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Modification Manual for Vacuum Tube Electronics.
Audio Dimensions, Inc., Suite K, 8898 Clairmont Mesa Blvd., San Diego, CA 92123. Price $25.00.
Are you an audiophile who builds, uses, or modifies tube equipment? If so, you may be interested in the Modification Manual For Vacuum Tube Electronics. The basic manual is a catalog of preamps, power amps, and their power supplies. A few other interesting schematics are presented here and there, including a dynamic expander and a nuvistor sub-preamp.
As the title implies, most of the circuits are aimed at modifying commercially manufactured gear or kits.
The position taken by the author/editor of the manual contends that vacuum tube audio circuits are absolutely superior to transistor circuits for voltage and power amplification and electronic crossovers, while peripheral functions, such as equalization, companding, and noise suppression, are usually done better with solid state devices. The emphasis has been placed on the sonic performance, although the introduction states that the circuits' measureable performance has been "validated by the finest test equipment available."
Although the author expects many readers to be far more technically qualified than himself, he remarks that modern technology has neglected the vacuum tube, and that few engineers have been given more than a cursory look at tube theory. Unfortunately, readers will not find much in the manual to answer their theoretical questions, and those less familiar with the rigors of electronics may be mislead by technical errors or unfounded generalizations. For example, when the author is discussing the difference between a tube and transistor power amplifier, he states: "This is usually attributable to the predominance of second harmonics, in the Eico's output, and to the fact that the output of a transistor is the logarithm of the input voltage, whereas the output of a tube is linear." (Fortunately, Nelson Pass wrote a letter, subsequently published, which rectified this erroneous statement for those not technically minded.)
Circuit modifications range in complexity from the simple addition of a bypass capacitor to the total replacement of all circuit components including external capacitors and transformers. Both power amp and preamp modifications are presented as a series of steps, each complete in themselves. It is left to the reader to decide how far he wants to go. Since the instructions are rarely stated in great detail, it must be assumed that the modifier has had sufficient technical experience to interpret and implement the text. A handy scheme is shown for checking the tracking of dual pots using a battery and a meter.
The instructions involve observing fluctuations on the meter. Since no guidelines are given for the type of meter to use, or the sensitivity of that meter, the reader must either already know or must find out what response is acceptable. The easiest modifications to perform are those for the popular Dynakits because they are the most detailed. A typical step for a Stereo-70 mod goes: "The two red leads (perhaps faded to pink) from the transformer are connected to the unbanded ends of the first diodes...." Some judgment should be enlisted before digging into the more sophisticated projects, especially when not following the step-by-step instructions.
Is the dual differential amplifier driver labeled the Perfect (?) Amplifier, going to blow away your Marantz 9 input and driver? Suppose that you build the nuvistor pre-preamp recommended by ADI but find it unusable in your system due to the microphonic problems with these tubes? What if you cannot stand 10 times the noise of your transistor pre-preamp? The manual too often skirts such possible limitations; allowing the reader to choose alternative circuits might be satisfactory for a particular use.
Nevertheless, the manual will provide a wealth of ideas to those interested. One may see a great cascode preamp front end, and try it with much success in an output stage.
Most of the modifications do make good sense too. One often suspects that a manufacturer would have liked to put in those larger filter capacitors or some metal film resistors in place of a less expensive type. Such practice is worth the few dollars and hours.
In addition to the basic Manual (with supplements 1 & 2), there are now at least three more supplements. The latest supplement includes Dahlquist speaker mods, reports on an unusual cartridge, and other varied and interesting data. It is encouraging to see that each supplement seems to be better than the previous.
So if you are interested in building or modifying for performance some tube apparatus, or you want to upgrade your system on a limited budget, you will want the Manual in your library. The cost is $25.00 for the book and all previous supplements, and future supplements on a bimonthly basis. In addition, those that buy the manual can consult ADI without charge if they encounter any stumbling blocks and need assistance.
If all this appeals to you, contact ADI.
The Album Cover Album: Edited by Hipgnosis and Roger Dean. Dragon's World, softbound, 160 pages, $10.95.
There's so much to like about The Album Cover Album that it's difficult to know where to begin.
This is one of the few books I've encountered which attempts to portray album cover artwork as an art unto itself, distinct from the music. (I'm not counting Roger Dean's Views, a one-man show which made no pretense to the overview that Album has. However, let me add that Dean's book is absolutely beautiful to behold and its success made the present volume possible.) Cunningly assembled and designed by English record design wizards Hipgnosis, who deal primarily with photographic effects in their work, and Roger Dean, who is best known for the remarkable series of paintings he did for Yes, The Album Cover Album is obviously a labor of great love and affection. As a large-sized book-a foot square, nearly the same as your basic record album-and lavished with vivid color reproductions, The Album is a banquet for the eyes, with many fine, little, almost imperceptible touches.
The covers on a given page have been coordinated to that page's mat color.
The mats themselves are arranged with sequential coloring that creates a real flow and pulse to the book. There are passages that subtly build, covers set in gradually increasing size and intensity until a full-page illustration explodes. Thus, the page designs vary consistently, giving the whole a life and verve few art books match.
In designing different parts of the book, and indeed individual pages throughout, Dean and Hipgnosis used an amazing number of clever hooks.
The brief, illustrated design history at the front of the book effectively contrasts the garish pop music covers of the 50s with the cool designs of that era's jazz albums, which in turn opened valuable design frontiers that helped bring on the psychedelic explosion in designs of the late 60s. The bright tan mats of the earlier albums yield dramatically to softer tones in shades of grey for the 70s. There are page displays on ways to use an individual portrait, how to use a group, different expressions of couples. Surprising similarities strike you in the use of train images and especially in the use of automobile imagery. A page shows views inside cars, and another shows variations on the false impression of a wrapped package. One page deals with stylized logos, and another with variations on Chicago. A delightful two-page spread shows albums with covers painted by the recording artist (Joni Mitchell, Bob Dylan, Cat Stevens, and others). Some pages just look nice together.
A powerful four-page sequence has four portraits to a page; softly focused ladies opposite stylized and distorted men, followed by contorted, kinky females opposite male model-type portraits. Coincidentally, both Carly Simon and David Bowie appear twice in the four pages.
Record fans will appreciate the text pieces. The forward gives a concise illustrated history of record wrappings, while the afterward relates the path of a cover from the art director through execution to the completed and stuffed commercial product. Both pieces are clear and succinct, adding much to the book.
The big point is that The Album Cover Album is all anyone could have hoped it would be. If you carp about certain selections, there are doubtless 15 others that will surprise and even delight you. And it does make the perfect holiday gift this year. Try to get an extra copy for yourself if you can't con someone else into giving it to you, but make sure you get to see it, because all any other designer can hope to do now is to equal this indispensible volume.
Michael Tearson, John Hammond on Record: Autobiography with Irving Townsend -- Ridge Press/Summit Books, 416 pages, Hardbound, $12.95.
No thrill in the process of recording music exceeds that of the man who hears something nobody else has heard before, then brings it to other people to hear, and watches a star being born before his amazed eyes. That kind of a thrill has not happened to anyone as often as it has to the legendary John Hammond. His discoveries include Billie Holiday, Count Basie, Teddy Wilson, Charlie Christian, Helen Humes, Aretha Franklin, George Benson, Bob Dylan, and Bruce Springsteen. Others he has championed include Pete Seeger, Leonard Cohen, Bessie Smith (who under his direction, late in her career, recorded Gimmie a Pigfoot), and Hammond's distinguished brother-in-law Benny Goodman.
I was previously acquainted with the man through the records that he has been instrumental in recording and the reissues he has assembled (there is a full discography included in the book). The autobiography begins his story in youth as a descendant of the Commodore Vanderbilt in a family of considerable wealth, and how, in spite of this, he forged an intense egalitarian spirit along with the mind of a reformer. Later, he served on the NAACP board for over 30 years, a side of his person previously completely hidden from me. Later, as a reporter, he covered the explosive and infamous Scottsboro trials for The Nation.
Avoiding the easy way out, he enlisted during WW II, and the account of his private war with the Army is delightful.
The core of the book, naturally, is the recollecting of the 30s and Hammond's era of discovery, in which you get rare personal glimpses into many great musicians. Hammond's narrative is comfortable, like hearing him ramble on, sitting in front of a fireplace.
He relates his thrill of making a discovery and the remarkable enthusiasm it would create in him. His greatest love (outside of his family, I'm sure he would hastily insert) is to be moved by great music, great performances, and great performers.
Hammond also mentions his failures. One eloquent example discusses his inability to properly capture Aretha Franklin on record only to watch Jerry Wexler of Atlantic make it all click.
The autobiography also reveals plenty about company politics, as well as the opportunities offered by large companies like Columbia, and smaller outfits such as the early Mercury or Vanguard Records, labels which John worked for.
(Source: Audio magazine, Feb. 1978, )
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