+9
Dave_in_Va
10-E-C
pedrocols
IEales
baddog1946
KenGaler
audiobill
Bob Latino
Dale Stevens
13 posters
M-125 Build
Dave_in_Va- Posts : 446
Join date : 2013-04-02
Location : Mid. VA
KenGaler- Posts : 76
Join date : 2019-10-11
Thank you
KenGaler- Posts : 76
Join date : 2019-10-11
Button head screws softened it up.
KenGaler- Posts : 76
Join date : 2019-10-11
AC Controller
audiobill- Posts : 425
Join date : 2014-03-13
Location : Albany, NY
Very cool!
KenGaler- Posts : 76
Join date : 2019-10-11
Between the two amps and the AC unit there are a total of 18 parts that need to be machined. Most need machining on 2-4 sides. The first quote I received using 304 SS was just under $6K. AL was only about $500 less. GASP!
I got lucky and a friend of a friend has a CNC in his garage. He quoted $2100 for AL. So, I'm going with that.
Ken
I got lucky and a friend of a friend has a CNC in his garage. He quoted $2100 for AL. So, I'm going with that.
Ken
KenGaler- Posts : 76
Join date : 2019-10-11
PCBs came in
avi.inc- Posts : 62
Join date : 2009-08-03
Age : 71
Location : L.A.
KenGaler- Posts : 76
Join date : 2019-10-11
I do like them and may wind up changing to them. Thanks
Dahlberg- Posts : 132
Join date : 2016-09-27
Age : 63
Location : Sweden
I used the Neutrik STX series for a project, they are really nice 
KenGaler- Posts : 76
Join date : 2019-10-11
Some electronics porn, PCBs stuffed. Waiting for cleaner to come in so a bit dirty. I added 3D printed mounts on the pre-amp PCB to keep the caps from moving too much.
Dahlberg- Posts : 132
Join date : 2016-09-27
Age : 63
Location : Sweden
Looks nice 
I'm guessing you are skipping the "supplementary cap module", but what's R2 for ?
I'm guessing you are skipping the "supplementary cap module", but what's R2 for ?
KenGaler- Posts : 76
Join date : 2019-10-11
Dahlberg wrote:Looks nice
Yeah, I replaced the cap module and the chassis cap. R2 is just a 500K bleeder, about 1/2w.
KenGaler- Posts : 76
Join date : 2019-10-11
I'm in a bit of a pickle. I have the transformers ready for painting but nowhere warm enough to paint them. Can't inside because it's toxic, the garage is too cold even in NC. ERG! Maybe I can use a couple space heaters in the garage.
Dahlberg- Posts : 132
Join date : 2016-09-27
Age : 63
Location : Sweden
A couple of halogen flood lights gets pretty hot. Don't know if anyone sells them anymore though, it's all LED now so....
Your project is inspiring and it gave me some new ideas now that I've decided to keep the amps so , thanks
Your project is inspiring and it gave me some new ideas now that I've decided to keep the amps so , thanks
KenGaler- Posts : 76
Join date : 2019-10-11
Dahlberg wrote:A couple of halogen flood lights gets pretty hot. Don't know if anyone sells them anymore though, it's all LED now so....
Good thought, I'll run down to home depot and see what they have.
Your project is inspiring and it gave me some new ideas now that I've decided to keep the amps so , thanks
I wish I thought to add VU meters.
audiobill- Posts : 425
Join date : 2014-03-13
Location : Albany, NY
In the winter, I've sprayed warm transformers in the cold garage, then brought inside to dry.
Repeat for 2-3 coats.
Repeat for 2-3 coats.
KenGaler- Posts : 76
Join date : 2019-10-11
I wound up having a freak warm day and got the trannys painted. Also, I got the machined parts in. I cleaned them up, sanded and then used Scotch Brite and WD-40 to brush them. They're presently at the plating co getting a Chromate Clear. I should have them tomorrow or Monday.
Finally, the most fun part is about here, the wiring. :-)
Finally, the most fun part is about here, the wiring. :-)
KenGaler- Posts : 76
Join date : 2019-10-11
The machined parts are back. Pics of the AC Control Unit.
KenGaler- Posts : 76
Join date : 2019-10-11
Finally ready for wiring but I really need to work on customers projects for a bit before they dis-own me. This project is addictive.
KenGaler- Posts : 76
Join date : 2019-10-11
Because I made so many mods I really can't use Bob's excellent wiring instructions. I'll wire both amps at the same time, in layers starting with the most unlikely-to-be-changed parts first such as filaments, Bias meter, fan, primary, output.. then work my way up to the signal lines. I'll yellow line the schematic as I go.
Dahlberg- Posts : 132
Join date : 2016-09-27
Age : 63
Location : Sweden
Beautiful work so far 
The TDK/Epcos caps needs a couple of days to settle, say 50-100h or so. I replaced the "two cap arrangement" for two of these instead (600v/220uf) and it worked out just fine.
The TDK/Epcos caps needs a couple of days to settle, say 50-100h or so. I replaced the "two cap arrangement" for two of these instead (600v/220uf) and it worked out just fine.
KenGaler- Posts : 76
Join date : 2019-10-11
Dahlberg wrote:Beautiful work so far
Thank you
KenGaler- Posts : 76
Join date : 2019-10-11
All nets except the signal lines.
KenGaler- Posts : 76
Join date : 2019-10-11
All wired!
Made some changes.
- The retro cloth wire is nice but doesn't work for the heater wiring. Too bulky.
- I'm not planning on ever using a tube rectifier so I removed the white heater wires and terminated.
- After a lot of thought and talks with a couple audio mentors I removed the audio GND from the chassis and tied it to Chassis GND via a 10 ohm resistor. (See section 9 here https://sound-au.com/earthing.htm#s6 )
Made some changes.
- The retro cloth wire is nice but doesn't work for the heater wiring. Too bulky.
- I'm not planning on ever using a tube rectifier so I removed the white heater wires and terminated.
- After a lot of thought and talks with a couple audio mentors I removed the audio GND from the chassis and tied it to Chassis GND via a 10 ohm resistor. (See section 9 here https://sound-au.com/earthing.htm#s6 )