 |
|
 |
| |
GM-70 Beast
Posted on Friday, August 07 @ 09:39:04 EDT by Shane
I have always wanted to build a big broadcast tube amp. At first I wanted to build an 805 amp but after researching quite and finding out how difficult they are to drive I switched to an 845 design. I tried to get tubes for a while and not wanting to break the bank I settled on the GM-70 as it’s almost the same and way cheaper. Good thing as the first day I got the tubes in the mail I dropped one on the cement floor. If that was an 845 I probably would have cried. I was going to use a Tubelab SE as a driver board with some 45’s through some 10M45’s to the GM-70s but went with a simpler design from Nicholas Chua that uses a choke loaded triode strapped 12GN7A and a fixed bias on the GM-70. I am glad that I did as his DC heater supply for the GM-70 is very good. Since I wanted to do this on a reasonable budget it took me over a year to get the parts together. The output transformers came from Taiwan, the tubes from the Ukraine, plate chokes from Thailand and the main power supply cap from Russia.
Click the picture for the full story.
|
|
 |
|
 |
| |
 | |  | | | Article Rating
Average Score: 0
Votes: 0
| |  | |  |
|
