The output impedance of the PV10A at its line output measured about 690 ohms, give or take less than 10 ohms depending on the channel, the setting of the level control, and whether the balance control was in or out of the circuit. The line-level input impedance varied between 39k ohms and 49.5k ohms, again depending on the above conditions. Phono input impedance measured 48k ohms (L) and 52k ohms (R). The output impedance at the tape output was 495 ohms with a 25 ohm source impedance, 1051 ohms with a 600 ohm source impedance; there is apparently a fixed…
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Sam Tellig wrote about the Conrad-Johnson PV10B in January 2002 (Vol.25 No.1):
The PV10B preamp, too, is a reprise of history. A direct descendant of such earlier C-J preamps as the PV1 and PV2, it's plain and simple, with no frivolous features. It's relatively cheap, has been upgraded over the years, and the phono-stage version is an especially good buy.
Despite dumping on me the entire contents of his car's trunk when he visisted to install C-J's MV60 power amplifier, Tor Sivertsen knows not to overload me with gear. He was more interested in my auditioning the PV10B…
Sidebar 3: Specifications
Description: Full-function tube preamplifier. Phono stage gain: 48.5dB. Line stage gain: 18dB. Phono overload: 125mV (frequency not specified). Distortion: less than 0.1%. Frequency range: 2Hz-100kHz (limits not specified).
Dimensions: 11" D by 16" W by 3.75" H. Weight: 12 lbs.
Price: $995 (1993); $1295 line-stage only (2002); $1595 with phono stage (2002). Approximate number of dealers: 103.
Manufacturer: Conrad-Johnson Design Inc., 2733 Merrilee Dr., Fairfax, VA 22031. Tel: (703) 698-8581. Fax: (703) 560-5360. Web: www.conradjohnson.com.
Nature and Nature's laws lay hid in night; God said, Let Newton be! And all was light. —Alexander Pope
Sex, religion, speaker cables, and the laws of physics—sparks fly when those topics are on the table. Witness the recent flare-ups in this magazine about Purist Audio Design's illuminated PAD cables. Many seem to feel this product is breaking new ground in the business of snake oil and pseudoscience.
What interests me in this dispute is the almost regular appeal to "the laws of physics." These get a lot of respect in the audiophile community—they make objectivists of us all. We…
The laws of physics also lie. According to philosopher of physics Nancy Cartwright, "really powerful explanatory laws of the sort found in theoretical physics do not state the truth" (footnote 2). This is because they are about ideal entities that behave, according to the laws in question, in ideal ways. Anything you might stub your toe on, however, or any component you might listen to, is not ideal—it's real. As a result, the laws of physics will lie about it.
Take one cornerstone of Newton's physics, the First Law: "Every body continues in its state of rest, or of uniform motion in a…
Once we've got the laws of physics talking, however, a new problem arises: Should we believe the model? Even if Jim Aud shed some light (sorry!) on all this by showing us a computer simulation of his cables, one which clearly showed how their optics affect their performance, I strongly suspect this case would not be closed. One should still ask: Is the model well-constructed? Does it leave out any relevant factors? Does it make illegitimate assumptions? Just as geophysicists and environmentalists continue to argue over models of global warming, audiophiles and engineers could argue for a…
PATRICIA BARBER: Companion
Patricia Barber, vocals, piano, Hammond B-3; John McLean, guitar; Michael Arnopol, bass; Eric Montzka, percussion
Premonition/Blue Note 5 22963 2 (CD). 1999. Barber and Michael Friedman, prods.; Jim Anderson, eng. John Larson and Tom Reinholdt, asst. engs. AAD? TT: 58:11
Performance ****?
Sonics ****?
Patricia Barber, vocals, piano, Hammond B-3; John McLean, guitar; Michael Arnopol, bass; Eric Montzka, percussion
Premonition/Blue Note 5 22963 2 (CD). 1999. Barber and Michael Friedman, prods.; Jim Anderson, eng. John Larson and Tom Reinholdt, asst. engs. AAD? TT: 58:11
Performance ****?
Sonics ****?
In an aviary full of extravagant mynah birds, Patricia Barber flies alone. For a sensitive lug like moi, she's the ultimate anti-diva, the failed romantic's last hope amid the antediluvian cant of the new classicism.
Now I ain'…
Here in Chicago the other day, I was on my way to an appliance store, so audio was the last thing on my mind. But, as if by some miraculous intervention (or just stupidity), I parked and went in the wrong store: "Why does this appliance store have bins and bins of CDs in it?" Realizing my mistake, I found the stoves and ranges I was looking for next door—but not before noticing bins and bins of used LPs behind all those CDs.
As Agim Perolli suggested recently in "Letters" (June 1997), the LP vs CD debate is wearing a little thin. It's become an endless ping-pong match: I say musicality,…
Note: These photos are a companion scrapbook to Wes Phillips' eNewsletter report.
Welcome to China
China My China
Steel goes in . . .
. . . screen comes out
Building a mold for a remote
Bench dogs in the tool room
Welcome to the machine shop
Casting aluminum baskets
Pressing aluminum domes
Cast speaker cabinets
Tweeter molds
Feeding the pulp slurry
"Pressing" a pulp driver
Finished drivers march off to be tested
The reference library
Old-school woodwork
Really old-school woodwork
Buffing a lacquer finish to perfection
Quality control
More quality control
Low-tech ports
Quad IIs and II-40s
It's Mr. Stretchy
Deburring Quad panels
Pressure molding a big 'un
Look at the size of that mold!
A clew, as they say in Blighty
My…