Anyone have any 1 ohm 2 watt precision resistors they want to sell?

[Slobrain]

Man,

I cannot find these anywhere without some minimum order from some of the different companies.

Anyone have any of these they want to sell, Its for biasing my tubes in different amps.

Thanks

[Slobrain]

Never mind, I found the 1 ohm, 3 watt at 1% at mouser, Bought enough to last for a good while...

[bob p]

3W is what I was going to recommend when I saw this thread's title. I also stocked up on 3W when I had to do my shopping. Glad you found a good answer.

[Slobrain]

Hey Bob,

I have new power tubes coming from New Sensor and need to set up the bias on three different amps once I get these. I have home made bias adaptors that only work for the 6L6 but I need to set one amp up for EL34s. I sure hope the Russian made Mullard EL34 is good, Seems that the JJ 6L6 are getting horrible. Just had a set go belly up in my bandmaster, looked like fireworks inside the bottle, yikes.....

[Bruce / Mission Amps]

Never mind, I found the 1 ohm, 3 watt at 1% at mouser, Bought enough to last for a good while...

Curious as why you need 2 watt or 3 watt for this....?

[Slobrain]

Curious as why you need 2 watt or 3 watt for this....?

Hey Bruce, I just didn't want these to open up when cranking up the amps. What would have been a better choice for a 50 watt amp?

Slo

[Enzo]

It isn't like they are wrong somehow, it just seems sorta like using huge welding cable as a power cord for a table lamp.


Use Ohm's Law. If you use a 1 watt 1 ohm resistor then it takes 1 whole ampere of current for the resistor to dissipate 1 watt. And it will do that forever. It takes even more current to heat the resistor up to the point it will fail. Even if your amplifier power supply can provide a whole amp, the only way this would flow through the resistor is if the tube fails. No power amp peaks are going to cause sustained currents remotely close to those levels.


Having said that, I like to use larger than necessary resistors for this simply because I find it easier to get a clip lead on them during tests.

[jbltwin1]

I use 1 watt 1 ohm simply because those were what I found first! I have installed 1/2 watt with no ill effects. Like Enzo says though, the bigger they are, the easier they are to work with.

[Bruce / Mission Amps]

Yeah, I was only going to point out that a 1 ohm, 1/2 watt 1% resistor (on each socket) is probably fine for this use and much, much easier to find.

[pdf64]

And I find it beneficial when they blow open in the case of a tube shorting; they tend to go much sooner than a T0.5A on the B+ winding.

[bob p]

I assume that everyone posting here is familiar with ohms law. That is to say, if I've figured this out, then I have to assume that everyone else has figured it out too.

I used the higher rating resistors because that's what was available when I was looking.
for some reason low power 1% precision resistors weren't available where I was looking.
Considering how many I needed to buy, the higher price for the higher power rating didn't bother me. it was actually cheaper to buy higher power resistors from the vendor that i was already ordering from, than it woudl have been to place a separate order for a cheaper part with another vendor. sometimes it just makes sense to buy the wrong thing.

[Enzo]

Oh certainly. Same thing shopping price on same parts, some cap might be 30 cents more at Mouser than at Allied, but it would be the only part I;d be getting at Allied while Mouser was filling a more substantial order, so I pay more for the part to save overall.


And this may be heresy, but I don;t even worry about the 1%, after all, nothing else about a guitar amp has that much precision, I am not too concerned if my bias is off a milliamp or two. Can you imagine worrying about 1% tire pressure gauges and fretting over a couple millibars of tire pressure? 1% resistors are pretty cheap nowdays, so if they are within a few cents, why not, but I won't pay much extra for them.

[bob p]

I sure can't see the point in buying wide tolerances. 5% CF resistors aren't very different in price from 1% MF resistors, so I just buy 1%.

but then I can't see any reason to buy CC resistors, so maybe my opinion isn't mainstream.

[Slobrain]

How about the best solder to use? non cancer causing....?

Well I always have used a 60/40 rosin core but now seeing on EBay the 63/37 rosin core from China. I wonder what the best solder to really use on guitar amps would be? Maybe something non cancer causing????

A buddy has stage 4 throat cancer and in the last months of his life, after seeing him go thru this horrible nightmare it makes me wonder should I have not breathed those fumes while soldering all these years?

[bob p]

there's no question about it -- you shouldn't breathe solder fumes. they don't provide you with any benefit, so why do it? i make a conscious effort not to breathe them, and to have an exhaust fan going.