Subcaster layout?

[cpnyc23]

Hi there

Anybody out there create a SubCaster layout which they would like to share?

Many thanks!!

-chris

[frequencycentral]

I can put you one together if you want. Perf or vero? Perf is better. There are simpler ways to power the heater than using the LM317 circuit. An 18 ohm / 3 watt resistor for example. Also, the 6111 is an unusual size component, so the layout very much depends on how you're going to mount it in the enclosure. I do it like this:



That's my Vintage Vibe, not a Subcaster, but the same size tube(s).

[cpnyc23]

Hi Rick

Thanks for the offer!  I use perf as my preferred method...  I would also be laying the tube on its side.

I've breadboarded the schem using the LM317T.  The heatsink is a little silly and large but I don't know where to find the 3W resistors.  All I found at Mouser was this: 

http://tinyurl.com/anxv9p

This 20 ohms so I know the voltage will be off a bit but it is within the 10% variable inherent in the resistor's composition.  Will this work?

Anyway, I think for now, the LM317T is what I'm looking to do...

Thanks!!
-chris

[frequencycentral]

Ok, I'll do you a layout similar to the one above and using a LM317 in place of the second tube. You should be able to get a heatsink about the size of the one on the LM317 in this photo. The resistor you linked to should be fine though.

[cpnyc23]

Awesome - thank you!   That is the style of heatsink that I have on the breadboard as well...

Thanks for the info on the resistors - I'll be adding them to my cart!

-chris

[frequencycentral]

Here you go:



This should fit in an enclosure as above, assuming your heatsink isn't HUGE.

I've numbered the parts as per the Subcaster schematic. There is no R3.

I find it best to solder the submini rather than use a socket.

I never got on with the LM317 part of the circuit. I find it a waste of space and unneccesarily complex when just a single resistor will do the same job.

You should just check it against the schematic - make sure I haven't made any mistakes!


EDIT: And you should put vents in the enclosure, both the LM317 and 6111 get pretty hot!

[cpnyc23]

That was crazy fast!!!  thank you!!!  Hopefully I'll be able to verify it tonight.

thanks again - much appreciated!

-chris

[frequencycentral]

That was crazy fast!!!  thank you!!!  Hopefully I'll be able to verify it tonight.

thanks again - much appreciated!

-chris

Yup - I'm getting the hang of electronics now!

Do me a favour and let me know if/when you verify the layout, then I'll put it in my gallery and in the 'Tube boost + overdrive running off a 9 volt battery' thread for others to use.

By the way, when I made my Subcaster, I had no end of trouble getting it to work. I ended up removing R1 and C2 to get it working. I've since taken it apart, as it ended up being a mess. I re-used the (desoldered) tube in my Vibracaster, with two 10 ohm / 3 watt resistors in series with the heater instead of the LM317.

[cpnyc23]

I will - if I don't finish it tonight, it will take me until next week (I'll be out of town for a few days).  I'll make sure to let you know however.

Thanks again - I really appreciate it!

-chris

[Ripthorn]

mouser has all kinds of small-bodied 3W resistors, I am ordering several for a tube project I am doing as well.

[cpnyc23]

Brian - could you possibly pass along a part # or 2?  Maybe my search parameters were wrong...

-chris

[frequencycentral]

I spotted a mistake in the layout, so here it is again, but corrected: