Non-invasive Spring Reverb mod!

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bender
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Non-invasive Spring Reverb mod!

Post by bender »

I've been looking for a way to enhance the drip on my Fender 63 Reverb Reissue for a while now and stumbled across a really cool mod on the Surf Guitar 101 forum. The cool thing about this is that it's completely external and will work on any amp that bypasses the reverb by sending it to ground (I believe this is how all the Fender Blackface amps work at least).

There are two parts to this- a resonant bump in the upper midrange to enhance the drip of the reverb (the initial attack, which has a kind of slap-echo vibe to it), and a pot that trims the level of the resonant peak.

The extra cool thing is that it's a completely passive circuit that simply plugs into the footswitch jack!

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As you can see, there's sweet fanny adams to it. It's a rotary switch and a pot wired in series from the output of the reverb pan itself (before it hits the recovery circuit) to ground. I've included a foot switch so I can switch between two different reverb sounds.
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The practical use of this is that I can now switch between 6 different reverb voicings, from the stock setting to bright and splashy and tame the effect a bit if it's too harsh sounding. The bonus is that, in the stock position (no capacitor), the pot acts as a reverb level trim, meaning I can set two different levels of reverb and switch between them.

My plan is to live with it like this for a while, and eventually pick my favourite capacitors and then build a smaller, tidier version.

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Re: Non-invasive Spring Reverb mod!

Post by SimonHirst »

That's a really great mod!! Very nicely done too, I might add :thumbup:

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Re: Non-invasive Spring Reverb mod!

Post by AiRdAd »

So cool!!!!
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Re: Non-invasive Spring Reverb mod!

Post by jeremyb »

Neat!!
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Re: Non-invasive Spring Reverb mod!

Post by GrantB »

Awesome Ben.

Poor Fanny Adams though...I never knew.
https://en.m.wikipedia.org/wiki/Fanny_Adams
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Re: Non-invasive Spring Reverb mod!

Post by Jay »

GrantB wrote:Awesome Ben.

Poor Fanny Adams though...I never knew.
https://en.m.wikipedia.org/wiki/Fanny_Adams
Blimey, that's so gruesome :sick:

Bender, would this circuit improve the VOX C15 pathetic (according to strummers) reverb?
When faced with quality, I recognise it every time.

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Re: Non-invasive Spring Reverb mod!

Post by rickenbackerkid »

fascinating mod! I'm surprised that the reverb tank output travels all the way to the foot switch to be bypassed, I would think that would be noisy and unreliable and there would be a transistor that pull the reverb to ground, and that would be what the foot switch switches. the concept makes total sense though, it's just a basic EQ over the reverb tail. I do the digital equivalent on sound desks all the time, EQ'ing the reverb to get the tonality I want

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Re: Non-invasive Spring Reverb mod!

Post by bender »

bbrunskill wrote:fascinating mod! I'm surprised that the reverb tank output travels all the way to the foot switch to be bypassed, I would think that would be noisy and unreliable and there would be a transistor that pull the reverb to ground, and that would be what the foot switch switches. the concept makes total sense though, it's just a basic EQ over the reverb tail. I do the digital equivalent on sound desks all the time, EQ'ing the reverb to get the tonality I want
Yeah, that weirded me out at first too. Shielded cable is essential!

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Re: Non-invasive Spring Reverb mod!

Post by bender »

jvpp wrote:
GrantB wrote:Awesome Ben.

Poor Fanny Adams though...I never knew.
https://en.m.wikipedia.org/wiki/Fanny_Adams
Blimey, that's so gruesome :sick:

Bender, would this circuit improve the VOX C15 pathetic (according to strummers) reverb?
Depends on how the reverb is bypassed, but possibly. I’ll post cap values and some sound clips when i get a chance.

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Re: Non-invasive Spring Reverb mod!

Post by StrummersOfThunder »

bender wrote:
jvpp wrote:
GrantB wrote:Awesome Ben.

Poor Fanny Adams though...I never knew.
https://en.m.wikipedia.org/wiki/Fanny_Adams
Blimey, that's so gruesome :sick:

Bender, would this circuit improve the VOX C15 pathetic (according to strummers) reverb?
Depends on how the reverb is bypassed, but possibly. I’ll post cap values and some sound clips when i get a chance.
bloody solicitors (literally).

Yeh the onboard vox ac15 reverb is not great. Sounds more like playing in a jail cell rather than spring reverb. Big droany steel drum tail and no boing. NO BOING!

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Re: Non-invasive Spring Reverb mod!

Post by sizzlingbadger »

The easiest fix on the AC15 is to replace the tank with something like a MOD reverb, costs about $30-$40, just plug and play.

https://www.amplifiedparts.com/products ... od-8eb2c1b
Tube amp and guitar tones straight from 1958… amazing how believable the sounds were back then, even without the modellers...

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Re: Non-invasive Spring Reverb mod!

Post by StrummersOfThunder »

sizzlingbadger wrote:The easiest fix on the AC15 is to replace the tank with something like a MOD reverb, costs about $30-$40, just plug and play.

https://www.amplifiedparts.com/products ... od-8eb2c1b
Improvement yes

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