The Dynaco Tube Audio Forum

Dedicated to the restoration and preservation of all original Dynaco tube audio equipment - Customer support for Dynaco VTA tube amp kits, all Tubes4hifi.com products and all Dynakitparts.com products


    VTA PH16X Build Thread (With SP14 to Follow)

    Share
    avatar
    edgobb

    Posts : 69
    Join date : 2010-11-09
    Location : Texas

    VTA PH16X Build Thread (With SP14 to Follow)

    Post by edgobb on Tue Feb 20, 2018 11:44 pm

    Hello all!  After a long distraction and period of satisfaction with my system, the itch has struck me again.

    It was 7 years ago that I built my VTA SP12 with a PH12 included.  It was one of the very first SP12 kits that Roy sold (possibly even the first SP12 not built by Roy, but I'm not entirely sure.)  I had just added to VTA board to my Dynaco ST70, and knew I needed to get into Roy's other designs.  Both Roy and Bob were great help as I dove into this hobby all those years ago, and they never fail to be a great resource when their help is needed. I would also be a fool to not mention how awesome it was to work with Kevin from Dynakit Parts too...couldn't have built my MKIIIs without him.

    I've since built my own set of speakers, a design by Paul Carmody called 'Sunflowers.'  They sound great!  I then built a nixie tube chessboard lit by induction coils designed by Tony 'Lasermad' Adams from the UK, and I've completely rebuilt a set of Dynaco MKIII Monoblocks, adding Roy's driver board to them with octal 6SN7s.  I also followed my tube obsession into amateur radio and became a ham a couple of years ago...so 73 from W8EFG.

    So........My birthday happened last weekend and my wife contacted Roy and bought me the PCB kit for the PH16X.  AND she gave me permission to buy the rest of it as well as to squeeze in an SP14 kit too.  Best birthday ever!!!

    If the interest is here, I'll try to document as well as I can my build progress in this thread.  Hopefully it can serve as a guide for someone who is doing their own build and give others an opportunity to learn from my mistakes and to tap the community for any help that I might need.  If that goes well, I'll chronicle my SP14 build in the same fashion.

    I am hosting my pics on my own server, and may take a few tries to get them to show properly.  Be patient with me over the next 24 hours as I get that worked out.

    This pic is the first one after I unpacked and started to lay out all of the parts before taking inventory. (If we can see it then I'll start the discussion.)


    Took me a little bit, but I am closer now to having the image correct.  Is it a good size or too big?

    I've been a quiet member of this community for quite a while and am glad that everyone is still passionate about playing with lethal voltage for fun!

    Best and more to come,
    Ed in Central Texas

    I would also be a fool to not mention how awesome it was to work with Kevin from Dynakit Parts too...couldn't have built my MKIIIs without him.


    Last edited by edgobb on Thu Feb 22, 2018 12:22 am; edited 1 time in total
    avatar
    tubes4hifi
    Admin

    Posts : 1476
    Join date : 2008-11-30

    Re: VTA PH16X Build Thread (With SP14 to Follow)

    Post by tubes4hifi on Wed Feb 21, 2018 1:47 pm

    thanks Ed, hopefully this will be a great post. Your photo is good about 50% larger would fill the page without being too big.
    BTW, I also have a pair of Sunflower speakers, which I just partially deconstructed as I'll be moving in a couple months so they are available
    with the front baffle and crossovers but without the large heavy enclosure for the bottom half if anyone is interested email or PM me.
    avatar
    pedrocols

    Posts : 115
    Join date : 2014-11-24
    Location : Western MA

    Re: VTA PH16X Build Thread (With SP14 to Follow)

    Post by pedrocols on Wed Feb 21, 2018 7:16 pm

    Great! Keep the progress pics coming!
    avatar
    tubes4hifi
    Admin

    Posts : 1476
    Join date : 2008-11-30

    Re: VTA PH16X Build Thread (With SP14 to Follow)

    Post by tubes4hifi on Wed Feb 21, 2018 8:21 pm

    not an actual build thread here, but photos I took during a build of one about 18 months ago . . .
    http://tubes4hifi.com/PH16X-2016.htm

    and here is a new page of recent photos
    http://tubes4hifi.com/PH16X-2018.htm

    and getting ahead of Ed, here's a link to the very latest SP14 photos, builds done January 2018
    http://tubes4hifi.com/SP14-2018.htm


    Last edited by tubes4hifi on Thu Feb 22, 2018 3:24 pm; edited 1 time in total
    avatar
    edgobb

    Posts : 69
    Join date : 2010-11-09
    Location : Texas

    Photos worked out, but too tired tonight...

    Post by edgobb on Thu Feb 22, 2018 12:32 am

    I took the time to get all of the photos I've taken so far uploaded to my website server tonight.  For some reason WordPress likes to load pics taken on mobile phones upside-down and sideways and it took me the better part of the last hour getting them formatted correctly...all 40 of them.

    I'll start the detailed chronicling tomorrow if all goes well and I don't get distracted actually building. Very Happy

    Thanks for your patience and I'm looking forward to sharing this story with everyone.  

    I'll leave you with a pic of my workshop music system...a necessity when building greatness.





    And yes.  That is an original chassis and original iron on that ST-70.  Decent shop rig. Smile

    Good night!
    Ed
    avatar
    tubes4hifi
    Admin

    Posts : 1476
    Join date : 2008-11-30

    Re: VTA PH16X Build Thread (With SP14 to Follow)

    Post by tubes4hifi on Thu Feb 22, 2018 3:26 pm

    nice shop speakers!
    avatar
    cci1492

    Posts : 192
    Join date : 2016-05-09
    Age : 57
    Location : Bergen County NJ

    Re: VTA PH16X Build Thread (With SP14 to Follow)

    Post by cci1492 on Thu Feb 22, 2018 9:25 pm

    Does the PH16-X have regular transformers instead of the toroidal transformers because the toroidals wouldn't fit in the lower profile chassis? Is the X version just as quiet, and are there any disadvantages to using the regular transformers in this amp?
    avatar
    edgobb

    Posts : 69
    Join date : 2010-11-09
    Location : Texas

    First Day of Building - Preparation

    Post by edgobb on Fri Feb 23, 2018 10:45 pm

    Alright.  I've gotten my server sorted out and had some time to get everything uploaded and oriented correctly.  There is a cool WordPress plugin called 'Fix Image Rotation' that takes care of the metadata embedded in mobile phone snaps.  I also have some time to document correctly this evening.

    I have to start on a side note.  I received the rest of my shipment from Roy yesterday, that contained the SP14 parts and chassis.  The packaging was rock solid.  It was professional and and neat.  I told Roy by email and wanted to state it here.  As a crazy builder and maker, (who often likes building more that I like using) even the experience of opening and exploring a new kit is a major part of the overall build for me.  I genuinely enjoyed the box opening...discovering the super high quality of the PCB, the chassis, and each of the parts groups organized and packaged separately was great.  I never thought that you could get that high-end, boutique feeling from a box full of parts, but I can...i know it's a little weird, but I had fun opening it and the stellar quality of everything was apparent.  Roy also drop-shipped the custom front and rear panels to me from CamExpert in California and the level of care and professional packaging from that supplier was impressive as well.  There is NO WAY that this kind of care and high quality can come in a mass produced piece of gear.  Our modern world of parts-to-the-lowest-bidder practices is really apparent when you get your hands on something like this that is intended to impress from the start.  The thick, through plated, silkscreened PCBs are top notch and the attention to detail have really just blown my mind.  I'm impressed.  Even as a repeat customer I was surprised.

    Away we go on the PH16X................

    First, I unpacked everything and took inventory.  I laid everything out on my bench to make sure that I had everything.  Thick, heavy chassis, all the bits, and the three PCBs. I've included a few ambiance pics as well.













    I checked off each item on the BOM as I located it at the beginning of each part description. (ie 33K 1W Resistor)  I save the component designation (ie R3 or C7a, etc) to check off when I actually install the piece.



    Next, I decided that I would build one PCB at a time.  I chose to do the main board first, the power supply board second, and the transformer PCB last.  I separated the parts and put each with their respective board, and put the chassis bits with the chassis.  Here's a shot with each of those sub projects grouped in their own areas:


    (Main board on left, Power supply next to chassis, and transformers and internal parts in the chassis.)

    I had already fired up my Heathkit VTVM that I restored a few years ago and checked each and every resistor for value and then rechecked them against the part numbers.  



    I labeled each one that could be labeled and the others I labeled directly on my workbench.  I have a huge roll of painter's masking paper that I use to cover my bench.  It absorbs spills, keeps me from burning my actual bench, and I always have a place to take notes or do math or help me organize.  When it gets super gross I roll a new layer right on top of it....i'm always afraid that some phone number or calculation may be needed in the year 2037 so it's really hard for me to just rip it off and throw it away.  (Ask me about the 100 yellow legal pads that I have in my storage.  I'll even claim that I can go to any piece of information at will in any of them. Exclamation )  


    Here are all of the parts for the main board value-confirmed, labeled, and organized for stuffing of the PCB.




    Equipment-wise, I have a regular old Weller soldering station, a Hacco 599B tip cleaner (which is worth its weight in gold), and some craftsman small pliers and clippers.  I use Cardas Quad Eutectic Solder which I have suspended in a little rig on my old-timey desk light.




    In my next post I have some technique pics...bending of component leads, soldering and then the PCBstuffing process.  I have to transition to some home stuff right now, but may add the next post a little bit later.

    Thanks for reading and feel free to drop any comments in this thread.

    -efg

    @cci1492 - I am pretty sure that the toroidal trafos won't fit in this chassis and that quality alternatives were found. Roy will have to answer for sure, he can especially speak to and noise floor differences. I had the same thoughts when I received the kit, and trusted that Roy had the noise floor under control.
    avatar
    edgobb

    Posts : 69
    Join date : 2010-11-09
    Location : Texas

    Techniques and Stuffing the Stage PCB

    Post by edgobb on Sat Feb 24, 2018 4:11 pm

    Good Afternoon all,

    The first step after I got prepped and organized was to install the spacers.  Super simple. There are six of them...stick in screw and twist on spacer.


    I forgot to mention it, but I cleaned the PCB with a little contact cleaner before I started.  I don't have any alcohol for some reason, so I sprayed the Deoxit onto a shop towel and wiped it down real good.

    My next step was a little vexing right off.  Installing resister R1 stumped me.  I searched for it on the board and the pictures but couldn't find it anyhwhere. After closer scrutiny, I saw that there was a (B) on the parts list after the R1 designation.  It turns out that R1 is actually resistor "B" in the loading section.  It is the resistor that gives you the standard 47K load for the MM cartridge.  It lines up with dip switch number 2, which is the only switch that is in the on position to get that load.  So don't get confused, just know that R1 = B.  tongue  You can see in the above pic that I installed R2 and R4 and was planning to come back to R1 later, but the answer occurred to me.

    In the PH16X, any components that would end up being taller than the spacers need to be installed on the bottom side of the PCB so the next step in my process was to stuff everything on the top side of the board.  This includes all of the resistors, the tube sockets, and two transistors (J1).

    To any of us regular builders the next descriptions are pretty common, but I want to show anyone that thinks that this stuff is too hard for them that it is a possibility and you have to start somewhere.

    Sizing and bending component leads; resistors in this case.
    I've got an LED magnifying lamp clamped onto my bench and readily available.  It seems that as my age advances, my vision up close contracts.  Time waits for no man, I suppose.
    Bending resistor leads to the correct size and orientation takes a little bit of practice.  I first make sure that the resistor size number is showing on the top to help with troubleshooting later.  My second goal is to try to bend the leads so that the resistor is centered over the screened picture.  I also work so that it fits into the holes snug enough that the piece doesn't move when I flip the board over.  I generally accomplish this second goal about 50% of the time...sometimes when I flip the board to solder the piece in, i have to bend the leads outward to hold them in place.  Winsome...losesome.

    Here are some pics of bending resistor leads with duck-bill pliers:








    Before I slide it in to the correct place on the board, I double check the part number from the BOM.  Then I slide it in snug against the board.  1/4 and 1/2 W resistors can lay against the board, but the bigger ones need some room to breathe. (More on that later.)


    If I bent it perfectly, it is just a tiny bit snug and centered over the printed location.  If not, I bend the leads out on the bottom of the board to hold it in place. Because of the symmetry of this particular board, I generally install and solder two resistors at a time.  Here's two ready for soldering:


    I then solder.  I put the tip on the board so that it touches the lip of the hole and the component lead.  After a few seconds it heats up sufficiently so that when you touch the solder to the lead it flows nicely.  It takes some practice but the learning curve is not too steep.  If you touch the solder to the iron, the solder melts but doesn't flow into the hole and bond to the lead properly because they are not hot enough and you may end up with a cold joint.  Joints should be shiny and not grey and dull. (Cold solder joint.)  If you do get a cold one, just re-heat it and flow a little fresh solder into the joint and it should fix the problem.


    After that I snip off the lead, hoping it doesn't shoot my eye out, and make sure that it is a good joint and isn't bridging over to any other spots on the board:




    From there I just continue to populate the board.  I always double check the part number on the actual component with the BOM, and I check each part off the list as I install it.  I just go straight down the list sequentially until I'm finished.

    Here's some incremental progress:




    As I mentioned earlier, the higher wattage resistors will produce more heat.  These guys need to breathe so they are spaced above the board a bit:



    Auto focus is tough, but you can see the space under the largers.

    Eventually, all the resistors are in.  Great success! Very Happy  I'm that guy that tries to align everything perfectly with everything pointing the same way. Even the slots in my screws tend to be in sync. (Skizo might be able to relate.)


    ****Helpful Note****  When I got to R26 and R27, I lost my groove because the lead holes on the PCB are a little bit further apart than EVERY OTHER resistor on the board.  My muscle memory was established and those guys wouldn't fit.  I had to resize my process when I got to that point!

    Next came the tube sockets.  I was able to stick all four of them on the board and then flip it over.  They were about one mm taller than the spacers so I could lay them flat on the bench.  From there I soldered two pins on opposite sides of each socket and then flipped it back over to double check that my sockets were level.  I've had some instances in the past where one of them wasn't quite level after soldering all nine pins and that is no fun to fix later.  For the OCD alter ego that lives within me, a tube that sticks up slightly crooked would deny me the ability to sleep nights.  Verifying that they were level, I flipped it back over and then soldered two more opposite pins on each socket and then checked for level AGAIN.  After I felt my inner peace exhale, I soldered all the rest of them into place and all was good with the universe.




    Next went in the transistors J1.  Transistors can get junked if they are cooked too hot for too long, so try to keep them away from the board a bit and don't fall asleep while applying heat to the leads.

    Slid in.



    I then clipped the leads and very gently bent them over to fit into the proper clearance, Clarence.




    And KABOOM!  cherry  The top side of the board is stuffed!



    I then got started on the bottom side of the board installing the capacitors.  I used the same process of checking against the BOM for each part number and each value, checking off each one as I installed it.

    C1 went in first and I used the heatsink from the PS board to prop up one side as I soldered:






    From there, everything is smooth like buttah. The rest of the caps go in. (Perfectly aligned with all print facing the same direction, of course.  bounce )

    No magic here, everything is easy because there's not too much bending and fitting to be done.

    A quick side note:
    I had to decide if I was going to install the load section resistors on the top or bottom of the board.  I debated that maybe I'd want to see the values of the resistors later if I ever needed to change cartridge load. Although i definitely want the DIP switches to be on the bottom, I decided to just leave the resistors on top.  It makes no difference functionally, but may make things easier in troubleshooting later if there is a problem.  I decided that I'd strive to just put everything in the right place the first time around.  study

    That is where I am right now.  I have to install the DIP switches and the load capacitors and then I'm ready to move on to the power supply board.

    .....what remains.


    More to come as I get to it.  Today I will receive the shielded cable that I ordered.  It should be in the mailbox right now.

    Thanks for reading again!
    -efg

    monkuboy

    Posts : 31
    Join date : 2016-03-23

    Re: VTA PH16X Build Thread (With SP14 to Follow)

    Post by monkuboy on Sat Feb 24, 2018 4:59 pm

    Thank you for such detailed pictures and your accompanying comments! I will be building an SP14 this coming week and this is a very helpful thread, which I just now bookmarked for future reference.
    avatar
    edgobb

    Posts : 69
    Join date : 2010-11-09
    Location : Texas

    Finishing Stage Board, PS Board and Starting Chassis

    Post by edgobb on Tue Feb 27, 2018 2:12 pm

    Alright! Getting closer to the end here...

    One thing that I didn't mention in the last post is to be careful with load resistors 'F' and 'C.'  One part number is 3320 while the other is 3302...an easy place to make an error if it wants to be made.  Mad

    All that remains for stuffing the stage board is the cartridge load capacitors and DIP switches. (Did you know that DIP stands for Dual Inline Package? I didn't.)

    I oriented the switches so that the numbers were on the outside edge of the board.  This kept the numbering in order from lowest to highest as if they were on the top.  I also switched the #2 switch for the 'B' resistor on for the default load.  The inability to get the capacitors perfectly inline gave me some heebie-jeebies, but I will have to go on regardless.






    From here I set up to stuff the power supply board.  I went through the same process as before with taking inventory, testing each resistor value ,and labeling and organizing each.  I don't know about you, but I am much more apt to make a mistake unless I remove all distraction as well as double and triple check myself, so I build the triple checking into the process.

    I forgot to take the pic after organizing and before starting, but here's one I snapped when I remembered:

    I have the resistor values and component designation numbers on my bench and cross them out when I install.

    So away I went on the power supply board.  First went on the spacers and then the resistors, with the larger ones given breathing room again.






    Next went in the diodes. Diodes have thicker leads and are less forgiving when it comes to bending them to fit in the holes.  Resistors will give you a little play and you can adjust the bend with your fingers, but diodes are stiffer and I had to take a couple back out and resize them.  Diodes are also polarized, so i had to be sure to double check each one as they went in.  The banded cathode goes into the square hole. So, good job! Circle gets the square!!!  (That band also lines up with the line on the schematic symbol for diode, btw.)

    I did the smaller ones first, and went up from there...with the part numbers all oriented in the same readable direction.   king




    I then installed the tube socket using the same method as before.  Just tacked it in to make sure it was level, and then soldered the rest of the pins.

    A couple to hold it and adjust.


    And in!


    For my next trick; Capacitors.  I went down the list and installed them in that order.  I was able to rest them on the bench to keep them in the holes after inserting them and used bench fodder to level the other end of the board. Electrolytic capacitors are polarized as well...they will vent or explode if they're incorrectly fed voltage so care is necessary yet again.  This time the positive, LONGER lead gets the square hole.  So good job! X gets the square!!!






    I worked through all of the caps, and then put in the U2-LD1084V heater regulator.  It came already connected to the heatsink.  Here is gets a little confusing on your brain when installing it on the bottom of the board. I had to remember that a voltage regulator has Input, Output, and Adjust pins.  They are marked on the PCB, but you have to flip the orientation of the piece when it goes on the bottom to make sure that the pins go into the correct holes.  This goes for all of the transistors on this board.  They needed to be oriented so that the pins are correct--which is in the opposite direction of the pictures on the PCB.  So when installing on the bottom of the board for the PH16X version, it is opposite day!

    Instructions say to not solder in the heatsink, so I followed them.  Here is a shot of the completed capacitors with the voltage regulator installed:




    In went the rest of the transistors, U1 and Q1, making sure they were oriented correctly:


    Add that board is STUFFED!!! (Both of them.)





    I put the rubber bumpers on the stage board, and then installed the three jumpers.  There are two in the the phono stage board and one on the PS board.  I used 20AWG instead of 22 because it is power voltage rather than audio signal, and the variety that I have is solid, pre-tinned from that glorious emporium, FRY'S!  I usually use stranded but this is what I have in 20AWG right now.  Here are the jumpers installed:





    In my next post, I'll finish the transformer PCB, install the 120VAC jumpers on it, twist some pairs and more!!! Tune in next time...

    -efg
    avatar
    edgobb

    Posts : 69
    Join date : 2010-11-09
    Location : Texas

    Already thinking tubes...

    Post by edgobb on Wed Feb 28, 2018 10:25 am

    I've been stockpiling NOS 6922 tubes for years while fantasizing about building this pre.  I think I've got 6 or 8 of them that I've come across.  I've got to remind myself what I actually got and will post some pics later after I get them out.

    Most of my tube luck is at Hamfests, where I come across them for $5 or $10...with guys that almost know what they have selling them for closer to $20.

    There is a local guy that I'm trying to meet with today who told me that he got a hold of a bunch of 7308s.  I've been wanting to check out these famed tubes but never had the chance.  Hopefully he's willing to part with them for a reasonable price.  Most of the Ham guys are more than reasonable when it comes to tubes.

    Meanwhile, the ePay auction has these listed for your consideration and entertainment...
    https://www.ebay.com/itm/RARE-QUAD-4-MULLARD-E88CC-01-7308-6922-BLACKBURN-TUBES-GT-BRITIAN-GOLD-PIN/302639137882?epid=573310595&hash=item4676b2c45a:g:qp4AAOSwBkRaC7YB

    Happy building and listening all!
    Ed
    avatar
    Dave_in_Va

    Posts : 236
    Join date : 2013-04-02

    Re: VTA PH16X Build Thread (With SP14 to Follow)

    Post by Dave_in_Va on Wed Feb 28, 2018 1:28 pm

    Keep an eye out for New York Amperex 7308 tubes from the early/mid '60's. These are very high quality tubes and sound very, very nice.
    avatar
    edgobb

    Posts : 69
    Join date : 2010-11-09
    Location : Texas

    Continuing onward....

    Post by edgobb on Fri Mar 02, 2018 12:22 pm

    I next got into the PC board with the transformers on it:


    High quality PCB mountable transformers.








    Notice that the pin numbering on the two units is different, was confusing when thinking about the voltage jumpers until i noticed that little detail:


    I soldered the transformers in place on the PCB, and then twisted wire pairs.

    Here is my pair twisting rig:




    I twisted me up three different colors, still using the 20AWG solid wire. I made enough to take care of the connections between the stage and power supply boards as well.  The instructions say that you'll need about 11 inches of wire coming off the transformers.


    Next I soldered them in place.  **Note** Although it doesn't really matter, it may have made the final wiring of the piece easier if I had soldered these onto the top side of the board. If I did it again, I'd probably do it that way, but this will certainly be fine.




    Because I soldered them on the bottom, I was sure to write down what color wire I used for each....and wrote it down to save me some headache later. I plan to use the same color wire for each voltage throughout the rest of the project:


    I also recommend installing the voltage jumpers before installing the transformers onto the PCB.  It certainly would have been easier.  
    It is screened directly on the board: For 120V in Jump 1-3 and 2-4.  Here's some jumper pics:
     





    I next had to drill some holes in the chassis.  There are eight connection points on the top panel, but only the side holes were drilled.  I screwed the top panel into place and drilled the holes onto the top lip.  I was terrified of slipping and scratching the top panel, but I was careful enough and had success!  




    I then installed the rubber feet:




    The transformers went into the chassis next, and I began building the top panel:




    Remembering that I had already installed the rubber isolators on the stage board spacers, I lined up the holes and then screwed the boards to the top panel.






    Next went in the IEC input filter, fuse holder, LED, and RCA jacks.






    And with that I ran out of time for the day.  I'm itching to get this completed and it is even harder to be patient when I'm so close to being done.

    My next post starts the wiring and I'll get that up soon.

    Thanks for checking it out!
    -efg

    (If you noticed that I forgot the third jumper on the stage board, don't worry. I noticed it in the next step and added it. Embarassed )
    avatar
    crkohut

    Posts : 12
    Join date : 2016-11-02
    Age : 57
    Location : Sudbury, Ontario, Canada

    Re: VTA PH16X Build Thread (With SP14 to Follow)

    Post by crkohut on Sat Mar 03, 2018 10:02 am

    Nice!! Top notch work!!
    avatar
    edgobb

    Posts : 69
    Join date : 2010-11-09
    Location : Texas

    Thanks.

    Post by edgobb on Mon Mar 05, 2018 12:02 am

    Thank you very much!

    More to come tomorrow. The finishing is upon me!!!
    avatar
    tubes4hifi
    Admin

    Posts : 1476
    Join date : 2008-11-30

    Re: VTA PH16X Build Thread (With SP14 to Follow)

    Post by tubes4hifi on Tue Mar 06, 2018 1:37 pm

    Hi Ed,
    I see that you are OCD like I am, that's a compliment, meaning you like to do things RIGHT !!
    OK, so this has to be the most detailed build thread I've ever seen! Beats the half dozen photos of the build thread on my webpage!
    I've always been a man of few words, I mean, if you can't figure it out, then how can you fix it, how can you know how it works?
    So all your words and photos are things that are already in my head, but for those builders that don't think, now they can just read!!
    Roy www.tubes4hifi.com/PH16.htm
    avatar
    edgobb

    Posts : 69
    Join date : 2010-11-09
    Location : Texas

    The home stretch...

    Post by edgobb on Tue Mar 06, 2018 3:26 pm

    Thank you Roy! I appreciate the compliment. Taking my time and being meticulous is a therapeutic exercise for me. It also makes it easier to troubleshoot when things get squirrelly and don't quite work right.


    So to get into the final wiring of this thing....


    Next I concentrated on the wiring connections between the main board and the power supply.

    As I wrote on my bench, red wires are for incoming 120V, yellow is for 12V, and white is for HV and B+. I connected B+1 between the boards, then B+2, and then the filament voltage wire, making sure i didn't screw up polarity.  (Have to remember that Heater and Filament are the same thing. The PS board is marked as H+ and H-, but the main board is marked as F+ and F- so they will try to trick you if you're sleeping on the job.)












    Routing them all nice and neat...





    At this point I realized that I didn't install the third jumper on the stage board, so I certainly had to do that...




    I ran the ground wire between the boards last, and here's the completed between-the-board wiring job:



    I decided to tackle wiring the RCA jacks next. I stripped the ends off the shielded cable that I have.  There are two wires plus the shield in this particular cable, so I decided to use the orange wire for the right channel and the white for the left.  I just clipped off the end of the wire that I'm not using and let it sleep inside the cable.  I then tinned each end and installed them between the board and the jacks.












    I hope that you like my 'hot rock' that I use when I need a safe surface to solder on that I can touch.  It is a piece of granite countertop that I found in my yard when I moved into my current house.  I stuck some felt disk feet on the bottom and added it to the tool collection on the bench!

    I then got the output RCAs wired:






    With all of the audio component wiring completed, all that remains is getting power from the wall to the preamp.  I first put the anti-pop capacitor on the switch. I tacked it on one post of each so that I could solder the wire and the capacitor lead in one shot when I added the wire to the switch.


    I'm usually more methodical, but my ADD got the best of me and I soldered in the power indicator LED next...


    Now back on track, I laid out all of the AC input wiring.  IEC to fuse to switch to terminal block...and the ground from the PS board.



    **Important discovery** The ground tab on the IEC filter will touch the bottom of the chassis if it is not bent out of the way.  It caused me great confusion for a while when putting it together.  It also prompted me to make sure that the live tabs were bent enough because they hover very near the nut where the rubber foot is attached. There may have been an incident......or not.  That is all.   Cool


    In hindsight, I maybe should have staggered where the power wires attach to the switch above.  If I put the bottom wire on the left instead of the right post it would have keept them separated a little better.

    I then soldered the transformer wires to their appropriate places.  AC in to the terminal strip, HV to HV on the PS board and 12VAC to the PS board as well.














    Next in went the tubes and the power up!!!!!!!!!!!!!!!!! bounce  bounce  bounce  bounce  bounce







    This concludes the building portion of this thread.

    Up next?  Troubleshooting.  Yes, I'm having a little problem.

    Thanks for watching!
    Ed
    avatar
    tubes4hifi
    Admin

    Posts : 1476
    Join date : 2008-11-30

    Re: VTA PH16X Build Thread (With SP14 to Follow)

    Post by tubes4hifi on Tue Mar 06, 2018 3:48 pm

    fantastic posts, thanks Ed.  BTW, that ground lug on the IEC filter should be bent in the opposite direction from the other two !!
    Kind of hard to see in my own photo, I'll try to improve that and make a note of it in the documentation

    http://tubes4hifi.com/PH16X-13.jpg

    Sponsored content

    Re: VTA PH16X Build Thread (With SP14 to Follow)

    Post by Sponsored content


      Current date/time is Mon Sep 24, 2018 4:32 am