Hook-up Wire for Hard Wiring a Power Amp?

vdi_nenna

Member
Paid Member
2000-10-10 7:27 pm
PA, USA
I want to hard wire my next amp project. There isn't a PCB for the design, but there are few components, so I want to hard wire it. Can anyone recommend a wire gauge? Stranded or solid? Stranded would be more flexible, I guess? Would you use a higher gauge for the input circuit and a lower gauge for the power stage? Or, would you use a single gauge throughout? The amp runs on a constant current of 3 amps. It's a 2-stage, single-ended output amp.

Is there any specific brand of wire you would recommend? I'd consider anything, but Cardas. It's tough to work with.

Lastly, can anyone recommend a grounding technique for power amps? Would Star-grounding be ok??

Thanx!

Vince
 
Hardwireing an amp is ok, as long as You use as thick a wire as possible for high current, and thin wire for small currents.
Stranded or solid is more a matter of tast/religion than science. Personly I prefere solid, but only because it can be made to look nicer than a casual bundle of stranded wires.
Brand or no brand is a matter of sonic fit or misfit with the total performance of Your system, so try different ones, and be prepared for surprises. Perhaps it is the cheapest one that fits the best.
Star-grounding is probably the best grounding method, but can be performed in various ways. Not all of them may work in Your project, so good luck ;o))
 
I have built several amps using point to point wireing and the best advice I can give is use a copper chassis or if that is not available (proably) use some copper strap to tie all the grounds together. I have been able to get this form a large electctrcal wholesale house that caters to the local electricians. Also check with the engineers at AM radio stations since they use this strap in thier antenna grounding systems. A peice of 3" strap has a lot less resistance that the usall aluminum chassis. Solder all your grounds directly to the copper. Most PCB projects can cause more problems than they solve if the design isn't done correctly.
 
Wire / Grounding

Hello,

Can also make a fair stargrounding point by taking some solid 10 gauge wire (~3 to 5 inches) and mount each end of it to a good sized screw (with paint scrapped away. Then bend the wire so is a positioned well to solder all your other grounds to. Comes out a a sort of U shape and makes for a good common ground point.

Regards,
Greg
 
"Bus" must only be grounded at one end

I am thinking of using the bus systems myself, but it is imperative that there is only one point of contact between all internals and ground. The reason for this is that one point does not allow current to flow -- which is exactly what we are trying to achieve. Connect it two places and you don't have star grounding.
 

vdi_nenna

Member
Paid Member
2000-10-10 7:27 pm
PA, USA
I'm thinking about buying bare pure silver wire and twisting my own gauges then putting it teflon tubing. I heard you can get 220 ft of (I think) 28 AWG pure silver from a jeweler in NY for less then $25 a spool. About an oz or 2.

I decided to build the Hoffman amp w/ some Pass variations in the circuit. The power supply will be based on the Aleph power supplies entirely.

Thanks for all the comments.
 
Silve Wire

Vince,

From what I've been reading and finding in signal carrying wires is that silver wires (or copper, for that matter), should be individually insulated before bundling together. I'm considering making my own sets of interconnects and speaker wires from silver runs, but every place I've read recommends individual insulation first. Just a heads up...
 

vdi_nenna

Member
Paid Member
2000-10-10 7:27 pm
PA, USA
Silver wire

I guess that's why some, like Cardas enamel each wire in there bundles. I don't like that. It's hard to work with I think.
But what you were saying...
maybe their isolation is used for the same reason you mentioned, but why, capacitance, dielectric(sp?) reasons or skin-effect? I don't know. Maybe it's just a design preference?

Funny thing is, I made CAT-5 speaker cables using the method you described, but it called for removing the jacket. I just braided them as is. They sound better then the Audio Quest F-14 cable I have. So far that's all I've compared them to, but I have a set of AQ 11 AWG w/ 8 solid wires per bundle I want to run my CAT-5 against.

Who knows?

Thanks for the input!!

Vince
 
Individuall insulated conductors

Vince, When I spoke to a few vendors like Audioquest, Cardas, etc., what I was told is that the individual conductor insulation removes the "grain" heard with "regular stranded" speaker wires. The grain was supposedly caused by the interaction of the bare conductors physically touching one another for the entire run of the cable...

I've seen many articles on using CAT5 for speaker wire, although there are different flavors of the recipe. What I've found most often calls for removing the outer jacket of the entire CAT 5 bundle, and then braiding the resulting insluated twisted pairs. I've heard claims that simply braiding entire sections of CAT5 "out of the box" without removing the outer jacket does not perform as well.

The trouble is that there are just too many variations and combinations to be able to try and compare them all for yourself (unless I quit my job...). I've had some interest in the CAT 5 speaker wire for a while, and then I came across the refernces for using silver rather than copper conductors. Chris VenHaus' plans for silver interconnects looks interesting, as do other plans for silver speaker wires. Although sources vary in actual braid/non-braid techinques...

The silver interconnects look inexpensive enough to build, but the silver speaker wires look a good deal more expensive to derive a somewhat heavy gauge from bundling such thin wires.
 

linuxguru

Member
2007-09-21 6:28 am
CAT-5/5e or CAT-6 OFC (Oxygen-Free Copper) cable is probably as good or better than silver for all practical purposes, and is dirt cheap - small lengths of scrap cable can often be had for free from IT depts., etc. Silver tarnishes easily; insulated OFC is very durable and the bare surface doesn't tarnish easily.

I use single strands as general purpose hook-up wire, and twisted pairs for short collector-emitter hookups, speaker-connector hookups, etc. OFC has one other advantage over stock Cu - it wets and solders much better.