Soft start resistance check

dw · 2992

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Offline dw

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on: April 03, 2011, 02:55:04 AM
I have completed the soft start for 2a3
Paramount. I'm getting 1 ohm at B9.
The chart says *. Standard Paramount
Table has this at 0 ohm. Did I mess up?

Thanks,
Dave



Offline dw

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Reply #1 on: April 03, 2011, 05:24:09 AM
Besides getting < 1 ohm at B9, I'm getting infinity at B8.
These readings are the same on both amps. The soft start manual says these both should be '*' or varying, but not zero.

Also, 7, 9, 19, a3, b4, and b6 all read close to 290k ohms and steady.
The manual has all of these at '*' as well. These readings are the same on both amps.

Thanks,
Dave



Offline dw

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Reply #2 on: April 04, 2011, 02:13:42 AM
B1 and B9 connect to the heater on the 5670 according to the data sheet.
For the 12at7 in the original Patamount the heater pins are all listed at 0 ohms.
So, shouldn't b1 and b9 be at 0 ohms for the soft start?

Thanks,
Dave



Offline Doc B.

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Reply #3 on: April 04, 2011, 08:50:17 AM
Yeah, close to 0 ohms at B1 and B9 should be correct, so the asterisk for B9 is a typo. The asterisk implies that you will get a random non-zero reading. I would consider 290K ohms to be in that range.

Dan "Doc B." Schmalle
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Offline dw

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Reply #4 on: April 04, 2011, 08:59:01 AM
Thanks, Doc.

Dave