point-to-point vs board: difference in SQ?

[euclid]

hi, im planning out a home 2ch setup. as a guideline im looking to build a preamp, power amp, and headphone amp.

havnt decided on integrated pre/power, pre/headphone, or are all seperates with 2 mono powers. i would like to do tubes and this leads me to my question.

would a custom point-to-point wired tube amp have any benefits over buying a circut board kit? i'd think the circut would be alot less work but point-to-point just seems like alot of fun w/ a very high sense of accomplishment!

i was inspired by the cayin ta30 is saw on TAD website. if anyone can give me info on this i'd appreciate it. thanks.

 

[Banfi T.]

Hi euclid,

welcom to the head-fi.org and sorry for your wallet.

I used to build to my preamps and headphone amps PCBs (that is Printed Circuit Board) and altough they were fun to make they are not too versatile. You decide the circuit, build it and that is it. Even the smallest change requires often a new board. On the other hand working with point-to-point wiring using test boards gives much more freedom. So it is up to you. If you like to thinker with things I would go to point-to-point. If you are about to build a certain kit and you do not want to change anything in it, go for the printed board. Also, if you are a complete beginner with electronics, then I would suggest to choose the complete kit with board.

As for the sound quality the point-to-point wiring gives more choise regarding the connection material, and it can be better than the printed board. But too complicated circuits can not be build in this way, things become too clumsy. That is why this technology is mostly used with tubes (mininal part count.) However, if you are a beginner stay away for tubes. I build my solid state ampifiers using point-to-point but I can consider myself an experinced builder and even so in the middle of the building I alway swear to myself, the never again...

P.s.: Component placing and signal tracking can alter the sound quality very seriously. So again, if you are a beginner, choose the proven complete kit. Otherwise you lose that small advantege you could have with better connection materials elsewhere.

 

[amb]

All valid points, but I should also point out that a "designed" PCB allows such things as ground planes or power planes. These have performance benefits in some circumstances that cannot be realized with p2p wiring.

 

[Banfi T.]

That is also correct. With too many parts you can be almost sure you make a ground loop somewhere. (You so don't want to have one...) Also tube circuits have high impedances all over the network so they are easily affected by electrical pollution. I really like to work point-to-point and do not want to sound too negative but it is not an easy path, which I assume you start too feel anyway

 

[rickcr42]

Quote:

would a custom point-to-point wired tube amp have any benefits over buying a circut board kit? i'd think the circut would be alot less work but point-to-point just seems like alot of fun w/ a very high sense of accomplishment!

Printed circuit boards are a must for the new generation of tiny chips but for discretes or tubes PTP is better.
What a board offers is repeatability of the circuit for either mass production manufacture,for those not able to do a PTP layout or for sale so others can build an identical amp to the original design without having any layout skills of their own.
Before all the recent board offerings there were far fewer amps being made by amatuers.
Kits use PCBs out of necessity not because the end product is superior.Manufacturers use them even in simple designs so the product can be repeated over and over to exact specifications by unskilled labor.

PTP done right is superior in my opinion and is infinately easier to update or change parts later but only if you build with all potentialities in mind and use good layout technique.

Quote:

allows such things as ground planes or power planes. These have performance benefits in some circumstances that cannot be realized with p2p wiring.

it is my personal opinion that you get an inherently better and cleaner (eddy currents and such) ground by using an individual wire to a central ground buss or even by using "global" grounds where each circuit block has a ground connection of everything in that group then that "group" ground goes to the central ground.

To keep the layout tidy use turret boards and chassis mount tie points for connections and attempt to use right angles for wiring which is in turn bundled into groups with tie straps for neatness.

for a good example of how it should be done check out the DRD amps at the Wellborne Labs site and also look at the turret board offerings.Nice parts for PTP (their solder is not too shabby either)

 

[euclid]

thanks to all for welcome and helpful replies. my cash is already DOA, i might actually GET something for it if i start building my own equipment.

i completely understand the work involved in the point to point process, i am more concerned about the engineering aspect than the labor and organization involved in the wiring. i dont have an electronics background and im hoping to find some schematics of proven designs to :cough: copy.

with that said i am going to start with the m^3 and steps. i think that build will teach me a wealth of information about the process... hopefully it wont deter me from a few p2p tube builds as well.

im going to keep reading ad hopefully with in the next few weeks i can post some pics of my first build.

also, is it elluding me or is there no search function on these forums?

 

[Fresno Bob]

http://www6.head-fi.org/forums/search.php? this should help

 

[rickcr42]

Quote:

also, is it elluding me or is there no search function on these forums?

heh,look at the top of every page the blueish tool bar:

user cp----faq----member list----calender---new posts--SEARCH---quick links-----log out

it's right there man

 

[euclid]

wow i do see it now, i definately looked there before b/c this forum is setup the same as xtremesystems.org

i just registered so its possible it wasnt ulocked untill i became a member???

 

[Banfi T.]

You can't search prior to registering.

 

[rickcr42]

I did not know that.I registered on day #2 of Head-Fi's existance and at that time there was nothing to search there being only a handfull of refugees and not much more than "Hey ! You here too ?"

 

[rickcr42]

BTW-PTP done right.simply beautiful if you are into seeing the "undies" of an amp well done :

from here :

http://www.welbornelabs.com/drd.htm

 

[amb]

Quote:

Originally Posted by rickcr42 BTW-PTP done right.simply beautiful if you are into seeing the "undies" of an amp well done

That's all very nice, but you won't get anything looking like it if you're dealing with integrated circuits with even moderate pin-density!

 

[PinkFloyd]

Quote:

Originally Posted by rickcr42 PTP done right is superior in my opinion and is infinately easier to update or change parts later but only if you build with all potentialities in mind and use good layout technique.

Indeed, and if using cranky opamps like the LM6171 good layout techniques and very short (shielded or twisted) cable runs are essential unless you want a visit from the oscillation god.... I've built a few of them and unless you keep the wiring to an absolute minimum and keep it short and tidy it acts as an antenna and tunes into radio OG (oscillation god) The LM6171 is one instance where P2P must be very well thought out and very well implemented.

Mike.

 

[rickcr42]

Quote:

That's all very nice, but you won't get anything looking like it if you're dealing with integrated circuits with even moderate pin-density!

read my first response to the thread where I suggested PTP for discretes and tubes and not for integrated circuits,though even there if DIPs are used dead bug is an option for the adventurous.