50s Stancor - Anyone have any info on these amps?

[MCK]

Super. Thanks for the clarifications. This makes it cleaner.

[MCK]

Layout created using JSchem. Attaching it here in both native format and pdf format. Would appreciate it if you can have a quick look at the layout. Just to educate myself I built it from ground up but will check against original 5B3 layout in the morning to see how close or far I ended up. Obviously the big difference is that I don't have the filter caps on board but will be using a multi-section cap can off board and will mount the dropping resistors right on to it. Thanks for all your help.

[MCK]

Any comments on my layout would be most appreciated. I tried to make the schematics work on the board layout but given this is my first time I am sure I made a mistake somewhere. Thanks much for all your help.

[Cliff Schecht]

Yeah I have a few critiques. I'll post pictures of my amp and point out what you should move. For starters move the pin 6 ground on V1 to the same spot as R6's ground. Also take the 1.5k resistors off of the board and put them directly on power tube sockets.

Been meaning to do that, sorry I haven't gotten around to it yet!

[MCK]

Thank you so very much!!! This is great guidance already. Will look forward to your photos. Sorry to hassle you like this. Your help is most most most appreciated. Thanks!

[MCK]

Made the adjustments you mentioned already. Will update once you have a chance to give me more input and share your photos. No pressure. I'm waiting on my parts anyways. No rush at all. Thanks once again.

[MCK]

Hi Cliff, you asked me to bug you so here it is... Hope your vacation is going good. Your further input on my layout and photos from your build will be most appreciated. Thank you

[Cliff Schecht]

If you have room in your chassis and small enough capacitors you might outta just mount the HV electrolytics and 10k dropping resistors on the board as well. I do this in all of my Fender builds as opposed to shoving caps in a doghouse (I'm not a fan at all of those things!). I mount everything on a single board and run the HV wires to the preamp nodes on the bottom side of the board (like how KF does it in an Express).

Follow the grounds in my build. There is one coming from under the board by the PSU caps that is the OT ground. Notice that I'm not relying on the chassis to carry any actual ground currents, it's sole purpose is to shield the circuit from external interference and provide a connection between the circuit and earth ground. All of the ground connect as directly as possible to the "-" side of the electrolytic caps. Since this is where ground currents eventually end up anyways, I like to make sure they get to where they are going quickly.

Please feel free to ask whatever questions you have. I'll leave the chassis out of the box if you need more detailed pics anywhere.

[Cliff Schecht]

Also notice the layout of the tubes, transformers and board overall. V1 is as far away from the PT as I can get it and the heater wires are as far away from the signal wires as I could get them. On a chassis like this I mount the power transformer right by the power switch at the front of the chassis, again like how KF did in Trainwrecks. Usually I have my output transformer right up against the PT as well but in this case the holes that were already in the chassis dictated this build. Since you have the same style of chassis I suspect a similar layout will get you similar results.

I don't know if I mentioned it but I flipped the chassis 180 so that the front of the original amp became the back of my 5B3 (notice the old labels I left on). With the faceplate on nobody will ever know and this way I got to build the amp using a more traditional Fender layout which has been proven successful a million times. I'm not trying to reinvent the wheel with my layout but I do like to follow what I know to be good design practice for any analog circuit, tube or otherwise.

[MCK]

Cliff, thanks so much. This is great info. I will go through your photos and update my drawings accordingly. Your help is most appreciated.

[MCK]

Ok. It just dawned on me... Counting the tubes over and over and turning up one short... You've gone SS rectification on this build eh. I'll stick with the 5Y3 thats in there already for the time being.

Also noted your reuse / recycle for some components. Great going there. I will try to salvage as much as possible from the old builds too. Lets see where it goes. Thanks once again.