Spud + DAB module: what valve & PS?
16 Dec 2017 13:54 #2566
As a winter project I'm looking to build a simple, single channel amp - used to amplify the output of a DAB module. Basically replacing the Pure DAB radio in the kitchen.
Keen to get opinions from the experts here on valve & transformer choice.
Some design thoughts:
valve(s) should be obtainable in UK / EU (I'm scarred trying to get 6JN6s for my DCPP...)
will drive a small (4-6in) speaker so fidelity isn't, in reality, a concern (but it's still nice to tinker and make it 'good' up to the speaker)
DAB module requires 6-24V DC (150mA @ 12V DC)
keep things small (ie, suitable for the kitchen)
I had thought a PCL82 or PCL86 as I could use the same DC supply for heaters and DAB. Basically a noval spud.
As for power supplies, initially, after searching around, I thought I could use a laptop PSU to give 19V @ 3A in to a cheap eBay SMPS for B+. I could also use the same 19V via a buck convertor for the heaters & DAB. Alas, I see this may be an awful thing to do noise/interference-wise.
So, nixing that idea, how would one easily generate a suitable B+ and the necessary DC? And for what valve?
I've had a go at knocking together a schematic below based on previous designs referenced here. This assumes a SMPS and a PCL86. I've added a CCS lifted from Merlin's book for the driver triode (just because I'd like to try it) and put a placeholder for OT to driver cathode NFB. I need to review the power supply situation.
I'll look in to getting a small PCB made and, if things go well, make a stereo version for the office!
I hope someone can help.
I didn't find the right solution from the Internet.