Welcome to TigersThatRoar

TigersThatRoar is dedicated to preserving the history of Southwest Technical audio equipment, and providing tips for collectors are restorers. Over time I will be presenting more and more content. My goal is to provide as much information as possible on each item, including construction details, magazine articles, photos, tech how-tos, and web resources. Stay tuned!

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10 Responses to Welcome to TigersThatRoar

  1. Gary Baebler says:

    Does anybody have documentation on that digital meter they made? It consisted of a display unit and interchangeable modules. I only had the multimeter one but I believe there was a freq. counter and a cap. meter.

  2. Bob Mohar says:

    I have a pair of Universal Tiger “B” #275 amps; with all documentation–schematics, wiring diagrams, parts list.

    I have SWTPC 1975 catalog.

    And 198/A preamp (missing wood cover) with all documentation.

    Anyone interested?

  3. Art Rivard says:

    I’ve been following and repairing Meyer amps since the 70’s; I own a pair of B’s, as well as magazine articles going back to Meyers FIRST EVER SS amp. I can’t lay my hands on it right now, but I think it was in Electronics World, about 1959, and used a pair of Delco TO36 Ge outputs. How would you like a scan of the L’il Tiger from Dec 1967? With 5 Si xistors, it puts out 22 w/ch, and has ZERO output bias! Definitely an early point on Dan’s learning curve. Come to think of it, the Brute 70 was better! (Dan supplied kits via DEMCO; ckt was RCA.) BTW, I can fix any ss amp, no matter how complex. I once repaired an sae 2400 that took 64 parts- all bad I don’t shotgun! Send me a msg if you want to continue. Perhaps the world needs to know how to fix these.

    • pacazo says:

      I’ll take whatever you have that isn’t already posted here. I have heard about Daniel Meyer’s RCA circuits. If you don’t have articles, but have pics I can post those would be welcome. The 1959 article would be super cool though!

  4. David says:

    Not sure this site is still active or not but since vintage audio never dies but just gets older and crisper. I discovered Daniel Meyer when he started Demco back in the mid 60s when I was in high school and I tinkered with his Ultrasonic Sniffer and was hooked on the guy. I then went on from tinkering to serious building with his audio products right up thru the 70s and into the 80s. I have a Univeral Tiger, a 275, 198A, Equalizer, Compander and used to have the Function Generator. I blew up the UT several times before it ended up in a box and water go into it finishing it off (but I still have it). The 198’s switches wore out (and the case fell apart) but I have used the little preamps boards in other things until they became outdated with the semis. I got hooked on Dynaco and Hafler and started collecting their amps as well until I finally decided to try and revive the 275 by converting it to a 207 but learning better audio theory and circuitry found out the most of the Tiger amps uses a power gain output stage (about 3x) that was really unstable and that is why most of them “popped” so easily. His protection circuits never worked. I redesigned all the best ideas I came up with and made my own amp built into the 275 case and modified the original PCB. It was a success. I tweaked the front end about as utlimate as you can with 2×8 transistors (pairs). Daniel Meyer probably was the one who took IC op amp front end design and turned it into discrete parts audio amps with very low distortion (Op Amps back then were notorious for audio distortion) that set the trend forever. Most all commerical audio amps since then have his footprint pioneer designing in it. If he had only went to MOS Fets for the output stages as Hafler (and his team) did, a whole leap ahead would have those antique amps still front line. I use Hafler power amps in my system still but none of the SWTPC stuff but then Danny boy is in there for sure. As far as SWTPC, anyone needing prints and documents for what I have, I can share it. I kept everything. It was a sorry time when Daniel passed on. For his time he really rocked the listening rooms (and the designer labs).

  5. Wilf Oswald says:

    Hi, Pacazo!
    Just found your website – I’ve always had an interest in SWTPC audio gear, and still have several of their products I built from kits: 215/A amplifier, 540 amplifier (anyone else know about that one?), 195 Preamp (pre-amp module as used in their 198/A); along with the full documentation packages for those. I may also have the doc’s for the EX-1 Stereo Compressor/Expander, and Stereo Octave Equalizer. I know someone has expressed interest in the 215/A doc’s, and will be glad to provide the scans. I’ve already copied – with gratitude – your documentation on the Tigersaurus. Hoping it will help me repair that amp that I bought used (& DOA!) not too long ago.

    • Brent Lambiotte says:

      I built and still have a 540. Think I planned to use it for PA system. Already had a Universal Tiger and SWTPC two channel preamp for my guitar. Haven’t tried the 540 for probably 20 years. Need to fire it up one day.

  6. Pieter Greidanus says:

    Hi Folks – also nice to see a web site dedicated to SWTP products! Back in the 70’s I built a number of SWTP kits including a pair of Universal Tigers that I did on a custom chassis as a stereo power amp (used a 4″ wide anodized aluminum commercial window extrusion for the faceplate) and a stereo preamp based on the graphic equalizer (mounted the boards back to back and brought the leads for the 18 slide controls to the front) with the SWTP compressor/expander, a Hafler rear channel decoder and a pair of small SWTP power amps packed into the thing. The power supply was outboard. They were ruined in a basement flood but I wish I still had them.

    I also built kits for friends including the 198A preamp and a pair of Tigersaurus amps for my boss who had bought a pair of power hungry Bose 901 Series 2 speakers and was trying to drive them with Pioneer equipment. The Tigersaurus amps just loaf driving them in spite of the huge bass boost introduced by the active equalizer.

    I “inherited” the Tigersaurus amps and Bose 901’s a number of years ago but since I was into tube equipment by then, used them as sub woofers for a while but then one of the amps developed parasitic oscillations so I packed them away.

    I lost my hearing over the years and about a month ago was going to sell the 901’s since I figured, what’s the point I can’t appreciate good equipment any more. I set up the Bose one last time and drove them connected in parallel with the good Tigersaurus amp. All I could say was wow – they sounded fantastic!

    I found this web site and inspired by other readers experiences, ordered new 10,000 mfd filter caps, replaced the pair of 36 volt zeners in each amp and minimized the bias setting in each amp (I don’t have a scope anymore to do the 10 KHz crossover notch adjustment) and voilĂ  – they work – amazing sound once again !!!

    My thanks to the contributors that prompted me to restore rather than sell the system.

    An interesting little note – when I built the Tigersaurus’s in 1978, I followed the instructions to the letter but couldn’t for the life of me get the voltage readings specified prior to connecting the output transistors. I triple checked everything and had not made any wiring errors. I phoned SWTP, explained my problem and asked to speak to an engineer. Daniel Meyer himself came on the line, heard me out and suggested I increase the bias control because no current was flowing! Duhhhh ! He was most gracious and I was most impressed.

    Those were the days – the days are long but the years are short – wishing all of you very pleasant listening.

    Pieter Greidanus
    London Ontario Canada

  7. Brent Lambiotte says:

    I built a Universal Tiger in about 1973. Actually built it 1.5 times after it overheated and blew up the output transistors. I vividly recall some of the resistors glowing cherry red. I ordered the amplifier section without power supply ($30, I think) and replaced the burned resistors and the output transistors. Gave the rest of the components to my friend who had built 3 or 4 Tigers which all blew up. I also built SWTPC 2 channel preamp (one channel with tremolo and reverb) and used it with the Tiger. SWTPC also supplied the Hammond reverb spring tank. After my rebuild of the Tiger, my guitar ‘head’ worked well for several years. After decades on no use; I recently turned it on. It worked; but very low volume level. I guess the filter caps need replaced. Originals were 4000 mfd. 50 volt. Seems like 4700s are more available. Any suggestions on replacing originals with different values? Also recently read a post about some of the resistors should have been 1 watt instead of 1/2. Guess if I’m going to replace the caps, I’ll change these resistors too.

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