andyfromdenver
Well-known member
Hi solder-slingers.
Data: using a 115V barely loaded PT for the 6N1P tube Bass DI.
wall voltage ~121VAC
Single tube drawing ~300mA Heater current. *edit: actual stated draw is 600mA +/-*
Plan: rectify 6.3VAC PT secondary (which is actually closer to 7. somethin' V due to see above).
feed 7805 (1A) with two diodes in series from center pin, raising the regulated voltage to obtain 6.4VDC
Questions: if I am using a large uf cap post bridge, do I still need the 0.3uf on the in from the datasheet, and do I need more than the datasheet 0.1uf on the out?
The PT has no heater center tap, if i exclude the chassis ground after the rectifier, will it work but hum?
assuming need, where do you like to ground on tube circuits post rectifier? ground the tube pin and circuit, and just run one wire to the other tube pin? or ground at the circuit to chassis and still run two wires to pins?
Lastly, what would you do to improve this design?
Bonus: need I worry about adding heat dissipation to my 7805 running less than a third of it's rating?
Bonus 2: should I fuse it pre bridge rectifier? 1A sloblo? 500mA sloblo?
Thank you!
Andy
Data: using a 115V barely loaded PT for the 6N1P tube Bass DI.
wall voltage ~121VAC
Single tube drawing ~300mA Heater current. *edit: actual stated draw is 600mA +/-*
Plan: rectify 6.3VAC PT secondary (which is actually closer to 7. somethin' V due to see above).
feed 7805 (1A) with two diodes in series from center pin, raising the regulated voltage to obtain 6.4VDC
Questions: if I am using a large uf cap post bridge, do I still need the 0.3uf on the in from the datasheet, and do I need more than the datasheet 0.1uf on the out?
The PT has no heater center tap, if i exclude the chassis ground after the rectifier, will it work but hum?
assuming need, where do you like to ground on tube circuits post rectifier? ground the tube pin and circuit, and just run one wire to the other tube pin? or ground at the circuit to chassis and still run two wires to pins?
Lastly, what would you do to improve this design?
Bonus: need I worry about adding heat dissipation to my 7805 running less than a third of it's rating?
Bonus 2: should I fuse it pre bridge rectifier? 1A sloblo? 500mA sloblo?
Thank you!
Andy