Hard wire as per schematic!

[jerryo]

If you wanted to build an amp without using a pcb design, could you use the general layout of the amp's schematic and hard wire it that way assuming that you reduce the distance between components to the very minimum possible?

If this is possible what are the pitfalls and what should one avoid and what should one look for. Or is it really not a good idea. I am thinking of simple amps like the JLH, Hiraga et al.

Did I see somewhere an amp that was hard wired on one side of a single sided pcb that used the copper side for the ground plane?

Any thoughts on this? I tried a search but did not find anything.

[Mooly]

To answer your question, yes, it's very workable.

Downsides and pitfalls. OK you did ask
It will look a mess.
You would have to support various components to prevent stress and fractures on wires.
You still have to get the grounding etc correct... wires to the correct places... and in fact point to point wiring could make that aspect easier.

There are advantages too, such as less stray inductance and capacitance between adjacent PCB print etc. It might run cooler... parts in free space.

Would I do it,
Nooooooo

[stormsonic]

something like this?

[currentflow]

An alternative approach which works reasonably well is to use a plain "PCB" with point-to-point wiring below. See my chipamp construction in Chip Amp Photo Gallery

This has the advantage of maintaining some rigidity but without the need for a PCB design. When viewed from the component side, there is no suggestion that the board isn't etched. Insulated wire jumpers can also be concealed in this way.

Regards,
Steve

[jerryo]

Hi Mooly,
why would you not try it; any particular reason? It would not be a mess if you took some time keeping all wires and components straight and aligned accurately with each other.

Hi stormsonic,
yes that is what I am talking about. What is the amp pictured? Did it work to your satisfaction? Does the layout follow the schematic?

Hi currentflow,
very nice build of your amp; like it.

What about the idea of using a single sided pcb and then hard wiring the components on one side and using the copper side for the ground plane. I have seen this on a photo on this site somewhere.

[multisync]

everything used to be made point to point with a few terminal strips thrown in, including colour tv's. Circuit boards are labour saving devices and increase reliability, and repeatability of performance. Buy a piece of vero board, a circuit board with tons of holes and little if no copper, and go for it. I used to make tons of little "air suspension" as my friends and I called it, circuits.

[joka22]

i would like to p2p a dx blameless es amp by carlos, the schematic although is readable you can get quite confused. I was looking for a program that you can upload a pcb diagram and then proccess it to layout your circuit as p2p then you can just copy it. Unfortuntely i dont know if this program exists tried searching for it but unsuccessful.

[currentflow]

Hi jerryo,

Thank you for your kind comment. It's debatable as to whether having a ground plane is particularly beneficial at audio frequencies. Perhaps more important is the use of correct earthing / star grounding techniques and low-impedance interconnects for high-current carrying paths. A good layout will also assist circuit stability.

Plain perforated board would perform identically (electrically) to my P2P technique although it's somewhat less aesthetically pleasing.

Regards,
Steve

[jcx]

schematics are drawn for human readability - not to optimize electronic circuit performance - circuit implementation in pcb layout or prototype is a critical part of the circuit's performance

power is usually shown top and bottom of the page for +,- most of the time they should be distributed in closely spaced traces to reduce the loop area that radiates magnetic feild

gnd also needs attention with ground plane being the simplest but star gnd principles are better for power circuits

power and gnd sould be planned with an eye to where the current flows and what it does in the "non schematic" parasitic RLC of real wires and how they couple to the circuit

sensitive feedabck or high impedance nodes don't have to be short on paper - in the real world you want to know which nodes are sensitve and how they drive parts placement for the best results


there are several prototyping techniques for building without a pcb layout

perf boad gives rigid mounting, can be had with clearance hole gnd plane for lower noise in low level circuits

"dead bug" on gnd plane is used for some high speed analog circuits

some pretty point-to-point air wiring can be better than a 2-d pcb for some parts of a circuit - but you won't likely get there by letting the schematic drawing be your physical layout guide


a possible aid to perfboard or ~ 2-d layouts could be to use a pcb layout package with "rats nest rubber-banding" mode - the part outline pads are shown with straight wire that moves with the part's releative position for all schematic connections, by moving, grouping and rotating parts you can minimize sensitive node length before you start routing

the free CadSoft Eagle demo package may be good enough for this use

[Mooly]

Originally Posted by jerryo

Hi Mooly,
why would you not try it; any particular reason? It would not be a mess if you took some time keeping all wires and components straight and aligned accurately with each other.

I just wouldn't.
Again you have asked the question and the answer is that to me it would always look a mess. I work to far higher standards than that.
But as I say it is workable, and done correctly should not give problems... and as long as you are happy with it, then that is all that matters.

It's so easy to design and make your own PCB's these days.

Have a look at posts # 22, 23 and 31.

http://www.diyaudio.com/forums/headp...phone-amp.html

Don't let that put you off... build it, enjoy, learn... and always strive for better.