Bias Probe & Plate Voltage Probe?

[sixstrings]

While shopping for an affordable bias probe, I came across the Amp-Head bias probe that has a switch to let you test plate voltage. Is this really necessary for the average amp user, or will a bias probe be enough just for replacing tubes in your amps?

 

[sixstrings]

Ok nevermind. The Eurotubes video answered my question. Ground the black multimeter probe and touch the 3rd pin to the right of the guide pin using the red multimeter probe. Sounds pretty simple for determining plate voltage. Cool!

 

[Death by Uberschall]

Get the Weber Bias Rite, it does both.

 

[Marshall Law]

BIAS RITE are awesome and very easy to use

 

[MrDan666]

Ok nevermind. The Eurotubes video answered my question. Ground the black multimeter probe and touch the 3rd pin to the right of the guide pin using the red multimeter probe. Sounds pretty simple for determining plate voltage. Cool!

Yes you can measure plate voltage that way. You need to set the DMM to read DC Volts in the highest range possible on the meter. Usually the 500v or higher setting.

Buy some insulated croc clips instead of using the multimeter probes. Trust me on this. It makes things easier as not all of us have very steady hands. If you slip with the meter probe and short the plate voltage to ground, you're gonna have instantly blown tubes on your hands and possibly a shorted out socket that would have to be replaced afterwards. Not fun!!

If you use croc clips, you can just clip it to the Pin 3 and then you don't have to worry about it

 

[sswanson]

Get the Weber Bias Rite, it does both.

These are worth every penny.

 

[sixstrings]

Ok nevermind. The Eurotubes video answered my question. Ground the black multimeter probe and touch the 3rd pin to the right of the guide pin using the red multimeter probe. Sounds pretty simple for determining plate voltage. Cool!

Yes you can measure plate voltage that way. You need to set the DMM to read DC Volts in the highest range possible on the meter. Usually the 500v or higher setting.

Buy some insulated croc clips instead of using the multimeter probes. Trust me on this. It makes things easier as not all of us have very steady hands. If you slip with the meter probe and short the plate voltage to ground, you're gonna have instantly blown tubes on your hands and possibly a shorted out socket that would have to be replaced afterwards. Not fun!!

If you use croc clips, you can just clip it to the Pin 3 and then you don't have to worry about it

Thanks, I'm going to do that.

 

[sixstrings]

Get the Weber Bias Rite, it does both.

These are worth every penny.

I'm going to buy one of those very soon, but for now I need something cheap to get by. I have two amps I need to replace tubes in.

 

[renato-rt]

Ok nevermind. The Eurotubes video answered my question. Ground the black multimeter probe and touch the 3rd pin to the right of the guide pin using the red multimeter probe. Sounds pretty simple for determining plate voltage. Cool!

Yes you can measure plate voltage that way. You need to set the DMM to read DC Volts in the highest range possible on the meter. Usually the 500v or higher setting.

Buy some insulated croc clips instead of using the multimeter probes. Trust me on this. It makes things easier as not all of us have very steady hands. If you slip with the meter probe and short the plate voltage to ground, you're gonna have instantly blown tubes on your hands and possibly a shorted out socket that would have to be replaced afterwards. Not fun!!

If you use croc clips, you can just clip it to the Pin 3 and then you don't have to worry about it

I'm trying to adjust the bias of a DSL 50 with a multimeter. It's quite easy and can pretty much be resumed as described here:

http://eurotubes.com/euro-Marshall-DSLTSLV.htm

https://www.youtube.com/watch?v=1CSZEjoWjgs&feature=fvsr

The only problem is that those 2 videos don't mention how to measure the plate voltage.


"Ground the black multimeter probe and touch the 3rd pin to the right of the guide pin using the red multimeter probe. Sounds pretty simple for determining plate voltage."

That's exactly what is described to measure the second power tube bias. What am I missing here?

 

[jerrydyer]

www.compubias.com

 

[lester]

I have the amp-head..works great, use it with my Fluke.

 

[renato-rt]

I have the amp-head..works great, use it with my Fluke.

What exactly do you mean?

 

[cyndicate]

Ok nevermind. The Eurotubes video answered my question. Ground the black multimeter probe and touch the 3rd pin to the right of the guide pin using the red multimeter probe. Sounds pretty simple for determining plate voltage. Cool!

Yes you can measure plate voltage that way. You need to set the DMM to read DC Volts in the highest range possible on the meter. Usually the 500v or higher setting.

Buy some insulated croc clips instead of using the multimeter probes. Trust me on this. It makes things easier as not all of us have very steady hands. If you slip with the meter probe and short the plate voltage to ground, you're gonna have instantly blown tubes on your hands and possibly a shorted out socket that would have to be replaced afterwards. Not fun!!

If you use croc clips, you can just clip it to the Pin 3 and then you don't have to worry about it

LOL this. I slipped and shorted the power tube pin to something when I was building a JTM45 and luckily only blew a fuse

 

[blackba]

http://www.compubias.com

+1. Love mine. Way easier than trying to measure plate voltage with a DMM.

 

[lester]

I have the amp-head..works great, use it with my Fluke.

What exactly do you mean?

+

 

[NS10Fan]

i'll +1 the amphead and a decent multimeter.

 

[chumbucket]

Amp-Head and a multimeter is the most bang for the buck out there unless you find something else used.

 

[guitarobert]

Why is a plate voltage reading needed? I have a bias rite and it always shows the same number for plate voltage. If you already know the target bias current for a certain amp is there any need to measure plate voltage?

 

[blackba]

Why is a plate voltage reading needed? I have a bias rite and it always shows the same number for plate voltage. If you already know the target bias current for a certain amp is there any need to measure plate voltage?

Plate voltage will vary by amp. Also, as you adjust the bias plate voltage can change slightly.

 

[renato-rt]

Well, thanks a lot for the help, blackba, NS10Fan, chumbucket, guitarobert, blackba, baron55 and specially lester for the patience of putting some pictures to clarify my dumb question.