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Author Topic: Crackatwoa Wild Voltages  (Read 550 times)

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Offline m0zillaf0x

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Crackatwoa Wild Voltages
« on: July 07, 2020, 01:23:19 PM »
I finally put my Crackatwoa together on Friday, and I have been having NOTHING but issues with it since it was completed. At first, all my LEDs lit up, and I was actually getting sound. However, I would only get sound when the left RCA jack was plugged in. If I plugged the right, neither would work, nor would the right work on its own. I tried checking the balance, and no matter where it was turned, it was the same. Switching outputs did the same thing, every output would only work the left until the right was plugged in. I decided to retrace EVERY step from the beginning, making sure to resolder each joint when specified in the manual.

After doing this, half the LEDs on the low current board (A side) don't light up, and NONE of the LEDs on the High current board above the B socket light. All the LEDs on the board above the D socket light, however.

The weirdest part is the voltages and resistances. All the resistances match what is specified in the manual, however, the voltages are comically incorrect.

Low Current Board Voltages:
IA - 0
OA - 0
KregA- 0
bRegA- 0
IB - 425 (not a typo)
OB - 158
KregB - 20 (not a typo)
bRegB - 425

High Current Voltages (B socket side):
All zero except OB, faint reading of 0.3V

High Current Voltages (D socket side):
IA - 429 (not a typo)
OA - 425
bA - 0
IB - 0
OB - 227
bB - 425

I'm not allowed to post external links to an imgur album I made containing pics of my solder joints and overall connections.


Offline Paul Birkeland

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Re: Crackatwoa Wild Voltages
« Reply #1 on: July 07, 2020, 01:25:29 PM »
I finally put my Crackatwoa together on Friday, and I have been having NOTHING but issues with it since it was completed. At first, all my LEDs lit up, and I was actually getting sound. However, I would only get sound when the left RCA jack was plugged in.

The weirdest part is the voltages and resistances. All the resistances match what is specified in the manual, however, the voltages are comically incorrect.
It is incredibly important that you stop listening to an amp that doesn't pass its voltage checks.  The voltage checks tell you whether the amp is working or not.  If you don't pass the voltage checks, you shouldn't use the amp. 


Low Current Board Voltages:
IA - 0
OA - 0
KregA- 0
bRegA- 0
IB - 425 (not a typo)
OB - 158
KregB - 20 (not a typo)
bRegB - 425

This is what I would expect from loose ground connections and poor solder joints.

High Current Voltages (B socket side):
All zero except OB, faint reading of 0.3V


I'm not allowed to post external links to an imgur album I made containing pics of my solder joints and overall connections.
You can just post the text and not embed the link.
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline m0zillaf0x

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Re: Crackatwoa Wild Voltages
« Reply #2 on: July 07, 2020, 01:28:19 PM »
I was told you should always have your inputs plugged in before turning on a tube amp. I never had the headphones on, if ear damage was the point you were trying to make.

imgur com/gallery/DNF1Kyt

Offline Paul Birkeland

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Re: Crackatwoa Wild Voltages
« Reply #3 on: July 07, 2020, 01:40:16 PM »
I was told you should always have your inputs plugged in before turning on a tube amp. I never had the headphones on, if ear damage was the point you were trying to make.
You don't need any inputs plugged into the amp to check the voltages.  The amp also doesn't need any load to operate properly.


imgur com/gallery/DNF1Kyt
If you sent me that amp for repair, I would reflow all of the solder joints and pull on each wire to be sure it was secure.
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline m0zillaf0x

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Re: Crackatwoa Wild Voltages
« Reply #4 on: July 07, 2020, 01:45:04 PM »
If you sent me that amp for repair, I would reflow all of the solder joints and pull on each wire to be sure it was secure.

At this point, I'm not sure I have any brain power in me to try for myself. I'd be willing to pay, plus shipping, as long as this piece of work, well, finally works, lol.

Offline Paul Birkeland

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Re: Crackatwoa Wild Voltages
« Reply #5 on: July 07, 2020, 01:49:21 PM »
The flat rate repair service is there if you need it!
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline m0zillaf0x

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Re: Crackatwoa Wild Voltages
« Reply #6 on: July 07, 2020, 01:52:51 PM »
The flat rate repair service is there if you need it!
Oh sweet, had no clue that page was there. Think I'm gonna bite the bullet. I had enough fun soldering my Crack, guess I'm just not good enough to finish the sequel 😞