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[Tim Halligan]

Phuckwit wrote on Sat, 26 May 2007 22:45

Andy Peters wrote on Sat, 26 May 2007 04:16 Maybe this explains the traditional British problems with all things electric (c.f., Lucas, Jaguar, etc.)?  You know, all of that point-to-point wiring. -a There is nothing wrong with the european XJS 5.3 its just Sir John Egan and his wiring bofins had no idea you wanted to drive it about slowly all day in death valley.

Anyone else remember this old joke?  I bought a British car....because I like walking. Ronnie Corbett...I think.





Cheers,
Tim

[Phuckwit]

Love the V8 Utes Mate
  Whats with that Handlebars Kovax he's mad!.

[maxdimario]

tom eaton wrote on Fri, 25 May 2007 18:25

maxdimario wrote on Fri, 25 May 2007 06:11 the advantage of point to point is that the leads between components can be kept extremely short if that's what's needed. you can also use different thicknesses of wire for specific purposes. one example is a ground buss wire which is usually very thick to minimize ground loops. so wherever you see a PC board, point-to-point does not exist. You know what? Leads on a PCB can be as short as a shared hole.  No advantage or disadvantage.  And if it's not painfully obvious, the traces on a PCB can be sized according to the needs of the job. Make music! t

you can do things with point to point you cannot do with PCB's... such as soldering parts vertically AND horizontally.

also the leads can be bent at right angles, coiled etc. etc.

these are minute issues in most audio gear BUT I can say that IF I am building something which is high impedance and high gain I spend MORE time on the layout than anything else..

sometimes you need to avoid PCB's...but not always.

and PCB's with lots of foil do not necessarily mean good shielding or lack of oscillation.. sometimes the opposite.

many times minute oscillations at ultrasonic freq. can create a hash which is hardly audible etc..

THE POINT REMAINS that point to point EXCLUDES the use of PCBS

but you could have one part of the circuit in PTP and another in PCB format..

[Larrchild]

I think the point remains that, if a guy making records, turns a knob, and the right sound comes out, and both PTP and PCB designs sound exactly the same, you smile and turn the dial.

Without regard to vertical or horizontal mounting.

[maxdimario]

some PC boards are too small and/or the layout is not done as well as it should be.. this is what causes problems with PCB's

I prefer point to point on tube mic pres and other stuff where layout is critical.. one example is soldering the components directly on the tube base instead of running wires.

at high impedance and high gain these little things make a big difference.

it's obvious that where there is no advantage there is no point in doing PTP.

[johnR]

maxdimario wrote on Wed, 30 May 2007 07:43

some PC boards are too small and/or the layout is not done as well as it should be.. this is what causes problems with PCB's I prefer point to point on tube mic pres and other stuff where layout is critical.. one example is soldering the components directly on the tube base instead of running wires. at high impedance and high gain these little things make a big difference. it's obvious that where there is no advantage there is no point in doing PTP.

Part of the problem with PCBs is that often the person who gets the job of producing the computer layout only understands how to operate the CAD software, and doesn't have the knowledge necessary to make a good physical layout. I've seen some bad examples of this, even from reputable manufacturers, eg. a guitar amp PCB with the reverb sends about an inch away from the high gain preamp input. This of course oscillated uncontrollably at high gain and high reverb settings. Only an inexperienced person would have designed such a board, but it was in a high end product from a very well known manufacturer. The problem isn't PCBs, it's who gets trusted to do the layout.

[Larrchild]

Yep.
I do my own layout.
And they are working on 3 levels .
DC, RF, and Audio.

Some days you have to choose which one is in order.
Grounds every inch in PCB are great for RF but not so great for audio. So some dude with an autorouter that makes computer boards is not a good person to hand-off audio designs too.

And letting them do the schematic-capture is bad if they are not engineers.

But you can get around on these softwares like Eagle pretty good, after a few days of cursing.