1 ohm resistors in the output tubes for biasing

Tatosh · Post by **Tatosh** » Mon Jan 02, 2006 7:12 pm

I was wondering about this, since I need to add these to my amps. 1 ohm, but what about watts? 1 watt? 1/2? 5? I already bought 4 1 watt ones. is this ok?

I was also wondering about the installation. George says that you should put it between pins 1 and 8, and then to ground (which I guess would be the bolt where the socket connects to the chasis, right?). in a Rockstah post he mentions joining pins 1 and 8, THEN puting the resistor between pin 1 and ground. It also mentions that this might be better. Which is best?

If I use this method, the pins 1 and 8 are already joined in my amp, for grounding. can I then just add the resistor and not do anything else? in which pin would I need to put the multimeter then? (I know in George's method it goes in pin

Last, regarding the filter caps, using alligator clips. the amp should be turned off? plugged???? Suppose I put one alligator clip to the turret with the 100watt resistir that also joins the .022 cap. Can I put my multimeter there also to check how the filter caps discharge?

I want to be sure.

Thanks in advance guys, I am learning a lot!!!!

OnTheFritz · Post by **OnTheFritz** » Mon Jan 02, 2006 7:26 pm

These are the ones I bought from George:

http://www.metroamp.com/store/product_i ... cts_id=279

Not sure about where it's best to have the resistor though, I just did it as per George's instructions. I'm sure someone will chime in with the best method.

rockstah · Post by **rockstah** » Mon Jan 02, 2006 7:33 pm

Tatosh wrote:I was wondering about this, since I need to add these to my amps. 1 ohm, but what about watts? 1 watt? 1/2? 5? I already bought 4 1 watt ones. is this ok?

I was also wondering about the installation. George says that you should put it between pins 1 and 8, and then to ground (which I guess would be the bolt where the socket connects to the chasis, right?). in a Rockstah post he mentions joining pins 1 and 8, THEN puting the resistor between pin 1 and ground. It also mentions that this might be better. Which is best?

If I use this method, the pins 1 and 8 are already joined in my amp, for grounding. can I then just add the resistor and not do anything else? in which pin would I need to put the multimeter then? (I know in George's method it goes in pin

i believe George chimed in on this that he used this method for different power tubes and it being universal - although with the information i found it was particular to el34 amps - pins 1 and 8 are tied together and the resistor goes from either pin since they are connected to ground - i left enough of the resistor to pin 1 that i connect my meter there when biasing ...or on the either of the pins if you like -

Billy Batz · Post by **Billy Batz** » Mon Jan 02, 2006 7:49 pm

Putting it between 1 and 8 then having 8 to ground then you cant read the voltage to bias. The resistor has to go between 8 and ground if nothing else. The way I do it is to tie both pins together with one leg of the resistor and have the other leg to ground.

Guest · Post by **Guest** » Mon Jan 02, 2006 8:58 pm

Billy Batz wrote:Putting it between 1 and 8 then having 8 to ground then you cant read the voltage to bias. The resistor has to go between 8 and ground if nothing else. The way I do it is to tie both pins together with one leg of the resistor and have the other leg to ground.

I was thinking on just unsoldering the ground, then soldering one leg of the resistor to that and the other leg to ground. That way I can use the part that is already tying together pin 1 and 8. That way I can check the bias on pin 8 right?

Santiago.

rockstah · Post by **rockstah** » Mon Jan 02, 2006 8:58 pm

Billy Batz wrote:Putting it between 1 and 8 then having 8 to ground then you cant read the voltage to bias. The resistor has to go between 8 and ground if nothing else. The way I do it is to tie both pins together with one leg of the resistor and have the other leg to ground.

the way i did it was to clip off a small piece of the resitor lead and bend it into a small horseshoe,..use that to connect pin 1 and pin 8 together then place the resistor on pin1 and to ground

Billy Batz · Post by **Billy Batz** » Mon Jan 02, 2006 9:16 pm

Just as long as pin8 is not shorted directly to grounbd its fine. Otherwise the current from the cathode is not going through the resistor and you cant bias. Not that way anyway.

sub · Post by **sub** » Mon Jan 02, 2006 10:07 pm

i'm confused now

Which is correct?

Pin1 -> res. lead -> pin8 -> resistor -> ground
pin8 -> res. lead -> pin1 -> resistor -> ground
pin1 -> resistor -> pin8 -> ground
pin8 -> resistor -> pin1 -> ground

Thanks

Sub

novosibir · Post by **novosibir** » Mon Jan 02, 2006 10:15 pm

Simly ty pin 1 and pin 8 together and go with the resistor to ground! No matter in this case, whether from pin 1 or from pin 8, because both are together (not married

)

Larry

sub · Post by **sub** » Mon Jan 02, 2006 10:22 pm

novosibir wrote:Simly ty pin 1 and pin 8 together and go with the resistor to ground! No matter in this case, whether from pin 1 or from pin 8, because both are together (not married )

Larry

..............

Danke schön Larry!

Sub

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1 ohm resistors in the output tubes for biasing

1 ohm resistors in the output tubes for biasing

Re: 1 ohm resistors in the output tubes for biasing