| In response to the outpouring of e-mails and phone calls
we have received
regarding the re-issue of the PDI-03, the original designer
and manufacturer,
Martin Schmitz, has graciously agreed to answer your questions.
Now you know everything we do!
Happy Reading!
JAMS Audio www.palmergear.com
INTERVIEW WITH MARTIN SCHMITZ - May 25, 2005
Would you tell us a little about yourself?
It all started with a Christmas present - an electronic
experiment kit. I was about 13 years old and from that time
on I spent most of my
pocket money for electronic components. It was the time when “The
Beatles” fever broke out in Germany and my interest
quickly focused on
musical electronics.
During my time at the university I got a side job as a repairman
in a music shop. This was the time when I received my “real” education
in electronics.
When and where did you start Palmer?
It was in the summer of 1978 when I started a small production
of tube amplifiers.
January 1981 is when Palmer officially became my brand name.
(In Germany, bureaucracy is a big lame duck which cannot
be by-passed.)
Very soon after we had started the amplifier production
I realized
that only by making our own transformers could I get complete
control over the sound.
It was a small step from tube transformers to quality microphone
and
line transformers. The growing public address (P.A.) market
in the 80’s
created a demand for audio tools we called the DI boxes,
signal
splitters, isolation boxes and so forth. I turned my focus
on
these products. In 1989 the amplifier production was ceased.
After about 500 amps, the decreasing quality of available
tubes at the time had crucified me.
What are you doing now?
I am in charge of the Palmer Products division of Adam Hall
GmbH.
Today many Palmer products are based on the transformers
which we produce
here in Germany. Additionally, to stay in touch with the
current
developments in live sound and recording studio technique,
I give classes
in electronics at an audio engineering school.
PDI-03 RELATED QUESTIONS:
What year did you release the original 03?
I built my first simulator in the seventies to use in my
tube amplifier
workshop. We used a special unit which we called the “silent
speaker”
which eliminated the noise in the air when testing our amps
fully cranked.
I did not like the load boxes made with resistors. As a
repairman I had
seen a good number of amps killed by the use of an Altair
Power Attenuator
(at that time a very popular item). Based on the literature
of
Thiele/Small I had built a circuit which simulated the impedance
behavior
of a guitar speaker in a box. This became the load part of
the silent
speaker. To have an acoustic control I included a filter
to simulate the
frequency response of the speaker as well and fed the signal
into my old
stereo. Everybody was happy with it, especially our neighbors.
Home recording had become popular. It was only logical to
convert our in-house "silent speaker" into a commercial
product.
The term "silent speaker" was altered to Speaker
Simulator.
During the Musikmesse 1989 in Frankfurt (this is the equivalent
show to the Winter NAMM in Anaheim) the Speaker Simulator
was first
displayed at a trade show. It was also in our product flyer
1989/90.
How many versions were there? What were the major differences?
The original unit was only labeled “Speaker Simulator”.
Inside is one
main pc-board. Potentiometers, sockets and switches are connected
with
leads to that board. The resistive part of the load comprises
3
aluminum cased resistors on a bent aluminum sheet metal.
Though the
resistors were rated at 150 watts, the unit got really hot.
The sound
could be varied with two switches, flat or deep for the low
end and
mellow, normal and bright for the treble end.
One of the first modifications was to replace the heat sink
with an
aluminum extrusion and to add one more resistor to make the
unit run
cooler.
In 1990 all Palmer products got stock numbers. Since we
had a passive
DI box (PDI-01), an active one (PDI-02), and the Speaker
Simulator was a
kind of Direct Box it became PDI-03. After October 1990 all
units were
issued with a serial number. In January 1994 the “battleship
grey”
housing was replaced with a metallic anthracite color and
the silk screen
printing was green. Also the metal knobs, a surplus from
the amp
production, were replaced with plastic types.
The last PDI-03 was made in July 1996.
The other electric modifications were marginal. For easier
production the potentiometers and sockets were put on auxiliary
p-c boards. The switch for the low end response received
a third
position which is between Flat and Deep. The 1K log taper
potentiometers were replaced with 10K linear types and
a 1K resistor,
because of the large tolerances. The potting boxes of some
components
have changed due to availability.
But I never ever have changed the filter circuit. It is
the original
filter design that was used for my workshop model. Since
the beginning,
we used 5% capacitors and 1% resistors in the filter network.
We've read reviews that say the PDI-09 and PDI-03 have the
same filter
circuit. Is that true?
Yes. The PDI-09 uses the same highcut-filter circuit as
the PDI-03. The
PDI-09 is nothing else than a PDI-03 without the load part
and the
signal splitter feature. The PDI-03 has an extra (switchable)
bass boost.
Oh! In the mid 90’s the “Normal” position
was made a bit softer, but
this is the only sound modification the PDI-09 has ever gotten.
What is the difference between the PDI-03 and PGA-04 filter
circuits?
The PGA-04 was my answer to customers asking for more versatility.
Though you may read many different comments, the heart of
the PGA-04
is the original filter circuit with the two switches replaced
thru
two potentiometers for a continuous control between the extreme
positions of the switches.
The original 03 is surrounded by
almost legendary status. We found
one on E-Bay today that was selling for $1200. If you can,
please explain
the mystique surrounding the PDI-03.
I can only guess, but the fact that the PDI-03 was used
and praised by some
very popular artists and producers, the unavailability in
the U.S.
for the normal customer, and that Palmer is a small boutique-like
company without publicity could be the reason.
We know you are excited about the re-issue of the PDI-03.
What prompted you to re-issue it?
There existed a patent for a unit that claimed to do the
same job as a PDI-03. Though I never had seen the unit before,
this guy threatened me with legal action and defamed me as
a thief having stolen his ideas.
Ridiculous. Palmer did not infringe upon anyone else's patent--and
now the patent has expired. It looks that there is still
a demand for a more authentic speaker sound even after all
the modeling amps with digital speaker simulation. E-Bay
is the confirmation. Shall I wait until I see a knock-off
copy from China?
How close to which original is it?
It will be a re-issue of the early 90’s model with
the "battleship grey" housing, metal knobs, and
of course the improved heat sink.
Is it the exact same technology as the older 03 or is it
a new design?
How much is it going to cost?
Fortunately we kept all the production paperwork and test
charts. And
hopefully the fact that the new housing is laser cut instead
of
punched will not influence the sound.
The price will be the same as for the PGA-04.
When do you expect to have it ready for release? What are
some of the
problems you have had with trying to get it back in production?
Since we had all the production documents I was very optimistic
to restart
the production very fast. But it turns out that we have had
some
difficulties in getting our components. Especially the switches
which
used to be “off the shelf components”. We are
now having to get them custom
made for us.
Martin, thanks so much for taking this time out of your
busy schedule for this
interview. Are there any closing comments you would like
to add?
Please allow one (very last) comment about the PGA-04 vs.
PDI-03 discussion.
The PDI-03 was a very simple to use piece of equipment. You
couldn’t go
wrong. With the more versatile PGA-04 you can produce some
really weird
sounds. But this does not mean that -as some people say-
the PGA-04 is
rubbish.
In case someone is telling you that, please charge him with
twice the price
for his PDI-03.
Martin. Martin. Martin. You know we can't do that! (Can
we???)
Thanks so much for a great interview! |
