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 products and all products

    Another convert, M-125 build


    Posts : 14
    Join date : 2014-03-01
    Location : Friday Harbor WA

    Another convert, M-125 build

    Post by 5/35 on Sun Apr 06, 2014 11:53 pm

    I just finished the dust covers a couple of hours ago and had to share.
    This all started in Oct. of last year when I heard a friends tube system and was blown away. I knew right there one of my Hafler 500s was dead to me. I do not have the disposable income that the Optimizer has, so I spent endless hours of web searching looking for the biggest bang for the buck. Building a set of amps was not on my list. However, after finding Bobs web site, reading, and saving to favorites both text and photos from this forum and others, it sure seemed like the way to go.
    I first contacted Bob just before Xmas last with a short list of newbie questions. He was gracious, and answered them all, for the two thousandth time I'm sure. Since I seem to enjoy holding onto what pennies I have tight enough to turn them into copper wire, it took until after the middle of Feb. for me to send Bob the cash. The package arrived on March 1st and that night I was painting transformers building a plywood assembly jig and buffing out the chassis. I took the rest of the parts upstairs and laid the out no the dinning room table, read through the instruction manual, three times, and thought what have I done!! Pin 6 of V3...what the..... Long story short, once I got started, I couldn't stop. I found ways to blow off work I had never even heard of before. The step by step, along with photos of others builds, posted here, gave me great confidence.
    On March 13th I plugged in my first tube amp and did not have to use the fire extinguisher I moved close to hand. An ground loop and a little buzz from a driver tube were quickly fixed. The second one was plugged in the next day.
    That is were the story should end, but I couldn't stop. A couple of evenings in the shop produced a test box for small adjustments of jigs and tooling. Next came one of my all time favorite woods, Zebra Wood. I knew I had to do the amps justice and really wanted them to be a piece of furniture. To that end tolerances were tightened and thirteen coats of lacquer applied. I still can't believe that they friction fit to the point of needing two people to remove them from the  box.
    Working with plastic was another first for me, but with the help of the tutorial videos on the Tap Plastics web site, it was quite easy and fun. I may build myself another pair as I made some adjustments to the jigs on the second one.

    The system;  Oracle Alexandria    Grace F9e cartridge
                       NAD 521 c  Cd player
                       Apt Holman pre amp
                       JBL 4311
                      Morrow Audio cables
    And turned on sometimes; Hafler 500 bi amped through a Rane ac22 running a set (yes I set set) of home built TL cabinets tuned to 42 hertz, crossed  between somewhere between 100, and 70 depending on recording.

    See  slide show here, I would love to hear some feed back.

    Oh, how do they sound?  Like I need to tell you guys.


    Posts : 366
    Join date : 2014-03-13
    Location : Philadelphia

    Re: Another convert, M-125 build

    Post by audiobill on Mon Apr 07, 2014 7:56 am

    Those are great!

    I've got an adequate supply of 20 year old straight 5/4 cherry and I may do something similar!

    I'm envious of the plastic dust covers!!

    Posts : 673
    Join date : 2013-03-19
    Location : It can get windy here

    Re: Another convert, M-125 build

    Post by corndog71 on Mon Apr 07, 2014 11:10 am

    Wow! Really great work there. I love the wood and the plastic covers. I hope you're not operating the amps with those covers on.


    Re: Another convert, M-125 build

    Post by Guest on Tue Apr 08, 2014 12:29 am

    now this is a really nice built!, well done!

    Posts : 14
    Join date : 2014-03-01
    Location : Friday Harbor WA

    Re: Another convert, M-125 build

    Post by 5/35 on Tue Apr 08, 2014 12:54 pm

    Thanks guys,

    For a guy who builds things for a living and as a hobby, these are real close to the top of the list as far as fun goes.

    If you know of anyone who might like a set of the boxes or dust covers, I would enjoy building more of them. Afraid that like most things with this hobby, they would not be what I call inexpensive.

    Posts : 491
    Join date : 2012-11-30
    Location : SF Bay CA

    Re: Another convert, M-125 build

    Post by arledgsc on Wed Apr 16, 2014 9:45 am

    Excellent work!

    Posts : 1508
    Join date : 2013-04-01
    Location : Michigan USA

    Re: Another convert, M-125 build

    Post by sKiZo on Thu Apr 24, 2014 3:27 pm

    Simple and elegant ... the bold grain of the wood really sets them off.

    A well deserved old school round of applause!

    Bob Latino

    Posts : 2708
    Join date : 2008-11-26
    Location : Massachusetts

    Re: Another convert, M-125 build

    Post by Bob Latino on Fri Apr 25, 2014 12:38 pm

    Hi John,

    Your amps look great with or without the dust covers .. Can you give any more info on how you made the dust covers for your two amps?


    Posts : 2035
    Join date : 2012-05-23
    Location : Wallace, Idaho


    Post by deepee99 on Fri Apr 25, 2014 12:53 pm

    What they're all saying! Beautiful work.
    In a week or so I'll have some beautiful 2-inch left-over maple butcher block from a kitchen re-do, can't give dimensions yet, but, hmmmm.


    Posts : 10
    Join date : 2013-05-03

    Re: Another convert, M-125 build

    Post by Sadface on Fri Apr 25, 2014 7:47 pm

    Simply tunning!

    Any information you could share on how you made them would be appreciated.

    I really like the look of a bit of wood on my amps and I'd been pondering how to modify the M125 Chassis to accomodate a bit of wood.

    I've been inspired!

    Posts : 221
    Join date : 2009-02-05
    Location : Central New Jersey

    Re: Another convert, M-125 build

    Post by Sal on Mon Apr 28, 2014 10:58 pm

    Excellent work on your M-125's. You have a looking nice setup and a nice view of the lake in your back yard.


    Posts : 14
    Join date : 2014-03-01
    Location : Friday Harbor WA


    Post by 5/35 on Sun Sep 07, 2014 1:12 pm

    Thanks for all your kind comments.
    Sorry it has taken so long to get back here, but work raised its ugly head.

    To catch up on your questions, I was able to fine the Zebrawood in slabs 3/8" thick X 3" wide and 12" long. They mill these for making knife handles. Thickness and width were just right for what I was planning and the length would work. The bottom of the chassis is 1/2" Baltic Birch ply.
    I made all millings on these using nothing but my routers. Using the outside dimensions of the stainless steel I built MDF templates for the inside dimensions of the wood. I then built a test box using 1/2" Baltic Birch so that I could make fine adjustments to pattern or to the setup of a specific router as I have enough routers to have one for each bit I use. A Senco micro pinner (a tiny nail gun) held the templates secure. After that, just judicious use of the routers turned out the pieces. I will say that the toughest part was the relief for the lapped portion of the SS chassis as this was scary close to the inside edge of the mitered corner.

    As far as the plastic dust covers go, I used the tutorial videos on the Tap Plastics web site. I also used MDF templates and a router to cut the plastic to size using very thin double faces tape to hold them in place. The only other thing I did was to build a jig to hold the first side and the top square to one another to start the assembly process. Because the cement used to weld the plastic together is thinner that water, I cut a relief in the jig where the joint between the two pieces of plastic meet. Without this, the cement will climb between your jig and the plastic marring the plastic forever.

    Hope tis helps


    Posts : 1
    Join date : 2015-01-11

    Re: Another convert, M-125 build

    Post by ShadeTreeMech on Sun Jan 11, 2015 10:43 pm

    Beautiful amps, 5/35! I'll bet they sound as good as they look

    Posts : 260
    Join date : 2015-02-09
    Age : 68
    Location : Folsom Pa.

    Re: Another convert, M-125 build

    Post by bluemeanies on Sun Mar 08, 2015 3:26 pm

    I just think that the job you did on those m125's is outstanding. What a class act!!
    Love the added touch of the dust covers.
    You have talent..thanks for sharing.

    Sponsored content

    Re: Another convert, M-125 build

    Post by Sponsored content

      Current date/time is Sat Dec 15, 2018 4:18 am