The 8.2K resistor drifts too much

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BoogieEngineer
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The 8.2K resistor drifts too much

Post by BoogieEngineer » Mon Jul 16, 2012 3:42 pm

I got a 8.2K dropper that reads 9.37K, so I had to get another one, planning on using the old on in place of the 10K. But this new one reads 9.41K :( Thoughts?

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toner
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Re: The 8.2K resistor drifts too much

Post by toner » Mon Jul 16, 2012 4:51 pm

I'm not sure why you posted this but... :what:

Maybe your meter isn't very accurate? The slight variation in resistance there will have very little effect on voltages, etc. so I wouldn't worry about it. In case you're talking about CC resistors, it's quite common for those to read higher than marked but I wouldn't use CC's there anyway.

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Re: The 8.2K resistor drifts too much

Post by Roe » Mon Jul 16, 2012 5:14 pm

9k4 is fine. try testing the one in old marshalls instead of only following the schematics
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Re: The 8.2K resistor drifts too much

Post by BoogieEngineer » Mon Jul 16, 2012 9:43 pm

toner wrote:I'm not sure why you posted this but... :what:

Maybe your meter isn't very accurate? The slight variation in resistance there will have very little effect on voltages, etc. so I wouldn't worry about it. In case you're talking about CC resistors, it's quite common for those to read higher than marked but I wouldn't use CC's there anyway.
Yeah they are both CC's. Why wouldn't you use CC's there? Almost every JTM45/100 build I've seen has got a CC in there. The ones I've got are both 2W if that makes a difference.

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Re: The 8.2K resistor drifts too much

Post by BoogieEngineer » Mon Jul 16, 2012 9:45 pm

Roe wrote:9k4 is fine. try testing the one in old marshalls instead of only following the schematics
Thanks, good to know. What about the 10K near the preamp cap? I guess I could use the 9.3K in place of the 8.2K and the 9.4K in place of the 10K? :)

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Re: The 8.2K resistor drifts too much

Post by toner » Tue Jul 17, 2012 10:43 am

BoogieEngineer wrote:Yeah they are both CC's. Why wouldn't you use CC's there? Almost every JTM45/100 build I've seen has got a CC in there. The ones I've got are both 2W if that makes a difference.
They can add noise and drift in resistance. They are historically correct though. (I was just making a general comment about CC's.)

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Re: The 8.2K resistor drifts too much

Post by BoogieEngineer » Tue Jul 17, 2012 12:48 pm

toner wrote:
BoogieEngineer wrote:Yeah they are both CC's. Why wouldn't you use CC's there? Almost every JTM45/100 build I've seen has got a CC in there. The ones I've got are both 2W if that makes a difference.
They can add noise and drift in resistance. They are historically correct though. (I was just making a general comment about CC's.)
I'm using CC's just for several spots. As for tone, general consensus is that there is no noticeable difference from what I've heard. I find them look cool though

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Re: The 8.2K resistor drifts too much

Post by Roe » Fri Jul 20, 2012 12:23 pm

BoogieEngineer wrote:
Roe wrote:9k4 is fine. try testing the one in old marshalls instead of only following the schematics
Thanks, good to know. What about the 10K near the preamp cap? I guess I could use the 9.3K in place of the 8.2K and the 9.4K in place of the 10K? :)
yes, it doesn't matter much though. different tubes will draw different amounts of current, affecting voltages and tone
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Re: The 8.2K resistor drifts too much

Post by BoogieEngineer » Fri Jul 20, 2012 2:44 pm

Roe wrote:
BoogieEngineer wrote:
Roe wrote:9k4 is fine. try testing the one in old marshalls instead of only following the schematics
Thanks, good to know. What about the 10K near the preamp cap? I guess I could use the 9.3K in place of the 8.2K and the 9.4K in place of the 10K? :)
yes, it doesn't matter much though. different tubes will draw different amounts of current, affecting voltages and tone
Thanks Roe. I actually got another 8.2K from Valvestorm which reads 8.4K on my meter, so it goes to the 8.2K position. The 9.4K goes to the 10K place, so I'm all good now :)

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