PT Wire Gauges?

[Roadrunner]

I had a little debate with a friend last night about power transformers and the wire guages one should use. He seems to think that the whole thing: heaters, 5 or 6v.AC, B+, and the other side with the 120v, 220v, 240v. ... can be handled with 22ga. topcoat, 600v. wire.

I'm a fan of larger gauges, like 14 or 16ga. for the heaters and the AC current. My friend said, "nah, you don't need to do that."

Who's right... or does it really matter?

Just wondering...

[PCollen]

I had a little debate with a friend last night about power transformers and the wire guages one should use. He seems to think that the whole thing: heaters, 5 or 6v.AC, B+, and the other side with the 120v, 220v, 240v. ... can be handled with 22ga. topcoat, 600v. wire.

I'm a fan of larger gauges, like 14 or 16ga. for the heaters and the AC current. My friend said, "nah, you don't need to do that."

Who's right... or does it really matter?

Just wondering...

Your friend is correct, for most amps...22AWG is rated for 7 amps and 20AWG for 11 amps, for chassis wiring. A typical 50 watt amp won't draw 7 amps heater current, while a 100 watt amp may, depending upon the type of power tubes used and number of other pre-amp tubes. Calculate your current needs and refer to this chart for wireguage requirements:

http://www.powerstream.com/Wire_Size.htm" onclick="window.open(this.href);return false;

However, for this amp, you just may need 16 or 14 AWG.... ....

http://www.youtube.com/watch?v=SY7mvH8wFdE" onclick="window.open(this.href);return false;

[VelvetGeorge]

Yep, 22g is good for 7 amps. Which meets specs for any 50 or 100 watt amp. Even still, I do like larger gauges for the output tube heater wiring in 100's.

george

[Roadrunner]

Thanks for the comments guys... I appreciate the input!

PCollen: cool site link... thanks man!

[StuntDouble]

Yep, 22g is good for 7 amps. Which meets specs for any 50 or 100 watt amp. Even still, I do like larger gauges for the output tube heater wiring in 100's.

george

George,

Do you hear a difference between the two? Is there a tonal difference b/w 22ga and 18ga wire for the heaters to the output tubes or would it be more of a difference in feel as far as how the amp responds?

I lovingly, painstakingly wired my heaters the other night and realized that I used 22ga 600v wire. I'm thinking that 22ga wire might result in a little more sag, which I want, but I'm not sure what the tonal effect would be, if any.

[rsi]

22AWG has a resistance of 0.001375 ohms per inch or 0.0165 ohms per foot.

18AWG has a resistance of 0.000543 ohms per inch or 0.00651 ohms per foot.

At 3 amps the difference in voltage drop would be:

(3*0.0165)-(3*0.0065)=
0.0495 volts - 0.0195 volts=

~0.03 volt difference in drop or "sag" between 1 foot of 22AWG and 18AWG heater wiring.

I am not saying it makes an audible difference or not...just the facts.

[ClassicTone]

As a amplifier transformer manufacture, we generally determine the lead wire size used on a power transformer based upon the magnet wire being used with that connection or the next lead wire size smaller (examples: with 20 gauge magnet wire, we would use 20 gauge lead wire or with 21 gauge magnet wire, we would use the next available size smaller of 22 gauge). We think this will provide a better and beefier connection since the magnet wire and lead wire sizes are matched more closely to each other.

ClassicTone By Magnetic Components, Inc.
http://www.classictone.net" onclick="window.open(this.href);return false;