converting a re-issue Bassman

[g1]

Out of curiousity, which 2 resistors burnt?
We're puzzle freaks here and will gladly go along with gutting & rebuilding as long as we can learn something about the original fault first .

[Stratosaurus46]

Out of curiousity, which 2 resistors burnt?
We're puzzle freaks here and will gladly go along with gutting & rebuilding as long as we can learn something about the original fault first .

Apprently, the mods performed inserted a couple 47K resistors to replace R28/29. The amp worked well for several years, but I think one of the output tubes died, and took those resistors out. Not sure.

[g1]

Those are plate resistors for the PI stage.
No idea how they could burn unless the ones installed were very underrated for the job.

[Stratosaurus46]

I know that, g1, and I don't know why they fried, either. I'm just going to put it back to stock, add a bias pot, and set it up. I hate trying to work on PCBs -- point-to-point is much easier to work, and MUCH easier to mod/repair.

[g1]

I'm the opposite, I can't stand working on PTP. Give me eyelet board any time. I even prefer pc board to PTP.

[Stratosaurus46]

Technically speaking, an eyelet board (what I ordered from Hoffrman) and a turret board are both considered point-to-point methods of construction. I prefer the eyelets, as well. Everything I've repaired/modded has been eyelet. They're just easier to handle.

[g1]

Fair enough. When I hear PTP, I think very strictly of sockets, pots, hardware, components and maybe the odd terminal strip.
For me this is the worst type of construction to work on, whereas eyelet board is my favourite. So no way I will call them both PTP .
Turret board is a toss up with PCB, but my PCB experience does not include much 21st century stuff, so the newer flimsy traces and lead free solder would probably make me less friendly to PCB construction.

[Stratosaurus46]

I dislike PCBs intensely. I also dislike the old lug-strip construction that Vox and several others used in the 50s and 60s. Some of the old PCBs would delaminate the circuit track if you looked at 'em cross-eyed. I can deal with turret and eyelet boards very easily. I work at a company which makes ECUs for automobiles, and dealing with four-level PCBs and surface-mount components is a major pain in the tuchis. And I managed to stock up on 60/40 resin-core before everything went lead-free. I think I've still got about five, one-pound rolls left.

[Justin Thomas]

I mainly build true PTP except for the cap boards, which I use turret boards for. Yeah, PTP is a PITA if you have to make extensive repairs & mods. So I just tack it all together & go from there... but I also work from salvaged organ chassis, etc. No room for a board!

Eyelets are my favorite to do repairs on, though - easy in, easy out! Just quit running wires underneath!

Re: PCBs, I.m fine with them til they break. And least with the oldies, there was enough room to drill a hole, stick in a few turrets, run some jumper wires, etc. On new stuff you can't do that. Maybe an old Ampegs board would delaminate, but at least I could repair or duplicate it. I copied the rectifier switch b board in my Prison if with G10 & turrets, and the new switch lugs fit right in the turret holes! I'm pretty proud of that one, given my limited tools & experience...

Justin

[Chuck H]

Just quit running wires underneath!

+1 to that!

Although I am guilty of doing it for a custom order where the customer mentioned repeatedly how he liked the old HiWatt wiring and other examples of neat, tidy appearance. I didn't actually line all my components up like soldiers and I didn't bend all my traces at right angles, but, since I run individual grounds with no daisy chains, I did put the ground points under the board. That way the multitude of individual grounds just appeared to hook from the eyelet to under the board. No visible lead. I was smart about it though. I included a couple of grounded leads from each point with the ends capped with shrink tube. So if I need to do a repair or modification that needs a ground I can just fish out one of the unused leads instead of lifting the board

[Justin Thomas]

Okay, let me clarify: I <DO> run wire under my turret boards. There's plenty of clearance, they don't get chafed, and I can wiggle them to find out what's what. But at least one end has to be visible, for tracing and inspection purposes. Same with Ampegs, or any amp where the boards are mounted on standoffs. I meant Fenders - there's no way to see either end of an underboard wire without a layout, board removal, or lots of poking. And you have to lift the board to get to it.

I aim for a good mix between appearance AND serviceability. Most people really like my true PTP, though, even if it is a little messy. Just has pure "old-school" written all over it. Viva la difference!

Justin

[Chuck H]

stratosaur,

Glad to hear you have chops. You certainly won't have much trouble with this sort of project.

Technically speaking, an eyelet board (what I ordered from Hoffrman) and a turret board are both considered point-to-point methods of construction.

Technically speaking they aren't. It's only in the audio genre that "professionals" refer to eyelet and turret boards as point to point. Probably because it reads spiffy in the sales lit. The existence of a board where most of the components and circuit paths are derived is NOT point to point. It's point to board to board to point. Point to point is a term used distinctly to indicate the absence of a board. Component leads are soldered directly between sockets, jacks, pots, switches, etc. as g1 described. I've heard the term point to point applied to many eyelet and turret board projects though. It's certainly common enough. It's just not correct. Some of the same people that call circuit board amps point to point are also guilty of using the term "hand wired" for certain types of PCB construction where the board is stuffed and some wiring is indeed done by hand. Shenanigans. PTP, eyelet and turret construction are hand wired.

I guess it's all in your personal position really though. It'd be hard to offer "proof" defining these construction methods that can't be negated by different "proof"

[wyatt]

s

Technically speaking, an eyelet board (what I ordered from Hoffrman) and a turret board are both considered point-to-point methods of construction.

Technically speaking they aren't. It's only in the audio genre that "professionals" refer to eyelet and turret boards as point to point.

Worse yet...it's only in the guitar community that they do that. If you sold a turret/eyelet/tagboard amp as point-to-point in the tube hi-fi scene, you would be crucified.

That said, I typically interpret the word according to context, especially on guitar amp dominate sites.

And I managed to stock up on 60/40 resin-core before everything went lead-free. I think I've still got about five, one-pound rolls left.

I take you aren't in North America? Where lead still flows freely?

[Justin Thomas]

I take you aren't in North America? Where lead still flows freely?

Sigged! Thanks!

[Chuck H]

The main source of lead pollution thus far in North America is actually due to fishing!?! Huge lead weights used to drop line for downrigger style fishing are dropped when a fish is hooked. "they" say the lower section of most river systems on the west coast are virtually paved with the stuff!!! But I can see where some clear thinking environmentalist recognized the problem infiltrating our land fills with all the disposable electronic appliances that have been, and are even more so, common to our culture. But it's a little like closing the barn door after the horses are out! Once you've tainted the water you're already "f"d.
Then again... Since so many land fills are still grandfathered in with sepate drainage on creek systems, and these creeks feed the reservoirs, ROHS for North America might stave off an apocalypse for an extra decade