Point to point wiring, what is it and why?

[mofugly13]

Does point to point wiring mean that there is no circiut board? Each component is connected to the next by wire, and solder??? Why is point to point wiring a selling point?

[TexGoneNW]

Most direct signal path.

Same reason you might want to use a shorter guitar cord when you don't really need a long one.

Silvertone 1482 is an example.

[tbp0701]

Right, all the components are wired together by hand rather than on a circuit board. As for the selling points and being better than PCB, that's one of those eternal debates, like maple vs rosewood. But in short, PTP amps often are seen as being more carefully built, often use higher quality components (but not always) and are seen as much easier to troubleshoot and fix.

Here's a photo (from Winfield Thomas Amps -- I hope he doesn't mind my posting it. But you can probably see that a lot of skill and care went into building that):

[Jaybird]

"There are five basic types of guitar amp wiring in my mind, and often two or more kinds are combined in a single unit (I'm ignoring solid- state amps, as they exclusively use the Total PCB method listed below).

Point-to-point - Each component is connected to a tube pin or solder lug or jack. There are no "boards" whatsoever. Examples of this style of construction include most old tube hi-fi equipment, 70-era Sunns, and more recently BadCats.
Tag Board - the classic Fender and "plexi" construction methods. Most components are soldered to a long board with eyelets. These are in turn connected by wire to the tubes, transformers, pots, etc.
Turret Board - The classic Hiwatt/Harry Joyce style, this is similar to tag board construction, but uses metal turrets which extend out from the board, which most of the components are connected to.
Partial PCB - Used by most modern large manufacturers starting in the late 70s/early 80s. Most components are soldered to a Printed Circuit Board, which has copper lines or traces on the underside of the board surface that the components are soldered to, and which also make circuit connections. Example of this style of construction include the early (vertical input) JCM800s, Biacrown-era Hiwatts, and Soldano SLOs. This method basically used the PCB as an advanced tag board, and many wires are still needed to connect the tubes, etc.
Total PCB - Used by most modern large manufacturers starting in the mid-80s to the present day. Everything is soldered to a PCB, including pots and tube sockets. This makes it easier and cheaper to manufacture, but harder to service and modify, and there is some question about the reliability of the PCBs holding the sockets of the extremely hot power tubes. "
A nice little bunch of info that I was reading the other day. at
http://mhuss.com/AmpInfo/.

[BrianF]

Point to point is the oldest of electronic assembly methods. All of the methods that came after were steps in simplifying the assembly process and removing most of the labor intensive work (reduce cost and faster assembly time), while at the same time improving the uniformity in the finished product and improving yield and quality.

[JohnnyCrash]

There is NO benefit to PTP.

It is NOT like using a shorter cable. A 50' versus 10' cable argument does not even really fit into PTP versus eyelet/turret/tagboard or even PCB. Loading, etc has no bearing. The length of "extra" leads to go from component to component could be the same, longer, or sometimes even shorter than an Eyelet or PCB built amp... either way your dealing with MAYBE a foot of material either way.

Another thing to consider is grouding (and ground loop hum) could be a WORSE situation in a PTP amp.

As far as handwired eyelet/turretboards, they are easier to repair, modify, and build.

True PTP is literally soldering resistors/caps directly to jacks, tube sockets, and other amp parts. In the earliest amps, it usually meant a rats nest to trace each lead and figure out what was what and how to repair what.

If all of the component values are identical a PTP, Eyelet, or PCB amp should sound the same... the benefits come down to:
1. Cost.
or
2. Ease of maintenance.

Sound is the same.

[GUITARmole]

Yeah, ditto what JohnnyCrash said.

Chances are the wiring length is LONGER with PTP boards...just look at that rat's nest inside most PTP amps. They make great antennas too!

PTP boards usually always sound better...not because of the board but because they're built with care and the best COMPONENTS...plus they're durable and easy to work on.

[sjhusting]

The Aiken tech pages have a good article on this; read that. There's nothing wrong with PCB, when it's done right, just like there's nothing wrong with true PTP, when it's done right, or turret board, or eyelet board. The type of construction per se has nothing to say about the quality. The execution is everything.

Here is a true point-to-point radio from 1957; it was the top-of-the-line Nordmende then. Note that every solder joint, component, and wire is original, as it came out of the factory in 1957:

http://www.stevenhusting.com/Radio/guts4.jpg

When I got this radio, I figured I would be replacing the caps, and so on, until I actually looked at it. Then I decided to leave it alone.

steven

[eddiewagner]

Originally Posted by sjhusting

Then I decided to leave it alone.

steven

yeah, thats premium german electronical engineering at it´s best. don´t touch, just look.

[11 Gauge]

I've had the pleasure of owning a small handful of PCB amps that were a breeze to work on - flying leads out to the sockets and such, and a handful of pots, which made pulling the board relatively painless.

My biggest gripe with many PCB amps is that even if you can get to the underside of the board to service it, you oftentimes run the risk of lifting a trace when unsoldering something, even if using desoldering stuff, and heatsinking the component.

Some manufacturers use a heavy clad board, with thru-hole plating. Unless you've got tons of off-board stuff to disconnect, these are pretty nice to work on.

For simple amps, turret/eyelet/etc. is the way to go, IMO. Servicing is a breeze (usually), and you can have the amp up and running quickly. If you are adding passive switching to a single channel, I also prefer this method.

I would never build a true PTP amp - it's a nightmare just trying to get everything attached to a very small space, without shorting anything out, or resorting to a rat's nest of hardwired jumper leads...

...I've also tried the terminal strip method. Also a pain. It's great for little additions to an existing circuit.

I just re-purposed an old bass head - early 70's stuff. I actually went back to the original PCB, stripped it, and traced the stock circuit layout with a Sharpie. I then rewired it with some brainbending, calculating where to put the new components, and jumpering stuff where the stock circuit would not allow. It worked out well, but the old board is one tough SOB - I didn't lift any of the traces while reworking the board.

[mofugly13]

Wow, point to point really looks like a troubleshooting nightmare. So, in the end, a properly done PCB with a good board is just as good, and easier to fix/mod?

One day soon, I want to build meself a nice tube amp, just gotta figure out which one to clone.

[Poppatwang]

Originally Posted by mofugly13

Wow, point to point really looks like a troubleshooting nightmare. So, in the end, a properly done PCB with a good board is just as good, and easier to fix/mod?

One day soon, I want to build meself a nice tube amp, just gotta figure out which one to clone.

My take away message would be turret boards for ease of service.
PCB soldering takes a more practiced hand.

[guitarbuilder]

I think I remember this from physics. When electricity passes through a wire, a magnetic field is created. When two wires (conductors) are separated by a dielectric( air) capacitance is created. When electricity goes through a coil of wire, inductance is created. It would seem to me that the difference between the two systems of wiring would cause the sound to be different ( however subtlely) due to the proximity of the conductors to each other. The wire would also have different resistances due to their cross section. If one pickup can sound different from another by winding it differently, it would seem that one amplifier could too.

[Freight Twang]

Johnny Crash wrote:

There is NO benefit to PTP.

It is NOT like using a shorter cable. A 50' versus 10' cable argument does not even really fit into PTP versus eyelet/turret/tagboard or even PCB. Loading, etc has no bearing. The length of "extra" leads to go from component to component could be the same, longer, or sometimes even shorter than an Eyelet or PCB built amp... either way your dealing with MAYBE a foot of material either way.

Another thing to consider is grouding (and ground loop hum) could be a WORSE situation in a PTP amp.

As far as handwired eyelet/turretboards, they are easier to repair, modify, and build.

True PTP is literally soldering resistors/caps directly to jacks, tube sockets, and other amp parts. In the earliest amps, it usually meant a rats nest to trace each lead and figure out what was what and how to repair what.

If all of the component values are identical a PTP, Eyelet, or PCB amp should sound the same... the benefits come down to:
1. Cost.
or
2. Ease of maintenance.

Sound is the same.


I have to completly disagree with this post. A true P2P amp sounds different than tag, PCB, etc. PCB create capatance and that is one of the reasons DRRI don't sound the same as a BF Deluxe.

As far a the length of leads, this does make a huge difference in tone, slew rate, and have oscillation issues. As for PTP being rat nests, have you ever seen the inside of a Carr Amp? Nothing ratty in there. And there are a few more that I can think of that are beautiful and EASY to repair. How many people on this board have a Peavy C30 or a Hod Rod Deluxe that you play 5 gigs and the input jack breaks off the board, and have to take the board out that would be a 2min. repair in a PTP.

The benefits :

Cost: All the major companies make PCB , not because it is better, because its cheap, made in Korea, and after they get your money, and it breaks, your amp becomes disposable. They want you to buy another, rather than have it fixed.

Ease of Maintance: Has anyone here had to resolder a wire in a HRD, Classis 30, or any PCB amp, what ease? No matter what some magazine article, a saleman at GC, or any other propagada. The sound is NOT the same. A PTP always has been and will be better mousetrap. Ha, (Get it mousetrap-rat nest?)

[Gee]

Originally Posted by Freight Twang

I have to completely disagree with this post. A true P2P amp sounds different than tag, PCB, etc. PCB create capacitance and that is one of the reasons DRRI don't sound the same as a BF Deluxe.

The BF Deluxe is not PTP. It uses a vintage eyelet board.

Originally Posted by Freight Twang

As for PTP being rat nests, have you ever seen the inside of a Carr Amp? Nothing ratty in there. And there are a few more that I can think of that are beautiful and EASY to repair.

Carr don't make PTP amps as far as I am aware.

The bottom line is that there is no reason for a well designed and laid out amp to sound just as good whether it be constructed using PTP, vintage tag board, vintage eyelet board or PCB. The reality is that many PCB amps suffer from layout induced artifacts, sound coloring, noise, etc. because they have been designed to a price point, ease of manufacture and assembled by low skilled workers or auto assembly.

PTP construction is pretty much dead these days. It requires a high level of assembly skill and an even higher level or fault finding to remedy problems.

Unfortunately, these days, PTP is mistakenly and misleading being used in amp marketing to describe a non PCB method of manufacture.

[Freight Twang]

As you can see from this chassis photo of a Carr Mercury, it is P2P. As for a BF DR , I know that it is built on a tag, the point I was making was the fact that a DRRI dosen't even sound that good.

[JohnnyCrash]

Every cap or resistor has a tolerance of anywhere from 5% to 20% depending on quality of components used.

Then consider even among the same manufacturers, no two tubes will be the exact same specs/tolerances.

A PTP, PCB, Eyelet will sound the EXACT same, -IF- the exact same values are used - and its the exact same circuit.

Given the variables - to anyone's ear finding a difference between PTP and PCB is impossible. I've heard reissue PCB amps that sounded better than their Eyelet original vintage counterparts and vice versa - no two amps are the same. There is no "sonic better," just easier to work on or not.

Working on a PCB amp, as mentioned above, can have headaches all its own. Lifted traces and pulling the board (or not being able to pull the board) for instance. PTP can be a headache in troubleshooting and cleaning up (rats nest), but Eyelets/Turrets are the easiest to work on later... otherwaise there will be virtually no SONIC difference given all of the variables.

[sjhusting]

The important point in the Aiken article is "well designed, well executed."

I would suggest that a Classic 30 or HRD (I've got one of those) is not "well executed" other than that it is designed to be manufactured as cheaply as a certain quality level allows. There are well made PCB amps - Soldano, THD, even Boogie. I've been inside those and they are built like rocks. I don't like playing through them though; not my kind of amp. I've never been inside one of Fender's "Pro Tube" series; I'd hope they would be built like the Mesas.

And as far as a tag or eyelet board being easier to repair and mod - yes, probably, unless there are a lot of components _under_ the board, and gadzillions of wires making it a chore to remove it. Again, it's all about execution.

It might be more accurate to say that inexpensive PCB amps are likely to be poorly made, rather than damning the whole race. But that shouldn't be a surprise, should it? Cheap means you are giving something up; whether it is millimeters of board thickness, time/money spent on traces, or use of Chinese components instead of, uh, stuff from other parts of the world.

As long as we all want more for less, this is what we'll get. You may have heard that "you get what you pay for." Globalization hasn't changed that one bit.

For me the best solution was to build my own. I can see that might not be for everyone, though, and if I were a gainhead, it might be a bit too much for me.

steven

[Gee]

Originally Posted by Freight Twang

As you can see from this chassis photo of a Carr Mercury, it is P2P. As for a BF DR , I know that it is built on a tag, the point I was making was the fact that a DRRI dosen't even sound that good.

That's an interesting picture inside the Carr amp. It uses tag strips and a high number of point to point connections. That's an expensive way of making an amp.

The BF DR and DRRI sound different for many reasons but probably a major factor is the poorly laid out PCB in the DRRI.

There are critical signals in a valve amp that should ideally be separated by a minimum distance and if they have to intersect should do so at right angles. Of course PCB's by their nature, have to run many signal paths parallel, close to each other and in the same plane which is the worst case in a valve amp.

[Rob DiStefano]

Eyelet or turret, don't matter to me - as opposed to a PCB, I can work on a PTP amp and I'm far from being an amp guru. A properly built PCB amp only gives me concern for maintenance in tracing and fixing the etchings (Mesa, THD, etc.) ... and a bad build PCB will have pots and sockets on the board, YUK! (way way too many amps to mention).

Here's a 5F1 Bluesboy that was "built in the air", with no board, just some terminal strips ...

[stax]

After trying differant methods I prefer turret boards, so much easier to work on with my dodgy old eyes.
This pic is one of my 18watters crammed onto tags and I won't be doing that again.
Stax

[teleamp]

Well, I have to chime in on this one.

A TRUE PTP signal path in a simple circuit does have a slight tonal advantage (those with tin ears might not be able to notice).

The benefits are that there are no added leads or solder joints.

The negatives are if a pot, jack or tube socket has to be replaced, the amp basically has to be rebuilt.

I did some prototyping for Mercury Magnetics a couple of years ago when the Valve Junior craze was starting. I ended up making a high-end combo with a TRUE PTP signal path that used a VJ circuit that Alan Cyre came up with and tweaked it slighly to my taste. I took one of the amps to the North Carolina Fall Ampfest last year and people were blown away. The room was 40' X 60' and my 5 watt amp followed Greg Germino's 100 watter, the promoter of the event apologized for scheduling my demo after the high wattage amps. I no longer build and sell these, but here is a link to a video of Greg Germino playing it (the video camera mic captured it nicely).

http://www.vintageamp.net/ampfest/mm5.html

Here are a couple of pics of the prototype (Note; The signal path is TRUE PTP, the powersupply is Garolite turret board);


And there are clips of that amp on Mercury Magnetics website.

True it is not feasable to build most circuits with true ptp, but Matchless does some really cool ptp/terminal strip construction.

Turret board and eyelet board are not ptp, but they are handwired, true ptp has no added leads an use the leads of the resistor/capacitor to connect directly to the origin and destination, 1 part-2 solder joints, anything else is another form of construction.

MikeY