Sound Skulptor forums

Build help and troubleshooting => MP573 Microphone preamplifier => Topic started by: slothproductions on January 03, 2024, 10:10:29 AM

Title: Resistor values
Post by: slothproductions on January 03, 2024, 10:10:29 AM

Hello

I’m just about to build the MP573!!

I’m measuring all of the resistor values. Their outputs are as stated except for the following:

- R60 (330K) measures 0.321 (DMM 2M ohm setting)
- R55 & R59 (1M) measure 0.955 (DMM 2M ohm setting)
- R61 & R65 (2M2) measure 1.85 and 2.00 (DMM 20M ohm setting)

Are those transistors defect/weak, or is it normal for high values to fluctuate this much? Or could it be my 27€ multimeter that is inaccurate?

cheers
Simon 

Title: Re: Resistor values
Post by: JPK on January 03, 2024, 11:03:46 AM

Or could it be my 27€ multimeter that is inaccurate?
Yes very probably. Low cost DMM are not very accurate with high value resistors.

Title: Re: Resistor values
Post by: slothproductions on January 03, 2024, 06:22:25 PM

Thanks for the answer!
I found the problem; I was measuring while touching the legs with my fingers.

Looking forward to build this amazing kit!