▲ WARNING.Never connect a classic reverb
unit to a contemporary radio. The two are incompatible. Connecting them will
likely cause a fire. Personal injury and equipment damage could result.
(The term “classic” refers to a period radio and reverb from 1964
to 1974.)
▲ WARNING: These installation suggestions are untried. Consider them to be speculative.
The basis for these suggestions is an analysis of schematic diagrams and other technical literature.
Proceed at your own risk. The webmaster can't predict what unfortunate results might occur if you
misconnect a reverb unit. But beware: Personal or equipment damage could result.
Incompatible? Ha! A classic spring reverb circuit is incompatible with today's
mobile electronics. But technology offers solutions. Now at last, you can add that dreamy,
romantic reverb sound to your own vehicle!
Fader pot. In a modern version of the reverb, we must eliminate the fader pot.
The fader simply can't cope with the high wattage outputs of today's audio circuits. In fact, try using it and
you're in store for reverb flambé!
Acquire a set of springs that has a 600-ohm, line-level input impedance. If you desire to mount
the entire reverb under the dash, buy a miniature tank. Something like this tank might be useful. Remember the requirement that the tank input must have a 600-ohm impedance!
Does your car radio have 600-ohm, line-out jacks?
YES: Proceed to the next step.
NO: Install an LOA. (Follow instructions that came with the LOA.)
Install a line-level reverb
Connect the tank to the back of the LOA (or line-out terminals).
On to the tank outputs: Add another PA. Connect this PA to the rear (or wet)
speaker. You must be able to control this rear PA remotely. That way, your rear-speaker
reverb channel can fade in and out as you desire.
The dashboard control unit should also have a way of equalizing the sound.
Reason: The reverb tank over-emphasizes bass notes, causing rumble. There's no useful
reverb effect at bass frequencies below 100 or 200 Hz. The tank also weakens
treble notes. You'll need to boost the treble up to a thousand or more Hz. Experts
differ on how high. (Certainly not above 5 kHz, but likely not even that high.) You'll
want to emphasize the midrange notes, where reverb shines. Another trick to attaining that
reverb magic is rolling off extreme low and high notes.
Reverb is an old
effect. To achieve period ambience, avoid trying to achieve broadband response. Instead,
think of your reverb as a musical instrument, like a trumpet or a clarinet: A mellow instrument
with a voice somewhere in the centermost tones. Let it be itself. And just like a moonlit '60s
night, reverb will bring you satisfaction.
▲ WARNING. Anyone who builds these circuits does so at his own
risk. I take no responsibility for your success or failure. If you
injure yourself, damage your favorite oscilloscope or burn your house
down, you pay the damages.
If you aren't an advanced builder and experimenter,
don't even attempt this project.
From time to time, I will update and attempt to improve the information on
this page. I will make changes without notice.
I assume no responsibility for errors or inaccuracies that might occur on
these pages.
♦ NOTICE. If you'd like to contribute ideas or suggestions,
email me. Submitted ideas and suggestions become the property of
Hawes Amplifier Archive. I try to mention the source of
anything I use.
♦ NOTICE: FURTHER INFORMATION. The details that I have appear on these
pages. As I learn more, I'll add more data. Please don't email me for more
information.
♦ NOTICE.None of the reverb units on this page is for sale by me.
You might find one on eBay, though.
♦ NOTICE: Repairs, Modifications. Buy a Sams PhotoFact (schematic)
set on eBay. I don't have, nor do I provide schematics. I don't repair or modify
reverb units.
