[Bill Thomas]

Tuesday, February 2nd, 2010 - Initial Update:  "Diggin' Up Bones!"

     It's been WAY too long since our last project.  Now that the dust is settling after my recent move, it's time to "get back on the horse."  This project has been waiting in the wings for FAR too long.  It's time to "deliver the goods!"  We're going to build "A Really SUPER Preamplifier!"  (I'll "spill the beans" in MUCH greater detail shortly!)

     Every project like this has a beginning and that beginning *usually* begins with the *end* of something else!  In this case, we're dealing with a rather sad end to a once proud Dynaco PAS-2 preamplifier.  How sad?  Well, much like a '65 Mustang "parts car," this little preamplifier has already donated *most* of it's "innards" to other units.  Here's a picture of what's left:

               

     It would be a lot easier describing what's left, rather than what's been "donated" to other "projects, but it always pays to examine what you DO have.  In our case, we have a good Front Panel and a good Main Chassis.  They'll need some cleanup, but they *should* serve pretty well as a foundation for our "project."

     It's immediately obvious that the Volume Control and the Balance Control have been "liberated" from the unit, but that's ok.  We won't need the originals for "the project."  We won't be using the Tone Controls for this build, so they will be "recycled" to another "project" later.  Of course, the missing Selector Switch is a *bit* more problematic, but I have one that was already "salvaged" from a preamplifier.  (It *might* have been THIS preamplifier - I have no way to tell now.)

     The Quad Capacitor is still there, but it won't be.  We'll be handling the Power Supply Filtering requirements in a completely different manner.  Notice the missing Power Transformer?  It wasn't "donated" to another preamplifier.  It was "donated" to the scrap heap!  It had melted down and was the original cause for the failure of this preamplifier.  (From the looks of things, it literally "let the smoke out" - there are scorched deposits all over the metal parts!)  We'll deal with *this* minor catastrophe a bit later.  Oh yeah, the Rear Panel.  We'll need one of THOSE things too!

     While we're examining things, take a look at the way someone replaced the selenium rectifier:

               

     Two old-style "top hat" rectifiers, soldered to a wire and "floating" in space!  The *problem* with this "arrangement" is that if the body of one diode touches the other, it shorts out the filament supply and will *probably* take out the Power Transformer!  (Gee, do you think that *might* have caused the demise of this preamplifier?)  Why do people DO these things?  Also, notice that the Filament Supply electrolytic capacitors are branded as "Dynaco Capacitors?"  ("Long Life" capacitors to boot!)  Sorry.  They've come to the END of their "long lives."

     We also have a Pilot Lamp Holder (that we won't need, so it will be recycled) and, of course, the two Printed Circuit modules.  (They'll become "donor parts" too - we have *other* plans for THIS unit!)  We also have a bottom "plate" for the Main Chassis.  (We'll have to see how well it "cleans up" before we can pass judgment on it.)

     THIS is the beginning of "A Really SUPER Preamplifier???"  Yep!  In a way, it's an "exercise" to show you that even a unit that has been nearly "parted out" STILL can have *real* possibilities!  I hope that when we're done, we'll have a lot MORE than *possibilities*.  We'll have "A Really SUPER Preamplifier!"

     MUCH more to come!

Sincerely,

Bill Thomas

[ArthurDent]

Bring it on Bill    Will be interested in the process/progress as usual.

[Bill Baker]

Way to keep'em coming back Bill. You have my attention.

[Bill Thomas]

Wednesday, February 3rd, 2010 - Update:  "Starting All Over Again"

     Yep!  There's a song title for EVERY need, isn't there?  Well, Mel and Tim were referring to a "difficult" relationship, but WE'RE dealing with our current, ongoing "relationship" with a "sad sack" of a PAS-2 preamplifier.

     Perhaps you're curious WHY in the WORLD I chose such a total "basket-case" of a preamplifier upon which to build our "Really SUPER Preamplifier."  Here's why:

               

     Yes, this is exactly the same Main Chassis you saw in the earlier picture.  Of course, all the components have now been removed and it has been SERIOUSLY cleaned up.  But let's not stop there.  Here's a picture of the underside of the Main Chassis after cleaning:

               

     Of course, you don't HAVE to clean things up like this, but since we're "Starting All Over Again," it just makes sense to "make it pretty" as well.  Sure, nobody will know how clean the chassis is once we have it all "buttoned up," but *I* will know.  Call it a "point of pride" or you can call me an "Anal Retentive" if you'd like, but at least *I'll* know it started out its new life with a nice looking chassis!

     The Front Panel cleaned up nicely too.  Here's a picture:

               

     And here's the "inside look" at the same Front Panel:

               

     So, what does it take to clean the metal parts to look like this?  Water, common SOS pads and a good bit of "Sweat Equity."  Plan to spend a couple of hours cleaning up all the metal parts (including the Rear Panel and the Bottom Panel.)  For those of you who find the "brushed steel" look from the SOS pads "less than ideal,"  you can add a few more hours with rubbing compound and polishing compound, but you run the risk of burning through the plating.  I'll take the "brushed steel" look ANY day!

     NOW you know why I chose these particular metal parts.  Yes, they were dirty and "crudded up" when we began, but they "cleaned up purty good" with just a *wee bit* of effort.  I can tell you ONE thing; it'll be a LOT nicer building our "Really SUPER Preamplifier" on a nice, clean foundation like this!

     I should mention that if YOU decide to build a preamp like this for yourself, you might not have the luxury of selecting a good "donor chassis" for your project.  Your unit just *might* be pitted, rusted, or stained.  In that case, use a rust "converter" to get rid of the brown rust spots first.  THEN go with the SOS pads and water.  Either way, once you have everything clean, make SURE you dry it thoroughly.  You certainly don't want to create any NEW rust spots!

     In our next update, I'll "spill the beans" about the actual *contents* (or "guts", if you will) that will be making our new preamplifier Really SUPER!  (I can feel the excitement level building already!)  We've got quite a journey ahead of us, but it's going to be a LOT of FUN!  Stay with us!

Sincerely,

Bill Thomas

[Bill Baker]

I'm glad I'm not a cat or I would be dead by now

Can you at least tell us if this is a 'production' unit that will be going into the chassis or a custom design

[Listens2tubes]

WEEE!!! A new project at last! I've been waiting sooo long.

[Vulcan00]

He got my attention. Since I need a good tube pre-amp. And I would like to learn more about them. Please continue sir!

[Bill Thomas]

Thursday, February 4th, 2010 - Update:  "Tell Me Something Good!"

     OK, I've kept you in suspense long enough.  It's time to reveal the "secret identity" of our "Really SUPER Preamplifier!"  I'm sure that some of you have already guessed that this time, we're building a "Super PAS-3" preamplifier from Audio by Van Alstine."  See?

                                   

     This is the cover page of the Construction Manual for Frank Van Alstine's "Super PAS Three Rebuild Kit."  The "Super PAS Three" preamplifier is a complete and total "re-thinking" of the original Dynaco PAS preamplifier concept.  Frank has *thoroughly* addressed almost EVERY issue with the original design in order to SIGNIFICANTLY improve the quality, performance and reliability of the PAS preamplifier.

     Take a closer look at the cover picture showing a completed unit:

             

     (Sorry about the fuzziness of the photograph, but the image is printed on non-photo paper and my camera doesn't do it justice.)  But you can see some of the important features of Frank's design.  Let's touch on a few of those features.

     First, the Power Transformer has been moved outside of the chassis in order to reduce any chance of hum pickup within the unit.  Notice the fuse holder where the Power Transformer *used* to be?  This was an important omission in the original PAS preamplifier design; especially since the PA-211 Power Transformer is *known* to be under a heavy load in the original design and is a common failure point.  Chalk one up for improved safety!

     It's pretty easy to spot the BIGGEST difference.  There's an extra printed circuit board on the Main Chassis where the old filament supply was located.  This third pc board contains the Power Supply components for the preamplifier.  It does away with both the quad capacitor AND the original DC filament supply components.  But it isn't just a "capacitor board."  This is *another* area where Frank has improved things by a HUGE amount.  Capacitance has been increased - a LOT!  On top of that, each channel of each circuit board is fed from a separate, isolated supply "leg" of its own!  This makes a HUGE reduction in the tendency for one channel to affect another channel through the Power Supply rails.  The filament capacitors are MUCH larger too - FIVE TIMES larger!  If there's a *trace* of ripple in the filament supply, I'd be STUNNED!

     In the High Voltage supply of the original PAS preamplifier series, the total capacitance of the quad capacitor was 80 micro-farads, but in Frank's "Super PAS Three" design, the Power Supply has (are you ready for this?) 1470 micro-farads!  Each of the four individual isolated "legs" have over 250 MORE micro-farads of capacitance than the entire original quad capacitor!  This is *one* Power Supply that'll be "kickin' butts and takin' names!"

     Take a closer look at the other two circuit boards.  Ain't *nothin'* "stock" about THOSE babies!  Both the equalized Phono Preamplifier module and the Line Stage module have been *totally* re-engineered for improved performance!  Special attention has been paid to FIX the "lumpy" bass response of the original Dynaco design and reduce the hum and noise figures THROUGHOUT the preamplifier.  Too good to be true?  Not likely!  And here's why:

     When you first open the box containing the "upgrade kit,"  you will IMMEDIATELY notice the OUTSTANDING quality of every part in the kit!  We're talking Vishay-Dale metal-film resistors, Panasonic (Matsushita) film capacitors, long-life electrolytic capacitors rated for 105 degrees Celsius, rather than the usual 85 degree Celsius parts and SO much more!  The new printed circuit boards are FR-4 fiberglass boards, rather than the old phenolic boards.  Circuit traces are MUCH wider than the original boards and the Power Supply traces are *truly* massive!  Almost EVERY facet of the original PAS preamplifier concept has been improved upon!  (I say "almost" because there is one *additional* "factory modification" available, but the completed "Super PAS Three" unit MUST be returned to the factory for installation.)

     The basic "Super PAS Three" upgrade kit can be augmented with new gold-plated RCA Jacks that are installed on a "ground plane" circuit board on the rear panel.  But be aware that you will have to do significant "nibbling" of the Rear Panel in order to install the new Jack Field.  Why?  Because the new jacks are "spread out" further than the original jacks were.  Remember those expensive interconnect cables you *wanted* to use but couldn't because the original RCA jacks were so close together?  That WON'T be a problem with the *new* RCA Jack Field!  Frank has also provided one thing that Dynaco *should* have included:  a "grounding terminal" (with a knurled nut, no less) for your turntable's "frame ground" connection!  There's even a new label for the back panel!

     There's one final "option" available (although we *won't* be using *this* one):  A brand new Selector Switch!  If your original selector switch is defective or noisy, just order the optional "upgrade" switch.  (Note: the "upgrade" replacement will NOT directly replace the original Dynaco Selector Switch - it does not provide the ability to switch the equalization circuitry the way the original Selector Switch does.)  But the "upgrade" selector switch DOES offer reduced crosstalk between sources and it makes it truly a "no-brainer" to convert the two unnecessary "Tape Head" and "Special" Inputs from low-level, to Line Level Inputs.  This can also be done using the original Dynaco Selector Switch, but it is a bit more difficult and cumbersome.  We WILL make that "conversion" in our "Really SUPER Preamplifier" project using the original Dynaco Switch.

     And this only "scratches the surface" of the entire "package."  Troubled by noisy or intermittent Volume and Balance controls?  You'll appreciate the VERY high-quality replacements included in the upgrade kit.  And, Hallelujah!  The Balance Control even has a center detent!

     OK, I've *finally* "spilled the beans" about our project!  In our next "update" we'll finally get down to some SERIOUS construction!  Up next:  we'll tackle the construction of both the Line Stage module AND the equalized Phono Preamplifier module.  Along the way, I'll offer a few additional "tips" that the construction manual doesn't mention.  Not that anything has been omitted from the manual.  The construction manual contains all the information you need to construct a "Super PAS Three" preamplifier, but this is a project designed for someone with more than a little construction experience.  For example:  you should know the resistor color codes, you should be EXPERIENCED at soldering good, solid solder joints and it would help if you already know how to measure and drill new holes in the existing metalwork.  We'll cover all that and a lot more, as our "Super PAS Three" preamplifier takes shape.  Our next "update" follows on Friday!  Don't miss it!

Sincerely,

Bill Thomas

[Bill Baker]

This should be an interesting build to follow. Actually, all your builds are great to watch. So what are your plans with it when completed?

Have fun with it and I am looking forward to all the step by step progress.

[Bill Thomas]

Friday, February 5th, 2010 - Update:  "Build Me Up, Buttercup!"

     OK, so I'm reaching with THAT one!  But in a way, it's *almost* appropriate, considering that the song was done by The Foundations!  (Just don't call me "Buttercup!")

     We're going "by the book" (mostly) in our buildup.  It all starts with assembling two of the three Printed Circuit assemblies, namely:  the FVA 875 Line Amplifier module and the FVA 874 Equalized Phono Preamplifier module.  Let's look at the Line Amplifier module first.

     Here's a picture of the blank circuit board:

               

     I mentioned previously that this project has been "waiting in the wings" for quite awhile.  The oxidation on the blank board's circuit traces wasn't there when I first received the "Super PAS Three" Upgrade Kit.  Here is my first "tip" that isn't included in the Construction Manual:  Before you start stuffing parts and soldering away, make SURE you clean the circuit traces THOROUGHLY!  How do you do that?  The same way I cleaned the metal parts - using SOS pads and warm water.  Here's a picture of the same board after cleaning:

               

     Thanks to the nice, thick plating, it'd take HOURS to scour away the circuit traces, but don't go overboard.  It doesn't take long to clean away all the oxidation so the traces we'll be soldering to are nice and shiny.  Remember, when it comes to soldering, you want to make SURE each and EVERY solder joint is solid and clean!  A "cold" solder joint will cause your preamplifier to develop mysterious noises and become unreliable.  You CERTAINLY don't want THAT!  Here's a closeup shot of a typical "good" solder joint:

                                                           

     It's a *tad* out of focus because my camera was having difficulty deciding whether to focus on the board, or on the component lead that was sticking up from the connection.  Still, you can see that the entire circumference of the soldered component's lead wire is completely soldered to the pad.  And the actual solder joint is clean and shiny.  When properly soldered, such a connection will remain reliable for MANY decades!

     To make SURE you produce solder joints like this, it is ESSENTIAL to *constantly* clean the tip of your soldering iron.  A wet sponge is *usually* the best way to clean the smoldering flux from the tip of the iron prior to soldering each new joint.  Frank includes solder with the "Super PAS Three Rebuild Kit."  USE IT!  Don't even THINK about using silver-bearing solder, no matter WHAT your "audiophile" friends tell you!  The solder Frank includes is basic 60/40 Kester "Radio Solder."  No, it's not fancy.  It's the same basic solder that has been around since I was a kid.  Before you try some "boutique" solder, ask yourself:  "Why has Kester 'radio solder' been around all these years?"  The answer is simple:  IT WORKS!  It's EXTREMELY reliable!  And it REALLY makes GREAT solder joints!  So USE the solder supplied with the "Super PAS Three Upgrade Kit."  DON'T try to "reinvent the wheel" by using something else!  With that little "caution" out of the way, let's get started!

     We've covered the proper techniques for assembling a printed circuit module previously, but let's cover it again.  It's actually pretty simple.  Start with the smallest parts and work your way up to the tallest ones.  The smallest part on the FVA 875 Line Stage board is the "zero Ohm" resistor.  It's the size of a 1/4 Watt carbon film resistor and it has the lowest profile.  What is a "zero Ohm" resistor?  If you guessed "a jumper wire," you're absolutely correct!  But using a "zero Ohm" resistor makes it easy to identify EVERY "crossover connection" on a circuit board.  Just look for the resistor with a single band in the middle.

     After soldering in the "zero Ohm" resistor, solder in the 1/2 Watt Vishay-Dale metal-film resistors.  The board layout makes it a LOT easier than the stock Dynaco board.  Both circuits on the board have IDENTICAL parts layout.  Populate one side of the board properly and you can simply copy the exact same parts layout on the other side of the board.  Thanks, Frank!  Here's a picture of the board after soldering in the resistors:

               

     When assembling your circuit board, take a little extra time to orient the resistors so you can read the value of each and every one from the top of the board.  It also pays to have the resistors "read" in the same direction.  If you ever have to troubleshoot an electronic component, you'll be MILES ahead if you can read the values of each part, don't you think?

     Here's a shot of the "trace" side of the board at this point:

               

     Make SURE you check each and EVERY joint after soldering to make SURE the joint is shiny and clean, not crystallized or incomplete!

     Once the 1/2 Watt resistors are installed, the manual tells you to mount the tube sockets.  But there are four capacitors that have a lower profile than the tube sockets.  Two are small film capacitors and two are *really* tiny mica capacitors.  I suggest that you mount these four capacitors first and THEN mount the tube sockets.  See if you can spot the little capacitors in this picture:

               

     By installing the capacitors *before* the tube sockets, you'll have an easier time making sure they are flush with the surface of the circuit board.  (And we want to make SURE each part is mounted straight and flush with the surface of the circuit board wherever possible!)

     By the way, you'll notice there are two metal-film resistors that use a color code, rather than a numerical marking.  (I *told* you it would be a good idea to know the resistor color codes, didn't I?)  These particular resistors use the "five band" system.  That's because these are 1% resistors and they are 511K values!  In case you aren't familiar with the five band color code, the first three bands are the integer value of the part, the fourth band is the multiplier and the fifth band is the resistor's tolerance value.  This can be confusing to "old hands" with resistor color codes.  using the five band system, a 10K resistor would be brown-black-black-red, NOT brown-black-orange!  Just a little something "extra" to keep in mind while you're setting up the parts for assembly.

     There are only six more capacitors to add and our Line Stage board will be finished!  Here's the result:

               

     From start to finish, we're talking about approximately three hours of assembly time - and THAT includes the extra time it took to snap the photos and make sure all parts were positioned so you could read all the values!  Frank has made the assembly process as simple as possible.  Having a GREAT pictorial diagram of the parts placement helps a TON!

     With the Line Stage module completed, let's turn our attention to the FVA-874 Equalized Phono Preamp module.  As with the Line Stage circuit board, the traces had oxidized slightly.  Here's a "before" picture:

               

     It's hard to see from the picture, but there was a bit of a "rainbow" coloration.  Time to get out the trusty SOS pads for THIS result:

               

     Solder actually *likes* to stick to nice, shiny traces like these!  Clean traces also promote better heat transfer from the soldering iron so a GOOD joint can be produced with a shorter application of heat - DEFINITELY a good thing!

     We begin the construction with the smallest parts; the zero Ohm resistor and the two small, glass diodes.  Make SURE you install the diodes in the proper direction!  The Cathode end (marked with a black band) MUST face toward the edge of the board.  Also, try to keep the diodes from getting *blasted* from the heat of the soldering process.  A "heat sink clip" between the joint and the body of the diode can help keep the heat from destroying the delicate diode.  Here's a picture of this initial stage of assembly:

               

     Again, always inspect each solder joint for proper integrity:

               

     Next, install the 1/2 Watt metal-film resistors and the two 1 Watt resistors like this:

               

     Again, the Construction Manual suggests installing the tube sockets next, but I suggest you install the four smallest capacitors before installing the tube sockets.  Two of them are to the left of each socket:

               

     The other two are dipped silver-micas located below and to the right of each socket:

               

     Once these four capacitors are installed, go ahead and solder in the tube sockets.  Here's a shot of our overall progress so far:

               

     You want the pins of the tube socket to be COMPLETELY soldered around each pin.  See?:

               

     The rest of the capacitors are taller than the tube sockets, so NOW is the time to install them:

               

     Hey!  We're done!  Pretty slick, huh?  Again, expect to spend about three hours from start to finish, but NEVER rush things!  Take ALL the time you need to do it *RIGHT!*

     We'll get to the Power Supply module in due time, but first we have to use the blank board to layout a few new holes in our existing chassis.  We'll cover all that too, but let's wait until the next "update", coming up within the next day or so.  Until then, keep your tubes nice and warm and Stay Tuned!

Sincerely,

Bill Thomas

[Listens2tubes]

Man Bill, you make me wish I kept that old PAS 3x

[Bill Baker]

As usual, very nice, clean job Bill. I love the looks of the 'vintage' gear when it's cleaned up to the nth degree like this.

[Brett Buck]

     To make SURE you produce solder joints like this, it is ESSENTIAL to *constantly* clean the tip of your soldering iron.  A wet sponge is *usually* the best way to clean the smoldering flux from the tip of the iron prior to soldering each new joint.  Frank includes solder with the "Super PAS Three Rebuild Kit."  USE IT!  Don't even THINK about using silver-bearing solder, no matter WHAT your "audiophile" friends tell you!

      As strong as you word it, it's still not strong enough!  I have built a lot of stuff over the years, and repaired any number of other people's projects, and the use of the various silver-bearing solders has been the bane of my existence at times. The rosin-core type is bad enough, what with the uncertain melting properties (as you mention in the FM-3 rebuild thread) and generally slightly higher temperatures required. You may be right when you say someone had mixed them together, but I have had very similar results when people used just the straight 4% silver-bearing solder from the hardware store. It's as you say - sort of lumpy and grainy. I never tried to remove it from the notoriously thin Dyna board but I can easily imagine that it would be a problem.

     But the worst is Sta-Brite - it comes with about the strongest acid-based liquid flux I have ever used. Unfortunately, it says it can be washed off with water. That's not true, and the worst mess I ever saw was after someone had put together a Venneman kit, and then "cleaned" it to get rid of the flux. You would think that anyone would know not to use acid flux on electronics, but apparently audiophool folklore/quasi-science is more important than reading the directions of ANY kit or basic soldering instructions published in the last 75 years. The results were predictable - every single conductor, wire, component, socket, was a dull gray and horrifically corroded, and most of the wires just broke when flexed. The corrosion ran as much as and inch or so under the insulation on the wires. You would think that someone would get a clue when it eats the tips off the soldering iron at a high rate *while you are using it".

    And don't even get me started on the guy who wanted me to put his Bottlehead kit together with *real* silver-solder/braze. I charged 5x as much as I normally do, told him it was (in so many words) a stupid and pointless exercise, but with the help of a little butane micro-torch, I managed it. I also determined that it wasn't worth it no matter what the payday, and refused the next time. Of course it would be impossible with any PWB but since it was point-to-point, it was at least possible.

    Plain old 60/40 eosin core is the way to go. The only notable advantage to the silver-bearing solder is not electrical, but structural - it's slightly stronger. But I also make model airplane fuel tanks for people (and myself) and 60/40 is plenty strong even for that, where it's just a lap joint on tin-plated steel. If you crash the airplane with significant fuel in the tank, it blows up the front of the tank like a balloon from hydrostatic pressure,  but generally doesn't break the solder joints. I doubt that anyone's preamp will be subjected to a 70-mph head-on-crash into the pavement, so the solder mechanical strength is probably a moot issue. It makes no difference electrically, no matter how many people write otherwise on the internet.

     Brett

[Bill Thomas]

Saturday, February 13th, 2010 - Update: "Get Ready"

     Yes, before we can build our Power Supply module, we need to use our blank Power Supply board to mark the original Main Chassis for the two additional holes that must be drilled.  No, this isn't "rocket science," but we DO want to "measure twice and drill ONCE!"  Our *first* attempt worked out like this:

                         

     Sure, this would *work*, but it isn't exactly as straight as it *could* be.  After careful consideration, (and since there is a *little* adjustment room available), I decided to give it another try.  Here's the result:

               

     If you look closely, you can see the original "dots" where things were initially positioned.  You can tell that the left side of the board has been moved farther from the rear of the chassis.  This brought the board position into nice, even alignment, rather than the original, slightly "skewed" position.  MUCH nicer.  No, it won't make a big "electrical" difference, but from an aesthetic standpoint, it just looks "right."

     We'll have a LOT more to cover in our next "update," but I'll make this a VERY short one - for NOW.  Tomorrow, I'll cover the construction of the Power Supply board along with the necessary pre-wiring.  (Yes, it's already completed, but I'm a little short on time this evening.)  Not to worry.  We'll show you a LOT of *real* progress in the next "update."  Thanks for the comments so far.  I'm ALWAYS interested in hearing what you think about our "projects."

     Until tomorrow, Happy Valentine's day!

Sincerely,

Bill Thomas

[Bill Thomas]

Sunday, February 14th, 2010 - Update:  "Heart and Soul"

     Yes, as promised, it's time to get to the "Heart and Soul" of our "Super PAS Three" preamplifier:  The Power Supply board!  Why do I call it the "Heart and Soul" of the preamplifier?  Because the Power Supply affects EVERYTHING.  If the Power Supply isn't truly SOLID, the entire preamplfier's performance will be compromised.  (Of course, this is true of ANY electronic device.)  But the Power Supply of the "Super PAS Three" is quite a different "animal" from a "stock" Dynaco PAS preamp's Power Supply.

     In a "stock" PAS preamplifier, the rectified High Voltage goes to a 30 uF section of the quad capacitor.  In the "Super PAS Three" preamplifier, this value is increased to 68 uF.  While this is probably a *teensy* bit more than the recommended capacitance for the 12X4 rectifier, this is truly a minor concern.  The relatively slow warmup of the tube rectifier serves to "ramp-up" the B+ Voltage rather gently - minimizing any potential surge problems.  (Besides, 12X4's are cheap and readily available for YEARS to come!)  The 68 uF capacitor then feeds a resistor which goes to a second filtering stage.  The stated value in the kit instructions is 100 uF, although an 82 uF capacitor was supplied with this particular kit.  It's a totally trivial difference.  Consider that the second stage capacitance in a "stock" PAS preamp is only 20 uF!

     Now for the BIG difference!  After the 82 uF capacitor, there are four resistors that lead to four separate 330 uF capacitors.  Two of those capacitors feed the Left and Right channel of the Line Stage board, while the other two capacitors feed the Left and Right channels of the Phono Preamp board.  In other words, each channel of each board is fed from its own separate, BIG filter capacitor for maximum isolation.  In the stock circuitry, there are only TWO capacitor sections feeding the Line Stage and the Phono Stage boards and the decoupling is MUCH smaller - a total of 30 uF shared by two capacitors!  Yeah, it *works*, but there is MUCH more opportunity for one channel to affect the opposite channel in the original design.  Not much chance of that in the "Super PAS Three" design!

     The Voltage Doubler in the filament supply isn't neglected either.  In the "stock" PAS design, the doubler circuit has a total of 4,000 uF.  But, in the "Super PAS Three" preamplifier, the doubler features 20,000 uF of capacitance!  There won't be ANY hum generated in the filament supply!

     So... let's get down to business!  It all starts with the bare FVA 873-A Power Supply printed circuit board.  Here's a picture of the board as it came out of the "parts bag:"

               

     The picture makes the board look a *little* dirtier than it really was, but by now, you already know what *I* did.  Yep!  I broke out the good ol' SOS soap pads and made it really SHINE.  Take a look:

               

     Sure, I *could* have bypassed this step, but cleaning the board like this gets rid of all the oils and other "nasty stuff" that just *might* interfere with making good solder joints.  It's just a little added "insurance" to make sure the solder joints are *truly* SOLID!

     As with the other circuit boards, we start with the smallest parts and work our way to the larger ones.  First, we install the Zero Ohm "resistors", the diodes and then, the rest of the resistors.  Here's a picture:

               

     Once again, take the time to orient the resistors so you can read their values.  It's little touches like this that make the difference between an "ok" build and a really "good" build.  It also helps if you can read all of the resistors from the same direction.  Left to Right and Top to Bottom.  Make sense?

     Once the diodes and resistors are installed, it's time to install the snap-in capacitors.  Start with the shortest ones first and make SURE they are *completely* "snapped-in" before you solder them permanently.  Now, just add the taller ones in the same manner.  Make SURE you install the capacitors according to the instructions.  Unlike resistors, if you install a capacitor backwards, it is likely to explode!  (Literally!)  So make SURE you observe the proper polarity when installing them!  Once you're SURE they're correct, here's how the board should look:

               

     Take a moment to inspect each and every solder joint on the "trace side" of the circuit board.  make SURE they are ALL good, solid and shiny.  Here's a picture:

               

     Once you're satisfied that all the solder joints are truly SOLID, you can go ahead and cut the lead wires.  That's *almost* it!  But before we can leave the Power Supply Board, we have to do a bit of "pre-wiring" since there is no way to solder wires to the circuit board once it has been mounted on top of the Main Chassis.  Just follow the pictorial diagram supplied with the kit.  Here's what *my* results look like:

               

     And here's what thinks look like from underneath the "busy side" of the circuit board.  Route your wires as shown in the pictorial diagram - just like this:

               

     And that's it!  It might look a little silly with all those wires sticking up in the sky, but we'll route them "nice and tidy" when we wire the board into the rest of the circuitry.  I'll also finish twisting the wire pairs when the time comes to wires them in as well.  (Don't worry, I'll show you how it all goes soon.)

     That's it for this "update," but we're going to "re-visit" a topic we covered in our "Last of the Dinosaurs" build of a PAS-3X preamplifier last year, namely:  dis-assembling, cleaning and re-assembling the Main Selector Switch (along with cleanup of the Blend Switch.)  It's all coming up within a few hours, so don't stray *too* far from your computer.  We're *almost* ready to get into the real "meat and potatoes" wiring of our "Really Super Preamplifier."  You don't want to miss a moment of it!  Stay tuned!

Sincerely,

Bill Thomas

[Bill Thomas]

Monday, February 15th, 2010 - Update:  "Take the Time (Do It Right!)"

     Who said disco was dead?  Who could *possibly* forget the sage advice of the SOS Band?  Today's "Update" covers two of the most IMPORTANT items in our "Really SUPER Preamplifier - the "reclaimed" Selector Switch and the Blend Switch.  Let's start with the Main Selector Switch.

     Here's a picture of our "candidate" for re-use:

               

     I mentioned earlier that our "candidate" might have even come from THIS original preamplifier.  Well, forget THAT idea.  If you look at the remnants of the wiring, you can see little "markers" or "colored sleeves" on some of the wires.  This switch came from a "factory-wired" unit, so it didn't come from THIS preamplifier!  Be that as it may, at first glance, it *looks* like this switch will wind up being a GOOD choice to recycle, but we won't *really* know until we get a MUCH better look at the actual switch contacts.  To do THAT, we need to completely strip all that wiring from the unit.  Here's a picture after all the wires and parts have been removed:

               

     Here's your *first* chance to "Do It Right!"  Before we can assess the switch contacts' condition, we need to clean the solder from each and every terminal.  Here's a representative picture after the "solder sucker" has done its job:

                                                 

     While the terminals won't look as if they've never been soldered to, you CAN get nearly all of that old solder removed.  If you get the terminals *this* clean and shiny, you'll have NO problem soldering the switch in later.  What's the best method to remove the solder from all these terminals?  Well, everyone seems to have a "favorite" method, but if you do a LOT of these "projects" yourself, a "powered" de-soldering gun will shave a LOT of time from this rather tedious chore.  I use a Hakko powered unit.  It has a motorized vacuum pump that is trigger-operated.  It's NOT a "precision" unit, but it WILL "get the job done" in one-tenth the time it would take you using a spring-loaded "solder sucker" and a soldering iron.  (Plus, you don't need three hands to operate it properly!)  It'll also keep you from positively DESTROYING the phenolic wafers from excessive heat when using de-soldering "braid" and an iron.  Granted, de-soldering "braid" can get the contacts pretty clean, but the amount of heat necessary to do the job is not "healthy" for the switch!  (And you need FOUR hands to properly use de-soldering "braid!")  With the Hakko unit, all you do is apply the tip to each terminal until the solder melts, and then you just "pull the trigger" to operate the motorized vacuum pump.  This will suck the molten solder through a hole in the gun's tip and deliver it to a small chamber on top of the gun.  It's a REAL time-saver!  (AND a "Switch-saver" as well!)  As I recall, I paid about $160.00 for mine about nine years ago.  If you're just doing ONE rebuild, it's hard to justify the cost.  But, if you do a LOT of rebuilds and repairs, it's worth its weight in GOLD!

     With the solder and wires removed, let's take a better look at the switch contacts to see if this really IS a good "candidate" for our preamplifier.  Here's a picture of the back of the Rear Wafer, prior to any cleanup:

                   

     Here's a picture of the contacts on the Middle Wafer, prior to cleaning:

                   

     And here's a picture of the rear side of the Front Wafer, prior to cleanup:

                   

     Look at all the "crud" that has accumulated on all those contacts!  We're going to have to dig a LOT deeper before we can actually determine whether this switch will be suitable for our preamplifier project.  This calls for careful dis-assembly of the switch.  Find a spot on your "bench" where the pieces of the switch can lie undisturbed.  Children and cats are a DEFINITE no-no here!  Prior to dis-assembly, turn the switch to its most counter-clockwise position.  (Then you can use these pictures to make SURE you are re-assembling the switch correctly when you've finished cleaning each wafer!)  Remove the two small nuts from the rear of the switch, then the two little lock-washers and then remove the two insulating washers.  Lay them all out "in-line" on the work surface.

     In the same manner, remove the rear wafer from the two long screws and place it next on your work surface with the back side of the wafer facing you.  Next, remove the two long "spacers from the long screws and position them to the right of the rear wafer.  Slide the middle wafer off the two screws and place it to the right of the spacers.  Then slide the NEXT two spacers off the long screws and lay them out to the right of the middle wafer.  Then, remove the front wafer from the screws and place it to the right of the intermediate spacers with the back of the wafer facing up.  Now just slide the remaining two spacers off the screws and slide the two screws out of the front "frame" of the switch.  Here's a picture of ALL the pieces, laid out IN ORDER on the work surface:

               

     Now that we have the switch dis-assembled, it's time to clean, Clean and CLEAN the individual wafers THOROUGHLY!  Here's what you need to do a "bang-up job" on the cleanup:  First, get a small "hobby brush" with fairly stiff bristles.  Next, buy a bottle of common lighter fluid.  Lighter fluid is naphtha and it will clean the greasy stuff off the wafers without harming the phenolic.  Now, buy deoxIT D5 and deoxIT GN5 contact de-oxidizer.  The GOOD news is, it's available at Radio Shack.  The *not* so good news is, two *tiny* spray bottles cost 15 bucks!  (But at least it's available ANYWHERE in the US so you won't have all those little parts just lying around while you wait for the BIG cans of deoxIT to arrive!)

     Ok!  We've got our naphtha (lighter fluid), we have our deoxIT D5 contact de-oxidizer, we have our *fairly* stiff bristle brush!  Soak the switch wafer with the naphtha and use the bristle brush to clean the wafers and the rotors of the switch contacts.  Use EXTREME caution around the "springy" contacts the rotor rotates between.  You DON'T want to bend those spring contact "fingers" in ANY way!  if you DO, you'll be looking for another switch!  It's nearly *impossible* to return those contact "fingers" back to an "un-bent" condition, so BE CAREFUL!!!!

     Once you've done the initial cleaning with just the naphtha, spray on a coating of deoxIT D5 to both the front and rear contacts of each wafer and scrub the rotor contacts with the bristle brush.  Turn the rotor so you can get to the entire rotor contact surface.  The deoxIT D5 will also coat the contact "fingers" and de-oxidize them as well.  Once the contacts are as clean and shiny as they can get, rinse the wafer with another shot of naphtha and allow the switch to dry.  Let's look at some "Before" and "After" pictures.  This "regimen" can yield some truly AMAZING results!

     Here's a picture of the back of the rear wafer BEFORE cleaning:

               

     And here's the result AFTER cleaning:

               

     Since there are contacts on BOTH sides of the Front and Rear wafers, clean both sides thoroughly.  Here's a picture of the front side of the rear wafer AFTER cleanup:

               

     NOW we can repeat the process with the other wafers.  Here's the middle wafer before cleanup:

                   

     And here's the same wafer after cleaning:

                   

     Here's the back of the front wafer prior to cleaning:

               

     After cleaning, it looks like this:

                         

     And finally, here's the front side of the front wafer after cleaning:

                         

     Now, we can FINALLY evaluate the condition of the switch contacts!  It turns out that this switch is in WONDERFUL condition!  Yes, you can see slight "tracks" in the rotors, but they are only slight color shifts, NOT a serious wear problem.  Whew!

     With the wafers all nice and clean, take a little extra time to cleanup the frame of the switch.  Squirt some naphtha into the front of the frame in order to dissolve the old grease and allow it to dry.  You can also clean the shaft of the switch with more SOS pads and water.  Allow it all to dry.  Using a toothpick, apply new white grease to the detent area.  I use "Lubriplate" because that's what the original manufacturer used.  It has great "shear-lubrication" and is water resistant to boot!  Here's a picture:

                                   

     Don't "load up" the detent with grease.  A small coating is all that's necessary.  You really don't want excessive grease to contaminate our newly-cleaned switch contacts.

     Now, make SURE each wafer is lined up EXACTLY the way you found it when you dis-assembled the switch (use the pictures above if you aren't SURE of the proper alignment!) and re-assemble the switch.  Here's the result:

               

     While you can't dis-assemble the Blend Switch, you CAN use the same technique to clean the switch contacts.  Just be careful when trying to get to the front of the wafer.  Here's how the Blend Switch contacts look after cleaning:

                         

     Now, break out the deoxIT GN5 conditioner and apply a VERY fine mist to the cleaned contact surfaces.  The thinner the application, the better it works, so don't "douse" it!

     And that's it!  Dynaco may have "economized" in a LOT of other areas, but the wafer switch contacts are all silver-plated.  If they clean up *this* nicely, you'll be good for YEARS of trouble-free operation.  Expect to spend the better part of an afternoon or evening to properly clean these switches.

     And with THAT behind us, it's time to make the "mechanical modifications" to the chassis and the rear Panel.  We'll cover it all in our next "update" coming up VERY soon!  Until then, just remember to ALWAYS "Take the Time" (Do It Right!)

Sincerely,

Bill Thomas

[avahifi]

Amazing work on the switch, Bill (and on the whole project so far. .)

I suppose this would be a good time to remind our viewers that we do have a shiny new replacement selector switch for the Super Pas Three rebuild project for $99.00.

The Super Pas rebuild kit manual shows how to wire the new switch into the circuit instead of re-cycling the original.  It will not make the unit sound better, but is a transparent replacement for the original if yours cannot be salvaged.

Note that our replacement selector switch is NOT a direct replacement in a stock original Dyna PAS series preamp.  The middle wafer on the original switch is not used and is not part of our project in the way it was used with the original kit.  The original used the middle wafer to switch phono equalization parts in and out of the circuit on the fly, to provide alternative high gain equalization curves (tape head and flat high gain) for the Dyna phono circuit board.  To use our switch as a replacement in a stock PAS, some of the passive parts on the original switch must be appropriately relocated directly on the phono circuit board.  We do not provide instructions for this process, although it is possible if you can read the schematics.

Note that our Super Pas Three rebuild kit manual provides for rewiring the switch and the jacks to change the now obsolete Tape Head and Special inputs into additional line level inputs for CD, or any other normal line level sources.

Regards,

Frank Van Alstine

[Bill Thomas]

     That is "high praise," Frank - undeserved, but *deeply* appreciated!

     I "touched" on the availability of the replacement selector switch in the "introduction" to the "project," but you have stated the benefits (and possible caveats) of the new switch MUCH better than I could!  During the cleanup of the original Dynaco switch, I *seriously* "hankered" for that new one, but (as you know) I *love* a challenge and the Dynaco switch really appeared to have a lot of hidden potential.  (It *did* turn out even nicer than *I* thought it would!)

     Now, if we can *just* get someone to manufacture a duplicate of the original Blend Switch...  (Without requiring a minimum purchase of 10,000 units!)

     I'm warming up the garage... er, "Metal Shoppe" for the chassis "modifications" and I'm evaluating potential candidates for the Rear Panel and the Power Transformer.  We'll be "drillin' and nibblin'" in the next 24 hours or so.  Then we'll cover the assembly of the BEAUTIFUL ground plane jack field!  I feel a lot of "thermionic goodness" coming, *just* around the corner!

Sincerely,

Bill Thomas

[Bill Thomas]

Saturday, February 20th, 2010 - Update:  "Choices"

     In the song "Choices,"  George Jones sings about taking responsibility for the choices he has made throughout the years.  In this "update," we're going to look at several "choices" in evaluating potential "donors" for the rear panel.

     Our first "candidate" for a Rear Panel comes from a later-model PAS-2 preamplifier.  Take a look at the panel after it had been thoroughly cleaned:

               

     Of course, the *first* "issue" has to do with the rather severe "staining" where the original label was located.  But if you look closely, you'll notice that we also have several "non-standard" holes drilled in the panel.  Granted, we're going to be drilling and removing metal from our final "candidate" for a Rear Panel, but those modifications won't hide the "problems" with this panel.  This just won't do.  So, it's back to the "donor pile."

     Our next "candidate" came from an actual PAS-3X preamplifier.  Here's a "before" picture showing the panel in "as-found" condition:

               

     There aren't any "extra" holes in this unit, but it's rather "questionable" whether this panel will actually clean up well.  Take a closer look.  First, here's the left side of the panel:

             

     Here's the middle of the panel where the label used to be:

             

     And finally, here's the area on the right side showing the cutouts for the RCA jack assemblies:

             

     Obviously, this unit was stored in a "less than ideal" location, but *maybe* it will clean up to an acceptable point.  The only way to find out is to give it that thorough sort of cleaning.  Here's a picture of the result:

               

     Frankly, I was quite surprised with how well this panel cleaned up, but there are a few "problem areas" that remain.  The *biggest* problem is the area in the center of the panel.  While I did my very BEST to "make it pretty," it's pretty obvious that there was no way to make the rust spot go away completely.  Since our new Rear Panel Label is smaller than the original, it won't cover this area completely so we'[ll have to classify this one as a "nice try."  Perhaps this is a case of "Third Time Lucky."

     Here's a partial shot of our Third choice prior to cleaning - complete with the original PAS-2 label:

             

     The overall condition of out third choice is substantially better than our first two "candidates."  If ONLY it will clean up completely - especially underneath the label.  Let's take a look:

               

     FINALLY!  Now THIS is a Rear Panel that is truly *worthy* of our "Really SUPER Preamplifier!"  This particular Rear Panel is a bit different than the first two potential "candidates" because it's from an early PAS-2 preamplifier.  Notice that the left-hand cutouts for the RCA jacks do NOT ground the "stock" RCA jacks to the chassis.  But this isn't an "issue" for US!  We're using the optional "Ground-Plane" replacement jacks that will be SOLIDLY grounded to the Rear Panel by the mounting screws.  But first, we have to make some "modifications" in order to install the replacement "Ground Plane Jack Assembly."

     In the Construction Manual, Frank suggests using a "nibbling tool" to remove the dividing metal areas between the left and right RCA jack assemblies, but since I now have access to air-operated tools, I decided to use a "cutoff wheel" to make short work of the metal removal.  There's nothing *wrong* with using a nibbling tool, but the air-operated cutoff wheel makes a MUCH straighter "cut" than I have ever been able to make with a series of "nibbles."

     Here's a picture taken "midway" through the metal-removal process:

                   

     The top cutout is in "finished" condition, but the bottom cutout shows how things looked prior to final filing.  When making your cuts, leave just a *little* extra metal.  Then you can file it down so the final edge matches the existing cuts so things will be nice and level.

     Here's a picture of the same area after filing both cutouts so they are nice and smooth:

               

     Use extra care when doing the final filing of the four edges.  Since this area is clearly visible, you *really* want things to be smooth, straight and level.  Notice that we have also drilled two extra holes between the two cutouts.  The hole on the Right side is for the new "Grounding Post" for the turntable chassis ground.  The middle hole provides additional support for the Ground Plane board so it won't "flex" when inserting an interconnect cable in any of the centrally-located jacks.

     Now, all we need to do is drill two additional holes on the Left Side of the rear Panel so we can mount the PA-211 Power Transformer and properly route the wires.  Just make sure you check CAREFULLY to make sure the hole for the grommet is located above the line where the Main Chassis will fit against the Rear Panel.  Here's a picture of the Rear Panel with the relocated Power Transformer installed:

               

     While we're dealing with "donor parts," let's go ahead and select a Bottom Panel for our unit.  Here's  our "donor" in "as-found" condition:

               

     And here's a picture of the unit after initial cleanup:

               

     I'll spend a bit more time on cleaning as we get closer to the completion of our "Really SUPER Preamplifier,"  but this Bottom Panel *should* work out just fine!

     While we're doing the metal "modifications," we mustn't forget drilling the two new holes for mounting the Power Supply Board in the Main Chassis.  Here's a picture:

               

     The two new holes are at the top of the picture.  It pays to remember to de-burr all new holes in the metalwork.  Sharp metal edges are no fun to deal with!

     Well!  We've conquered the most difficult portion of our "Really SUPER Preamplifier" build.  Some folks LOVE to do metalworking.  Others become *quite* intimidated when faced with carving up an original PAS preamplifier chassis.  The key to making it successful is:  "Take your time" when making these "modifications."  This isn't a "race."  Always measure CAREFULLY and don't cut or drill ANYTHING until you are absolutely SURE you have the markings in the correct location!

     That's it for this update, but next, we'll cover the assembly of the Ground Plane RCA jack field.  Don't stray too far - that "update" is coming on Sunday, so Don't Miss It!

Sincerely,

Bill Thomas

[Bill Thomas]

Sunday, February 21st, 2010 - Update:  "Fields of Gold"

     In *this* case, we're talking about "RCA Jack Fields,"  since we're adding the optional Ground-Plane, gold-plated RCA jacks to our "Really SUPER Preamplifier" project.  Since the modifications have been completed to the metal parts, all we have to do now is install 18 gold-plated RCA jacks into the pre-drilled, single-sided FR-4 board and tighten them securely.  Ahh, THERE'S the rub!

     In the construction manual, Frank recommends tightening the RCA jacks "firmly."  For a neat appearance, it would be nice if we could position the jacks so the terminals all have the same orientation, but this is a bit more difficult than it sounds.  In order to do that, it is necessary to find some way to "hold" each RCA jack in the proper position while "firmly" tightening the nut on the reverse side of the board.  Trouble is, there is no "flat" surface to grip with a wrench or a pair of pliers and if we simply "grab" the surface of the jack with pliers, we'll REALLY mar the surface.

     My initial thought was to search for a pair of "cushioned-jaw pliers."  But, once I started pricing them, (The *cheapest* version I could find was over $40.00!)  I decided to try a different method.  In discussing the situation with my Brother, he came up with the idea of using a miniature "bar clamp" from "Hobby Lobby."  Here's a picture of the little gizmo:

               

     Isn't it cute?  I *know* it looks like it's a heavy-duty item, but it's really quite "dinky."  The bar is only about 6" long!  But it DOES have plastic-cushioned jaws so I decided to give it a try.

     Sadly, it turned out to be the wrong tool for the job.  Yes, it *did* work, but by the time I got to the third RCA jack, the clamp began slipping on the bar.  On top of that, it was nearly impossible to make SURE it was clamped on the *shoulder* of the connector, rather than the contact surface.  Obviously, this was NOT going to yield a satisfactory outcome.

     Since "necessity is the 'mother' of invention," I came up with something that turned out to be the *ideal* solution!  Total cost?  About $15.00 plus tax!  Here's the secret:  I decided to make a pair of cushioned-jawed locking pliers!  (Using the absolute CHEAPEST Vise-Grip "clone" from Big Lots!)  The locking pliers cost $4.00!  And the "cushioning material" I used was "Plasti Dip," available from Ace Hardware.  Here's a picture:

                                                 

     Ace Hardware sells "Plasti Dip" for just under $11.00, but you can also find it online for less than half that price.  All you have to do is open the can, stir the "Plasti Dip" and then dip the jaws of the locking pliers for about five seconds and withdraw them from the "goop."  Hang the locking pliers and allow them to drip onto a piece of cardboard.  It takes at least four hours for the coating to fully "dry" before you can use the tool.  Here's a picture of the end result:

                   

     You'll notice that the coating is VERY thin.  If you're concerned and want a thicker coating, you can dip the jaws again and allow them to dry.  You need to allow at *least* four hours between "dips," but I found this one thin coat to be all that was necessary to protect the gold plating.  The locking pliers could gently, but firmly, clamp the shoulder of the RCA jack without harming the gold-plated surface in any way!

     Here's the end result:

           

     And here's a look at the "terminal side" of the board:

           

     looks pretty good, doesn't it?  but looks CAN be deceiving.  Let me warn you about a potential "pitfall."  Two of those jacks are NOT properly tightened because... I BROKE them!  Here's a picture:

                             

     If I may, I'd like to make a STRONG suggestion to you:  Don't use a 1/4" drive ratchet with a socket to tighten the mounting nuts.  Use a nut driver instead.  Unless you are Mark Henry from the WWE, you *probably* won't have enough strength to break the jacks, but if you use a 1/4" ratchet, you'll be able to EASILY break them!  Aren't you glad *I* learned this the HARD way, rather than YOU?

     Before we finish this "update," I DO want to show you a detail of the "Phono Input" jacks,  Here's a picture:

                       

     These two jacks MUST be insulated from the ground plane.  The fiber insulating washers solve the problem.  But make SURE you use the "ground lugs" included with the kit and orient them as shown in the picture.  Tighten them "firmly," just like the other jacks.  (Not TOO firmly now!)

     By the way, once Frank finished laughing, he graciously volunteered to send me replacements for my mistake.  (He even tried to "let me off the hook" about my part in destroying the two jacks, but we ALL know who is responsible, don't we?)  Still, it's SO nice to have such WONDERFUL and personal "customer service" backing me up!  I am TRULY thankful!

     I'll be taking things *slightly* out of order while waiting for the two replacement jacks.  Instead of mounting the ground plane jacks onto the Rear Panel, I'm going to perform the necessary mechanical assembly on the Front Panel, the Main Chassis and the REST of the items on the Rear panel.  We'll have pictures of the whole thing coming up in our *next* "update, coming up on Monday.  Stay tuned!

Sincerely,

Bill Thomas