Any Southwest Technical Products Builders/ Owners Out There?

Thanks for the link to the tigersthatroar site. I have set up RSS and hopefully eventually there will be something that relates to the 275.
 
I'd forgotten all about this old thread 'til the "new post" e-mail popped up this morning. Read the entire thread... Felt like I was visiting an old friend...

Sorry to say I lost the Tigersaurus kits to Hurricane Ike a couple years ago when they (and my house) spent a night in Galveston Bay... Technically I guess Galveston Bay spent the night in my house...

Anyway they were among the audio pieces that I either forgot about or didn't get quite high enough before I evacuated. The salt water was unforgiving.
 
Back in the 70s, I built a couple of monoblock SWTPCs - don't remember which dinosaur name they were at ~100wpc - but used a set of Ampex 351 chassis for them! I found the Ampex chassis at a metal re cycler and stripped out all the old tubes and parts.

They came up and ran ok and I ended up selling them to a band for their PA. Frankly, the JBL SA600 power amp I got to follow them sounded far, far better in my little apartment in Ripple City - that part of town just off a major university where all the grad students and hippy hangers-on lived.

I also built some of the SWTPC preamp kits for folks. Well, that's not completely true; I got them working for friends when they tried to build them - pretty much rebuilt them again.

Cheers,

David
 
I built 2 universal tigers 80watt jobs, still have em but they need all the upgrades installed I have most needed parts. Blew one up while testing, they did that hence the upgrades. got all paperwerk, upgrade articles, wireing diags/schems. anyone in San Jose Ca interested PM me.
 
rbarline said:
Hi, I just joined this forum and wondered if anyone is still watching this thread. I have a SWTP amplifier Tiger B/275 that I built back in the 70's and really never used much, but it worked perfectly and still does. Anyway, I of course misplaced the original documentation, so I was wondering if anyone out there might have one of these and still have the schematic. I realize this is VERY unlikely but I thought I'd try anyway. It's not that I need to repair it (as I said it works great) but I would just like to have it. Thanks!
Click to expand...

I think you mean 175 or was the 275 the stereo version of the same amp?
Here is the schematic of the 175 MKII with current limiting protection, the one without is at the start of the thread:
http://www.diyaudio.com/forums/solid-state/41926-universal-tiger-18.html#post2598334

SPICE simulation:
http://www.diyaudio.com/forums/solid-state/93637-swtpc-universal-tiger-improved-simulation-3.html

http://www.swtpc.com/mholley/PopularElectronics/Oct1970/PE_Oct1970.htm


You might also find these interesting:
http://www.swtpc.com/mholley/PopularElectronics/Popular_Electronics.htm

http://www.swtpc.com/mholley/index.html
 
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If you still have the DOCs to that CD4, can you send them up to tigersthatroar.com? It is a site about SWTPC audio products.
 
I have several SWTP items I built back in the 70's and a couple of the little catalogs they sent in the mail every month or so. I have a twin UT MKII I housed in a custom solid walnut cabinet with twin Lafayette VU meters. I even have a pair of power sweeps from a 1972 MacIntosh clinic I took the Tigers to. As I remember, the Tigers embarrassed the Mac techs, because they were cleaner and had more power than some of their units. I assembled them both without a hitch and set crossover distortion using a 200 watt 8 ohm dummy load. I drove the Tigers with a Dynaco PAT 4 preamp and matching FM5 tuner also in matching solid walnut cabinets. I should dig them out and take a few pics.

I also have the function generator, one of the "Digital Light Organs" , and a few other audio pieces I know are packed away somewhere.
 
I have two.Ran for years as my keyboard rig,(JBL 4530 cabinets and a Leslie rotor- yeah, I played loud to keep up with the guitar players),then all it took was someone shutting off the keyboard mixer first,and popped them both.They are out in the shed-one of these days they will go on Ebay.I built them both from the kit,but stood off the WW resistors and the predrivers from the PCB.They would put out close to 350W apiece before starting to clip.
 
My Universal Tiger has been transplanted into a rackmount case with a pretty aluminum face. By the time I finished that project I was employed by a hi-fi store, and had access to stuff at such good prices that I stuck the UT on a shelf and haven't used it. 80 watts back then seemed huge!
 
Dead thread walking! ;-)

I didn't have this in my car Saturday morning when I went to the NEARC* fleamarket... but it was in there when I got home. What can I say? :)


SWTPc preamp 1 by mhardy6647, on Flickr

The balance control is frozen in positon - I wonder if the normal CAIG products will dislodge it?

Further details as events warrant :)

* www.nearc.net

Page2.jpg


source: http://www.swtpc.com/mholley/
 
Stand it up on its back with the face up. Then use Fader Lube on the slider. Let it sit for a few days. Test for any movement. If things break up a bit, more Fader Lube and another few days.

I remember building one of these for this cute girl who showed up in my analog design class in college. I wonder what happened to her and the preamp?

Cheers,

David
 
dshoaf said:
Stand it up on its back with the face up. Then use Fader Lube on the slider. Let it sit for a few days. Test for any movement. If things break up a bit, more Fader Lube and another few days.

I remember building one of these for this cute girl who showed up in my analog design class in college. I wonder what happened to her and the preamp?

Cheers,

David
Click to expand...

Thanks for the advice!

Cannot help vis-a-vis the cute girl or her preamp, though; sorry ;-)
 
I home built a stereo power amp based on the Universal Tiger design (or Tiger 01, not sure). I laid out and etched the PCBs, designed the mechanics of it (the hard part). It's still working fine.

It was very, very interesting and a lot of fun. As an electronic tech, it really makes one appreciate engineering.
 
Picked up a pair of Tiger 01 amps this summer but have not hooked them up yet. They were playing along just fine at the seller's house so I know they work. To be honest I dont want to blow up any of my gear. Is there any particular mod I should make to help protect my speakers? Was considering fuses either in the cases or on the speaker wires as a layer of protection without messing with the design.
 
I have 4 of them sitting in my closet. I picked them up at a garage sale untested. This was before I really started getting into DIY audio (aside from some home built speakers) Two worked the others didn't. The working pair lasted about a week before failing in a quite spectacular way one after the other. Now that I'm older and a tad bit wiser I may drag them out and try a rebuild. or sell/donate them to fund a different audio project.
 
I normally post on VideoKarma as I am mostly a restorer of antique tv's. I found this thread while surfing here.

Back in the early 70's I was building a lot of PA equipment for my brother who played base in a couple of the local bands. I built two multi channel power amps using the SWTPC Universal tigers.

System one consisted of 6 channels of Universal Tigers each one powering a 15" Altec Lansing HD base guitar speaker. I ordered a special power transformer from Signal Transformer that had a 20A 120vac secondary that was center tapped. I powered 6 Motorola bridge rectifier assemblies and the associated computer grade filter caps which in turn powered the 6 Tiger amps.

System two was similar in design to system one except that it consisted of 12 of the Universal Tigers from an even larger power transformer that put out 40A at 120vac center tapped.

During the design and testing stages, I too found that the amps had a tendency to want to break into oscillation and fry themselves. It was most prevalent when you adjusted the cross over trimmer on the driver board so that there was no crossover distortion. After much trouble shooting we discovered that the oscillation was around 10mhz. I ordered a bunch of various kinds of ferrite beads from Stackpole and strung them on the leads from the driver board to the output transistors. With a bunch of experimentation I found a ferrite composition that was able to strip off the 10mhz that was riding on the driver leads to the outputs, and that solved the problem of the amps breaking into osculation. They ran very reliably for many years after that, even being hauled off to many a band job.

The two rack cabinets that were used to build these are still sitting waiting for me tear them down and sell the Universal Tiger amps off on ebay. Though I have no idea of there will be any interest in them.

I still have a stereo version that I built and housed in a very nice wooden cabinet that I made. I drag it out from time to time to drive a pair of Altec Lansing Voice of the Theater speakers, when I have a back yard party. I drive the amp using the head phone jack output from my Pioneer SA9100 amp which is part of my primary home stereo system.
 
Listening to mine this AM

I built mine in 1978 and have seen off again on again duty since. Were replaced by strapped Hafler Dh 200s, then Adcoms, then AV units from HK, and finally Denon AVRs. Recently made a decision to go back to discrete amps. So I pulled the three amps out of retirement (two Tiger 01s and a tiger 215), and replaced the PS components. Tuned them up with some resistors and a couple of coupling caps, new rca's and Power switches. and mounted them to a new front panel. Controlled from a Sony E2000 esd with a Squeezebox touch and a Nak BX 300,running Zilch modified Minimus 7's and a honking 15 in dual voice coil sub from Eminence, in a 3cf TS box. I am in heaven. Best this has sounded since the Adcoms. and better than the Denons, which I loved. In my quest to go discrete, I first tried a sony STR 7055, and was disapointed, Then a Kenwood KR 6030 which was real good but lacked Pre-outs, and would only fit in my stack with the cover removed, so it was down to the SWTP's. Couldnt have worked out better. PICs to follow. Jim :music:
 
ohohyodafarted said:
I normally post on VideoKarma as I am mostly a restorer of antique tv's. I found this thread while surfing here.

Back in the early 70's I was building a lot of PA equipment for my brother who played base in a couple of the local bands. I built two multi channel power amps using the SWTPC Universal tigers.

System one consisted of 6 channels of Universal Tigers each one powering a 15" Altec Lansing HD base guitar speaker. I ordered a special power transformer from Signal Transformer that had a 20A 120vac secondary that was center tapped. I powered 6 Motorola bridge rectifier assemblies and the associated computer grade filter caps which in turn powered the 6 Tiger amps.

System two was similar in design to system one except that it consisted of 12 of the Universal Tigers from an even larger power transformer that put out 40A at 120vac center tapped.

During the design and testing stages, I too found that the amps had a tendency to want to break into oscillation and fry themselves. It was most prevalent when you adjusted the cross over trimmer on the driver board so that there was no crossover distortion. After much trouble shooting we discovered that the oscillation was around 10mhz. I ordered a bunch of various kinds of ferrite beads from Stackpole and strung them on the leads from the driver board to the output transistors. With a bunch of experimentation I found a ferrite composition that was able to strip off the 10mhz that was riding on the driver leads to the outputs, and that solved the problem of the amps breaking into osculation. They ran very reliably for many years after that, even being hauled off to many a band job.

The two rack cabinets that were used to build these are still sitting waiting for me tear them down and sell the Universal Tiger amps off on ebay. Though I have no idea of there will be any interest in them.

I still have a stereo version that I built and housed in a very nice wooden cabinet that I made. I drag it out from time to time to drive a pair of Altec Lansing Voice of the Theater speakers, when I have a back yard party. I drive the amp using the head phone jack output from my Pioneer SA9100 amp which is part of my primary home stereo system.
Click to expand...

Tell us more about the ferrite beads you used. Also, did you place them on all three leads?
 
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