|jrdamien||5/19/2017 11:10 AM|
|Pro Jr. Layout?|
Hey all. I'm looking for a Pro Jr. layout of any kind. I can't seem to find anything online.
|The Dude||5/19/2017 11:33 AM|
|Not trying to be nosy, but isn't this a PC board with circuit board designation numbers? Why would you need a layout? Or, are you looking to build one and want a turret board layout?|
|jrdamien||5/19/2017 12:15 PM|
|mozz||5/19/2017 2:04 PM|
|Did you try hoffman's el34 site?|
|jrdamien||5/19/2017 2:16 PM|
|Enzo||5/19/2017 5:00 PM|
I just entered "Pro Junior Layout" into google, and right there were multiple images, several of which were layouts.
|jrdamien||5/19/2017 5:45 PM|
Give be a link and prove me wrong, please.
|jrdamien||5/19/2017 5:50 PM|
Please provide a link and prove me wrong.
Edit: I do not like this new forum format.
|nosaj||5/19/2017 6:04 PM|
|nosaj||5/19/2017 6:08 PM|
|Jazz P Bass||5/19/2017 6:58 PM|
|Edit: I do not like this new forum format.[/QUOTE]|
What 'New Forum Format'?
|eschertron||5/19/2017 8:41 PM|
Probably the display mode is set to 'threaded'. I think that's default when you log in (and you don't stay logged in).
|Enzo||5/19/2017 8:45 PM|
|Well, you did say a layout of any kind, you didn;t specify a particular variant.|
Yes, the layouts I found were 18 watt Fender Pro Junior at least in title.
How different are the layouts?
|jrdamien||5/19/2017 8:56 PM|
What 'New Forum Format'?
|jrdamien||5/19/2017 8:58 PM|
Those 18 watt Pro Jr layouts are people who build an 18 watt into a Pro Jr chassis using PJ iron. They're not Pro Jr's, though.
|Enzo||5/19/2017 9:11 PM|
But is the phase inverter stage about he same? Fender schematic shows LTP as do the 18watt pix. The push pull output stage ought to be the same or darn close. That leaves the other 12AX7 to program. It is at least a short cut through part of it.
|jrdamien||5/19/2017 9:52 PM|
|nosaj||5/19/2017 10:00 PM|
|Enzo||5/19/2017 10:05 PM|
|OH three four years ago, I'd hop right in and build something. My shop is just a memory, my parts and gear are in a storage unit, and I have no delusions I will ever operate a shop again. My shop work is done vicariously through others these days.|
|jrdamien||5/19/2017 10:07 PM|
If I was good at turning a schematic into a layout I'd just do it. But I am not good at it.
|J M Fahey||5/19/2017 10:15 PM|
Of course you need a layout, you canīt randomly throw a bucketful of parts inside a chassis and solder them where they fall or plain *try* to interconnect them without further thought.
I used to build guitar amps on terminal strips before using eyeletted or printed boards and had to spend a good afternoon or two with pencil, paper and a good eraser to layout what I was about to build.
And if you need to build more than one unit, you need a layout for consistency and repeatability, because "thereīs more than one way to skin a cat".
|Enzo||5/19/2017 10:19 PM|
|The 18 watt schematic shows the input 12AX7 paralleled for one triode effectively. The Fender has two stages in that tube. So it would be a matter of keeping the input stage but using one triode, then adding part board space for the second triode stuff. So the part board would be a little larger.|
|jrdamien||5/19/2017 10:23 PM|
|vintagekiki||5/19/2017 11:30 PM|
|jrdamien||5/20/2017 12:06 AM|
|Enzo||5/20/2017 12:08 AM|
|The fender literature - at least the service manuals - includes layouts, but for the printed circuit board, which doesn;t help you.|
|olddawg||5/20/2017 3:12 AM|
|Every time I see one of these threads I wonder "why" ? I can see maybe doing it if you have a hopelessly buggered board. But to gut a functioning amp just to rebuild it point to point always seems a bit ludicrous to me. Will it really sound different with the same component values, speaker, PT, OT, and tubes? I mean the amp might age better than a board after 20 years... but other than that... what is the advantage?|
|J M Fahey||5/20/2017 7:35 AM|
Only advantage of rebuilding on, say, eyeletted board is ease of modding; eyelets tolerate hundreds of leg/wire removals and resoldering, while PCB pads get destroyed after a few replacements.
In fact, when I build something on eyeletted board I add a few "unused" eyelets on free spaces, they may prove handy later on.
If you have a complex amp replacing its PCB is hopeless and frustrating, ; yet I often recommend junking a PCB on some amps, not to rebuild the same but to junk a buzzy crappy sounding high gain multi mode monstrosity and build instead a simple but killer sounding classic.
It will sound better not because of construction technology but because *the design* is better, as simple as that.
|vintagekiki||5/20/2017 8:14 AM|
Layout is on the next page after schematics.
Fender Pro Junior- A Look "Under the Hood"
|jrdamien||5/20/2017 10:41 AM|
|jrdamien||5/20/2017 10:46 AM|
What you're talking about isn't happening. But I don't know who wouldn't rather have a ptp circuit and discreet components (jacks, sockets, etc) over a pcb. It makes it endlessly easier to work on and to repair.
|Jazz P Bass||5/20/2017 10:52 AM|
|I really think the OP should print this out and present it to his friend.|
The pcb IS the whole amp.
To make it point to point you will need a tag board for at least the power supply.
Add to that you will have to source the tube sockets.
Also the front panel controls are pcb mounted. So they will have to be purchased.
(the pots & the jack)
In the end you will have most of the components swinging in the breeze as you will probably have to use the socket pins for attachment points.
Add to that all of the wire to connect things.
Waste of time is what your friend wants from you.
|jrdamien||5/20/2017 11:05 AM|
I have the schematic. I have the PCB "layout." I was looking for a ptp layout. Why I need it or whether it'd be a waste of time or money was never a question or concern.
Yes, to build an amp from scratch you need to buy all the things needed to build an amp from scratch. That's the whole idea.
|g1||5/20/2017 12:02 PM|
|No offence intended and just to be clear, there was never such an animal in production? Or was there a custom shop PTP version?|
If not, you are looking for someone who has done a conversion, or scratch build of Pro Jr. and is willing to share their layout?
|Justin Thomas||5/20/2017 12:08 PM|
|Okay, maybe I can help. I don't know if the "scale" of the innards - trace spacing, etc. - will allow this. But here's what I did with my Prosonic's rectifier switch board. The switch broke, and so I had to replace it. Being a 12-pin switch, mounted on a tiny PCB, I removed the PCB from the switch, carefully. Yes, traces had come up. I folded them back in place, and it was a double-sided board. |
I took pictures from every angle of that little board. Then I drew a picture of it, to scale, showing where the traces were on both sides. Next, I sanded both sides of the PCB, so that there were no more traces. I drilled out the 12 holes for the switch and put a turret in each. Then I mounted the new switch on the backside of the turrets and soldered the pins in. The switch was mounted on what would have been the underside of a traditional board. On the turret side, I ran the hookup wires as the traces had been.
As far as making a turret board OUT OF a PCB, that would depend on the quality and thickness of the PCB material, and whether or not the traces are widely enough spaced to allow for turrets or eyelets. I don't know if a Pro Junior would allow it, but I could do it with an older Ampeg or Marshall from the 70s. But yes, it is POSSIBLE to make a layout, especially since turrets can have connections on both sides.
That said, I bet that any old late-50s Tweed Fender layout with two preamp & 2 power tubes would be close enough. Yes, you'd absolutely have to adapt your pots, switches, etc. to fit, but the layout itself isn't that hard. And the reason nobody has one MAY be because nobody has had the need to MAKE one. Question: IS THIS A SCRATCH BUILD, as in, you're building a clone, OR are you gutting a perfectly good PJ to cram a PTP circuit in it? If the former, yes, be a pioneer and make a layout from the schematic! Otherwise, don't gut a perfectly good amp until it flames out irreparably.
Just my opinions,
|nosaj||5/20/2017 12:29 PM|
|Jazz P Bass||5/20/2017 12:37 PM|
|The op wants a layout.|
Guess you are on your own.
Edit: please take all posts with a grain of salt.
I do not see any particular post that contained "unsolicited condescension."
More in fact, most are intended (in my mind) as a 'sanity check'.
PtoP from scratch can be a noble, if very time consuming, effort.
In this case, as no actual physical layout exists, the ball is in your court to be the first to post one.
|Justin Thomas||5/20/2017 12:47 PM|
|I think most of the confusion here is whether we are gutting a Fender Pro Junior and putting PTP guts in it, or if we are simply building a CLONE of a PJ in a new cabinet, chassis, etc. The sanity check is, please don't gut a perfectly god amp. Otherwise, yes, pioneer a layout. |
Which then begs the question: are we talking <TRUE> PTP, or what is commonly CALLED "PTP"??? If you are wanting an eyelet or turret board, tyhen I agree - any small Fender tweed or maybe a brown Deluxe layout would help, <IF> you can adapt it to a PJ chassis. Personally, I build true PTP as much as possible, one at a time, in different chassis. As such, no, I do not use layouts. Now, if you are Matchless, yes, a layout CAN be drawn, UPON SUCCESSFUL COMPLETION OF A WORKING AMP. Again, as others have said, you are on your own.
|vintagekiki||5/20/2017 1:59 PM|
With the attached schematic and the layout of the components, with little effort and the corresponding PCB Design Software, PCBs can be designed and manufactured
Another variant is to dismantle the PCB from the amplifier and photocopy it.
|Enzo||5/20/2017 4:24 PM|
|But he has no interest in a pcb, in post #3 he told us, he has a customer who wants him to build a ptp wired Pro Junior. He doesn;t have an existing amp.|
As I read it, he is hoping someone has already done this, and he would like such a person to provide a layout.
|g1||5/20/2017 6:30 PM|
|Thanks for the reminder of the intent Enzo.|
Better searching will be had from looking for 'Pro Junior build'.
Such as these:
Hoffman Pro Jr Turret board
Tweaking my Pro Jr rewire.
Pro Junior Conversions - s2 Audio Technology Photo Gallery - Powered by Phanfare
|J M Fahey||5/20/2017 6:40 PM|
|Just thinking aloud:|
1) just checked the Pro Jr schematic.
Itīs a simple amp, single channel, no FX loops, no reverb, not even a tone stack.
2) Itīs very doable either as true PTP (terminal strips) , eyeletted board or turrets, so choose one and do it.
No, it wonīt be perfect on first try, thatīs why the third design element I suggested was an eraser.
You can reach an acceptable layout in an idle afternoon, then let it rest 1 or 2 days and go over it again, youīll find some details you hadnīt noticed.
Then build it.
If you wish, you may later share it here.
|mozz||5/20/2017 7:31 PM|
|I do these all the time, scratch builds. Just get your board and start building it. I love challenges. I do have a pro junior here i got cheap and eventually it will be built with one of these. Just finished 2 AO-35 Hammonds into a spitfire and carmen ghia and a filmosound build. Just lay it all out through the eyelets before you solder. Ali express has these boards cheap.|
|jrdamien||5/21/2017 9:17 PM|
|Worked out today over at el34. |
|minim||5/22/2017 8:50 AM|