martin manning wrote:When I've tried doing larger, thicker boards I found it difficult to get good adhesion of the toner to the copper, and I believe it is due to the increased thermal mass of the board. I thought it might be a good idea to pre-heat the board to 200-250F before attempting to make the transfer.
EDIT: I'm looking back through this thread and updating stuff. That press is nice for flatting prints but not enough PSI for a good toner transfer. It gave enough toner transfer that I could color in the rest with the Sharpie pen but I'd not want to do a bunch of boards that way. Doing this one board was very tedious.
Last edited by ic-racer on Thu Jan 17, 2013 8:37 am, edited 1 time in total.
"You feel like you're floating on a football field filled with marshmallows." -Dumble
It is starting to take shape. Test fit of the capacitors. I'll need only 1/4" standoff on the board mounting to the chassis so that the capacitors fit.
Anyone building this in the future, make note of the reversed polarity of the one capacitor. That is not the bias cap. That capacitor is flipped 180 degrees by Dumble so the underlying traces will work out.
bcook wrote:You were able to discern this from that one picture? Awesome is right!
I did a pretty intensive analysis. At one point I even did a forensic ELA analysis to see if the image had been tampered. I had convinced myself that someone had smeared the PC board image with the smear tool in photoshop. However that bright area near the PC board is actually a reflection of the shiny chassis, and not evidence of image tampering.
I ordered most of the parts today.
Due to the thickness of the chassis, 0.375 inch threads are needed on the Pots and phone jacks. Although CTS makes pots with 0.375" long bushings (the 450T3 series) good luck trying to find one. I could not.
So, I went with Bourns pots. Seems most of them come standard with 0.357" length threads anyway.
In terms of Switchcraft phone jacks, the L12A has the long 0.375" bushing, so I went with that one.
No need for a FET switching jack on this amp
"You feel like you're floating on a football field filled with marshmallows." -Dumble
The 2k Presence pot with 0.375 threaded shaft was a little problematic. Honeywell makes one and it is a little different than the others. The picture of the real Manzamp suggests Dumble may have also gone with a Honeywell in that position:
M Fowler wrote:I use CTS pots made for Mojotone they are .375 and work well with the Alpha pots made for Mojotone .375 and Burns from Apexjr which are .375.
They are the only pots I use. Otherwise I would get 1w RV4 PEC pots.