Vintage Guitar - June 2018 - open - 51
all-solidstate replacement model came out.
Cavallé's research indicates that a mere 20
to 30 examples are likely to exist today. So,
yeah, they're pretty thin on the ground.
The quest appeared to have borne fruit
when Cavallé tracked down what was advertised as a UL 730 head and speaker cabinet.
He and the seller agreed to a price, and the
rig was supposedly shipped, but when the
cab arrived - after a long delay - it was the
version designed to accompany the UL 430
bass head. The amp head never did surface.
Still, Cavallé had something - and PayPal
was able to get a refund for him.
Further searching eventually turned up
a UL 730 head for sale in France. After a
few inquiries and a long drive, the amp
was his. The UL 730 did indeed deliver
Beatles sound, as Cavallé had hoped. But
getting there involved another journey.
"At the beginning, I was disappointed," he said. "The tremolo, reverb,
and distortion are not remarkable, to
say the least, and the distortion is the
most primitive I've ever listened to. It's
between fuzz and distortion. I don't
think the Beatles used the effects too
much... maybe in the 'Taxman' solo,
but it's hard to control. At low volume,
it's not interesting. But played louder,
when the amp itself starts to distort,
things start to make sense. It's the exact
same sound you can hear in most of the
Revolver songs. It's a different overdrive.
The sound of 'Paperback Writer' and
all the rest. It's so cool, that I was no
longer disappointed, and actually had
the feeling I have a treasure here."
The circuit (above) is wired much like an earlier all-tube AC30, with Philips "mustard cap" coupling
capacitors and other discrete components. Like the earlier "Vox Blue" Alnico speakers, the ceramic
speakers in the UL 430 (below) were manufactured by Celestion and relabeled for JMI-Vox.