PART TWO: What can one do with a single speaker? Why not make a monophonic system! Mono? Sure, Mono LP records!

Gentle reader,

Just yesterday morning, September 24, 2017, I posted the following article: 

What can one do with a single speaker? Why not make a monophonic system! Mono? Sure Mono LP records!

The photo above was added on September 27, 2017 to replace the original photo. It features the single Dynaco A25 speaker is now mounted (and secured with Blu Tack) on one of the wall mounted TV shelf. The bracket is similar to what TVs in Hospital rooms once used before the advent of flat screen TVs. 

WHILE it appears that the speaker is tilted to the right, it is not. It's a result of using a wide angle lens. When I first took photos and then looked at them, I thought that it was tilted. So, I pried the speaker off and checked with a level. It IS level. When the speaker is pointed straight ahead, it does not look so tilted.

I have two and they were originally bought to hold the BOSE 301 speakers my wife bought for me.  The image below is from 2010. You can see the "umbilical cord" speaker cables. My wife came up with that moniker. The big speakers are DCM models with 12" woofers. I don't recall the model number.

I removed the large nut that secures platform to the wall bracket. Underneath the large washer seen below. Underneath there are four or five holes that one can choose for tilting the platform and once tightened, it will not slip from your chosen position.

I also rotated the platform so that the folded-up edge is no at the back to stop the speaker from sliding off. 

I don't know if Peerless Industries still makes these wall mounted stands. I was about to add both of them to the to-the-dump things in the back of my pickup and glad I didn't since it solved the slipshod method I'd used for the speaker when it was on the floor.

The photo below was taken without flash because with flash, many components are too bright in some parts and too dark in others. Thus, the "photoshopping" of the image to lighten it has digital noise. Nonetheless, as shown in both photos above, I chose to position the PROTON D540 beneath the wider Dynaco Stereo 200 amp for the simple reason that the ST-200 amp's left channel gets warmer than the right, thus the muffin fan. Plus, the speaker switch is semi-permanently attached to the amp with Blu Tack. So, even though it is wider than the D540, it needs to be on top.

BEFORE I GO FURTHER, THE SOUND is MUCH better than the previous setup. To begin with, I rooted through my wiring drawer and pulled out a section of plain-old lamp cord. Sometimes called zip-cord. About six feet long. For the D540's end I simply stripped it about 1/2 an inch The Nakamichi "bent pin" plugs, while of great quality, stick up above the back of the D540, so I did not use them. The D540's speaker terminals are not banana plug capable. The speaker's end of the cord has a pair of Nakamichi banana plugs. 

There are many that strongly feel and have even done double-blind testing to prove to themselves, that there can be no improvement in the sound of music by replacing inexpensive wires and cables with aftermarket "audiophile" versions. Some have stated to me that they use solid core house wiring, the kind that's inside the walls and ceilings of your house, as speaker wire. That is of course their choice. If they think that is the way to go. More power to them.

In the case of my recreated 1976 stereo and now this mono-only offshoot, I have had to use what I feel are inferior cabling. Yet, it does not sound bad! In the stereo, I am using top-of-the-line Monster Cable Z-Series speaker cables. I KNOW they sound better than almost anything I have tried over the decades. 

Yet the prime example here, I proved to myself with the twisted pair Monster Cable twisted-pair speaker wire, sounded lousy. And the simple lamp-cord wires do not.Who knew?

This photo is a stark contrast in signal carrying choices. The thick, braided THX Certified interconnect cables which tie the PROTON 1100 preamplifier to the Dynaco Stereo 200 power amplifier are within inches of the simple lamp cord that I am using from the PROTON D540 to the solo Dynaco A25 speaker in this monophonic subsystem.

In my task to neatly incorporate the mono amplifier into the already crowded shelves I decided to try something different. At first, as stated in the previous post, I took the signal from the Dynaco PAT-5 preamp (the silver one) OUTPUT 2 terminals to the CD (marked DAD, Digital Audio Disc) inputs of the D540. For this iteration, I decided to take it from the TAPE 2 outputs to the DAD inputs. My thinking was this: the PAT-5 simply converts the weak signal from the turntable and amplifies it to be passed to a power amplifier. Using the tape-outs bypasses any adjustable amplification and/or modification by the PAT-5's controls. This eliminates the volume, balance and tone controls. Thus allowing the D540 to use it's own controls and circuits. In other words, the PAT-5 is a straight wire with gain. The signal from TAPE OUT is of a constant level of volume.

You may be thinking, "Why doesn't he take the cable from the turntable and hook it directly to the D540?" I thought about that, but that would entail reaching around the back of the PAT-5, unplugging the cable by feel, threading it up to the phono inputs on the D540 every time I wanted to play a mono record. Not practical. Plus, I don't have room for yet another turntable.

I mentioned "shorting" plugs, sometimes called "dummy" plugs. Those are the objects plugged into the Phono inputs on the D540. You can see clearly the "cheap" RCA wires here as well.

This photo also contrasts the cheap RCA wires and the when-new expensive Liberty Cable RCA cables. Note also the PANGEA AC-14 power cable that supplies AC power to the Dynaco Stereo 200 power amp. PANGEA products are excellent upgrade items for a tiny fraction of the competition's costs. They perform well and have rave customer reviews.

I've written, in the past, about the connection between NAD, PROTON and the Panor-era Dynaco components as having all been made in the same Taiwanese factory. And that in at least one case and probably more, that certain components were sold with the same model number with either the PROTON or Dynaco nameplate. Look at the two serial number stickers and how the unit's name/number is the beginning of both serial numbers. The fonts are the same and both stickers are yellow. One appears lighter, but they are the same yellow. Coincidence? I think not.

The following photos are shots that show some of my established ways of connecting everything and the choices of cables. The first photo shows what the Legend LE412 speaker switch looks like from the rear. I made changes to it. Originally, all the terminals were like the ones beneath the "Amplifier" label. Note that "R" is on top and "L" below. Well, the terminals, top-to-bottom are the industry standard 3/4" apart to allow use of "double banana" plugs. I rearranged all the wiring and plugs years ago so that red was on top and black on the bottom. Note the double banana plugs in the amplifier inputs. Well, over time and my constantly trying different things, the inexpensive three-way banana-binding posts, that the Legend people chose started breaking. In the past, I replaced them with heavier duty ones. As you can see. Their plastic knobs were to thick to be so close to each other, so I had to make them smaller in diameter. Looks lousy, but it works.

The grey speaker cables are part of the Monster Cable M-Series. This particular series had no markings for polarity. Red Sharpie to the rescue.

Above and closer in the shot below, shows the details of the rear of the Southwest Technical Products Company compact stereo power amplifier. See how they used "phone" (mono headphone/microphone) terminals for the speaker cables? Someone replaced the factory AC cord with the white one in the past, too. Again, the contrast in size of the cheap RCA wires at the left and the thick Liberty ones at the right. Yet both do the same job.

Above is a very clear shot of the rear of the PAT-5 and the cheap RCA wiring. It is patently obvious just how close together the RCA terminals are in this shot.

I should have properly made new cables using the shiny phone plugs soldered directly on the M-C Z Series speaker cables that send the amplified signals from the SWTPC amp to the speaker INPUTS on the PAT-5. But, I was in a hurry to get it together and simply crimp-spiced the two pairs of cables together. I will correct that in the future. 

To take the strain off the phone plugs above and the PAT-5's plugs on the bottom, I decided to support the loops of heavy cabling as you can see with a loop of Velcro-type binding wrap over the framework of the shelves. 

You can see the difference between the well made, attractive and grippy Nakamichi banana plugs and the much simpler (and insulated!) banana plugs from Parts Express. Why Nakamichi chose to make what is normally insulated covering for banana plugs out of metal, I do not know. I found out they are all metal when one channel cut out and I found two Nakamichi plug bodies had briefly touched. Fortunately, the Stereo 200 has high speed circuit breakers that reset themselves after such incidents. I believe the Dynaco PAT-5 is the only preamplifier made to incorporate speaker terminals and switching into a preamplifier. 

A NUMBER OF readers have brought up the question of why I would bother to set up a strictly monophonic system when I can listen to them through two speakers. 

Well, I have over 2000 LP records and a few ten inch and 7 inch ones too. OF that number, over 400 are monophonic. The majority of my Big Band records are mono. Thinks about it, stereo was not commercially available until the late 1950's. So, until then and much later for most people, music coming out of ONE speaker is all those people knew. 

Today, I was picking out Big Band records and listening to them through that one A25 speaker. I was getting into the spirit of the times when that wonderful music was what SO many people listened to. 

So, that is why.

Well, that's it for now. The weekend is over so back to work on redoing the kitchen.

Thanks for looking,

Scott

What can one do with a single speaker? Why not make a monophonic system! Mono? Sure Mono LP records!

Gentle reader,

This will be a relatively short post. As you have read in my recent post, the replacement SEAS H 086 tweeter finally arrived from Poland (I LOVE EBAY!) and at last I had two working Dynaco A25XL speakers.

Well, I then parked the now unneeded A25 speaker in a corner. In the past, I would have simply put it on eBay and sent it off to a new home. However, some items I've enjoyed until something else came along that caught my eye, and then of course I sold them, I now regret selling. And now the prices are too high to re-buy that which I once owned!

Also, I also had my "spare" PROTON D540 integrated amp which has PRE-OUT and MAIN-IN RCA terminals with "U" shaped jumpers in them. One can use such integrated amps and receivers made like this  as either a preamp or as a power amp by removing the U jumpers and hooking up another preamp or power amp to the appropriate terminals. A photo of the back of a D540 is further down in the article. In fact, the first PROTON D540 I bought specifically TO use it as a preamp until the day that I bought the PROTON 1100 preamp seen below.

Now, who can tell me, aside from the LP records, what is different in this photo? Look closely, now. What? You clearly can't remember what the last photo shows? OK, I'll take pity on you and ad that photo.

Now, surely you must see the difference..........Right! The subwoofer and awesome dragon are gone. Well, only moved. I had taken the sub out of the system anyway. It was to enhance the tiny speakers at the top of the totem-stack. However, despite their tiny 4" mid-bass drivers, they sound like they are bigger. Don't worry, both the sub and dragon are in the corner in which the A25 was. I can display the dragon on top of the LUXMAN turntable. It may look like aged bronze, but it isn't. So, the weight is not significant. Those clever Chinese!

Believe it or not, stereo music recording and reproduction was invented sometime in the 1930's and patented. However, there was no practical way to build and market the technology. So, mono was IT for decades. It wasn't until the mid-1950s that someone realized that a LP record's groove could carry one channel's sound on one side and the other's on the opposite side of the V shaped groove. Some artists, especially the Beatles, preferred to make their records in mono. But the powers-that-were, prevailed by compromising, thus both mono and stereo pressings were made. The mono ones being the more valuable.

ALSO, until there was FM-Stereo radio, all records played on the radio were mono. Most of my PROMO LPs are monophonic.

Here is a closeup of the A25 with my D540 atop it. Normally, I would never place a component on top of a speaker. But this is just an experiment. The D540 has TWO power transformers to supply their patented Dynamic Power On Demand circuits, so the left side of the amp is considerably heavier than the right. Plus, to avoid scratching the vinyl veneer on the speaker, I placed the last four of my special rubber isolation feet under the amp.

Who can tell me the 1st year the Long Playing 33 1/3rd RPM vinyl records first hit the market? Don't all raise you hands at once. Give up? The answer is 1949! I came across this LP's date when creating my searchable data base of all my records. The cool thing is it is of the only opera I like. 

A now-former coworker (since I'm retired) and fellow stereo enthusiast gave me this cool record player. It is of course mono only. Plus it's portable because it runs off D-cell batteries. I wired in a transformer to play it in the house. Sound quality and record wear are concerns, however.

BACK to the subject at hand. My mono experiment. The Dynaco PAT-5 (silver one in the photos at the very top) has two pairs of audio-output RCA plugs, as seen below. 

As you can see, all the RCA terminals are very close together. When these came out there were no "audiophile" RCA interconnects with their thick heavy plugs and cabling. So, to wire my recreation of my 1976 stereo system, I had to buy the cheap thin cables they had in the 1970's. So, anyway, I decided to use the second pair of outputs to hook up to the D540's MAIN-IN terminals. Here is the back of a D540, showing the terminals with the U shaped pins in them:

Here's where it got weird. I attached a second pair of cheap RCA stereo interconnects to OUTPUT 2 on the PAT-5 to both MAIN-IN 2 terminals above after removing the U pins. I was getting a loud 60 Hertz hum, even with the volume at zero and the woofer was visibly moving in and out. Whiskey Tango Foxtrot? I unplugged the cables, hum is gone. Looking at how I routed the cable, there was no contact nor close alignment with any AC 120 volt cable. So, I got a portable CD player, turned the volume down on it, attached the appropriate patch (interconnect, in this case with 2 RCA males on one end and a 1/8" or 3.5mm stereo-headphone plug on the other) between the Discman and the D540 MAIN-IN terminals. Pressed play and slowly raised the CD player's volume. Nice hum-free music was coming out. Hmm. No pun intended. So, what gives?

This made no sense! So, to complete the test, I decided to put the U pins back in their holes, and plug the RCA cables from the PAT-5 into the CD inputs on the D540. This worked, with no 60Hz hum, nice clean sound. I hooked only ONE speaker cable to the LEFT (or RIGHT, doesn't matter) speaker terminal on the D540 and into the A25 speaker and turned the Balance control all the way to the left. I chose a short piece of Monster Cable speaker cable that I once used years ago then stopped using.

The cable on the left, above, is the "umbilical cord" as my wife dubbed it. The M-C I used is to the right and also below. Sorry for the blurriness of the above photo.

Take a look at the photo above. See the extra silver "wire" inside the clear covering that houses the twisted cables? I forget what Monster Cable called it, but it is not wire at all, more like kite string! Yet, they intimated that it serves some mystical purpose.

Well, first of all, as the photo above shows, aside from looking silly with the amp atop the speaker and off-center, the speaker is at floor level which is not ideal except for large/tall speakers because the tweeter is so far below ear-level. Secondly, I hate things that are done slipshod like this. Like the power cord for the amp just limply hanging there. Uggh!

Above is more my style, everything neatly routed. AC cords/cables kept separate from the signal (music carrying) cables. Of course, these are good RCA interconnects, not the cheap/thin ones I have to use with the PAT-5. As a matter of fact, the lighter blue ones are Liberty Cable and the darker blue ones are Monster Cable.

AT ANY RATE, about the sound. Aside from the aforementioned speaker placement, something didn't sound right. Couldn't put my finger on it, but the more I thought about it, I started to remember why I stopped using these clear covered, twisted pair M-C cables. Because they don't sound good!

Here's the thing, aside from that magical string, that M-C does with all their speaker wires and cables: Inside the twisted strands of fine copper wires is what they call the "Flux Tube". Can you think of another thing with flux in it's title that does magical things? That's right! The magical "Flux Capacitor" of the time traveling Delorean car in the Back to the Future movie series. So, although the copper wires appear to be, say, 14 gauge, once you cut off the little piece of clear tubing inside the stripped wire, and re-twist the copper, do you realize, the actual conductor is a LOT thinner than it appears.

THIS SAGA IS NOT DONE, I am going to get a proper power amp, such as an old Dynaco one, and place it somewhere more suitable and perhaps raise the speaker some too.

Stay tuned for further episodes in my building a monophonic setup to listen to monophonic records in the state they are meant to be listened to.

Thanks for looking,

Scott