Use of Bias control upgrade board in non Dynakit amp.
This is for a push pull 6BQ5/ EL84 style amp. If you are not at least a minimally a seasoned hobbyist do not bother! Dynakit will not warranty this being put in a non Dynakit amp! See page 2 of the instruction manual. I will offer only the below, if you cannot “wing it” from this don’t start!
You are solely responsible for the use and outcome of this information.
1.Assemble the PC Board per instructions on page 7.
2.Do steps 29- 32 page 8. Also add Green wire to the G hole.
3.Take covers Off. Find pin #3 of the 4 6BQ5/ EL84 sockets. Remove any and all wiring from this point to ground. The two most common configurations will be all four pins will be wired to a resister to ground and it may be bypassed by a capacitor. This is how the ST 35 and The SCA35 are done. The other style is two will be connected and then go to a resistor to ground and may have a capacitor bypassing it and the other two will have the same configuration. This is how the amp I did the insulation was.
4.The real fun begins. Find a place to mount the board so you can get all 5 wires to where they need to end up. ABCD go to the pin #3’s, AB will be V1&2 put on one channel. CD will be V3&4 other channel. G goes to the power supply ground and do make SURE it is the ground!
5.Go back and double if not triple check everything.
6.Go to page 9. Follow the Bias adjustment steps.
7.You’re done and it works, Yeah!
This is the outline of how I put the Dynakit ST 35-BCU in a receiver I rebuild. It is a SCA (never heard of them either) made in July 1963 when I was a year and a half old.
Good luck.
Tazsmonn
04.16.11
[i][img][/img]
This is for a push pull 6BQ5/ EL84 style amp. If you are not at least a minimally a seasoned hobbyist do not bother! Dynakit will not warranty this being put in a non Dynakit amp! See page 2 of the instruction manual. I will offer only the below, if you cannot “wing it” from this don’t start!
You are solely responsible for the use and outcome of this information.
1.Assemble the PC Board per instructions on page 7.
2.Do steps 29- 32 page 8. Also add Green wire to the G hole.
3.Take covers Off. Find pin #3 of the 4 6BQ5/ EL84 sockets. Remove any and all wiring from this point to ground. The two most common configurations will be all four pins will be wired to a resister to ground and it may be bypassed by a capacitor. This is how the ST 35 and The SCA35 are done. The other style is two will be connected and then go to a resistor to ground and may have a capacitor bypassing it and the other two will have the same configuration. This is how the amp I did the insulation was.
4.The real fun begins. Find a place to mount the board so you can get all 5 wires to where they need to end up. ABCD go to the pin #3’s, AB will be V1&2 put on one channel. CD will be V3&4 other channel. G goes to the power supply ground and do make SURE it is the ground!
5.Go back and double if not triple check everything.
6.Go to page 9. Follow the Bias adjustment steps.
7.You’re done and it works, Yeah!
This is the outline of how I put the Dynakit ST 35-BCU in a receiver I rebuild. It is a SCA (never heard of them either) made in July 1963 when I was a year and a half old.
Good luck.
Tazsmonn
04.16.11
[i][img][/img]
