DSL100HR Bias Help

ehehat

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Seems like it should be easy AF to bias this thing so I must be an idiot. Do I have a bad/wrong multimeter? Everywhere I've looked it says to use mV and set somewhere around 70/76mV but when I hook this thing up I get .2-.3. When I use VDC I get like .032 or some crap. What the hell am I doing wrong here? Thanks!

Bias Points.jpg Bias Reading.jpg
 

Kutt

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What you're doing looks correct. Is the amp out of Standby (in "play" mode) while you're getting that reading?
 

ehehat

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What you're doing looks correct. Is the amp out of Standby (in "play" mode) while you're getting that reading?
Yes, It's in "full" mode. connected to speaker cab. Same reading whether I have a cable in the input or not.
 

Kutt

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I'm not an amp tech so my input will be minimal here, but I have the same amp and have biased it exactly like you're trying to do. My multimeter is not auto ranging, I hard set it to the 200mV setting. Do you happen to have a second multimeter you can test with to rule out if it's the Fluke?

You probably did this but also make sure your test leads are plugged into the correct ports on the Fluke. Apologies in advance for asking the obvious.
 

ehehat

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I'm not an amp tech so my input will be minimal here, but I have the same amp and have biased it exactly like you're trying to do. My multimeter is not auto ranging, I hard set it to the 200mV setting. Do you happen to have a second multimeter you can test with to rule out if it's the Fluke?

You probably did this but also make sure your test leads are plugged into the correct ports on the Fluke. Apologies in advance for asking the obvious.
No man, Really appreciate the input! I dont have another multimeter but think I may try to order something different. If I may ask.. What do you use? Again, thanks!
 

Kutt

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I have a Klein MM100 digital multimeter. I got it at Home Depot about 6 years ago. Fluke is a reputable brand as you probably know, but there could in fact be something wrong with yours.

Another obvious suggestion, but if you have another tube amp you could try measuring that one too. If the Fluke acts up there as well, then it's not a fluke. (See what I did there?!)
 

ehehat

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I have a Klein MM100 digital multimeter. I got it at Home Depot about 6 years ago. Fluke is a reputable brand as you probably know, but there could in fact be something wrong with yours.

Another obvious suggestion, but if you have another tube amp you could try measuring that one too. If the Fluke acts up there as well, then it's not a fluke. (See what I did there?!)
Ha! Nice one! Thanks for the help!
 

ehehat

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You have it on the wrong setting you need it DC not AC . You need amp meter not voltage reading .
Based on the pic of the dial I uploaded, what setting should it be on? I tried it on V DC and It read something like 0.032, would that then be 32mV? Or do I need to get a different meter? Thanks for your input!
 

fitz288

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Here's a shot of my meter on a probe when I was balancing the 6V6 tubes on my Haze.
Mostly irrelevant, except the meter setting.
upload_2021-11-23_10-57-8.png
 

ehehat

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Here's a shot of my meter on a probe when I was balancing the 6V6 tubes on my Haze.
Mostly irrelevant, except the meter setting.
View attachment 98326
And mine doesn't read mA. I was on Eurotubes and their how-to vid says you can use the bias points set at mV. Doesn't seem like this should be so difficult. lol
 

fitz288

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And mine doesn't read mA. I was on Eurotubes and their how-to vid says you can use the bias points set at mV. Doesn't seem like this should be so difficult. lol
I think your meter is probably good for other stuff around the house, but perhaps a better meter for your amp(s) would be a good idea.
 

pedecamp

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Seems like it should be easy AF to bias this thing so I must be an idiot. Do I have a bad/wrong multimeter? Everywhere I've looked it says to use mV and set somewhere around 70/76mV but when I hook this thing up I get .2-.3. When I use VDC I get like .032 or some crap. What the hell am I doing wrong here? Thanks!

View attachment 98317 View attachment 98318
Measure something simple like a 9v battery or something to make sure your meter is working properly. Put new batteries in your meter too. You got the amp warmed up and in play mode right?
 

ehehat

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Measure something simple like a 9v battery or something to make sure your meter is working properly. Put new batteries in your meter too. You got the amp warmed up and in play mode right?
Yes absolutely. I'll check something else tonight. Is there a consensus that it needs to be reading DC voltage and not AC?
 

Kutt

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Ah! I missed the "AC" on your picture. Yes, it needs to be DC volts. I just double checked my Klein meter as a sanity check.
 


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