OT - point to point wiring - why?

[petemoore]

My brother had to replace some tubes when the Fender Twin [old reliable] fell out of the back of a moving truck...the transformer had broken two of the stays, and was hanging diagonally.
 He was might pleased when the public adress system/guitar amp for his band came out 'fine' after such abuse.

[casey]

This is kinda funny, if you think about it - here's a thread on PTP, and not one picture of a PTP amp in it, not even a terminal strip layout, just tagboards (and that ain't true point to point  :wink: ). FWIW, RG covered this ground pretty much comprehensively quite a while back:

Point to Point Versus PCB Amps - What's the difference?

well, turret board to be exact....if you do true point to point it's often times a mess... :



it's really being silly to say that turret board is not point to point......

i would bet NOBODY can tell the difference....in tone that is....

whether it's posts holding the resistor or "terminal strip" it's all essentially electronically the same, just not cosmetically....  pcb on the other hand can have issues if not designed well...

[R.G.]

well, turret board to be exact....

Turret board is simply a neater way to terminate the parts than fender's tagboards. You can make the same mistakes with turret that you can with tag. It's the *wires* that are the problem, and they are relatively a constant.

if you do true point to point it's often times a mess... :

That's because true point to point is a more difficult layout problem than PCB layout. Your options are much more restricted in terms of conductor length, and the possibilities to get it wrong are much larger. On a PCB, you have only two dimensions to make mistakes in. With point to point, you have all of three-space.

Nota Bene:
I believe my PTP/PCB analysis preceeded Randall's by a significant amount of time. It's not as pretty, though.

[casey]

Nota Bene:
I believe my PTP/PCB analysis preceeded Randall's by a significant amount of time. It's not as pretty, though

yup r.g. i saw that earlier today and was thinking the same thing.... too funny.

:lol:

[Paul Perry (Frostwave)]

I don't see a problem with PCB amps.. until people start mounting heavy items on PCB!! and a LOT of amp components are heavy.

There was a notorious case of one early analog synth that had a power tranny mounted on a PCB tht regularly broke loose in transit & smashed everything else :x  :x
I've seen large filter caps vibrate loose, too.

[Paul Marossy]

PTP doesn't have to be messy. Check out these pictures of my Octal Fatness. I had to be neat with the wiring because of the size of the enclosure that I had to use! The last picture is after I replaced the coupling caps - I originally built it with a bunch of caps I had laying around. One day I decided to get news ones and put 'em in there.






And here is a few pics of my Firefly: (my first ever tube amp build) Sorry for the lo-fi pics...  :oops:

[Alex C]

about 8 years ago i worked on a soldano and it had absolutely no pcb.

i dont know about their more recent stuff....  this was a custom head i worked on with special tolex and the whole bit...

I didn't realize they did custom jobs.  I bet that's it, because this page shows guts pics from SLOs from the "late 80's" and 1992, and both are on PCBs.   They're laid out so well, I love it!  I absolutely love guts pics of any circuit, and hand-wired or well-crafted tube amps really get me going.

And Paul, instead of saying "sorry for the lo-fi pics," how about "sorry I attained perfection on my first try- yet again!"  

[brett]

It's gotta be pretty PTP inside because even if nobody else ever notices the difference, YOU will know.
:wink:  

Just as importantly, what about the

special tolex

.

Seriously, I've done 1 1/2 valve amps now in PTP style because that's the way they were done in the golden age, and I have a serious sense of heritage and hommage.

cheers

[Dai H.]

I read some where that large pcb's added capacitance.

Large PCB's added capacitance what?

Mesa/Boogies and Bogners are both PCB amps.  Reinhold Bogner has a treatise on PTP vs. PCBs on his website.  Randall Smith of Mesa/Boogie takes great pride in designing his PCBs BY HAND.  Those boards in particular are two sided with plated through holes so that repairs can more easily be performed.  When was the last time you heard of a tech cursing Petaluma for the copper lifing off their boards?

This dribble is a bunch of bollocks if you ask me...

And those amps posted are not truly PTP; real PTP have NO boards (like some real early pedals), just components all hanging to each other, soldered at their leads.  Those in the pictures are called eyelet strip construction or something like that.

probably comes from Gerald Weber's book, "co-planar traces" etc. Pretty silly, IMO. You have to watch out for some of his info, like putting alu electrolytics under a hot lightbulb to re-form them... I remember one time where a salesman in a music store was trying to give me the PTP sales pitch. He wasn't very happy when I said there was no difference in sound but PTP makes it easier to work on the amp, lol. I've seen stuff like where a reiss. Marshall w/a PCB was re-wired w/tag strips for a supposed improvement in tone. Big waste of money, (from all the labor costs) IMO. Besides that, classic Marshalls had tag boards. People will believe what they want to believe though, seems like.

[R.G.]

probably comes from Gerald Weber's book, "co-planar traces" etc. Pretty silly, IMO. You have to watch out for some of his info, like putting alu electrolytics under a hot lightbulb to re-form them...

Don't get me started on Gerald Weber's book.

...oops, too late, you already did...

In general (IMHO), if Gerald Weber's book gives a technical description of why something happens, it is at best an incomplete explanation, or almost completely misguided. A fair number of things in there are flatly wrong.  I'm sure he tries hard, but the poor guy either doesn't know or does not really say what's happening in his stuff in print. I bought the second edtion, primarily to extend my schematics collection. I was shocked at the misinformation. Likewise in his columns in Vintage Guitar.

It's plain cruel to spin out incorrect stuff to people who are trying to learn.

[casey]

about 8 years ago i worked on a soldano and it had absolutely no pcb.

i dont know about their more recent stuff....  this was a custom head i worked on with special tolex and the whole bit...

I didn't realize they did custom jobs.  I bet that's it, because this page shows guts pics from SLOs from the "late 80's" and 1992, and both are on PCBs.   They're laid out so well, I love it!  I absolutely love guts pics of any circuit, and hand-wired or well-crafted tube amps really get me going.

And Paul, instead of saying "sorry for the lo-fi pics," how about "sorry I attained perfection on my first try- yet again!"  

o.k. - now you've got me doubting myself....it was about 8 years ago....

ill have to research it out.....  i remember being super impressed with the construction of this amp....it had "supposedly" been owned by neal schon at one time....if i see that fella again, ill have to ask him about it.

[Paul Marossy]

And Paul, instead of saying "sorry for the lo-fi pics," how about "sorry I attained perfection on my first try- yet again!"

:lol:

I just think things through for a while before I do a project like that. Then I go for it and solve the problems as I go. Not unlike what I do at work every day designing HVAC systems and finding ways to lay stuff out in seemingly impossible situations. It also helps that I have seen quite a few tube amp layouts and I noticed the things that they all had in common in terms of layout. :wink:

On another note... Gee, I'm glad that I never bought that Gerald Weber book! I was under the impression that he was the tube amp guru. I guess not.  :shock:
(Actually, I have been hearing that a lot for the last week or two)

[lovekraft0]

it's really being silly to say that turret board is not point to point......

i would bet NOBODY can tell the difference....in tone that is....

Point well made - however, I doubt anyone could tell the difference from a well-designed PCB layout, at least by listening. Besides, splitting hairs is what this mojo stuff is all about!  :wink:

RG, thanks for verifying what I was seeing in the Weber book - I was beginning to fear that he knew something the rest of us didn't.

[casey]

it's really being silly to say that turret board is not point to point......

i would bet NOBODY can tell the difference....in tone that is....

Point well made - however, I doubt anyone could tell the difference from a well-designed PCB layout, at least by listening. Besides, splitting hairs is what this mojo stuff is all about!  :wink:

RG, thanks for verifying what I was seeing in the Weber book - I was beginning to fear that he knew something the rest of us didn't.

yup, i've heard some great sounding pcb amps.....