6.3v indirectly heater valve PCB (possible group buy?)

little eddy · Post by **little eddy** » Tue Apr 17, 2012 9:18 pm

Andrew,

Are you checking numbers once you have finlised the design as I'll probably be up for at least a couple.

Andrew · Post by **Andrew** » Wed Apr 18, 2012 1:10 pm

I'll probably get a 100, should be plenty to go around.

Andrew

Andrew · Post by **Andrew** » Fri Apr 27, 2012 1:39 pm

Andrew wrote:
Nick wrote:Just a thought, I assume pad4 is to ground the centre of the heater supply. Is it worth splitting C4 into two, and taking the centre of the two to the virtual ground? Otherwise there is no low impedance path to ground to AC.
That's not a bad idea! The 'center tap' idea is just gilding a lilly really but if its worth doing, it's worth doing etc....

Although you can always de-couple at the valve pins.

I was going to use the center tap but I wasn't sure who else might.

I'll add it to the list of refinements for the next rev, not sure if that will be the final thing or another prototype. I'll see how this one goes.

Andrew

I'm still debating what to do about these capacitors, its hard to get anything more on the PCB. I am happy to persevere and see if I can fit them on but I wondered, would these caps not be better off placed closer to the valves pins? What does the panel think?

PS first very rough prototype back from my mate and I'm just waiting for an SK129 heatsink which I need to order to try it out. I will post photos when its running.

Andrew

Paul Barker · Post by **Paul Barker** » Fri Apr 27, 2012 4:11 pm

I would be content doing it at the valve pins Andrew if it is easier on real estate.

Andrew · Post by **Andrew** » Fri Apr 27, 2012 4:35 pm

Well, at this point in time, l I do think close to the pins is a better solution electrically, need to do more digging around.

Andrew

Greg · Post by **Greg** » Sat Apr 28, 2012 11:27 pm

Andrew, sorry, late to the thread but I'll also be up for 2 boards in due course and if you were to supply kits, even better

Thanks.

cressy · Post by **cressy** » Sun Apr 29, 2012 1:08 pm

hi andrew, stick me down for 2 boards please, cheers ant

Andrew · Post by **Andrew** » Fri May 11, 2012 5:49 pm

Been bogged down with work and other stuff, but finally here's the prototype PCB up and running. Just need to tweak the voltages a bit.

Andrew

Andrew · Post by **Andrew** » Wed May 23, 2012 10:30 am

Nick wrote:For small runs and prototypes I use

http://www.pcbtrain.co.uk/

For larger quantities

http://www.quick-teck.co.uk/index.php

100 off 50 * 80, 1oz copper, silk screen, £140 + VAT + postage 12 day service.

Hi Nick.

Was that 2 mm thickness you got the quote for?

Andrew

Andrew · Post by **Andrew** » Wed May 23, 2012 8:25 pm

For those interested in me kitting this, its roughly £6 odd for the parts from Farnell. Now, that's without any bulk discount applied, it may get cheaper if I can get the numbers up. That's with the 1.5" inch high heatsink, the 2" high is a few pence dearer but should run cooler. Then you'd need to factor in the cost of the PCB, a jiffy bag and stamps.

Oh and 3 resistors but that won't break the bank, the transformer used is up to you and is not included.

How does that sound?

Andrew

Greg · Post by **Greg** » Wed May 23, 2012 8:52 pm

Andrew, thanks. Sounds very good to me.

davebms · Post by **davebms** » Wed May 23, 2012 10:14 pm

How does that sound?

Andrew[/quote]

sounds fine

dave

Bizzie · Post by **Bizzie** » Wed May 23, 2012 10:42 pm

sounds good to me as well

James · Post by **James** » Thu May 24, 2012 2:21 pm

Sounds good Andrew.

Best Regards,

James

pre65 · Post by **pre65** » Thu May 24, 2012 2:34 pm

Andrew, are the resistors needed standard values, I can check my big box if you give me the values.

audio-talk

6.3v indirectly heater valve PCB (possible group buy?)

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