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November 30, 2021, 01:09:34 PM

Author Topic: Measuring voltages while playing a 60 Hz sine wave. [resolved]  (Read 1396 times)

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Offline Colonl_Charisma

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Re: Measuring voltages while playing a 60 Hz sine wave. [resolved]
« Reply #60 on: August 25, 2021, 07:01:02 PM »
Okay, I believe that I got the wiring figured out! Let me know what you think PB.
Looking from the back of the chassis here are the connections that I made to the balance pot.

RCA to balance pot:
Left RCA --> top left lug balance pot
Right RCA --> bottom right lug balance pot
Right RCA ground -- > top right lug balance pot
Left RCA ground --> bottom left lug balance pot

Balance pot to volume pot (I just went off the picture for these connections):
Ground wire --> between bottom left lug of balance pot and bottom right of volume pot.
Ground wire --> between top right lug of balance pot and top right of volume pot.
Left input --> between top middle lug of balance pot and top left of volume pot.
Right input --> between bottom middle lug of balance pot and bottom left of volume pot.
33K resistors between top left of balance pot and top left of volume pot + bottom right of balance pot and bottom left of volume pot.
« Last Edit: August 25, 2021, 07:04:44 PM by Colonl_Charisma »
Ross

Online Paul Birkeland

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Re: Measuring voltages while playing a 60 Hz sine wave. [resolved]
« Reply #61 on: August 26, 2021, 05:34:16 AM »
Let me know what you think PB.
Does it work?
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline Colonl_Charisma

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Re: Measuring voltages while playing a 60 Hz sine wave. [resolved]
« Reply #62 on: August 26, 2021, 08:14:57 AM »
I'm letting some standoffs settle into epoxy under the chassis. I had to raise one of my film caps up to get it out of the way. Once the standoffs get settled and I solder the film cap connections, I will turn the amp on and see if everything works.
Ross

Offline Colonl_Charisma

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Re: Measuring voltages while playing a 60 Hz sine wave. [resolved]
« Reply #63 on: August 31, 2021, 12:25:04 PM »
Hi PB! I confirm that the balance pot works, and my Crack amp is up and running just fine. I've been listening for about 30 minutes with no issues.

The balance pot clearly changes the prominence between the left and right channels. For instance, when I crank the balance pot all the way to the right, the right channel becomes more prominent with sound still coming from the left channel. My volume pot is working just fine too.

I threw on some mono tracks to test everything out.

If any issues arise, I will post them here. I really appreciate all of your help! This is a very cool mod.
Ross

Offline Colonl_Charisma

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Re: Measuring voltages while playing a 60 Hz sine wave. [resolved]
« Reply #64 on: September 02, 2021, 06:58:41 AM »
I have noticed a couple semi-issues.

1) When I turn my amp on with my volume knob not in the zero position, I get really loud buzzing coming from my headphones. It only lasts for like a minute or so before going away. However, semi-issue #2...

2) When I turn my volume knob there are occasional loud scratching and popping noises. Much louder than what I have heard pots generate. Loud, as in I need to take my headphones off to turn the volume knob.

None of these issues occur with the turning of the balance pot. Other than these two things, everything sound great!
Ross

Online Paul Birkeland

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Re: Measuring voltages while playing a 60 Hz sine wave. [resolved]
« Reply #65 on: September 02, 2021, 07:07:10 AM »
You can spray some electronics cleaner into the pot if you'd like, as the pots we provide are open and debris can get in there.
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline Colonl_Charisma

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Re: Measuring voltages while playing a 60 Hz sine wave. [resolved]
« Reply #66 on: September 02, 2021, 07:17:25 AM »
I have a PEC pot that is closed. I would get some scratching before, but never any pops when turning the volume pot.  The scratching is also super loud. Do you think I can do anything about it?
Ross

Online Paul Birkeland

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Re: Measuring voltages while playing a 60 Hz sine wave. [resolved]
« Reply #67 on: September 02, 2021, 08:13:42 AM »
Just be sure that all your solder joints are solid.
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline Colonl_Charisma

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Re: Measuring voltages while playing a 60 Hz sine wave. [resolved]
« Reply #68 on: September 02, 2021, 10:52:08 AM »
Thanks, PB, and I’ll double check all my solder joints. The buzzing at start up is weird. No idea why that is occurring.
Ross