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Projects => Tech Help - Projects Page => Topic started by: jimilee on January 13, 2020, 12:19:14 AM

Title: Rustbucket 2019 confusion
Post by: jimilee on January 13, 2020, 12:19:14 AM
IC10 Pins 2 and 7 and IC7 pin 4 have around 14v each and I don't know why. I have reflowed, scratched between joints on the bottom to make sure that there are no solder bridges and tediously looked at each resistor and made sure I had the right ones. Each cap and trannie are all correct. I even replaced those two ICs. I'm not sure where to go from here. Is something not dumping to the ground that should be?
Title: Re: Rustbucket 2019 confusion
Post by: Scruffie on January 13, 2020, 12:52:41 AM
What's the problem? IC10 Pin 7 is pulled to voltage via R45 & IC7 pin 4 is connected to it, comparators & CMOS go high and low...

Is it not working?
Title: Re: Rustbucket 2019 confusion
Post by: jimilee on January 13, 2020, 01:33:01 AM
Quote from: Scruffie on January 13, 2020, 12:52:41 AM
What's the problem? IC10 Pin 7 is pulled to voltage via R45 & IC7 pin 4 is connected to it, comparators & CMOS go high and low...

Is it not working?
They're supposed to be like 16mv. I'm having troubled getting the mn 3007 biased. The signal is hot. IC 10 and 7 were the only anomalies I could find.


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Title: Re: Rustbucket 2019 confusion
Post by: Scruffie on January 13, 2020, 01:40:46 AM
As I said, they swing high and low and they're not connected to the BBD, they only function as the attack/decay portion and telling the VCA when to open/close.

How hot are your pickups? There's quite a bit o' gain and a compressor up front of the BBD which will bring the signal level up quite a bit.

We chatted about the Downtown and this uses a pretty similar front end apart from the low pass filter so I'm wondering if it's your pickups or your sensitivity setting, which should be pretty set and forget.
Title: Re: Rustbucket 2019 confusion
Post by: jimilee on January 13, 2020, 01:49:23 AM
I was using burst buckers. Not too hot, I may switch to my tele and see if that's the difference.



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Title: Rustbucket 2019 confusion
Post by: jimilee on January 13, 2020, 03:27:07 AM
Quote from: Scruffie on January 13, 2020, 01:40:46 AM
As I said, they swing high and low and they're not connected to the BBD, they only function as the attack/decay portion and telling the VCA when to open/close.

How hot are your pickups? There's quite a bit o' gain and a compressor up front of the BBD which will bring the signal level up quite a bit.

We chatted about the Downtown and this uses a pretty similar front end apart from the low pass filter so I'm wondering if it's your pickups or your sensitivity setting, which should be pretty set and forget.
Here's the problem. I have an 18v one and the 9v one. I can't get the envelope to open smoothly on the 9 v one. It's either barely there or abruptly opens, not smoothly. Switching to single coils didn't help.


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Title: Re: Rustbucket 2019 confusion
Post by: Scruffie on January 13, 2020, 01:56:07 PM
Ahh, right, so it isn't just the BBD. Well they're swinging high because they're jammed open which would fit your description so I would look further down stream to the input section.

You know the drill, pictures etc.
Title: Re: Rustbucket 2019 confusion
Post by: jimilee on January 13, 2020, 02:39:38 PM
Quote from: Scruffie on January 13, 2020, 01:56:07 PM
Ahh, right, so it isn't just the BBD. Well they're swinging high because they're jammed open which would fit your description so I would look further down stream to the input section.

You know the drill, pictures etc.
Thank you sir.


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Title: Rustbucket 2019 confusion
Post by: jimilee on January 13, 2020, 09:21:47 PM
(https://uploads.tapatalk-cdn.com/20200113/1a47a1ad7fe53865b2cc5961e885daf9.jpg)(https://uploads.tapatalk-cdn.com/20200113/62646be7a6d2ec72ca56816ec324692b.jpg)


Sent from my iPhone using Tapatalk(https://uploads.tapatalk-cdn.com/20200113/d114f4c1f249d0218bdb975d38be98a5.jpg)
Title: Re: Rustbucket 2019 confusion
Post by: Scruffie on January 13, 2020, 10:02:00 PM
You didn't mention IC8 was nearly all 14V, that looks more problematic...
Title: Re: Rustbucket 2019 confusion
Post by: jimilee on January 13, 2020, 11:53:04 PM
Quote from: Scruffie on January 13, 2020, 10:02:00 PM
You didn't mention IC8 was nearly all 14V, that looks more problematic...
It was a mess, I didn't realize it was. Whatchoo think it's coming from? It all looks connected.


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Title: Re: Rustbucket 2019 confusion
Post by: Scruffie on January 14, 2020, 12:22:35 AM
It is all connected (the 4066 is a quad SPST) and it's too late at night to go through the datasheet seeing where everything connects.

Pop it out and see what happens to the voltages then.
Title: Re: Rustbucket 2019 confusion
Post by: jimilee on January 14, 2020, 01:27:02 AM
Quote from: Scruffie on January 14, 2020, 12:22:35 AM
It is all connected (the 4066 is a quad SPST) and it's too late at night to go through the datasheet seeing where everything connects.

Pop it out and see what happens to the voltages then.
Cool man, I appreciate all of your help.
Title: Re: Rustbucket 2019 confusion
Post by: Thewintersoldier on January 14, 2020, 02:42:09 AM
Watching this to learn something new but as my board for this is in the mail right now. This is also why I love this forum, everyone helping each other without the condescending BS of some other forums
Title: Re: Rustbucket 2019 confusion
Post by: jimilee on January 14, 2020, 11:20:48 AM
Turns out, the 4066 was bad. After I took voltages without it in there, I knew what to do. I'll recheck the rest of the voltages later today.


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Title: Re: Rustbucket 2019 confusion
Post by: jimilee on January 15, 2020, 03:09:56 AM
swapping out the 4066 cured it. All of the voltages are looking great. No we move on to the Total recall....