Point to Point or Printed Circuit?

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Niteshade

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Point to Point or Printed Circuit?
« on: 27 Aug 2010, 11:51 pm »
I've been thinking about this for some time and wanted your opinions on it: Do you care whether tube gear is point to point or made on a printed circuit board?

Berto

Re: Point to Point or Printed Circuit?
« Reply #1 on: 28 Aug 2010, 12:14 am »
I've been thinking about this for some time and wanted your opinions on it: Do you care whether tube gear is point to point or made on a printed circuit board?

My 87yr old amp tech who is responsible for the transistor radio and the first stereo setup told me printed circuit boards will accumulate dust and everntually leak. He builds doomsdays amps and there all point to point. :thumb:

jtwrace

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Re: Point to Point or Printed Circuit?
« Reply #2 on: 28 Aug 2010, 12:16 am »
I've been thinking about this for some time and wanted your opinions on it: Do you care whether tube gear is point to point or made on a printed circuit board?

I think the first question should be about how many you plan to make.  Sonically, I really don't think there is a difference. 

Niteshade

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Re: Point to Point or Printed Circuit?
« Reply #3 on: 28 Aug 2010, 12:47 am »
Those first two posts hit a home run!  :eyebrows:

I see several highly successful tube amp & preamp models selling with printed circuits(PC's). That leads me to believe people are not very concerned about how something is put together. Don't get me wrong! PC's can be made well and there are several 40 year old amps around with them. (Heathkit, Dynaco)

Construction time is significantly reduced with PC's, thus is becomes easier to get orders shipped on time AND it increases production capacity. The cost, naturally is no more point to point (P-P) wiring, except to rear mounted plugs, switches & sockets, etc..

It's a nifty topic- I want to see what everyone thinks. For the sake of this thread, I am not advocating either wiring method. As was mentioned so far, both wiring techniques have pro's & con's. It's a matter of what you're comfortable with.

JohnR

Re: Point to Point or Printed Circuit?
« Reply #4 on: 28 Aug 2010, 01:13 am »
Depends. For mass produced equipment PCBs will likely have better quality control I would think and less likely to have grounding issues (i.e. it only has to be gotten right once). If you want to open it up and tinker around inside then point to point is a lot easier to deal with. Circuit complexity is more limited with point to point.

kingdeezie

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Re: Point to Point or Printed Circuit?
« Reply #5 on: 28 Aug 2010, 01:23 am »
I don't think it matters as long as the circuit is sound, and the company behind the product is serious.

Most of my equipment is point to point wired, but that is only because of where I ended up purchasing the product; which was smaller internet based companies with great products.

But a company like Manley, which is known for its quality products, doesn't believe in point to point wiring if I remember reading it correctly.

Something a long the lines that they felt that point to point wiring makes it harder to provide a consistent product.


*Scotty*

Re: Point to Point or Printed Circuit?
« Reply #6 on: 28 Aug 2010, 03:45 am »
I vote for point to point wiring in tube gear wherever possible. Even solid state benefits from reducing the length of the traces that power and signal travel through and the condensation of the circuit layout on the board. I don't believe anyones first choice for an interconnect would a circuit board trace on a fiberglass board.
Scotty

srb

Re: Point to Point or Printed Circuit?
« Reply #7 on: 28 Aug 2010, 06:12 am »
My 87yr old amp tech who is responsible for the transistor radio and the first stereo setup told me printed circuit boards will accumulate dust and everntually leak.

Printed circuit boards of the past and homemade boards had/have exposed traces.  Modern quality PCB's have solder masks and nothing is exposed except the component pads.
 
If the design is well implemented, 4 layer boards can have a technical advantage due to the ability to design a strategic power layer and a ground layer.  Point to point wiring, if not well routed, can add hundreds of little antennas to the circuit.
 
Some tube component manufacturers, like PrimaLuna, use a combination of point-to-point wiring and printed circuit boards.
 
Steve

chlorofille

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Re: Point to Point or Printed Circuit?
« Reply #8 on: 28 Aug 2010, 08:21 am »
I think point to point is great if less than 10 components are used.
For a more complex design, a good double sided PCB with thick traces can be just as good. So maybe point to point for your pre-amps and PCB for your amps?

Of course with an all PCB, your labour costs go down, and you can pass the savings to us  :green:

FullRangeMan

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Re: Point to Point or Printed Circuit?
« Reply #9 on: 28 Aug 2010, 08:27 am »
I can speak only for myself:
A good tube amp must obligatory have not only point to point wiring, but hard wiring too, stranded wiring definitely not good.
A point to point service allow the builder to select a good wire, a important option to voicing and to sound quality.
A tube amp or preap with PCB are a bastard to me, a second class job, suited to low price gear or hurry serial assembly line.
Some tube makers love it as JOLIDA, BAT, LAMM, even the ML3 at 140,000 dollars use PCB, a shame, JOLIDA and BAT inside tube amps images do not exist on the web.
On tube amps tests in magazines this subject are hidden and not mentioned, when the equip use PCB.   
I especially hate PCB, some reasons:
> PCB traces are no OFC copper or silver, only cheap lead solder.
> PCB traces may loose and corrode with the hi heat from tubes and fast coolling after turn off.
> Change a tube socket in a PCB are awful, some tube socktes lasts around 5-10K hours only, before starting false contact and need replace.
> PCB are convenient, practical to made a tube amp, to simplify the work and may give hi profit to a manufacturer.
Regards

Guy 13

Re: Point to Point or Printed Circuit?
« Reply #10 on: 28 Aug 2010, 08:48 am »
I can speak only for myself:
A good tube amp must obligatory have not only point to point wiring, but hard wiring too, stranded wiring definitely not good.
A point to point service allow the builder to select a good wire, a important option to voicing and to sound quality.
A tube amp or preap with PCB are a bastard to me, a second class job, suited to low price gear or hurry serial assembly line.
Some tube makers love it as JOLIDA, BAT, LAMM, even the ML3 at 140,000 dollars use PCB, a shame, JOLIDA and BAT inside tube amps images do not exist on the web.
On tube amps tests in magazines this subject are hidden and not mentioned, when the equip use PCB.   
I especially hate PCB, some reasons:
> PCB traces are no OFC copper or silver, only cheap lead solder.
> PCB traces may loose and corrode with the hi heat from tubes and fast coolling after turn off.
> Change a tube socket in a PCB are awful, some tube socktes lasts around 5-10K hours only, before starting false contact and need replace.
> PCB are convenient, practical to made a tube amp, to simplify the work and may give hi profit to a manufacturer.
Regards
Hi FULLRANGEMAN and all.
Well said and I agree 200% with you.
Even Audio Note Kits uses PCBs...
For me, I only want to buy units with point to point wiring.
If you want to keep your equipment for the next 50 years, PCB is definitely not the way to go.
The amplifier I bought from Blair at Niteshade Audio is a 100% point to point and I like that.
Have a nice day.
Guy 13.

Niteshade

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Re: Point to Point or Printed Circuit?
« Reply #11 on: 28 Aug 2010, 10:50 am »
I can't help but agree with the content of all the posts. Confusing?  :duh:

Well- not really. Wiring/hookup technologies are usually abused.

Reasons for abuse:
1] To make things look tidy
2] To save production costs regardless of repercussions

Some observations from both camps:
1] PC's should not have sockets soldered to them that are large

2] Wire twisting, looming, etc.. creates extra work and uses more wire than necessary much of the time AND makes repairs more difficult. It is necessary with some circuits, generally not audio.

3] My favorite PC's use surface mount components for at least 95% of the components. A PC board made with SM components that is not plated through for leaded components is not bad to work with and will work very well even with tube audio.

4] P-P runs should be direct. That means wires should go directly from point A to B or at least as close as they can. This method is not as pretty looking as twisting or looming but works the best every time. Scott, Fisher, Conn, Hammond and many others used this approach and so do I.

What would think of a "hybrid" wiring approach? Marshall's 9005 1990's EL34 amp did it well. The PC's were well made modules and all sockets were mounted on the chassis.

Good ideas are often twisted and made into bad ones. I was thinking that the proper(let's make that ideal) use of both techniques may please the PC and P-P camps.

Guy 13

Re: Point to Point or Printed Circuit?
« Reply #12 on: 28 Aug 2010, 11:28 am »
I can't help but agree with the content of all the posts. Confusing?  :duh:

Well- not really. Wiring/hookup technologies are usually abused.

Reasons for abuse:
1] To make things look tidy
2] To save production costs regardless of repercussions

Some observations from both camps:
1] PC's should not have sockets soldered to them that are large

2] Wire twisting, looming, etc.. creates extra work and uses more wire than necessary much of the time AND makes repairs more difficult. It is necessary with some circuits, generally not audio.

3] My favorite PC's use surface mount components for at least 95% of the components. A PC board made with SM components that is not plated through for leaded components is not bad to work with and will work very well even with tube audio.

4] P-P runs should be direct. That means wires should go directly from point A to B or at least as close as they can. This method is not as pretty looking as twisting or looming but works the best every time. Scott, Fisher, Conn, Hammond and many others used this approach and so do I.

What would think of a "hybrid" wiring approach? Marshall's 9005 1990's EL34 amp did it well. The PC's were well made modules and all sockets were mounted on the chassis.

Good ideas are often twisted and made into bad ones. I was thinking that the proper(let's make that ideal) use of both techniques may please the PC and P-P camps.
Hi all.
Why do they always have to change everything in the name of improvement. I am happy with point to point wiring, why change ? There is nothing wrong with it, it works well !
They say PCB will save money ? Who will save more money ? The manufacturer or the customer ? Many times the manufacturer does not pass on the saving to the customer.
I don't want to change, I like it like that, what's wrong with that ?
I am stubburn, norrow minded, old fashion, well that's me and I like it like that.
Audiophiles are going back to vacuum tube amplification, why not also stay with point to point wiring ? It as provent itself reliable for decades.
That's my opinion for what it's worth.
Have a nice day.
Guy 13.

JohnR

Re: Point to Point or Printed Circuit?
« Reply #13 on: 28 Aug 2010, 11:31 am »
Point-to-point wiring isn't all that reliable, actually.

Niteshade

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Re: Point to Point or Printed Circuit?
« Reply #14 on: 28 Aug 2010, 12:18 pm »
The whole point in a hybrid system would be to make a better product. PC's have contact issues if what's installed is heavy, thick-leaded or a socket and causes cracks in between the pad and solder. P-P issues are often related to solder flow and not weight or movement. Often several wires are put on a single lug in a P-P system. Judging the proper temperature and amount of solder that must be used is not easy. We don't want to damage components, insulation or bakelite supports yet want solid contacts.

Using the two techniques together and properly will make a good, clean, reliable circuit. I completely understand those who oppose either method. Has anybody ever had issues with properly designed PC's OR P-P circuits on a mechanical level? I bet not! On the other hand, I have had multiple issues with both when not used with only their strengths in mind. The idea behind any hybrid system is to take advantage of only the strong qualities and discard as many con's as possible.

Note: PC's, at least for us have to be outsourced. I doubt there would be any monetary savings.

One of my favorite commercial amps: The Marshall 9005 EL34 stereo instrument amp. I have seen very few amps put together like these that contain printed circuits. This is a hybrid wiring setup:



Their circuit isn't one of my favorites (though it does work well!). Look at the construction. WOW! She's a tank alright. Everything is fastened perfectly, the PC's are modules and fiberglass. No plated through holes makes repairs much easier. This is a very good example, but it's not entirely perfect. It can be improved upon. There are very few compromises here, if any.

srb

Re: Point to Point or Printed Circuit?
« Reply #15 on: 28 Aug 2010, 02:02 pm »
Blair,
 
Here is another hybrid that I mentioned earlier, a PrimaLuna integrated amplifier.  Point-to-point wiring, chassis mounted tube sockets and PCB's for sub-assemblies where it makes more sense.
 
Steve
 
PrimaLuna Dialogue Two integrated
 

DaveC113

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Re: Point to Point or Printed Circuit?
« Reply #16 on: 28 Aug 2010, 03:41 pm »
I think there has got to be some advantages in wire routing in pcbs... would be nice for an EE or a PCB designer to chip and and let us know. I bought a PCB to make a tube amp... a Simple SE from tubelab. It works perfectly with no noise at all right off the bat. I'm not sure I could have possibly done a better job if I recreated that circuit with PP wiring.... and I'm not so sure anyone could but maybe it is possible?

Wayner

Re: Point to Point or Printed Circuit?
« Reply #17 on: 28 Aug 2010, 06:47 pm »
Printed circuit boards can offer the smaller manufacturers some interesting advantages. First, it allows for sub-assembly, which simply can't be done with point to point wiring. Boards can even be purchased "stuffed" with all surface components pretested (CNC type QC), soldered and ready to go.

Careful designing can minimize noise and other issues one might associate with a PCB. It's also much easier to keep track of revisions in the board (or circuit) design. It will also speed up the assembly process, which means the product can be delivered to the customer in a more timely fashion.

Above all of this, is the toll it takes on assembly people, wiring amps point to point. It's mentally fatiguing and after doing 20, 30 or 50 amps, can drive one to the edge (or over).

Oh yeah, only small signal tube sockets should be installed on a PCB, no rectifier or output tubes because of the already mentioned weight and heat.

Wayner  :D

avahifi

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Re: Point to Point or Printed Circuit?
« Reply #18 on: 28 Aug 2010, 07:05 pm »
I have done thousands of both all hand wired and mostly PCB wired amplifiers over the past sixty years.

For a "one off" or very low volume production unit, hand wiring may be useful because the designer need not know how to design a good circuit board and be aware of all the pitfall therein.  Also this eliminates the up front PCB design, tooling, and de-bugging costs.

However, a well designed PCB circuit insures repeatable, consistent, and very quiet and durable operation.  Modern boards have very tough mask layers on top of the circuit traces, so that dust, moisture, and surface contamination is a thing of the past.  One writer herein is correct, it is harder to remove and replace tube sockets, but then again its not so easy to do that in hard point to point wired circuits either.  The "trick" in removing multi-pin parts from a circuit board is to simply cut all the leads as close to the body of the part to be removed as possible, and then remove the bloody stubs one at a time.  A absolutely essential tool for circuit board re-work is wooden toothpicks.  We often use these to open solder closed through holes based on the fact that you can't solder to a toothpick. :0  Unless, as my late wife once did when I told her I needed more toothpicks, brought me home a nice box of multi-colored plastic toothpicks.  Whoops.

Do note that the days of point to point wiring are becoming numbered as more and more high quality parts are become available only as surface mount devices.  Its really hard to do point to point bare wire layouts with surface mount parts.  :)

I have heard really great audio components both with point to point hand wired and with PC cards, and really lousy ones done both ways too.

Back when I was twelve years old and building my first Heathkits, my friends were in awe of the great audio system I put together all by myself.  They tried building the amp kits too and I almost always had to fix them, and that is how I got my start in this business.  One friend built a nice 20 watt per channel tube amplifier, and it worked, but if you even got near it and barely touched it, it went,  Boooooooong!

I looked inside.  Unfortunately nobody told him to cut the leads of all the resistors and capacitors inside short enough to make tidy point to point connections.  He was afraid that cutting a lead might ruin the part, and left all the leads untrimmed.  The internal layout was amazing, he actually fit all that extra lead length inside the chassis without anything actually touching or shorting out, however, it was microphonic city.  For him, a PCB design would have saved him hours of work.

I would suggest that is is really hard to get the degree of circuit shielding with a point to point layout as it is with a good multi-layer circuit board design incorporating a well engineered ground plane and grounding.

Hey guys, quick worrying about this and just pay more attention to the music.

Best regards,

Frank Van Alstine

bigjppop

Re: Point to Point or Printed Circuit?
« Reply #19 on: 28 Aug 2010, 08:42 pm »
I'm a big fan of the hybrid approach mentioned here (and shown in the Primaluna amp).  I think a well designed PCB is a great thing; keeps things where they should be, (hopefully) well thought out design, they can be done again and again the exact same way, etc.  The only thing I hate... sockets on the PCB. 

I built the Tubelab Simple SE that Dave built  (actually even copied much of his chassis design) and I love that amp; I just hate the the sockets are wired to the board.  That's pretty much the only thing keeping me from building all the other amps Tubelab sells.

PCB's can be great things; use them for what they're good for and use point to point for areas where it excels.  Sticky to one particular design philosophy purely on principle is crazy.  Take the best of everything.