Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Stuff4bikes on July 19, 2021, 01:52:36 am

Title: My first schematic
Post by: Stuff4bikes on July 19, 2021, 01:52:36 am

Simple one but am I missing anything or any needed changes.....

Title: Re: My first schematic
Post by: Latole on July 19, 2021, 03:46:41 am

No volume.
7868 specs ; https://frank.pocnet.net/sheets/168/7/7868.pdf
 Grid resistor to pin 7 on 7868

Title: Re: My first schematic
Post by: Leevi on July 19, 2021, 03:48:00 am

I would add a grid leak resistor to V1 pin 2.
/Leevi


P.S. sorry there is it I didn't see


/Leevi

Title: Re: My first schematic
Post by: sluckey on July 19, 2021, 04:31:32 am

Bad idea to connect cathodes together on cascaded stages. Need separate resistor/cap for each triode.

Title: Re: My first schematic
Post by: Stuff4bikes on July 19, 2021, 08:27:48 am

Thanks for all your help......trying to move out of my turret board comfort zone and start simple...

Title: Re: My first schematic
Post by: thetragichero on July 19, 2021, 11:38:43 am

i would also suggest a small (1k5? maybe larger if needed) grid stopper resistor connected directly to the power tube socket

Title: Re: My first schematic
Post by: sluckey on July 19, 2021, 11:46:32 am

Schematics are easier to understand/visualize if you draw the individual tube elements, ie, plate, grid/s, cathode, inside the envelope, rather than just putting the pin number on the schematic.