Since moving to the Twin Cities, most of my business relationships
have begun via e-mail. And, because it’s sometimes hard to judge
whether the “Johns” want real service or are attempting to
engage in some fantasy-based role-playing, the interaction has the
feeling of an online porn message board. Once successfully past the
courting/screening phase, however, relationships are generally
long-term.
THE WRITE STUFF
Until writing this article, I never thought that the
courting/screening phase would be such a challenge, especially with
those curious souls who won’t (or can’t) compose a decent e-mail,
leaving me to figure out their all caps/no punctuation/complete
stream-of-consciousness messages. Did these people ever go to high
school or are they just so “excited” about the release of
audio information that they can’t write and think at the same time?
IS IT WORTHWHILE TO UPGRADE?
I welcome (and congratulate!) those correspondents who ask the
“right” questions; you’ll find the answers below. On my
good days, my proactive response to the “wrong” questions
is to write an article or update my Website. On
“crustaceous” days, some people find out just how sensitive
my trigger can be! Somewhere in between Captain Nice and Captain Nasty,
I become the nearly apologetic Great Inquisitor, grilling the
techno-curious so that they better understand their goals. I often ask
for CDs of their best work or a sample of whatever the problem might
be, and only go for the jugular after discovering an ulterior
motive.
Way back in October 2000, capacitor and op amp upgrades were
featured in “Tech’s Files,” a topic that generated numerous
inquiries. The question is not whether an upgrade is possible —
anything can be done for a price — but what other impediments to
sonic bliss are taken into consideration. You wanna make the investment
worthwhile, right? What good are faster op amps and low-leakage caps if
the pots are scratchy and the switches are intermittent? I’d fix those
items first, or bail.
Exact replacement parts for a recording console that is 10 to 20
years out of production are not likely to be readily available. In this
case, older is better, because newer products use application-specific
pots in terms of bushing, shaft and knob dimensions. The better
“generic” pots are easily $5 to $10 a pop. Their shafts
will be round and not keyed, longer than required and not compatible
with the old knobs. Upgrading 24 channels of mic preamp hardware could
cost $600 in parts — a deal if D.I.Y. — but add the labor
and you might as well have bought new preamps.
OP AMP OFF-RAMP
Some of the replacement pots for a Sony MCI 600 Series console, for
example, would be customized parts that typically cost $25 to $50 each
and require a 25-piece minimum from a pot manufacturer. I do not
believe those parts are available from Sony, but www.blevinsaudioexchange.com is worth a
look-see.
Because of the Internet, awareness of op amp options has never been
higher. Every geek has a preference: Some may arrive at their choice by
extensive research, others may be content just finding a better part. I
don’t really want to compete or pass judgment on what other people are
doing, yet many people put me in that position. If you’re looking for a
turnkey upgrade, www.audioupgrades.com has a list of popular
recorders, consoles and signal processors — including prices. I
can’t speak for the company’s work, but you gotta admire the site for
its detail; it’s definitely a great reference source.
Of course, there are improvements for the oldest op amps, such as
the 709, 741, 4136 and 301, but not every op amp can be easily
upgraded. Here’s one very obtuse example: An Eventide Omnipressor uses
an LM301 single-channel op amp in the DC sidechain as a comparator via
pin 8. The circuit in question, detailed in Fig. 1, allows users to
limit the maximum gain and attenuation. Figure 2 shows the
standard single op amp pin-out (I/O on pins 2, 3 and 6, power on
4 and 7) plus the LM301’s pin 8 idiosyncrasy.
YOUR PIN CONNECTION
Also note the 1k-ohm input and 33k-ohm feedback resistors;
comparators typically have lots of gain. Two identical resistors would
result in unity (zero) gain. A careless attempt at a
substitution/upgrade would make the Omnipressor nonfunctional. A lucky
guess and a spare IC fixed that problem. An LM301 is more than adequate
for the application.
DAT ATTACK
Eighties-era Panasonic and Otari semipro products featured XLR
connectors but were unbalanced: One company chose pin 2 hot while the
other chose pin 3 hot. Interfacing with standard XLR cables did not
yield a signal. Combine external wiring, patchbay variations and a
slightly unstable circuit design, and the unexpected will be the norm:
mysterious crosstalk, oscillation or worse — smoked and fried
tweeters. At the patchbay, for example, are the sleeve/shield
connections independent or bused together? If the latter, are they tied
to ground? I bus and ground patchbays, wired to multipin
connectors and then hold up the garlic when a client wants to rewire a
punch-block bay.
POWER 2 THE PEOPLE
Consider the DAT machine for sale on eBay for $150. Some people are
willing to take their chances rather than paying more for a rebuilt
machine with a warranty. Worth at least $450 with a 90-day warranty,
the chances of finding a machine in good condition for $150 are pretty
slim. Reading an eBay seller’s comments, you’d think that they were
pitching a fine used car. I guess I’m just too honest. I recently sold
some tape machines and accessories to a guy who spotted an ad on my
Website; the stuff had been “up” for at least a year. I
spent several days making sure that everything worked. Who wants the
hassle of shipping stuff back and forth?
ALL YOU NEED IS TRUST
A customer with money to burn put a deposit on a balanced power
transformer and then asked my opinion. After a little inquiry as
to why they bought their BPT, it was determined that they weren’t
concerned about noise issues but rather, in the summertime, the high
level of power demand in their neighborhood dipped the juice to below
acceptable levels. One solution is to contact the power utility
company, get it to confirm the sag and retap the transformer to bring
the voltage swing within an acceptable range. Another solution, an
uninterruptible power supply, was posted by John Klett in the October
2003 edition of “Tech’s Files.” A UPS would regulate and
clean the voltage, two things that a BPT cannot do.
READER INVITATION
The moral here is that the quality of service delivered is directly
proportional to the amount of freedom, respect and trust given to the
service provider. Trust in a relationship is an intangible, but
nonetheless critical, component in love and business. Mortgage
companies call it “good faith.” When two parties enter into
an agreement, understanding and trust can ensure mutual satisfaction
and a long-lasting relationship.
Who do you trust and why? Nominate your favorite geek, mentor, lover
or pet.
There are plenty of items to conquer in Eddie’s pursuit of
knowledge — antenna theory being of current interest. Twin City
citizens should checkwww.tangible-technology.comfor the frequency of
his pirate radio station.
