Know of Any Examples of a True PTP 5F6-A?

[bob p]

I've been thinking that it might be fun to build a 5F6-A using old-school, true PTP wiring techniques. By PTP I mean REAL PTP wiring, with no use of a turret board or an eyelet board. I was just wondering if anyone here has already done this and if so, if there's any on-line documentation of their build. Thanks!

[Enzo]

Nothing cosmic about it. In fact, you could even keep the basic layout of an eyelet board to reduce confusion. Just mount a couple rows of terminal strips down the chassis center, roughly the distance apart of the edge rows of eyelets. Then for places you would have center eyelets, like the PI parts or some plate resistor, mount smaller terminal strips in the center.

COnsidering you will have a hard time getting a resistor to reach from the front panel all the way to a tube socket and maintain anything familair in terms of chasis spacing, you will need component support points like terminal strips anyway.


Radios, TVs, most any electronic equipment was made point to poi9nt for years and years.

A friend of mine and I built a little Champish EL84 amp from scratch one night. Made it point to point simply because it was less hassle than making an eyelet board and fitting it in the little chassis.

[mort]

As silly as it sounds, I've wondered what it might look like to build a P2P tube circuit without a chassis. Just use 14 or 12 solid copper for conductors and to serve as a 'frame' of sorts. It could come out looking like a christmas tree or an amoeba, who knows!

I would have to be pretty damn bored to actually do it though

[loudthud]

Early Sunn amps were point to point. They used terminal strips with many components connected between tube socket pins and the strips. A laced wiring harness connected everything together. Solid state circuitry was used for tremolo and reverb recovery and that was on a PCB. The Model T amps had a 5F6A preamp with a Master Volume and push pull parallel ultralinear output stage.

[bob p]

Radios, TVs, most any electronic equipment was made point to poi9nt for years and years.

That's the point of doing an old-school amp build. I want to avoid an eyelet board type of layout altogether, because it doesn't take much creativity to solder up passive components in a line and run jumper wires to them. I'm thinking about an old-school build, with direct connections and 3-D features like an elevated ground bus wire running beneath the tube sockets.

My interest in asking if anyone else here had done it wasn't to help me figure out HOW to do it -- I just wanted to know if anyone here still bothers to do it the old fashioned way and could show off some pictures of their work. Like you said, if you're not already set up for it, it can take too much time and effort to put together the mechanical stuff to build a pancake board with turrets or eyelets. And when you're done doing that, you end up with an amp that looks like six million other cookbooked kit amps out there.

If anyone reading this still bothers to build there amps the old-school way, please feel free to post some pictures or links that show off your work!

[Bruce / Mission Amps]

... I want to avoid an eyelet board type of layout altogether, because it doesn't take much creativity to solder up passive components in a line and run jumper wires to them. I'm thinking about an old-school build, with direct connections and 3-D features like an elevated ground bus wire running beneath the tube sockets.

I resent that!
LOL.
It takes a whole hell of a lot of creativity to design an eyelet board from scratch!!
True PTP looks helter skelter to me...

[Enzo]

Seriously true. That is part of why I suggested your terminal strips in a layout similar to eyelet boards. The layout is already figured, and IT WORKS, it is systematic and easy to locate parts, easier to troubleshoot.

[Tom Phillips]

...My interest in asking if anyone else here had done it wasn't to help me figure out HOW to do it -- I just wanted to know if anyone here still bothers to do it the old fashioned way and could show off some pictures of their work....

I’ve done it. I happen to like building true point-to-point. I don’t preach to others trying to convince them to do it and I know that it’s not practical for production. But building point-to-point is satisfying to me as an art form and to create circuitry that doesn’t have “features” such as hidden connections under the parts board.

I don’t have photos of my scratch built amps from yesteryear but attached is a photo sequence showing the gut & new circuit installation in an old chassis. The donor amp was a Gibson Atlas bass amp head that was abandoned at a local music store and then given to me instead of being tossed in the dumpster. The cabinet had lots of white paint over spray on it when I brought it home. I neglected to get a before photo of the cab but the before photo of the chassis gives a good indication of the overall condition as received.

Cheers,
Tom

[R.G.]

I don't know of any examples, but it's not that hard to do from scratch. It's kind of an exercise in paper dollies.

Place your tubes in a drawing of the chassis. Full size is best. Make some computer drawings of the parts you'll use, full size. Start placing parts, putting the things that connect directly to a tube closest to the socket. Ideally, each tube socket will look like a star with parts radially from each pin. Once each tube has all the parts around it, add the parts from tube to tube. Now start fudging the radial-ity to meet imaginary terminal strips of unlimited size, as small or large as needed. Worry about power second to last and ground last. Once you've solved the inevitable practical placement problems and non-planarity (which is much easier in 3-space than on a PCB) start running imaginary wires where needed.

It's a special case - and a less restrictive case - of circuit layout like is done for PCBs.

[leydenjar]

Find a gutshot of a Carr amplifier for a good example of true ptp.

Nice amps.

[MWJB]

I've used a pair of terminal strips & mounted tone caps & slope resistor to pots...it's faster to layout & build than an eyelet board, but as Bruce says, doesn't have the visual appeal. Fender most likely used eyelet boards so the amps could be assembled modular style.

[MWJB]

Google "Vero Gotham amp circuit" and some gut shots pop up...not necessarily the way I'd do it, but just goes to show...