What are PCBs?

[ndemattheis]

I have seen this term used in regard to discussions on amplifier quality. (I hope I got the acronym correct). I have no electrical knowledge, but I am curious as to what this means and whether this is something to be avoided.

1.What is a PCB?

2.Does this affect an amps tone?

3. Does it affect an amps reliability?

4. How do you know whether an amp has a PCB?

Thanks.

[CzarIvan]

1. Printed Circuit Board.
2. some people swear by point to point wiring... tone is subjective
3. pretty much every electronic device you have has a PCB... no chance of loose wires. at best, a cold solder joint, but even then, they're usually mechanically, vs manually soldered so there is less chance of that.
4. if you open it up and there are more than just resistors, caps, tubes and wires, you've got a PCB. Most modern amps have them. very few, if any, mass produced amps are true point to point wiring.

[DAB]

PCB

Printed Circuit Board

Instead of "hand wired" where the components are connected either directly to each other which is true hand wired or soldered to a turret type board, they use a printed circuit board that replaces the "wire" with pre-printed electrical paths.

Typically used because it is easier and cheaper and allows mass production using machines that "populate" the board with components instead of using people.

Lots of discussion about pros and cons. The only thing I can say is I had a Rivera M100 for years that used PCB and it sounded great and was very reliable.

Here is a link that supports one side of the discussion:

http://www.londonpower.com/pcbinfo.htm

[PRNDL]

PCB stands for printed circuit board. Electronic components are mounted on them and connected with copper traces that are "printed" on the board.

The reliability depends greatly on how it is designed and the quality of the board (i.e. thickness, etc).

Unfortunately, many mass produced amps are made with low cost components (i.e. cheap), which are prone to failure.

In general, its harder to repair a PCB because the components are usually smaller, close together, and soldered through the board. This is even more difficult with surface mount components, which are very small.

On the other hand, a well designed PCB amp can be very reliable. For instance, my last two repairs were a Laney and an Eden Bass Amp. The latter is a fantastic amp that also had a preamp tube for tone.

I'm certain others will add to this thread.

[jamison162]

My favorite amps that I've played happen to all be PCB. I've played plenty of PTP and have been let down numerous times, it's just as hit-or-miss as PCB's.

[rog951]

PCBs are my nemesis. I design them for a living and I have nightmares about them!!! :crazy

[RedMan]

It also stands Polychlorinated Biphenyls, which is used in many transformers and capacitors of vintage amps. These are deadly to humans, so think twice before eating your lunch while working on a vintage amp with a leaky capacitor or tranny.

[ndemattheis]

Thanks to all for the layman's explanation.

[mbratch]

3. pretty much every electronic device you have has a PCB... no chance of loose wires. at best, a cold solder joint, but even then, they're usually mechanically, vs manually soldered so there is less chance of that.Automatic solder flow doesn't necessarily reduce the chance of a bad solder joint. Also, don't forget: cracked traces, or thermal issues when designed with tube sockets on board.

BTW, I have nothing against a PCB-based guitar amp. The well-designed ones are great. Fender, for example, does a great job with theirs (e.g., keeping the tubes on a separate board).