spring reverb q.

[JimRayden]

Everyone's talking about the reverb. So I thought, what the heck, I might start a topic on it too.

I have an old SS Vermona guitar amp. From around 1986, I believe. It has a spring reverb wich is the most awful I've ever heard. It doesn't give a smooth sustaining reverb, instead, it says "boyoioioing", wich is a cool effect on it's own, but not as a reverb.

Do you think I could improve the sound of the reverb by taking the tank out and making a new circuirity for it? Or is the sound fully made by the tank itself, not the electronics that drive it?

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Jimbo

[ryanscissorhands]

Springs could be loose.

[Mark Hammer]

I had a mid to late 60's GIbson SS amp once with an atrocious reverb sound.  Hated it, hated it, hated it.  Found the key DC-blocking (low-end rolloff) cap in the drive circuit and changed it for a smaller value so the springs wouldn't be slammed quite as hard by the bass and go "splat-kaboing".  Improved the sound immensely.

[Peter Snowberg]

(for me) Fender amps have the opposite problem that Mark just mentioned.... they use a 500pF cap for DC blocking that also blocks way too much midrange for me.

The tone will also depend on the tank used... is it a long or short spring tank and are there two or three prings?

Sometimes it seems like the engineers finish the design of an amp and then the marketing people say, "No, we need to add effects". A crude reverb or tremelo then gets graphted onto an otherwise well-rounded circuit.

Are you driving your amp with a boosted signal? If so the reverb send amp could be overdriven. You might want to add a pot to ground right after the DC blocking cap with the wiper headed off to the send amp. There's your "dwell" control.

[zeta55]

Hi.
Check out this link http://sound.westhost.com/project34.htm
Read the "Description"  section.

[JimRayden]

Thanks. I'll open it up tomorrow and see how many boingers are in there.


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Jimbo

[JimRayden]

There's one little spring, with 3/16" of diameter and 6,5" of length. Though it looks like there is also a place for another one. The unit is alot like Accutronics type 1. But with one of the springs removed.
The sign inside says that it has input impedance of 600 ohms.

BOING

Oh and the reverb pan is built on the 27th February of 1986, if anyone's interested. (Propably not though )

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Jimbo

[Mark Hammer]

One short spring.  There's your problem.  Typically, the more springs are used, the better the tone.  Why, you ask?  Because when you stand in a large hall with many surfaces of diverse acoustic absortion/reflection, you get a rich variety of reflected sounds, arriving at a variety of times over a longer period (especially when you hear the same waves bouncing off this remote surface after they have bounced from THAT remote surface).  Short springs, and especially individual springs will yield a reverb that is roughly like standing in the stairwell of a cinder-block 6-storey building.  Very resonant (in the bad way) and boxey-sounding, because of the short distance and uniform surfaces.

I suppose it might be possible to improe the sound from this spring a bit, but this sow's ear can only be made into a much prettier sow's ear, not a silk purse.

[JimRayden]

Ok, I think I'll have to try to get the second spring from somewhere... Anyone know a place that sells reverb springs of various sizes.

I also thought to leave it as it is and use it as a bouncey special effect...


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Jimbo

[Mark Hammer]

You may be able to get a substitute pan from Accutronics.  They sell 3-spring short pans.  I am assuming there are some space constraints, but if not, score yourself a long-spring pan.  Pay attention to the input and output impedances, however.  They should match what your amplifier expects to see at each end.  If you can't find an exact match, it is also possible to stick a transformer between the pan and driver circuit (or recovery if the problem lies there) to better match impedances.  The Accutronics site has loads of info to help you identify the needed item.

[JimRayden]

Well, I'm rebuilding the amp. Rip the SS stuff out and stick a tube amp in. I was thinking about leaving the effects where they are. So I'll consider replacing the reverb tank.

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Jimbo