Any Reason To Avoid Brass For Bus Bar?

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Phil_S
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Re: Any Reason To Avoid Brass For Bus Bar?

Post by Phil_S »

briane wrote:I often strip and use copper romex. its cheap and good, just put in a vise and pull on the end with pliers and that seems to make it pretty straight.
-b
Me too. Works great. Not quite as neat as a bar, but easy to solder. No one is looking inside when the amp is in use. Besides, that bit of irregularness is good for even order harmonics. :o
Mitch Roberts
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Re: Any Reason To Avoid Brass For Bus Bar?

Post by Mitch Roberts »

In my Bassman build I used some very heavy guage copper flashing I had on hand. Seemed to work very well. You can see the copper color where the typical Fender brass plate would go.

[img:1023:764]http://i863.photobucket.com/albums/ab19 ... G_0453.jpg[/img]
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statorvane
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Re: Any Reason To Avoid Brass For Bus Bar?

Post by statorvane »

I often strip and use copper romex. its cheap and good, just put in a vise and pull on the end with pliers and that seems to make it pretty straight.
Ditto.
TUBEDUDE
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Re: Any Reason To Avoid Brass For Bus Bar?

Post by TUBEDUDE »

I use 6 gauge bare copper off the large roll at Home Depot. I run the bus in an L shape down the row of pots and bent 90 to the power supply. I coat it with WBT silver solder to avoid oxidation. I do have to use my 300W Weller solder gun to make the ground connections however, but there's not a milliOhm of difference from one end to the other.
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M Fowler
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Re: Any Reason To Avoid Brass For Bus Bar?

Post by M Fowler »

My favorite copper bus is that stranded copper wire that comes with lighting chain swag kits. It tins nice and is just the right diameter. I need to get out to a store and shop for some, I'm out.

Mark
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rp
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Re: Any Reason To Avoid Brass For Bus Bar?

Post by rp »

Glad this came back up, first the good question:

If all my HT, signal, and ground wiring is 20 or 22awg and my component leads are all modern (small and dinky) what is the need for a big hunking piece of bus? Were talking 12"-14" tops here, shouldn't any gauge that offers the structural support needed be enough, even if it's only a 20awg rod? This has been bugging me for years so I hope someone has a good answer.

Also for the raw copper guys, doesn't that raw copper turn green down the road? Then what, don't you have to scrape or steel wool before you can do mods or repairs? Isn't that a PITA? I used real silver plated hook-up once and never again.

As for tinning your own romex etc. good Kester solder is too expensive to waste on tinning, I'd rather just try and find a pre-tinned piece of bus or just live with the otherwise excellent square stuff from AES. BTW found this at Tube-Town and I'll be ordering a length and see what it is. It says silver but I hope it's just tin. I emailed but their reply was ambiguous, don't think they understood my concern, maybe someone here knows. As I mentioned, silver sucks, turns all black.

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Cliff Schecht
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Re: Any Reason To Avoid Brass For Bus Bar?

Post by Cliff Schecht »

The wires that carry high voltage are all low current. The opposite is true for wires (and buss bars) that carry the ground return currents from the OT secondary. These can be in the amps and need big fat conductors to handle the current without inducing a voltage drop (and hummmm). I typically run a wire from the output jack to the buss bar so that I'm not relying on the chassis to carry any current.
Cliff Schecht - Circuit P.I.
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martin manning
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Re: Any Reason To Avoid Brass For Bus Bar?

Post by martin manning »

I like the square tinned stuff from AES. Both copper and brass will tarnish eventually, and might well require cleaning to get a good solder connection down the road. Note that the brass grounding plate in old Fenders is a common source of problems. My last couple of amps have no bus per se, just wires from local grounds to chassis star points. For the panel pots it's easy enough to connect the grounded lugs in sequence with hookup wire, and then finally to a chassis ground at the input end of the chain.
Last edited by martin manning on Thu Oct 04, 2012 11:48 am, edited 1 time in total.
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rp
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Re: Any Reason To Avoid Brass For Bus Bar?

Post by rp »

Cliff Schecht wrote: I typically run a wire from the output jack to the buss bar so that I'm not relying on the chassis to carry any current.
I never gave the OT secondary ground much thought. My knowledge is limited but luckily my instincts are good -> images
martin manning wrote:I like the square tinned stuff from AES... For the panel pots it's easy enough to connect the grounded lugs in sequence with hookup wire, and then finally to a chassis ground at the input end of the chain.
The square stuff's great but you'd get a much tighter wrap-around if it was round. I give each pot that has a ground conection a home run rather than daisy chain, doubt it matters but I haven't had a grounding problem in ages and it makes it easier to remove a pot. I don't bother with the cases. The pot has a nut and a star washer, no more no less than the chassis earth, HT ground, and heater ground. Should a pot come loose it'll get tightened.
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Last edited by rp on Fri Oct 05, 2012 3:40 pm, edited 1 time in total.
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Structo
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Re: Any Reason To Avoid Brass For Bus Bar?

Post by Structo »

I think a common mistake among people just starting out is to use a large gauge buss wire.

The problem being it takes a lot of heat to get it up to soldering temperature.

14 gauge copper wire is fine.
It has a current capacity of 32 Amps.

16 gauge is 22 Amps.

14 ga is a good size since it stiff enough to be a good buss wire and small enough to solder to easily.
Tom

Don't let that smoke out!
TUBEDUDE
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Re: Any Reason To Avoid Brass For Bus Bar?

Post by TUBEDUDE »

for grounds and large gauge wire, orany massive heat sinking connections, i use the Weller 300 watt soldering gun. It's quick and easy, heats up in 4 seconds and makes the connection immediately, so you don't overheat the work. It might sweat pipes together also.
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rdjones
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Re: Any Reason To Avoid Brass For Bus Bar?

Post by rdjones »

rp wrote:
Cliff Schecht wrote: I typically run a wire from the output jack to the buss bar so that I'm not relying on the chassis to carry any current.
I never gave the OT secondary ground much thought. My knowledge is limited but luckily my instincts are good -> images
Ideally, the low side of the OT secondary should be connected directly to the output jack sleeve so there's no low impedance (high current) signal running through the chassis.
Some situations like the early Deluxes where the secondary is bonded to the transformer frame require some current to pass through the chassis but this can be minimized.

RedDog Steve
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