Hiya, have you lit the amp up yet? I am so curious to find out if you have listened to her yet?
Ah well back to the bench and a very csick Citation 15 tuner.
S
Ah well back to the bench and a very csick Citation 15 tuner.
S
Hi Shawn,
That's looking like a nice neat job. Way to go dude! (in the best possible way). 😉
-Chris
That's looking like a nice neat job. Way to go dude! (in the best possible way). 😉
-Chris
Raise your glass...
it works! 😀 It's alive and playing music. I dialed it up on the variac with a 1/2 amp fuse in it and started tweaking the potentiometers to adjust the bias settings, which I don't really have a guide for but I used the values on the schematic for reference.
It sounds fantastic. There is nothing wrong with the sound but I will not be able to give any true assessment until I listen to it in a proper set up. More on that later as I still have some serious measuring and adjustments to make.
Everything worked on the first try and I can't believe it! 🙂 I'm missing the ceramic OpAmp, the large filter caps and two decent volume controls. The heat shields that were made were too short but I will have new ones early this week. The front plate is waiting for me to find a small firm that will polish it and anodize it gold tint. The labels and decals will be replaced as well.
DC300A Revisited:
it works! 😀 It's alive and playing music. I dialed it up on the variac with a 1/2 amp fuse in it and started tweaking the potentiometers to adjust the bias settings, which I don't really have a guide for but I used the values on the schematic for reference.
It sounds fantastic. There is nothing wrong with the sound but I will not be able to give any true assessment until I listen to it in a proper set up. More on that later as I still have some serious measuring and adjustments to make.
Everything worked on the first try and I can't believe it! 🙂 I'm missing the ceramic OpAmp, the large filter caps and two decent volume controls. The heat shields that were made were too short but I will have new ones early this week. The front plate is waiting for me to find a small firm that will polish it and anodize it gold tint. The labels and decals will be replaced as well.
DC300A Revisited:
Attachments
Rectifier
The 50 amp Bridge has a new location under the driver plate. It can sink some of its heat, if it has any, into the metal.
I'm a happy dude. I think I'll have a smoke and a beer right now. I have to go find Van Halen Women & Children First...
The 50 amp Bridge has a new location under the driver plate. It can sink some of its heat, if it has any, into the metal.
I'm a happy dude. I think I'll have a smoke and a beer right now. I have to go find Van Halen Women & Children First...

Attachments
I'm gonna vote you DIY'er of the year. Unbelievable (again). Well done.
Raise my glass....for sure...where's that bottle opener....
Cheers
Q
Raise my glass....for sure...where's that bottle opener....
Cheers
Q
WELL DONE Shawn! I think these old Crowns sound remarkable too!
Now if I could only get the notes I have taken from this thread I will try to completely rebuild a couple of my old Mark one DC 300 a's!!!!!
Dont forget to swithch your dvm off!
S
Now if I could only get the notes I have taken from this thread I will try to completely rebuild a couple of my old Mark one DC 300 a's!!!!!
Dont forget to swithch your dvm off!
S
more pics
misc. pic
I need to spray it down to remove the flux generated by soldering the thing together. You can see little specs of it eveywhere and it bothers me.
You guys posted at the same time it started running?
Shawn.
DIY'er of the Year? Good times! 😀
misc. pic
I need to spray it down to remove the flux generated by soldering the thing together. You can see little specs of it eveywhere and it bothers me.

You guys posted at the same time it started running?
Shawn.
DIY'er of the Year? Good times! 😀
Attachments
Hey Shawn, how about another pic. One from 73.2619 deg from perpendicular would be great .....
LOL
Q

LOL
Q
quasi said:Raise my glass....for sure...where's that bottle opener....
Cheers
Q
I have back ups if you so require? 😉
stewartwen said:WELL DONE Shawn! I think these old Crowns sound remarkable too!
Now if I could only get the notes I have taken from this thread I will try to completely rebuild a couple of my old Mark one DC 300 a's!!!!!
Dont forget to swithch your dvm off!
S
I have to build a web page (ugh) to document this gig. It is a special job and I would like more people to see it. DVM, is now off, thanks for pointing that out. 🙂
rdf said:Congrats! Great work, and great to see the old beast rise again.
The Beast it back for another 30 years plus!!! I am very happy I am able to share this wacky project with you all. I guess this too is by a fanatic for the fanatics ! Who else would do these things? 😀
Thank You,
Shawn.
...
This is the only request I'm taking but ok, here you go: 73.2625 not exact but close, yes? 😀
quasi said:Hey Shawn, how about another pic. One from 73.2619 deg from perpendicular would be great .....![]()
LOL
Q
This is the only request I'm taking but ok, here you go: 73.2625 not exact but close, yes? 😀
Attachments
- Home
- Amplifiers
- Solid State
- Resurrecting a Crown DC300A