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View Full Version : Difference between medium and long reverb decay


randuro
12-26-2006, 12:54 PM
In my quest for a new reverb tank. I could only locate a match with a medium decay vs. long decay.....I am not sure if decay is the correct term, I've heard people call it decay and delay. Anyway, can anyone describe the difference and is it that significant?
Thanks
M.

reaiken
12-26-2006, 01:58 PM
Decay time is very significant. If you buy a long decay tank, it will likely be too much for guitar, unless you play surf music.

As a general rule, for a clean Fendery type tone, the medium decay tank sounds best. If you are using the reverb for a distorted tone, a short decay might sound better to your ears, especially if the amp is designed for output stage or phase inverter distortion, where the distortion will come after the reverb. If it is a preamp-distortion-based amp, with the reverb circuit after the entire distortion, you can get by with a longer tank, but again, you may still prefer a shorter decay time.

If you have access to a stand-alone rack type reverb unit, you can experiment with varying the decay time to see what suits you best.

Here are the decay times for the "standard" Accutronics tanks:

Short: 1.2 - 2 seconds
Medium: 1.75 - 3 seconds
Long: 2.75 - 4 seconds

Here is a link to the Accutronics tank specs:

http://www.aikenamps.com/Accu.pdf

Randall Aiken

randuro
12-26-2006, 08:25 PM
Decay time is very significant. If you buy a long decay tank, it will likely be too much for guitar, unless you play surf music.

As a general rule, for a clean Fendery type tone, the medium decay tank sounds best. If you are using the reverb for a distorted tone, a short decay might sound better to your ears, especially if the amp is designed for output stage or phase inverter distortion, where the distortion will come after the reverb. If it is a preamp-distortion-based amp, with the reverb circuit after the entire distortion, you can get by with a longer tank, but again, you may still prefer a shorter decay time.

If you have access to a stand-alone rack type reverb unit, you can experiment with varying the decay time to see what suits you best.

Here are the decay times for the "standard" Accutronics tanks:

Short: 1.2 - 2 seconds
Medium: 1.75 - 3 seconds
Long: 2.75 - 4 seconds

Here is a link to the Accutronics tank specs:

http://www.aikenamps.com/Accu.pdf

Randall Aiken

Thanks, finally a real answer:) Now I can order my tank.

mad dog
12-26-2006, 08:34 PM
My ears agree with Mr. Aiken. Recently picked up the RI fender outboard reverb, did all the suggested mods, using very nice tubes, still it was too over the top for me (and I like lots of reverb.) Ordered a 3 spring, medium tank to replace the 2 spring long. Big difference. It is more usable to me, sounds much better. I play well short of surf, so YMMV. I'm guessing the tone difference had more to do with medium than with the extra spring, no way to be completely sure of that.

riverastoasters
12-26-2006, 09:58 PM
Decay time is very significant. If you buy a long decay tank, it will likely be too much for guitar, unless you play surf music.

I really love the amps I have which have the three-knob reverb, partly because you aren't dialed in to just one sort of decay.

Another thing I like is the Demeter Real Reverb which has a long-ish decay reverb spring and a medium-short decay reverb spring which an be combined in a few interesting ways.

thesedaze
12-26-2006, 10:13 PM
I wrote a thread on this a while back that compiles a few sources:

http://online-discussion.dhenderson.com/SteveKimock/viewtopic.php?t=126&highlight=reverb

MichaelK
12-27-2006, 01:59 AM
I know from other threads that the original poster was inquiring about this for use in an AC30 Custom Classic. The tank that comes stock is a Belkin with a very long decay time. Fully opened up with the Dwell switch on "high drive" it's about 5 seconds.

That's an interesting beast because I've noticed with the "Dwell" switch on "low drive" there is significantly longer pre-delay time and shorter decay time, which allows the clean part of the mix to stand out clearly. It's great setting for me because I like a touch of reverb almost all the time, even when it's "off." In other words, not so you hear it obviously as reverb, just enough to thicken the sound.

Anyway, IMO the long reverb works well in that amp because of the variety of ways one can dial it in.

randuro
12-27-2006, 08:23 AM
Michael,

You are correct. I am looking to replace the tank in my AC30cc. I checked out the tank you recommended, but the ohms input did not match. The only tank I could locate without getting into calling the manufacture, had a medium decay. I could not find anyone who had the Belton(not Belkin) tank. Thanks for your input, it's very much appreciated.

M.

AdmiralB
12-27-2006, 08:43 AM
The Marshall DSL heads use a long-decay tank, and it's one of the best spring reverb implementations I've heard.

I don't understand this statement:

I really love the amps I have which have the three-knob reverb, partly because you aren't dialed in to just one sort of decay.

The three-knob reverbs with which I am familiar have these controls:

Dwell - essentially a gain control for the reverb input signal
Tone - treble-cut on the reverb output signal
Mix - gain control on the reverb output signal

None of these affects decay, in any way that I can understand.

randuro
12-27-2006, 08:57 AM
Any thoughts on tank size Long vs. Short? Does size make a big difference....in tone?
And leave this one alone fellas, I couldn't think of any other way to word it;)

riverastoasters
12-27-2006, 11:31 AM
The Marshall DSL heads use a long-decay tank, and it's one of the best spring reverb implementations I've heard.

I don't understand this statement:



The three-knob reverbs with which I am familiar have these controls:

Dwell - essentially a gain control for the reverb input signal
Tone - treble-cut on the reverb output signal
Mix - gain control on the reverb output signal

None of these affects decay, in any way that I can understand.

It's not a direct "delay length" control. But because there are a few nonlinear things in the picture, you can tweak them to get a different length sound. The point is that you can jigger the amount of drive to the reverb to get a little compression of the reverb which makes it sound longer.

The other thing is that Blues Pearl amps have "Dwell Depth and Tone" controls. I don't know if that is a slightly different circuit than the Fender three knob or if he just renamed the mix control.

Now if you do a reverb gong with your amp, you will find that the harder the amp is hit, the more treble "spack" is in the sound, and on the front end of the sound. The different frequencies decay at different rates in the spring. So the tone control on the three knob reverb also interacts with the apparent length of the reverb tail.

MichaelK
12-27-2006, 11:33 AM
>> I checked out the tank you recommended, but the ohms input did not match.

That recommendation was not from me.

>> The only tank I could locate without getting into calling the manufacture, had a medium decay.

Yeah, I noticed the same thing.

My Belton (not Belkin!) tank is intact, but I've got emails into both Accutronics retailers asking them if they can get one with the same specs but long delay. According to Vox, Belton is Accutronics' Czech factory. I'd like to compare both and see which I like better. Considering the retail price is under $30 it's not an expensive experiment.

>> Belton(not Belkin) tank

Yes, thank you! I had Belkin on my mind from a cable I ordered.

AdmiralB
12-27-2006, 11:37 AM
The point is that you can jigger the amount of drive to the reverb to get a little compression of the reverb which makes it sound longer.


Still doesn't add up to me. The one control you DO have in most reverb amps is the 'mix' control, which is at the tail end. 'Dwell' is replaced with a 1M resistor and is as such always wide-open, so any compression you'll get from the reverb circuit is always full-on - all you can do with the control is reduce it, not increase.

riverastoasters
12-27-2006, 11:40 AM
Still doesn't add up to me. The one control you DO have in most reverb amps is the 'mix' control, which is at the tail end. 'Dwell' is replaced with a 1M resistor and is as such always wide-open, so any compression you'll get from the reverb circuit is always full-on - all you can do with the control is reduce it, not increase.

The compression comes from your power section.

AdmiralB
12-27-2006, 11:42 AM
Now I'm really confused - if the compression comes from the power section, how does anything upstream of the mix control contribute?

MichaelK
12-27-2006, 11:50 AM
The different frequencies decay at different rates in the spring. So the tone control on the three knob reverb also interacts with the apparent length of the reverb tail.

Yup.

I have a German rackmount spring reverb in my studio that has two controls on the front: Input Level and Mix.

For electronic effects I set the input (and output) at unity gain, the mix at 100%, leave them there forever and make all adjustments using send and return levels in ProTools. But with the spring reverb, dialing the input level changes the tone, the saturation and decay. Changing the send levels alone doesn't do the same thing. I move the Input dial each time I use it. Mix stays at 100% though.

riverastoasters
12-27-2006, 12:43 PM
Now I'm really confused - if the compression comes from the power section, how does anything upstream of the mix control contribute?

The tone control on the reverb interacts because different frequencies decay at different rates in the reverb spring.

The spring itself is not entirely linear - so by changing the Dwell you get another element of compression.

The easiest thing for you to do is to spend some time with a three knob reverb. Going through the mechanics is one thing, but musically, what is important is that you can do stuff with them that you really can't get from one knob reverbs.

randuro
12-27-2006, 12:52 PM
>> I checked out the tank you recommended, but the ohms input did not match.

That recommendation was not from me.

>> The only tank I could locate without getting into calling the manufacture, had a medium decay.

Yeah, I noticed the same thing.

My Belton (not Belkin!) tank is intact, but I've got emails into both Accutronics retailers asking them if they can get one with the same specs but long delay. According to Vox, Belton is Accutronics' Czech factory. I'd like to compare both and see which I like better. Considering the retail price is under $30 it's not an expensive experiment.

>> Belton(not Belkin) tank

Yes, thank you! I had Belkin on my mind from a cable I ordered.

Sorry, I thought you made the recommendation. I think I will try the medium delay, I very rarely use reverb, so this may work out fine....please P.M. me if you find out any further information. Thanks again,
M.