Resistance Check at 26

[hpleung]

Hi I have posted my resistance check list below.

There is a major mismatch at 26. It is showing me a fluctuating resistance between 70 to 100+ kohm. It really should be 0.

The other one that is suspicious is at 21; it is giving me 0.6 ohm when it is expected to be 0.

I have not attached a picture yet as I don't even know where to take the picture.

Are there any guidance on where i should look or what pictures I can attached?


   Observed
1   4.5
2   390kohm
3   0.3
4   5.6
5   0.3
6   145 kohm
7   470.5kohm
8   0.3
9   0.3
10   1.8mega ohm
11   145kohm
12   468kohm
13   0.3
14   0.3
15   12 mega ohm
16   4.3
17   388kohm
18   0.3
19   5
20   0.3
21   0.6
22   15 mega ohm
23   0.3
24   0.3
25   2.7 mega ohm
26   Fluctuating 70-100 kohm
27   0.4
28   0.3

[Paul Birkeland]

There are black wires going to and leaving terminal 26 that help tie it to the audio ground.  If you don't see the appropriate reading there, one of those wires is missing or not well soldered.  Definitely you will want to fix this before turning on your amp.  Posting a build photo if you can't see what's wrong is also a great idea.

[hpleung]

Hi,

Can you please take a look at this picture? I cannot find in the manual any black wires that goes to 26.

I do have a black wire that goes to 38.

Thanks

[hpleung]

I did search for 26, 26L and 26U from the pdf and did not find any instructions to wire a black wire

[Paul Birkeland]

Oh, you have a BeePre 1, that changes things a bit.  You can completely ignore what's going on at terminal 26 in a BeePre 1.  Not having 0 ohms here may just be a matter of having slightly loose hardware, but that on its own isn't going to cause and problems.

[hpleung]

Thanks. ok interesting.  So I need to know which resistance check values I can ignore before i plug in the power.

I plugged in all tubes.

Here are those resistance checks where they don't match, can you tell me if that is ok to ignore like in 26?

1. C2, D2 ==> Expected was 215ohm but Observed = 429ohm      [This is the biggest mismatch]
2. A1 ==> Expected was 4 ohm but observed = 5 ohm
3. A4 ==> Expected was 5 to 6 ohm but observed = 4.4 ohm

4. 21 ==> Expected was 0 ohm but observed = 0.6 ohm
5. 26 ==> Expected was 0 ohm but observed = fluctuating 70-100kohm
6. 32 ==> Expected was 0 ohm but observed = 0L
7. 33 ==> Expected was 0 ohm but observed = 0L

The full list below:

Expected   Observed
1   4                    4.5
2   >100kohm   390kohm
3   0   0.3
4   5 to 6   5.6
5   0   0.3
6   >30kohm   145 kohm
7   470kohm   470.5kohm
8   0   0.3
9   0   0.3
10   20kohm   1.8mega ohm
11   >30kohm   145kohm
12   470kohm   468kohm
13   0   0.3
14   0   0.3
15   >20kohm   12 mega ohm
16   4   4.3
17   100 kohm   388kohm
18   0   0.3
19   5 to 6   5
20   0   0.3
21   0   0.6
22   >100k ohnm   15 mega ohm
23   0   0.3
24   0   0.3
25   >100k ohnm   2.7 mega ohm
26   0   Fluctuating 70-100 kohm
27   0   0.4
28   0   0.3
29   *   600 fluctuating
30   *   fluctuating
31   *   fluctuating
32   0   0L
33   0   0L
34   *   ok
35   *   ok
36   *   ok
37   0   0.3
38   0   0.3
39   0   0.3
40   >100k   20mega
41   0   0.3
42   0   0.3
43   >100k   ok
44   0   0.3
45   0   0.3
46   >100k   ok
47   N/A   OL
48   603ohm   607
49   0   0.3
50   N/A   0L
51   603   604
      
A1   4   5
A2   >100   3790kohm
A3   0-50kohm   1.52 ohm
A4   5-6ohm   4.4
      
B1   5 to 6ohm   4.3
B2   >100kohm   2 mega
B3   0 to 50   1.5kohm
B4   4   5
      
C1, D1   N/A   0L
C2, D2   215ohm   429
C3, D3   0L   0L
C4, D4   >100ohm   0.8 mega
C5, D5   >100ohm   0L
C6, D6   N/A   0L
C7, D7   >30kohm   290kohm
C8, D8   N/A   0L
C9, D9   >30kohm   290kohm

[Paul Birkeland]

1. C2, D2 ==> Expected was 215ohm but Observed = 429ohm     

What resistance reading to do you get at the center post of each 9 pin socket?  Those resistance readings should be 0 ohms and there's a 215 ohm resistor from the center post to C2 and another to D2.  These should be dead nuts on.

4. 21 ==> Expected was 0 ohm but observed = 0.6 ohm
5. 26 ==> Expected was 0 ohm but observed = fluctuating 70-100kohm
6. 32 ==> Expected was 0 ohm but observed = 0L
7. 33 ==> Expected was 0 ohm but observed = 0L

21, 26, 33, and 38 will all connect together through the power transformer cover. If you see the correct resistance reading at 38 but not at 21, 26, and 33, then either you do not have the power transformer hardware installed properly or the hardware isn't tight enough.  The same goes for 27, 32, 39, and 44.

The resistance values you posted on the 4 pin sockets for 1 and 4 are sufficiently close to what we are looking for that I wouldn't worry too much about them.

[hpleung]

Hi Paul,

Thanks again. I am a bit confused about your last response. Do I need to care about the resistance values at 26? You mentioned earlier i do not need to.

I do have the older BeePre. Consistently I am getting

38 = 0.3 ohm
21 = 0.6 ohm
26 = 29 ohm
32 = 0L
33 => 1.2 ohm

Below has been resolved.

"What resistance reading to do you get at the center post of each 9 pin socket?  Those resistance readings should be 0 ohms and there's a 215 ohm resistor from the center post to C2 and another to D2.  These should be dead nuts on."

I resolved this part; basically the way i was taking the measurement was wrong.

[Paul Birkeland]

Thanks again. I am a bit confused about your last response. Do I need to care about the resistance values at 26? You mentioned earlier i do not need to.

Your resistance readings tell me your power transformer screws aren't tight enough.  This isn't going to stop your amp from working, but you could also resolve this by tightening that hardware.