Am I assembling it right? [resolved]

hoy83 · 1740

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Offline hoy83

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Reply #30 on: July 25, 2021, 04:20:01 AM
so... I THINK, I finished assembly of the crack.. problem is I don't know how to test resistance.. the instruction says to attach the black lead to the ground buss, I don't know which one is the ground buss on terminal 12u.. I attached pictures of where I clipped my black lead for the multi meter. and where should I set the multi-meter dial to? to 12 o clock on the ohm sign?
.

anyway if I got it right and clipped the black lead on the correct place, I'm getting more than 0 ohms on some that needs to be 0 ohms..

here is the breakdown:
Terminal:
1. * (I don't know what this asterisk means so I didn't measure those with asterisks)...
2. *
3. 0.1 to 0.2 ohms
4. *
5. *
6. 0.1 ohms
7. 2.952 k ohms
8. 0.1 ohms
9. 2.944 k ohms
10. around 39. something with an M beside an ohm sign in the dmm
12. 0 ohm
13. *
14. 0.1 to 0.2 ohms
20. 0.0 ohms
22. 0.0 ohms
B3. 2.952 k ohms
B6. 2.954 k ohms
RCA jack center pin black. 103.1 ohms
RCA jack center pin red. 99.1 ohms
RCA jack ground tab black 1.1 ohms
RCA jack ground tab red 0.3 ohms

I think I got it wrong..
thanks in advance for any help..
« Last Edit: July 25, 2021, 04:31:11 AM by hoy83 »



Offline Thermioniclife

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Reply #31 on: July 25, 2021, 04:25:34 AM
Touch the clips together, what does your meter read?

Lee R.


Offline Paul Birkeland

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Reply #32 on: July 25, 2021, 04:26:11 AM
I don't know which one is the ground buss on terminal 12u..
12U is a ground connection. I'm not quite sure what you're asking, that's where your black meter probe should connect.


1. * (I don't know what this asterisk means so I didn't measure those with asterisks)...
The asterisk is explained on page 47 where the resistance values are posted.
6. 1.0 ohms
7. 2.952 ohms
8. 1.1 ohms
9. 2.944 ohms
10. around 43. something with an M beside an ohm sign in the dmm
The values at 7 and 9 should be 2.9K, not just 2.9 (same for the center pin of each RCA jack).  43m would be OK on 10 (that would be 0.04 ohms) but 43M would definitely not be OK.

The value at 10 would have me wanting to see the headphone jack wiring and the octal socket wiring in a bit more detail.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline hoy83

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Reply #33 on: July 25, 2021, 04:32:15 AM
Touch the clips together, what does your meter read?

0.0 ohms when I switch my multi-meter to the ohm sign



Offline Thermioniclife

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Reply #34 on: July 25, 2021, 04:36:29 AM
0.0 ohms is very good, most meters read around .02-.03 ohms with the probes touching and you can consider that 0 ohms.

Lee R.


Offline hoy83

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Reply #35 on: July 25, 2021, 04:37:20 AM
12U is a ground connection. I'm not quite sure what you're asking, that's where your black meter probe should connect.

The asterisk is explained on page 47 where the resistance values are posted.The values at 7 and 9 should be 2.9K, not just 2.9 (same for the center pin of each RCA jack).  43m would be OK on 10 (that would be 0.04 ohms) but 43M would definitely not be OK.

The value at 10 would have me wanting to see the headphone jack wiring and the octal socket wiring in a bit more detail.

yes I corrected the values on my previous post, it's k. not sure with ten, do you mean a small letter m or big letter M? I switched to manually holding the probes with my hand with the black lead on the 12u terminal and using the red lead to measure, it measure below 1ohm as opposed to using an alligator clip which I think is a bit inaccurate in giving me readings a while ago. I updated the values on my previous post.. so is it correct that I just attach my black lead to 12u that would be the correct way? I'm really suspicious about the terminal 10.



Offline hoy83

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Reply #36 on: July 25, 2021, 04:42:23 AM
with terminal 10 my dmm goes crazy, going from 40kohms to 80+kohms..



Offline Paul Birkeland

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Reply #37 on: July 25, 2021, 05:49:14 AM
with terminal 10 my dmm goes crazy, going from 40kohms to 80+kohms..
The value at 10 would have me wanting to see the headphone jack wiring and the octal socket wiring in a bit more detail.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline hoy83

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Reply #38 on: July 25, 2021, 05:59:22 PM


Thanks, that seemed to work, there was a loose connection on the headphone jack, soldered it and terminal 10 was 0 ohms..

Ran into a problem again though.. the voltage test was a little over the limit specified in the manual.

Here are the terminals:

terminal 2 188v - 189v
terminal 4 189v
terminal 7 116.8v

In the manual it says terminal 2 and 4 should be around 170v, and terminal 7 is at the maximum 115v. Is this ok?

thanks in advance.



Offline Paul Birkeland

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Reply #39 on: July 25, 2021, 06:56:31 PM
I wouldn't be too concerned by those. 

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline hoy83

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Reply #40 on: July 25, 2021, 07:05:14 PM
well I guess I made it.. thank you very much for all the help.. I'm using the amp right now with my headphones, sounds good. Thank you to sir Paul Birkeland for all the help and the others too.



Offline hoy83

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Reply #41 on: July 25, 2021, 07:12:04 PM
Is it normal for the chassis to be a bit hot when running the amp?
« Last Edit: July 25, 2021, 07:22:42 PM by hoy83 »



Offline Paul Birkeland

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Reply #42 on: July 25, 2021, 07:14:00 PM
Yes, the 3K/10W resistors will warm up the chassis pretty well.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline hoy83

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Reply #43 on: July 25, 2021, 08:08:58 PM
ah alright thanks again..