Friday, June 22, 2012

Raffle amp is almost complete -- Drawing soon!

Hey everyone!  I know it has been quiet here, but this almost always means that I have been busy amp building instead of blogging.  Just to update everyone, on 3 June, I ran the San Diego half-marathon with the Leukemia and Lymphoma Society's "Team in Training".  Although I ended up dropping down from my originally planned full marathon to the half, and I didn't set any speed records this time, I'm proud to say that this was the sixth event I have completed with Team in Training as either a participant or as a fundraising mentor.  With over 2500 Team in Training participants at San Diego, it was a great experience, and at this one event alone the LLS raised over $7.3 million for cancer research.  To those of you that have donated, thank you very much -- you are making a real difference.   For those of you that have not yet donated and wish to get in on the amplifier raffle, the fundraising page is here.  Remember, each $25 donated counts as a ticket in the amp raffle!

Team Wombat celebrates! When anyone asks I tell them, "Yes, I *did* win, thank you for asking!"

So the run is over, and the fundraising will also soon be coming to an end.  With only a couple of days left before the amplifier raffle (the raffle is happening on this Sunday 24 June!), I wanted to post a few more more build pictures before the amplifier is totally completed.  Right now, virtually everything is done, except for tweaking the final wiring of the sockets and the pots, which I should be able to knock off on Saturday morning.  After that, we'll be ready for first fire-up and final tweaking.

The guts, awaiting final harnessing up.

Close-up of the solid-state tremolo board.  It's a good illustration of the hybrid turret and PCB approach I tried out for the first time with this amp.   The board with the green capacitors is actually a hand-fabricated PCB, while the surrounding main board is traditional turret board construction.  So far, I'm pretty happy with how this worked out.

Close up of the main board.  The TO-220 packages visible in the foreground are the ultra-low noise "Stealth" rectifier, and the STF3NK80Z MOSFET that at the heart of the capacitor multiplier on the screen supply.

Something else that I've tried that's slightly unusual on this amp is to have a dedicated turret board for all of the power tube associated circuitry. I got tired of the screen grid resistors vibrating around, and it just made sense for this layout.

No comments:

Post a Comment