by Gary A. Galo, Contributing Editor
IN THIS ISSUE I'LL CONTINUE with the fourth installment of my survey of electronics supply houses, including a source for component cases, to house your projects with a 'professional' look.
Sunix, Inc.; 3850 Steeles Ave. W., #5; Woodbridge, Ontario, Canada L4L 4X6, (416) 856-2222.
Sunix makes rack mount steel cabinets at very reasonable prices, and these appear to be their only products. Their single sheet flyer lists seven different sizes, from $14.50 to $37.50. Each cabinet contains an aluminum front panel, four steel side panels, steel top and bottom plates, aluminum handles, screws for assembly and rubber feet. The front panels and handles are black anodized and Sunix also carries white rub-on letters to complete the projects.
Unfortunately, steel is not the best ma terial to use for audio equipment chassis, due to its permeable nature. All-alumin um chassis are preferable. I realize some dispute this and claim that a ferrous chas sis will have no effect on the sound, but I wish Sunix would offer their cases in all aluminum versions. Perhaps these com ments will persuade them to consider this possibility. These cases should be ideal for test equipment projects.
Ora Electronics; 20120 Plummer St., PO Box 4029, Chatsworth, CA 91313; 1-800-423-5336, outside CA; or 1-800 382-3663, (818) 701-5848, locally.
Ora is the best source I've seen for Japanese transistors of the 2SA, 2SB, 2SC, and 2SD varieties, with eight pages of listings for these devices. They also carry the Hitachi 2S] and 2SK series of MOSFET power devices, including some which are used in the Hafler power amplifiers. Beyond this, Ora's offerings are oriented toward the service techni cian. Their catalog is filled with replace ment switches, cables, connectors, lamps, motors, tape heads, fuses and the like.
Several bench power supplies are also of fered. There is little here to help audio amateurs, but those hard-to-find tran sistors alone may be worth a phone call for their catalog.
East Coast Transistor; 2 Marlborough Rd., W. Hempstead, NY 11552; 1-800- 645-3516, outside NY; or 1-800-632-3323.
Like Ova, East Coast Transistor is an excellent source for those hard-to-find Japanese devices, with ten pages of listings, including twice the number of 2SJ and 2SK MOSFET devices as Ora, and this catalog is oriented toward the service technician, also. There's little else for the audio amateur, but they might be just the place to find MOSFETs for your next power amp project.
Jensen Tools, Inc.; 7815 S. 46th St., Phoenix, AZ 85044; (602) 968-6231.
Jensen's is the Mercedes Benz of tool catalogs, with premium quality tools for any electronics need, featured in abundance. Jensen is not a bargain-basement, discount operation. You pay premium prices and receive quality commensurate with your investment. They have the nicest selection of tool cases I've seen, including aluminum, wood-vinyl, polyethylene and injection molded types.
Jensen also features complete tool kits for a wide variety of professions. A typical kit includes a premium quality case, with the tools you are likely to need for a specific line of work. For example, their Basic Service Technician's Kit (#523B710) consists of over 40 tools, including various types of pliers, screwdrivers, nutdrivers, alignment tools, a soldering iron and much more, with a wood/vinyl case, for $189.
If your needs are more elaborate, you might consider their JTK-87 Portable Electronic Service Center, with over 100 tools and a ‘Super Tough ' polyethylene case, for $456. You can also buy it complete with a B&K portable 15MHz dual trace 'scope and a Fluke 8021B Digital Multi meter for $1440.
In my opinion the Fluke meter is over priced. You get much more for your money from the Tenma products carried by MCM Electronics (see this column, issue 2/88). Jensen also supplies smaller tool kits. The beginner might consider their JTK-1 Basic Tool Kit, which they recommend for student technicians and kit builders. Twelve tools are included, with your choice of vinyl roll pouch or metal box, for $59.
Most kits appear to be supplied with a Jensen soldering iron. Jensen claims these modular irons are made for them by a 'leading US manufacturer. ' They look similar to the Ungar irons which I continue to prefer. They also carry the Weller irons and Weller desoldering stations, including the most expensive one I've seen, priced at $933! Jensen carries a variety of test equipment, from B&K, Fluke, Beckman, Trip lett and others. Again, many of these items can be found for less money else where. When it comes to tools, however, I don't believe in cutting corners. I'm still using a pair of Chan-Nel-Lock long-nosed pliers I purchased for $5, from a local hardware store 24 years ago-a lot of money for a seventh grader, in 1964. Yet these pliers have received as much use as any tool I own, and they remain the equal of anything you can buy today. Long-term investments do pay off, and this is the level of quality you are likely to receive from Jensen.
Dick Smith Electronics USA, PO Box 468, Greenwood, IN 46142; (317) 888 7265. Catalog is $2.
Dick Smith, an Australian entrepreneur, founded a chain of stores for electronics hobbyists in Australia many years ago. He is also a bit of an eccentric. A catalog a few years back showed a photo of him jumping a dozen or so motorcycles with a double-decker bus.
The motorcycles were trashed, but he attracted a lot of attention. Dick Smith's initial expansion to California was financially unsuccessful, but in 1987 john Styles stepped in, bought the US branch and moved it to Indiana.
Dick Smith still caters to electronics hobbyists and offers many kits and projects of the Popular Electronics variety.
They do carry audio kits, including the Playmaster 45W/channel MOSFET integrated amplifier for $199.95. I believe this was originally a project in Radio Electron ics. There are also inexpensive MOSFET power amplifier kits and preamplifier kits. A 100W MOSFET power amp kit sells for $64.94, not including power sup ply and chassis. I have no idea how good these are. [A review is upcoming this year.-Ed.| Dick Smith carries a variety of low cost test equipment, some available as kits. A 500MHz frequency counter can be built for $129.95. They also carry assembled test gear from B&K, and for amateur radio operators, the complete line of Kenwood ham gear is listed. I thought (hoped) the CB craze ended years ago, but Dick Smith's catalog features CB radio gear in abundance.
The Dick Smith catalog also features books, including a large assortment from Sams and TAB. Amateur radio and short wave enthusiasts will find the complete ARRL book listings, as well as well known items from Gilfer Shortwave.
Many boxes and cases for projects are carried. Perhaps the most valuable discovery is their line of 19-inch rack mount enclosures. Like the cases from Sunix, these are steel with aluminum front panels (I called to confirm this). Their all aluminum 'high-tech' enclosures are also extremely attractive, and the lack of permeable metal will probably have positive sonic effects on your projects.
Many electronics parts are stocked, including the Texas Instruments TL070 series of bi-FET op amps; the 25K134 and 25J48 power MOSFETs, along with many other transistors; polystyrene capacitors in values as low as 33pF, and 1% metal film resistors. I don't have experience with their capacitors and resistors, so I can't vouch for the quality. You'll also find a variety of panel meters. Much in this catalog may not be of interest to audio amateurs, but these items make it a worthwhile investment. You pay $2 for a catalog, plus it seems to bring a subscription to your door.
ARS Electronics, 7110 De Celis PI., PO Box 7232, Dept. C, Van Nuys, CA 91409; (800) 422-4250; (800) 422-4277 (California only).
ARS Electronics bill them self as a vacuum tube specialist, and their one page flyer lists a variety of interest to TAA tube advocates. They claim to cater to audiophiles and offer premium quality tubes for high-end gear from such manufacturers as Tungsram, Telefunken, Gold Lion, Mullard, Siemens and Amperex. If you're looking for tubes for your next project, or replacements for existing gear, matched power output tubes are available, and they advertise tubes for popular amplifiers, such as Audio Research, Conrad Johnson, Counterpoint, McIntosh, Jadis, Quick Silver, Dynaco and others. They require a minimum order of $50, but that's easy, given the current prices of tubes.
K.E. Lang, 6501 Lancret Hill, Austin, TX 78745; (512) 441-3479.
In my latest turntable article, (TAA 3/88), I recommend the Lang cartridge mounting hardware. This stainless steel hardware is the best I've seen for this purpose. I recently received a new flyer and letter from Colonel Lang. Contrary to what I stated in my article, he informs me more than one length is available- the screws come in 8mm, 12mm and 20mm.
Lang also carries some other items of interest to TAA readers. His Ultimate Speaker Connector is a solid brass (no plating), dual binding post of sturdy construction, supplied with OFHC copper ring terminals; $12 a pair. Lang's flyer gives a lengthy discussion regarding the disadvantages of gold-plated contacts in high current applications. Items for con trolling unwanted resonances include Ultimate Damping Compound (which he says is better than Sorbothane) and Ultimate Tube Dampers.
Lang carries Neglex 2534 cables and connectors (I prefer these also), plus Neglex hookup wire, and has a small selection of Siemens polypropylene and polystyrene capacitors. I recommend sending for Lang's flyer; a stamped, self addressed envelope is appreciated, but not required.
Printed Circuit Boards With 17 Projects by Calvin Graf; TAB 1988, 207 pp., soft bound; $15.95.
How to Draw Schematics and Design Circuit Boards With Your IBM PC by Steve Sokolowski; TAB, 179 pp., soft bound; $13.95.
Two books on printed circuit board design have recently been released. New from TAB, Printed Circuit Boards With 17 Projects, by Calvin Graf, covers a great deal more than circuit board design. Five chapters are devoted to introductory material, including Graf's introduction to basic electricity and his explanation of the atom, which is among the most understandable I've seen. He presents a survey of the commonly used electronic components, and a brief tutorial on reading schematic diagrams.
He also devotes an entire chapter to electronic assembly tools. Novice audio amateurs should find these introductory chapters extremely useful. Soldering and desoldering tools are given special attention, including a photo of Radio Shack 's
$7.99 desoldering iron, which I still find ideal for pulling those 28-pin D/A converters out of the Magnavox CD players.
Circuit board repair techniques are covered, along with construction tech niques appropriate for prototyping, including breadboards and perfboards.
Roughly half the book is devoted to ac tual circuit board design and construc tion, including various commercial products and mail-order sources. The book concludes with seventeen projects you can build, but don't look for any high end audio projects here. These simple de vices include a light sensor alarm, auto motive headlight reminder, low-level audio amplifier and a battery eliminator.
For the advanced builder, this is not a replacement for the Goldberg book sold by Old Colony, but beginners should find it useful.
Among the kit suppliers listed by Graf, the address given for Dick Smith Electronics is no longer current. I discussed this firm in my survey of suppliers in this issue.
Also from TAB, Steve Sokolowski's How to Draw Schematics and Design Circuit Boards With Your IBM PC is a disappointment. Also supplied is a 5% inch disk containing 15 programs for the IBM PC, written in BASIC. According to Sokolowski, these programs will run on any IBM compatible computer equipped with BASICA or GW BASIC, but with my fully compatible XT clone with GW BASIC, I didn't get very far with these programs. The first, INTRO.BAS, gave me a 'syntax error in 150' message. I checked the disk and line 150 was not in agreement with the code printed in the book. Many other programs gave a ‘line buffer overflow ' message when I at tempted to load them.
I tried these programs on a genuine IBM PC with similar results. I loaded his DESIGNER.BAS program, but the reset function, which clears the drawing window, did not return the drawing window to its original position. Each time I selected reset, the drawing window moved upward and was eventually off the screen. Since the author mentioned the programs should run on a Tandy 1000, I visited my local Radio Shack and tried them on a new 1000 SL. I loaded IN TRO.BAS, but CLEARSCR.BAS gave another 'line buffer overflow ' message.
I loaded DESIGNER.BAS, but the drawing window was filled with vertical lines that I could not remove.
The disk would be much more useful if these programs were written in an up to-date programming language and com piled as stand alone (.EXE) files. Interpreted BASIC is an obsolete PC language, and has become unnecessary with the excellent BASIC compilers available.
Microsoft's QuickBASIC and Borland's Turbo BASIC are both available at street prices of around $55. I use QuickBASIC 4.0 and find it excellent. Supplying com piled programs would eliminate any chance of incompatibilities with various interpreters. As it stands, users had better be proficient BASIC programmers, since rewriting a lot of code may be necessary to run the programs on whatever version of GW BASIC or BASICA they use.
These programs only support the old CGA standard in the 640 x 200 mode. I don't believe anyone can do serious circuit board layouts using these programs, even if you can get them to work. The Color Graphics Adaptor is not a PC standard to be taken seriously anymore. It really never was, which is why the Her cules Graphic Card became so popular prior to the introduction of EGA (IBM's Enhanced Graphics Adaptor). Mono chrome or not, Hercules was the highest resolution graphics standard generally available before the PS/2 VGA standard came along.
Serious CAD work is a real nuisance with mediocre CGA resolution. For these programs to be more useful, EGA resolution must be an option. The author justifies this book, stating CAE (Computer Aided Engineering) software is not available to hobbyists of modest means.
That is no longer true. Excellent CAD programs such as DesignCAD 3.0 and Generic CADD 3.0 are available at street prices of around $150. Although not specifically designed for schematic drawing, both programs have electronics symbols libraries for this purpose. Generic CADD is modular; you buy only what you need.
DesignCAD contains all features at one price. They can also be used effectively for PC board design and high resolution VGA color graphics, as well as EGA, CGA and Hercules, are supported by these programs.
Audio amateurs have a great deal to gain from personal computers. I'd like feedback from readers on this matter. If there is a positive response, I'll comment from time to time on computer matters of interest to audio amateurs. Let's hear from you. O SOURCES Design CAD 3.0 American Small Business Computers Inc. 118 South Mill St. Pryor, OK 74361 (918) 825-4844 Generic CADD 3.0 Generic Software 8763 148th NE Redmond, WA 98052 (800) 228-3601 QuickBASIC 4.0 Microsoft Corp. 16011 NE 36th Way, Box 97017 Redmond, WA 98073 Turbo BASIC Borland International 4585 Scotts Valley Dr. Scotts Valley, CA 95066 Perhaps the fastest and cheapest mail-order source for these products is: Telemart 8804 N. 23rd Ave. Phoenix AZ 85021 (800) 426-6659 READERS' QUESTIONS Regulator Woes I'm building Pat Amer's Aurora preamp (TAA 3/87)and I've run into a bit of trouble. The power supplies are built and in stalled. The filament supply works fine but the B+ regulator passes the full voltage (+ 337V). I've replaced the tran sistors and resistors twice and the zener diodes three times, and still no success.
Could TAA offer any help? (I'm sure Pat Amer is sick of hearing from me.) I recently purchased the Waldron crossover (the Old Colony kit sale was too good to pass up) and the all-tube B + version of the power supply looks like it would be great for the Aurora preamp.
I've changed it for the Dyna transformer (see schematic, Fig. A) but can't find a formula for calculating the resistor value (to limit the current to the regulator tubes). I tried Ohm's law on series resistance and current but got a very high resistor value. I appreciate any help you can offer.
By the way, I've found it impossible to find 5W Zeners of any large size with an amperage rating of more than 10mA; most places suggest 10W stud mount Zeners.
Alan Johnson Lynn, MA 01902
REPLY
The formula for calculating the resistor value is:
R = (Es – E)/1
where R is the series resistor, Es is the unregulated source voltage, E, is the rated voltage of the regulator tubes and I is the maximum tube current.
With most regulator tubes, the value will be 40mA. (See The Radio Amateur's Handbook, 1986 edition, pages 6-13 and 6-14).
------------- FIGURE A: Aurora power supply.
From the formula, it would seem that your resistor value is way too low.
Assuming that E is around 350V, and that your regulator tubes in series are 255V, the correct resistor will be 2,375 ohm, with a current value of 40mA.
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REVIEWS By Gary Galo