Calculating PSU load

[DortoH]

I am in the powersuppy design stage for a 6V6 based SET

You can see a rough idea of what I am doing in this schematic. Ignore the part list and specifications, none of it was calculated, I am just using this topology and copied the schematic.

http://dortoh.ca/crap/simpleset.jpg

This is the PSU I have got so far:

http://dortoh.ca/crap/simpleset.psu

I am using PSUD2 to design a power supply and am stuck with calculating the load that will bw drawn. The input will be handled by a single 6SN7 and the output will have a 6V6 on each channel for 3 tubes in total.

180V for the 6SN7 and 250V for the 6V6's.

Anyone have any pointers?

[Shannon Parks]

Looking at the original datasheets give some valuable insights into operating points. Go to Duncan's website, choose a tube and then go to the bottom for datasheet links. Usually Uncle Ned has the classic RCA-style multiple page gifs. This schematic in particular looks like the datasheet 'Class A Amplifier' specs would be very close.

Schematics with all the voltages listed (like the Sam's schematics), really enable backward engineering.

Lastly, Tube Cad from Glassware is a fantastic tool for tweaking that 6SN7 stage. Gives you a good feel for the tubes operating points.

I'd swag 4mA for the 6SN7 and 50mA for the 6V6. That looks like a nice little Fender Champ clone.

Shannon

[DortoH]

OK so according to the datasheets I get 49mA for each 6V6 and 4mA for the 6SN7 totaling 102mA.

In PSUD2 I would take out the 5K load an change it to a constant current load of 102mA? That makes sense, sometimes the simple answer right in front of you is the one you are looking for :)

Now seeing as I am taking two different B+ 250V and 180V, should i simulate it with a 98mA load, then the dropping resistor and a 4mA load on the end, or can I just put the whole load at the end of the chain in the simulation?

I sure wish PSUD2 had ACTIVE forums :) but I do appreciate the help and advice. :D

[Shannon Parks]

Now seeing as I am taking two different B+ 250V and 180V, should i simulate it with a 98mA load, then the dropping resistor and a 4mA load on the end, ....

Correct.

Shannon