delay to do "fake" reverb all the time. Basically set the delay time as short as it can go and mix to taste. On my delay pedal, I can actually set it so there is really no delay note, just a kind of reverberant sound. It's shorter than a slapback delay.

I often prefer this sound to a "proper"reverb sound.

TG


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## rollingdam (May 11, 2006)

I use a Carl Martin Red Repeat for the same purpose-just to give the sound some "air".


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## mhammer (Nov 30, 2007)

In the real world, reverberation involves sound bouncing off of multiple surfaces, which vary widely in their reflective properties, and provide many different arrival times. What this means is that there is no *single* reverb sound, much as there is no single fuzz sound. That's cool, though. It means that pretty much anything can count as an attempt at reverb.

What IS generally true of reverb in the real world, however is that the multiple reflections provide a kind of defocussed "smear" that is distinct from audible repeats. It is also the case that since there is no active circuitry "out there" to maintain the signal, it often dies out quickly after bouncing off a surface or two. More importantly for our purposes, whatever parts of the signal have the least energy die out fastest. Treble content is generally much lower ampllitude than bass and mids.

Analog delays are generally designed to provide maximum bandwidth, so as to have each repeat be as audibly close to the original signal as it can be. Not the same clarity as a decent digital delay, but since analog delays preceded digitals, they were aiming for the same general goals as tape-based echo and the digital delays that would follow them historically. That maximum bandwidth is true of both the overall delay signal, and the recirculated signal which provides the 2nd and subsequent repeats. 

In various experiments with analog delays over the last 25 years, I have found that I can mimic some of the "blurring" and some of the treble die-off that is characteristic of true reverb by performing two small mods to an analog delay. 

1) If a small-value cap is inserted after the repeat/feedback pot, you can bleed off some of the treble in a progressive fashion, such that each repeat has less and less treble...just like real reverb. The trick is to make that filtering very modest such that there is still some treble to bleed off after the first time the signal is recirculated. The actual capacitor value will depend on the individual circuit.

Take a look at the venerable Boss DM-2: http://www.freeinfosociety.com/electronics/schematics/audio/pictures/bossDM2.jpg

You can see that there are two 50k pots labelled Intensity and Echo. The Intensity control adjusts how much of the delay signal is fed back to the input to produce additional repeats. The Echo control adjusts how much delay signal will be mixed in with the dry signal.

If you solder on a .01uf capacitor from the wiper (middle lug) to ground, for each of those controls, something interesting starts to happen. For the Intensity control, depending on the control setting, additional treble content will be removed each iteration. If the control is set to halfway, the rolloff starts around 640hz. That may seem severe, but remember that it is a very shallow filtering effect. If the control is increased to around 3:00 or 4:00, the location of the rolloff moves upwards to around 1.6khz. So the amount of treble reduction is least when you crank the Intensity up, and most when the intensity is turned down. If the effect is too severe for one's tastes, drop the cap to .0047uf.

2) If you do the same mod to the Echo control (and the cap value does not have to be the exact same one), then you get a fixed, rather than progressive, treble-cut effect. The amount of treble cut will work the same way as the intensity control: less when the control is dimed, and more when it is turned down.

The treble attenuation on both the overall delay signal, and the progressive treble reduction over multiple repeats, has some interesting effects. First, it accomplishes that smudging or blurring that helps to clearly separate the real-time signal and delay signal in the listener's mind. You'll find you can tolerate more regeneration/feedback because of that. Less audio clutter.

A second perk is that the sound quality in an analog delay normally degrades with each repeat. That degradation is largely in the treble region, where the tone gets gritty-sounding. Shaving off more treble with each repeat helps the sound to seem clean, even after multiple repeats, simply because you're losing the ugly and keeping the nice.

Will these two mods instantly transform a delay pedal into a reverb pedal? Nah. Can they successfully produce sounds with are more ambient-like, possessing some of the subtlety of real reverb? Actually, yes. The nice thing is that they are easily reversible and require no fiddling with the board itself; you can simply add the cap to the pot. If you want to reverse it so that you can get full bandwidth repeats, it is as simple as installing a toggle to either connect or lift one end of the cap in question.


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## Joey D. (Oct 16, 2006)

So, who votes we combine all of mhammers posts into the single greatest tome on effects pedals of all time? 

:bow:


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## keefsdad (Feb 7, 2006)

Yeah, this dude knows his stuff!!:rockon2:


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## mhammer (Nov 30, 2007)

Thanks, guys. I guess it goes to show you that if you waste 35 years of your life puttering *just the right way* it can pay off in the end, eh?

Not to take anything away from this board, but there are a great many equally, if not more impressive, people posting over on the Music Electronics Forum (formerly Ampage) - http://music-electronics-forum.com/ - and the DIY Stompbox Forum - http://www.diystompboxes.com/wpress/. Do pop over there when you have a chance, if you haven't already. Not just doofuses like me. These boards have REAL designers on them. For example: Andy Marshall (THD amps), Jason Lollar (Lollar pickups), Zachary Vex (Z-Vex effects), RG Keen (Visual Sound), Antonie Barmentloo (EHX designer - Flanger Hoax, Pulsar, Tube Zipper, and many others). You'd be surprised how many of the boutique guys (Robert Keeley, Alfonso Hermida, Brian Wampler, Marcus Dahl, et al) got their start there. Over the past 16 years, I must have at least 25,000 posts on both of these. You get a little better at explaining things after a while. :smilie_flagge17:


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## allthumbs56 (Jul 24, 2006)

Greg Ellis said:


> I'm a bit equipment challenged at the moment (financially challenged too).
> 
> I'm contemplating buying an amp that doesn't have any reverb built in.
> 
> ...


Hey Greg,

I too have an H20. I am quite fond of using my 68' Princeton (non-reverb) and when I play clean I find that it is more than satisfactory to set the H20 for a slapback (switch set to short delay and delay knob about halfway or a bit less). You can make it feel more "reverby" by uping the repeats.

Doing this makes the amp as equally (or even more) satisfying as using my 79' Princeton Reverb or my DRRI.

Give it a try.


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## Teleplucker (Feb 5, 2006)

I do this often. I prefer non-reverb amp and delay to amps with reverb. It seems the note get lost in reverb too easily.

Anyway, I do it a different way than the other posters. I'll set a fairly long delay time with an analog delay (DM-2 and Carbon Copy are current favorites). Then, I'll adjust the number of repeats until it sounds natural. Finally, and this is the key with longer delay times, I'll adjust the mix until it sounds like the natural decay of a reverb control on an amp. That usually means that I have the mix control below 1/4.

BTW, I think the DM-2 is the best delay pedal out there for faux-reverb. I think it decays nicely without mods...and I wouldn't mod a $200 used, semi-collectible pedal anyway. If you want to mod, get a DD-3 and look up mods for treble roll-off. Or, buy a DOD FX90, which I did, and is a great, overlooked analog delay, IMO, for under $100 used...mod the DOD :smile:.


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## mhammer (Nov 30, 2007)

Like I say, there is no single "correct" reverb tone, and no wrong ones. Teleplucker is not wrong in what he suggests. Analog delays all come with slightly different lowpass filtering, and some folks (like yourself) find that whatever their pedal comes with is bang on for what they want/need/expect. I'm happy when that happens. The mods I suggested are for those folks that find their pedal comes close but not close enough for cigar territory, and feel they cannot afford another pedal. Which one of those you are depends on your particular context.

Robert Keeley has a thriving business because plenty of people buy decent pedals that come soooooo close, but juuuuust miss the mark for their needs. At the same time, realize that Boss has a monster business because they make pedals that a lot of people feel do EXACTLY what they need. Sometimes your dog does tricks when you ask. Sometimes you have to use the right treats to get your dog to do the tricks when you want. Sometimes you have to tack on a mod or two to get your pedal to do the tricks *you* want.


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## Greg Ellis (Oct 1, 2007)

Thanks all!

I wasn't really considering mods to the H2O pedal, but I'll certainly keep that in mind. Considering that I could just sort of "crimp" a cap onto the pot lugs temporarily, this might be worth playing around with.

One of these days I'll pick up a real reverb effect, so I don't need to "make do".

I've actually got a (garbage) Behringer Delay (D-400 or something like that) that I picked up several months before the H2O came my way. Maybe I can find someone with a similar reverb willing to swap. Or maybe I can mod the Behringer. I've certainly got no qualms about messing that thing up - I think it cost me $29 plus shipping or something in that range.


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