Resistance Checking Questions

[AndTheCookies]

Hello everyone.

I just completed a build of the Bottlehead Crack. I am at the point of checking resistance, and I have some very basic questions:

- When checking the terminals that are supposed to say 0 OHMS, my voltmeter does say "0.00" at first, but then it will fluctuate between "0.01" and "0.03," and not any higher. Is this a problem?

- The instructions say terminal 13 should climb "toward" 270k OHMs. Mine gets to 130k tops and no higher. Is this OK?

- Where it says to measure the RCA "ground lug," is that just where the black cable braided with the right and left channels terminates? So the two ground tabs at the RCA connectors? No?

- The RCA center pins just means measure the cable where it feeds into the RCA connectors, right?

Sorry if these are dumb questions. I'm kind of nervous about doing the electrical check next, so I really want to make sure everything is 100%. Thanks!

[adydula]

Hello,

I just finished mine today and did the resistance checks ok.

Mine is up and working well.

I don't know what type of volt/ohmmeter your using.

When you measure things make sure you have a good solid contact to help prevent inaccurate measurements.

Sometime the flux on the solder joints might impact some measurements slightly and this may be why your 0 ohms move around abit.

Also it may be your ohm meter. Touch your probes together and see if it displays 0.00 or floats around a little.

I use a really cheap $10 DVM and make sure your on the lowest scale for resistance you should get a solid 0 ohms.

My measurement climbed to 200 K Ohms and I had to change scales because my meter has a 200K scale.... it never got to 270K Ohms but its a good indication that the cap is charging from the battery in your meter and polarity is ok.

The RCA ground lugs are the little metal tabs you installed when you fastened there RCA input jacks. It has the small hole in it that you attach to a black ground wire.

There are no dumb questions!! Many people are afraid to ask!

Most likely someone more knowledgeable will add to your concerns!

All the best

I hope your Crack works, be careful measuring the voltages!

Alex

[OldManNiko]

I just finished my crack as well.  If you're unsure about powering your amplifier then I would try to get the best readings you can, and then post your resistances here.  To get a good reading, you will need to make sure your digital multi-meter (if it is indeed digital) has a good interface with the wiring.  You don't need to press the test lead so hard that it moves on the contact, just a touch to the test point.  Resistances can fluctuate when you are moving your test leads.  So find a spot where you can comfortably hold the leads then measure.   Hope this helps!

[Strikkflypilot]

0.01 ohms to 0.10ohms (0.13ohms on my meter) IS 0 ohms (short Your probes together and You see how low You get on Your meter)
The resistances marked with * vary from meter to meter. Make sure it isnt 0 as per manual.
And Youre right about the RCA connectors

[AndTheCookies]

Thanks for the replies everyone. The tests are complete and I have put a couple of hours into the amp.

No hum, hiss or pops. Clear and dark sound. Invisible noise floor.

Next up is the speedball upgrade. I am going to wait a few weeks first. Thanks again!