Audio Proz Service and Sales

Spring Reverbs and Modifications available: (Response to a letter RE: Master Room XL 404)

(Modification)

Mar 9th, 2015

Spring reverbs are popular again. This unit has been serviced the spring pan assemblies opened and the transducer pick up coil assembly aligned and glued down to maintain reliable operation. The springs have also been “tuned” to make the reverb smoother over a wider frequency range. This is done by slightly shortening and slightly stretching the spring in sections to tune out severe spring resonances and excessive ringing. Both channels have matching service done. The unit still sounds like a spring reverb system, but the dynamic range and quality of the reverb is richer. This unit uses 2 sets of 3 springs per channel (quite a sophisticated version).

I collect and modify the Orbans, Teacs, Fostex, Furmans, and AKGs. All get the same treatment (except the AKG “torsion spring” systems which remain untouched). Often times I am also adjusting the gain/level drive to and from the spring to improve the noise and to reduce the spring “rumble”. The result is better clarity, punch and air of sound quality. Some units can be made to sound like plate reverbs with proper tightening of the springs.

Virtually all of the older mechanical “reverb spring tanks”, including Fender, are Hammond spring tanks virtually identical manufacture and type invented by Hammond (an electrical engineer who ironically had little interest in what this device would ultimately do). He held many novel patented ideas in the fields of science and technology in the 1930’s and 40’s. The Hammond Castle organ is another notable contribution to the musical world. The castle itself in Gloucester, Massachusetts was also his creation. We here at AudioProz always truly appreciate the renaissance minds. Three cheers for Sir Hammond.

Now, let’s get back to reverbs. I have also done a redesign on some models (not the 404) which use electromagnetic dampening of the spring, or a very novel tunable decay of spring electro mechanical damping, which makes the spring very tight and intense sounding. This is achieved with magnets or wires attached at selected points to the spring. In general, my modifications reduce the spring sploosh and decay time by about 25% (or more depending on clients’ personal taste), resulting in a cleaner, tighter sound, while still retaining a noticeable but less obvious spring character.

Be aware almost all of these older spring tanks will get out of alignment. The coil/driver/receiver and ferrite modulator positioner do get out of alignment due to stress of spring tension. The laminates in the coil transformer often become loose from aging or by design. I glue these tight together and center the ferrite modulator accurately. This also improves the quality and clarity of spring sound. People often buy out of whack units and become disenchanted when the reverb buzzes and rattles when used. Even some new spring tanks are not optimized for best performance.

So the bottom line is my modified units are more expensive, but awesome sounding. For more info give a call.

Thanks.

-Vince

Inquire about this Modification