Radiocraftsmen RC-2

[s-petersen]

I don't think it matters with the orientation of the power transformers relative to each other,everything is in phase,or out 180, not sure about the chokes relative to the PT's

 

[Edo]

I don't think it matters with the orientation of the power transformers relative to each other,everything is in phase,or out 180, not sure about the chokes relative to the PT's

Thanks for your input.

 

[Edo]

These are pictures of my layout of the components on the chassis for my new Amp.
I ask again, does any one have any advise, good or bad? Please let me know.
Notice the orientation of the PT's in the two pictures. Which way is correct?
If you see any bad ideas in the layout let me know your ideas.
I would like too get it right before I start punching holes.
Thank you before hand for your comments.

 

[Tom Bavis]

Upper one. Power transformers won't interact - might as well have them parallel. OPTs should be at right angles to PTs. If you use chokes, orientation won't matter unless it's choke input. In that case, be sure they're at right angles to OPTs (won't couple with PT, so OK to be parallel).

Keep in mind that the axis of COIL is what matters, not the core. In top pic, PTs have axis across the chassis, OPTs have axis lengthwise. Many chokes have axis vertical.

Keep AC away from inputs, especially high voltage AC.

 

[Edo]

Upper one. Power transformers won't interact - might as well have them parallel. OPTs should be at right angles to PTs. If you use chokes, orientation won't matter unless it's choke input. In that case, be sure they're at right angles to OPTs (won't couple with PT, so OK to be parallel).

Keep in mind that the axis of COIL is what matters, not the core. In top pic, PTs have axis across the chassis, OPTs have axis lengthwise. Many chokes have axis vertical.

Keep AC away from inputs, especially high voltage AC.

Thanks for your input. It's kind of hard to keep the high voltage away from inputs. I know that is the way it should be but I have too get it to the OPT's.
I usually run the HV down the center and the filament down the side rails of the inner chassis.
I am going to use DC for the filaments this time. This Amp is in process. No holes drilled yet.
The small shields are for 12AX7's if I use them for tone control or 12AU7's for first pre-amp instead of 6J5's.
Last time I built this Amp. it was in 1956, I was 14 years old. Believe it or not, it worked and sounded good for the time period.
Thanks again for your input.

 

[Selmerdave]

Thanks for your input. It's kind of hard to keep the high voltage away from inputs. I know that is the way it should be but I have too get it to the OPT's.

I don't think you want AC in the OPTs...

 

[Edo]

I don't think you want AC in the OPTs...

No AC to OPT's. (HV) High Voltage DC is what I am talking about.
The 120 VAC will be below the PT's in the under side of the chassis away from the tubes as far as I can get it.
If I am not using the right terminology please let me know. You guys call them bulbs I always called them tubes. Also transformers = Iron.
I will try to learn the slang you guys use. I am not being sarcastic, I am new to this BB so please bear with me.
I made the first hole today for the power plug socket and it fit. So far so good.

 

[Selmerdave]

That's cool, I just mentioned it because his comment was about AC. HV on the plates of the tubes should not be an issue.

 

[Edo]

Thanks for your input.

 

[BillWojo]

Nice job on the chassis work. Going to look nice when it's finished. Keep us posted on the build as it progresses.

BillWojo

 

[Edo]

Nice job on the chassis work. Going to look nice when it's finished. Keep us posted on the build as it progresses.

BillWojo

Thanks. Now comes the socket orientation and wiring. Waiting on 6 volt DC regulators for the filaments. I wanted PTP wiring but some of the Amps I see on the Net use turret boards and they sure look nice. Still trying to decide.

 

[knockbill]

Any of your comments will be greatly appreciated.

How about something like this? short leads are pretty quiet...
Good luck with your build...

 

[Edo]

On my way. I messed up one tube socket location by about 3/16 of an inch. Pissed me off. Too late to start over.
Also I wish now that I had put two fuse holders beside the power plug instead of one. The list goes on and on.
I also wish that I had room for the Chokes. There is no room on top and they are too large to be mounted under side of the chassis.
Guess I am getting too old to think that far ahead. It has been over 60 years since my last build.
Also I haven't made up my mind if i'm going to use a 12AU7 instead of the 6J5 or just by-pass the 6J5 altogether.
I want to add tone control, volume and presence controls to this Amp. Not sure just how to do this MOD.
Anyone have some ideas?

 

[s-petersen]

I don't see it from here,it looks fine without measuring.I would build a separate preamp, it reduces complexity,and takes 20 watts less from the power supply

 

[Edo]

6 VDC un-populated regulators came today. Put them together today and will test them tomorrow. O where o where do I mount them?
Running out of places to put stuff and haven't even installed any of the caps or resistors yet.
Nothing better too do on this rainy week-end.
Have a good day everyone.

 

[Edo]

I don't see it from here,it looks fine without measuring.I would build a separate preamp, it reduces complexity,and takes 20 watts less from the power supply

I am working on ideas for preamp. I really want everything in one chassis, I know it's not a good idea.
My hands shake and it is hard too hold the iron steady, takes both hands. I will put up some more pictures of my progress in a couple days and don't make fun of my work.

 

[Edo]

Upper one. Power transformers won't interact - might as well have them parallel. OPTs should be at right angles to PTs. If you use chokes, orientation won't matter unless it's choke input. In that case, be sure they're at right angles to OPTs (won't couple with PT, so OK to be parallel).

Keep in mind that the axis of COIL is what matters, not the core. In top pic, PTs have axis across the chassis, OPTs have axis lengthwise. Many chokes have axis vertical.

Keep AC away from inputs, especially high voltage AC.

Sorry about the large pictures. I don't know how to delete them.

 

[s-petersen]

Sorry about the large pictures. I don't know how to delete them.

The pictures are fine.

On my way. I messed up one tube socket location by about 3/16 of an inch. Pissed me off. Too late to start over.
Also I wish now that I had put two fuse holders beside the power plug instead of one. The list goes on and on.

2 years ago I built my first scratch builds, I made many mistakes, I have started on my 3rd now,they get better each time.

 

[Edo]

I have a question. Where is the best place to tie in a solid state tone and volume control board to a tube amp?
Also, how do I isolate the solid state circuit from the higher tube voltages?
I have never cross bred circuits before so I need some ideas please.

 

[Selmerdave]

I would think near the input jacks would be good.

Voltages should not be an issue as there will be no dc voltage at the grid of the input tube which is presumably where it will connect to the amp circuit.