September 17, 2026
#552
Gentle reader,
For those that are new to this blog: Welcome! I write about Nancy's and my passions, and no, not that kind of passion. Our collections. One of my main, since I was a kid, I'm now 70, is building a great sound system on a budget.
NOTE to the reader about best viewing: I write this on a Windows 11 PC using a 27 inch monitor. For best results for viewing the images, I recommend using some kind of non-handheld device. Click or tap on any image and a new window will open over this one with the image full sized. The text in the catalog is quite small and will be hard to read, otherwise.
A quick history: It all started in 1975, in Richmond, Virginia when I made a new friend.
His name is Philip Stubbs. That was him, on the far right. This was the 1970's so, long hair had a firm hold on us back then. It is making a resurgence with some of the male youths of today. Anyway, Philip took me up to his room, inside, I beheld the BIGGEST speakers I had ever seen! Then, I saw a REVOX reel-to-reel tape deck, a big Pioneer integrated amp and more. He put on Pure Prairie League's LP Two Lane Highway. When that blast of loud and CLEAR music hit me, I knew that I was doomed: to a lifetime of trying to be able to reproduce such an epic sound in my home.
I was reading Stereo Review and High Fidelity magazines at the time and saw a small ad in the back of both magazines for the book pictured above. When it arrived, I was surprised how large it was! It was unbiased and not beholden to advertisers. I read it cover-to-cover and chose Dynaco equipment based upon: Quality, sound and affordability.
I did not own a camera for many, many years. This image is from 1995. Seen is one of the Dynaco A25 "floor model" speakers I bought from Dixie HiFi fifty years ago. Behind the farthest pot can be seen the PAT-5 preamplifier kit I built. I bought a matching FM-5 tuner to match it somewhere local.
I wrote a letter to Dynaco and they sent me their brand new catalog which is what I am featuring in this article.
While I would like to claim that this image is of the SAME catalog, that would be a lie. As time marched on and I was finding more and more equipment to play with, I sold my catalog on eBay. Years later, I regretted doing so. All I could find was one in black and white. Until recently, that is.
As previously stated, I bought and built their new top-of-the-line preamplifier kit, the PAT-5. A view inside of it is seen above.
At the time (1976), I could not afford to buy a Dynaco ST-120 60 WPC Power Amplifier kit. I instead chose to buy two SWTPC* Tiger 0.1 60 watt mono power amplifier kits. They were way less expensive and, it turned out, harder to build. They did not last long. *Southwest Technical Products Corporation. See below it's catalog number.
This image is from an eBay auction for ONE Tiger 0.1 60 watt mono amplifier. Rather forlorn looking too. Their chassis width was set so that four mono amps, side-by-side, would fit in a standard 19 inch rack. Quadraphonics was in back then.
As noted at the top of this article, the text is quite small.
I can attest to the claim above.
This image is NOT from this Catalog, although a much smaller version is featured in it. It is to demonstrate just how thoughtful Dynaco engineers were at creating POSTER sized wiring diagrams which clearly show where each and every wire goes.
Those components were stacked for the photo, not during use. After eventually buying and enjoying a Dynaco: ST-120 and then a ST-150 power amplifier, (the former was dual mono in one chassis!) via eBay, I was able to finally get my hands on the mighty ST-400! Three of the original knobs were missing and the wrong kind of fuse holders were in it, but it worked and at last, it was mine!
I put the one original all-metal knob on eBay and someone gleefully bought it.
YEARS later, I attempted to recreate that original stereo system. A Dynaco PAT-5 was easy to find. Not so, working, Tiger .01 amps. I settled for a stereo 35 WPC version power ampifier in one chassis. Links to the two-part article are here: The Robb Collections: Reliving the 1976 sound of Dynaco PAT-5 preamplifier and SWTPC power amplifier! and The Robb Collections: PART TWO: Reliving the 1976 sound of Dynaco PAT-5 preamplifier and SWTPC power amplifier!
I would (no pun intended) to have loved to have the optional walnut wood case for my PAT-5. Mine PAT-5 had the later, silver faceplate, verses the goldish faceplate above.
Full-bore (and price) deluxe ST-400 with meters, a cooling fan and rackmount brackets.
A photograph of the "guts" of the Stereo 400 power amplifier.
The "budget" ST-400, simpler controls. less fusing, simpler heatsinks of the Stereo 410.
In case you haven't picked up on it, Dynaco named their power amplifiers based upon watts-per-channel, combined. ST-120: 60 WPC, ST-150: 75 WPC, etc. Stereo 150's above, deluxe in the front.
Their first solid-state preamplifier, the PAT-4 (#4 after their last tube model: PAS-3) with FM Tuner in their double-height walnut cabinet.
Dynaco also made upgrades for some of their kit products.
Left half of the "Centerfold" image of the catalog.
Right half. Shown on these two pages was their entire Speakers line.
A very concise explanation of Dynaco's patented Aperiodic "vent" cabinets.
The continuation of their speaker's design philosophy.
As mentioned above, Quadraphonic Sound was THE thing in the 1970's.
Their AF-6 AM/FM stereo tuner beneath SCA-80 (40 WPC) integrated amplifier.
I was not crazy about the way they designed the smaller Dynaco power amplifiers as far as how they laid out the connectors goes.
Their least expensive power amplifiers are described and shown, above.
Below, are images of the dual-mono ST-120 I bought via eBay.
Obviously, someone with electronic modification confidence combined two ST-120's power supplies into one chassis. This thing was HEAVY!
It all fit neatly in the chassis, however.
No way to put it with other components since the power switch and cord enters in one side and the inputs and outputs come in on the other side. I did not keep this amp for very long.
I just looked for other photos of ST-120s online. Where there is a toggle switch now, there once was a black fuse holder. The toggle switch was to turn on the second power supply.
One of THE rarest of vintage Dynaco solid state equipment is the QSA-300 quadraphonic power amplifiers. Especially the deluxe model with the four meters. 75 watts per channel of quadraphonic fun. Basically, two Stereo 120's in one chassis plus the Dynaquad circuitry.
The last of their Tube Dynaco equipment available new in the mid-1970's. The PAS-3X was the latest (from 1966) tube preamplifier. The Mark III was a monaural 50 watt power amplifier. According to the catalog it was a twenty-year-old design. The Stereo 70 survives to this day. 20 WPC from 50 (not 20) Hertz to 20,000 Hertz. 
Again, look at how small the font is! Remember, just click or tap and there it is, BIG.
Detail specifications, for sure!
Dynaco, the original company was formed in 1955. Here is what Wikipedia's article says about it at the end:
Thanks to eBay, I finally was able to afford Panor-era Dynaco equipment. I started with a Stereo-200 power amplifier, left, above. Years later, the left channel started cutting out, I figured it was heat related. With the added fan atop it, that solved the problem for years. To it's right is the QD-2, nestled to the left of the PAT-6 Preamplifier/Tuner. I still have the PAT-6. It sits inches from me on a shelf to the right of where I am sitting typing this. I even found the remote control for it and the factory owner's manual on eBay one day!
As of 2025, this is most of the current system. I replaced the Dynaco PAT-6 with a 1990's American-designed-and-built B&K Components, LTD, Sonata PRO-10 preamplifier and matching ST1400 power amplifier (not shown above). The latter lost one channel(!) and I decided to replace it with a new (I've bought 98% of all the audio equipment over the last fifty years USED) Marantz MM7025 stereo power amplifier. Their LAST stereo unit made. I wrote a review of it.
After getting the Marantz settled into the system. I took a look at the insides of the ST1400 and found one of the four fuses open. I realized they were from 1991 and replaced all four of them with quality new ones. That fixed it! 
This is a black and white image of the rear of a B&K Components, LTD, Sonata PRO10 preamplifier. Note the THREE stereo outputs on the left. One pair of XLR and two RCA stereo pair outputs. That means it can drive THREE stereo power amps! Unprecedented!
First, I put the B&K Components, LTD, ST1400 power amplifier on the floor in front of the Classical records shelf. I used it to drive the ONLY vintage Dynaco equipment I still enjoy: my A25XL speakers. I snagged them for $99 via eBay. I couldn't believe that no one else bid on them!
A wide-angle lens shot of the listening room before all the amplifier dramatics. The ST200 had two pairs of outputs.
The inside of the back cover. Note the tiny image of the poster-sized wiring chart for the Stereo 400 power amplifier kit.
I made this, the back cover, original size, to show you all the details not visible, even if the smaller images are clicked or tapped on. The Quadapter unit at the top came out late in 1960's. While not a true quadraphonic, the sound produced is interesting. More on that later.
Dynaco, the original company was formed in 1955. Here is what Wikipedia's article says about it at the end:
"Dynaco was acquired by ESS Labs, LLC in 1979; the Dynaco division was closed in 1980 and its assets acquired by Stereo Cost Cutters (later called Sound Values and Sound Valves).
In 1991 the Pan Orient Corporation (later Panor Corporation) acquired the Dynaco trademark, and in 1993 began marketing electronic audio components with the Dynaco brand. Panor introduced some new products, such as the Stereo 70 II. Panor/Dynaco's most ambitious stereo tube amplifier was the Stereo 160, a 75 wpc, all-tube stereo power amplifier with switchable pentode/triode modes, adjustable tube bias potentiometers, and 6550 output tubes.
While Panor owns the Dynaco brand name and trademark, there is no longer any direct connection with the company founded by David Hafler.
As of 01/30/2026 Dynakit, LLC now owns the Dynaco US trademark."
When I saw a small add in Stereophile magazine in the early 1990's about the NEW Dynaco, I (again) wrote them a letter requesting information. This is everything they sent me. All I could afford back then was their modern, five-channel iteration of the original Dynaquad Quadapter. 
Over time, I bought one of every upgrade to this unit, ending with the QD-2, below.
The previous owner sprayed something on the faceplate which I never could get off.
Unlike the QD-1 iterations, the QD-2 has proper metal three-way binding/banana terminals instead of the cheap spring terminals. I still use it to this day. It is the last Panor-era Dynaco equipment I still use.
Plus, the QD-2 does some amazing things. Sometimes, all of a sudden, there is a musician right next to my chair playing their instrument!
I have written extensively about Dynaco previously. Those articles are some of my most popular. Just Google: The Robb Collections Dynaco and all kinds of links will show up.
Below is all BONUS content. Feel free to keep reading.
One set drove the large black front and rear speakers through the QD-2. The second set drove the Dynaco A25XLs in stereo.
The front black speakers are the LAST Cerwin-Vega! speakers made in the USA: Model LS-12. Super efficient and fantastic sounding.
The rear speakers are British designed Tannoy C88 tower speakers. Through the Dynaco QD-2 they make the room sound like no two speakers alone could ever produce.
Later on, I bought a Chinese designed stereo tube amplifier for less than $280 via eBay. I wrote a review of it here: The Robb Collections: World Premiere Review of Douk Audio's Exciting new Class A DJ587 Tube Stereo Power Amplifier!Soon after that, my new next door neighbor offered me his father's home theater equipment. At first, I was hesitant, no room. But, when I saw KLIPSCH, I said, "Yes, I will take everything off of your hands. I wrote about that here: The Robb Collections: Having Friends Who Are Neighbors is a Wonderful Thing! Gifted Klipsch Speakers And More.I added this DOUK Audio beast to the system which allows me to drive either the Dynaco or Klipsch speakers separately or at the same time, by either of the power amps! 
ALL three of these pairs of speakers have super sensitivity. All (in an anechoic chamber) put out mid-90's decibels from ONE watt! The Chinese amplifier puts out a whopping FOUR watts per channel. With any of the speakers, turned up the tiny tubes make it too loud to stand! WHEW!
Well, if you have made it this far, congratulations! No, seriously, I truly appreciate each and every one of my readers. I had NO idea that anyone, let alone almost a million people would want to read anything by me. But, you do. And, I cannot thank you enough.
Feel free to leave a comment below, or via Facebook.
Scott Robb
September 17, 2026
#552
