Dynaco Museum in Mesa, AZ has Acquired Rare Stereo 400 Series II Power Amplifier

 September 12, 2023

#470

Gentle reader,

Bob Berne, of Mesa, Arizona has acquired a number of rare original Dynaco stereo equipment over many years of searching. He, along with Bruce Woodrow, both readers of this blog, and I have become real-life friends.

Recently, Bob was able to win an eBay auction for a super-rare 1990's (Panor-era) Dynaco ST-400 Series II power amplifier.

As you may know, I have a Panor-era ST-200 power amplifier, matching PAT-6 Preamplifier/Tuner and QD-2 five channel update of the 1970's Dynaquad. All were purchased used via eBay over several years.

While the ST-400 Series II power amplifier has twice the power output of my ST-200, that means ONLY a 3 decibel increase in sound output! 3 decibels is the smallest increase or decrease in sound levels which most people can detect. For each 3dB increase in audio output, a DOUBLING of power output is needed.

The twelve photos above are the seller's which he used to post this super-clean and ultra-rare Dynaco ST-400 Series II power amplifier on eBay.

Bob, who has forgotten more than I ever knew about electronics and audio equipment in particular has provided me the following photos of the insides of his Dynaco ST-400 Series II power amplifier.

With the top cover removed, one can see the interior is dominated by the large toroidal power transformer and two huge power capacitors. The front of the amp is at the bottom of the photo.

Both sides have matching circuit boards attached to huge heatsinks which form the side walls of the power amp.

"DYNACO 17-0002 REV A Copyright© 1992"

"MISAPPLICATION HAZARDOUS" means, do not touch the terminals!

Below are photos of my ST-200 from a previous article I wrote about it when I purchased it (also via eBay) comparing it to the Kenwood amplifier I had been using. 

Notice the completely different design of the ST-200 compared to the layout of the ST-400 Series II images above.

Note the yellow serial number sticker on the ST-200. Also note that the RCA inputs are together compared to single RCA inputs on each end of the rear panel of the ST-400 Series II. The ST-200 has switched output for two pairs of speakers.

The ST-200 also utilizes a toroidal power transformer and matching left and right boards with large heat sinks for the power transistors. 

A closer look at the PC board. 

The toroidal power transformer close-up.

The ST-200 differs from the St-400 Series II in other ways. The small PC board above is for individual adjustment to each channel's volume.

Below are some of the very FEW photographs I could find of Dynaco ST-400 Series II power amplifiers I could find on the Internet. 

Note the lack of a serial number sticker on this ST-400 Series II which was for sale in Canada. Other images of this follow further down in the article, but from the US.

These images are of a preamp/power amp duo for sale. I also found the same images, but larger when this pair was again offered for sale by a different seller. Note the lack of a serial number sticker on this ST-400 Series II as well.

Below are some images I had found earlier of ST-400 Series II power amplifiers. I spent years gathering a large collection of Panor-era Dynaco stereo equipment which I found on the Internet.

Note the "US Audio Mart" verses the SAME image having "Canuck Audio Mart" seen further above in the article. This amp has stickers on the rear which Bob's does not.

I often wonder why some folks post poorly displayed items for sale. Not that I am an expert photographer.

Years ago, I subscribed to several audio magazines and when I saw an add for the "new" Dynaco company, I wrote (yes, before the Internet was a widespread thing) a letter requesting information on their products.

These are what they sent me. When I saw the prices, I realized that I could not afford to buy anything but their cheapest item, the QD-1. YEARS later, I decided to sell these as a LOT. Stupidly, I did not SCAN them. Now that I think about it, I did not own a scanner back then. OK, now I will stop mentally kicking myself.

I chose to put these scans full sized. Some of them are not readable at the same size as the other images. Things highlighted in yellow are equipment I have owned.

These are scans I made of pages from the Orion Blue Book of AUDIO equipment. It includes original Dynaco equipment and later Panor-era equipment information and prices. If you look at the retail prices of the 1990's equipment, you can see why so few were purchased then and likely why the company went out of business. Which equates with why finding them for sale is such a rare and often pricey treat.

I have never had my hands on a ST-400 Series II power amplifier. I did own one of the original ST-400 power amps (below, that stack was for photographic purposes). So, I cannot comment on the weight (gotta be heavy!) or SOUND of it, but based upon the incredibly wonderful sound of my Panor-era stereo equipment, I am sure that Bob is enjoying it's musical output.

Yes, the four knobs AND the fuse holder are incorrect. It only came with one knob, So, these substituted just fine. My very first piece of REAL stereo equipment was that PAT-5 preamplifier which I built from a kit in 1976. FM-5 was a later (used) purchase as was the ST-400.

Above is a photo of all the brochures I had received from the original Dynaco company when I wrote to them in the 1970's. 

This is the system which I have painstakingly assembled over MANY years of buying and trying equipment since 1976.

Below are links to two other articles I have written about latter-day Dynaco equipment.

The Robb Collections: Dynaco Given a Second Life. Pan Orient Company: Panor for Short. A Photographic History PART ONE.

The Robb Collections: Retail Prices Specifications and More On Classic And Modern Dynaco Stereo Equipment

Thank you for taking the time to read my humble blog. Feel free to leave a comment below or on Facebook. 

Scott Robb

September 12, 2023

#470

Marin County California a Developer's Nightmare Antique USGS Maps and More

 August 1, 2023

#469

Gentle reader,

I want to thank your right now for taking the time to read my blog. I had NO idea that anyone would when I began. Yet, almost 400,000 of you DO read it and that truly humbles me.

Dad was a Presbyterian Minister. They prefer Pastor nowadays. He attended San Francisco Theological Seminary which is situated on Seminary Hill in San Anselmo, California.

San Anselmo is in Marin County, which is the northern anchor of the famed Golden Gate Bridge.

I shot this and many images when my wife, Nancy, surprised me in 2010 with a trip to California to visit Dad and his wife Beth, as well as my Aunt Ardith. Ardith still lived in Marin at that time and Dad and Beth lived in Los Gatos, south of San Francisco.

Nancy and Beth in Golden Gate Park in San Francisco. The park takes up a large area of land in The City, which must really annoy developers.

The Marin Headlands. All three images above I shot. NOTE the complete LACK OF HOUSES on those hills and Mount Tamalpais (in the background). 

The people of Marin decided early on that they did not want to defile the beauty of their Pacific coastline just so wealthy people could have an amazing view. All to THEMSELVES.

This is a 1948 road map of Marin County, California. The long slit in the county which forms Tomales Bay was formed by the San Andreas Fault. Hitchcock's horror film THE BIRDS was filmed in the town of Bodega Bay, due west of Santa Rosa.

This image is of a 1954 (I was born two year later) USGS topographic map of a portion of Marin County which they named: San Rafael Quadrangle. Do you see the black squiggly line on the map to the left of ROSS? I drew that to emphasize the foot trails outside of the towns of Ross and San Anselmo. We lived in California before and after I was born and again from 1965 to 1971 when I attended 3rd through 8th grade at Ross Elementary school. Sidenote: Robin Williams movie JACK was filmed in the school and the actual house his parents owned when he was a boy in Ross. He was in 8th grade. My sister knew him by the roles he played on the stage of Drake High School.

Anyway, even though we were all in elementary school, our parents let us explore all over the place. Our best friends lived to the left of this house on the Ross side of the street. Several small houses were for seminary faculty members. Davy's dad also taught at the seminary with our dad did while Dad was earning his Doctorate. Davy's dad was a runner, very unusual in those days. He was also a hiker and showed us how to hike to the top of Bald Hill and even the east peak of Mount Tamalpias. A ten mile hike, one way!

Dad was promoted and we moved across the street to the San Anselmo side. This is the IDEAL house in my mind. Redwood shingle sided, redwood deck, French doors inside and out. Huge matching separate garage. HUGE redwood tree in the front yard. Paradise.

Nancy looking up at a giant Coast Redwood tree in one of the parks dedicated to preserving the iconic and rare trees. Redwoods are in the Sequoia family of trees. I planted a Giant Sequoia tree in our backyard.

This is it two years ago when it was around thirty-five feet tall. It was a three-foot tall stick when we planted it. Now, it is over fifty feet and who knows how tall it will eventually get?

This is a modern road map of Marin County.

I found out recently that one can buy for $14.95, newly reprinted USGS maps. I bought the 1955 update (middle) and 1969 update, which is when we lived there. 

1955 update map.

This is the 1969 update map. The lighter pink/violet color is development that has happened in the intervening fifteen years. Not much.

This photograph is of the San Francisco Bay Side of Marin. It has plenty of water view houses. This and the following photographs I found on the Internet. The US Supreme Court ruled some years ago that if a photograph is uploaded to the Internet, it no longer has a copyright.

These images, all of the Pacific side of Marin County, show the complete LACK of "development" on the Pacific coast. 

There ARE beaches in Marin, but not many. Stinson Beach is one. What homes there are are old and small and at beach level. 

The rows of building you see above are at US Army Fort Cronkite. And, no, it was not named after Walter. They predate WWII. We used to go there in the summer time. Even then, the water is cold and bad rip currents. My middle sister, Judy, was almost swept out to sea, but for two men who ran into the surf and rescued her!

Just stunning!

This is a GETTY image and is a long-exposure of Highway 101 as it enters Marin from San Francisco. 101 splits and Highway 1 continues up the Pacific coast.

We would LOVE to be able to live in Marin. But, super expensive to do so. The two houses which came with Dad's job are worth between 1.5 and 2.5 million dollars.

Another place of interest within Marin County is Skywalker Ranch. It was featured in the fun movie titled FAN BOYS. It takes place before the release of Star Wars Episode One. "The Maker" George Lucas and his wife, Marcia, who edited some of the movies lived in San Anselmo for many years before he bought the land and had the ranch built.

If you ever visit California, I highly recommend crossing the Golden Gate to see the beauty and wonder of Marin County.

Scott Robb

August 1, 2023

#469