The Robb Collections: Unique PROTON D540 Integrated Amplifier has entered the Listening Room

Gentle reader,

Firstly, (yes, that IS a word) my wonderfully supporting wife will surely be shaking her head as she reads this. If you follow my blog, thank you so much! I have bought, enjoyed and passed on to others a lot (a whole lot!) of audio gear, photography gear, music, well, a lot of things.

My wife and I both have the collector gene. She doesn't do so much anymore and I definitely have slowed down. Occasionally I will buy something unique, like the Philips speakers and Technics integrated amplifier seen in the last two posts.

I just finished cleaning out several things and passing them on to others via eBay. The huge and heavy Technics made it safely to New Jersey and the new steward, Ian, is thrilled:

The Robb Collections: Rare in the US: Vintage Technics SU-VX800 200 watt Integrated Stereo Amplifier

I started my interest in good sounding audio equipment in the mid-1970's. Quadraphonic was all the rage then. What is quadraphonic? It was the precursor to surround sound. Two rear speakers would provide ambiance or maybe other instruments would appear behind you. All I could afford was a cheap system that had a built-in 8-track tape player that also played quad tapes. Electrophonic was the name. At the time that was the only quad format that truly used for separate sound sources. It came with four cheap speakers.

There were competing companies trying to dominate the quadraphonic scene: SQ, QS, EV, CD-4 and DY. The last was Dyanco's answer to fancy circuits. Sansui's format prevailed in that Dolby used their form of quad decoding to come out with Dolby Pro Logic for movie sound.

Below shows the new-to-me PROTON D540 amplifier beneath the YAMAHA C-45 preamplifier I've been enjoying for a while now.

One more thing about quadraphonic sound. Long ago, I came across a massive Sansui quad receiver at a thrift store and bought it. We used it with our VHS player as a surround sound provider and it decoded the sound perfectly. We were in awe watching Operation Dumbo, I think it was called. A Viet Nam gun boat was chasing the hero and the elephant in a boat (hey it was Disney and the 1980's) they fired and we heard the boom and the shell flying over our heads. It was AWESOME! From then on I was going to have a theater-like experience when watching a movie. Here is a Sansui similar to the one we had:

Back to the story. Once I started making money at my first job, I was an apprentice car mechanic at a Mobil station in Denver, Colorado. I started researching what kind/brand of electronics I wanted.

Kids, believe it or not, back then, there was NO Internet (at least for ordinary people), no cell phones, no Google. What did one do? Went to the library. Read magazines about your interest. Asked around. But mostly, we went to the library. I settled upon Dynaco for the preamplifier and another company (based upon price) for the power amplifiers.

Still with me? MANY years later, I found a Dynaco A/V receiver. Here is is:

It was unlike any Dynaco component I had ever seen. So, thanks to the Internet, I was able to determine that it was in fact a PROTON component sold as a Dynaco. The PROTON model was AVS-2583. Other than the name, they were identical. What's called "Badge Engineering" in the automotive world.

That's when I found thought that PANOR was possibly part of PROTON. Or the other way around. I have yest to find the connection. PANOR bought the rights to the Dynaco name and began making audiophile quality tube and transistor stereo components and their own updated versions of Dynaquad:

I had enlarged the spring terminals to accept banana plugs. I hate spring terminals. Only the cheapest equipment has them for speakers. Dynaco came out with a better version that had all three-way binding/banana post terminals.

PANOR made tube preamplifier and one transistor model called the PAT-6. My original 1970's preamp was a PAT-5. The PAT-6 also has a tuner in it. It has only a few inputs and I need at least five, six is better. So the PAT-6 was out.

So that got me to thinking. My power amplifier, as you know, is a 1990's Dynaco Stereo 200. It was made by PANOR and is the same size as their top-of-the-line Stereo 400 and actually was more useful. Perhaps there was a PROTON preamplifier from the same era that I could buy and try out.

Well, I don't think PANOR made a preamplifier,* but they did make some integrated amplifiers that contained "Pre-Out, Main-In" RCA terminals. My research revealed the model D540 would fit the bill. First off, here is a link to a site that has some history of PROTON:

Proton Electronic Industrial Co., Ltd; Taipei manufacturer i

*Until I found this site, which lists a preamplifier, that is. It is called A-1000, there is also an 1100 and they are quite rare.

I chose to make this picture large so you can see the different approaches each maker chose for the front panel/controls. The PROTON is almost plain in execution. See that DPD symbol on it on the right side? That something PROTON came up with. I have a contemporary review from Stereo Review magazine by Julian Hirsch which completely explains the way it works He said, "The Proton D540 is not only the most powerful '40-watt' amplifier we have used, it is one of the few of any rating whose capabilities begin to encompass the dynamic properties of live music."

Found this: "Winner of the 1987 Audio/Video International Magazine Hi-Fi Grand Prix Award." on this site:
Proton D-540 solid state amplifier

Here's a link to a brief review:

Proton D540 - Manual - Stereo Integrated Amplifier - HiFi Engine

They designed the power amplifier section with two transformers and sets of capacitors. In normal operation it is Class A. When a crescendo (I love that word, say it out loud: cre-shen-doe) happens, super-high-speed switches cut in the second transformer and it provides the needed power, up to 150 watts into 8 ohms, 280 into 4 ohms and a staggering 530 watts into a 2, yes a TWO ohm load! It will last up to 1/2 second! It revolutionized audio thinking. Hirsch concluded that this design practically negated the need for large heavy expensive and power hungry amplifiers. It was more than capable of meeting 99% of music needs for a fraction of the size, weight and price of far more powerful amps.

But, I bought it as a preamplifier. Some more photos of both front and rear:

The less often used controls are behind the door on the front. BTW, I bought the original owner's manual from the same seller. Very glad I did because there was much to learn.

Above shows their different approaches to choosing what can be recorded while listening to something else. Yamaha: a small knob, PROTON: duplicate push buttons. My Adcom GFP-565 preamplifier used identical large knobs side-by-side to accomplish the same task.

The smaller sized PROTON, which is much heavier contains all that the larger Yamaha has PLUS all the power amplifier components too. Their unique design shrunk the normal component's footprint.

Only the Phono inputs are gold plated on the D540.

These speaker terminals, which at a glance look like three-way binding/banana posts are in fact just like the Technics: For bare wire only.

ABOVE are the terminals I told you about. Those U shaped metal pieces connect preamp to power amp. A.C.C stands for Anti Clipping Circuit, since CDs can contain much more sound energy than the average LP, they added this protective feature. Just in case. The Bridging switch allows one to make the stereo power circuits to act as one much more powerful mono amp.

Note the choices of turntable cartridge it provides for: Moving Coil; high and low output. Moving Magnet three levels of capacitance. While the Yamaha has the former, it does not have the latter.

The manual tells one to put "shorting" RCA plugs into the MAIN-IN terminals so the power amplifier circuit will not turn on. I'd sees the things before (LONG ago) but did not know their name or what they were for. The Technics had them in the Phono inputs and I kept them. Little did I know that a couple weeks later they would be needed.

I used contact cleaner spray on all the external connections which is why it looks like something wet got on the rear panel. It did.

Now, the sound? I do not claim to have "golden ears" but my humble ears have quickly decided that this PROTON D540 sounds phenomenal. I glad I took the advise of someone posting on an audio website's advice to buy a PROTON.

Back to the Dynaco-PROTON connection. After an exhaustive search, I found a connection, at least as far as the golden 2583 A/V integrated five-channel amplifier goes. I have been finding a LOT of pictures of PROTON equipment. It has got me to thinking, new research project, maybe?

Some web sites state that the PROTON factory in Taiwan also made NAD components. Both the PROTON D540 and Dynaco Stereo 200 have very similar black anodized aluminum face plates.