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Projects => Tech Help - Projects Page => Topic started by: DGWVI on February 12, 2023, 09:29:21 PM

Title: Two Retrogrades, indentical issues
Post by: DGWVI on February 12, 2023, 09:29:21 PM
Except for the transformers and electrolytic types, I used identical values. Diodes are all 1N5817.
I've looked them over, and I think I have all the values correct. They pass signal, but I have to really dig in for them to respond.
I'm guessing I got a value or two wrong, but nothing's popping out

Voltages (they're almost identical for each)

Q1 - C 8.56
        B 8
        E 5.53

Q2 - C 9.14
        B 8.56
        E 3.20

Q3 - C 2.59
        B 3.20
        E 2.52

2N5087s and 2N4401s used
Title: Re: Two Retrogrades, indentical issues
Post by: jimilee on February 12, 2023, 10:31:28 PM
Your voltages look way off as compared to the build doc. Have you checked your resistor and cap values? Also, no GEs?


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Title: Re: Two Retrogrades, indentical issues
Post by: DGWVI on February 12, 2023, 10:48:29 PM
Quote from: jimilee on February 12, 2023, 10:31:28 PM
Your voltages look way off as compared to the build doc. Have you checked your resistor and cap values? Also, no GEs?


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I've visually checked, and all values look correct.
When I get back home, I'll measure them

I do have some d9k and GAZ51, but meh. I've been using the 5817s in all of my recent octup builds, including another Retrograde I built recently, and haven't had an issue.
Title: Re: Two Retrogrades, indentical issues
Post by: madbean on February 12, 2023, 11:05:47 PM
Are those two tantalums in parallel in the first pic? If so, you may need to put them back to back. Honestly, I'm not sure due to their sensitivity to voltages.

Title: Re: Two Retrogrades, indentical issues
Post by: DGWVI on February 13, 2023, 12:13:11 AM
Quote from: madbean on February 12, 2023, 11:05:47 PM
Are those two tantalums in parallel in the first pic? If so, you may need to put them back to back. Honestly, I'm not sure due to their sensitivity to voltages.

They are parallel, as I didn't have any 220u tants on hand. They're 100u / 35v.

Title: Re: Two Retrogrades, indentical issues
Post by: DGWVI on February 13, 2023, 02:10:21 AM
Soz I went over it again, measuring the values
of all the resistors, and noticed R11 was 1.3k. while that wouldn't be causing the issues, I did replace it with the correct 1.2k.

I've followed all the traces, and everything seems to go only where it's supposed to do I'm kinda at a loss at this point
Title: Re: Two Retrogrades, indentical issues
Post by: gordo on February 13, 2023, 04:32:23 AM
I'm on the road right now so can't check my build but I remember agonizing over the orientation of PRI/SEC on the transformer.  I can't imagine that having an effect on voltages though.
Title: Re: Two Retrogrades, indentical issues
Post by: DGWVI on February 13, 2023, 05:04:35 AM
Quote from: gordo on February 13, 2023, 04:32:23 AM
I'm on the road right now so can't check my build but I remember agonizing over the orientation of PRI/SEC on the transformer.  I can't imagine that having an effect on voltages though.

Yeah, the transformer s shouldn't be effecting em. I do have them oriented according to the screen print and build doc. I've also bypassed them just in case they were somehow interfering.

It's almost like there's a messed up trace or short somehwere, but I can't see it. Q1 is especially baffling me. I can't see any reason why it'd be getting almost full voltage
Title: Re: Two Retrogrades, indentical issues
Post by: jimilee on February 13, 2023, 04:21:11 PM
This doesn't have anything to do with voltage, but your effect in wire is connected to the jack in pad. It needs to go to the in pad at the bottom.


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Title: Re: Two Retrogrades, indentical issues
Post by: DGWVI on February 13, 2023, 04:25:29 PM
Quote from: jimilee on February 13, 2023, 04:21:11 PM
This doesn't have anything to do with voltage, but your effect in wire is connected to the jack in pad. It needs to go to the in pad at the bottom.


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Nope, not on this one. Your suggestion was how I originally had it wired, and no input was getting to the effect
Title: Re: Two Retrogrades, indentical issues
Post by: jimilee on February 13, 2023, 07:11:35 PM
Thank you, that's counterintuitive for sure.


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Title: Re: Two Retrogrades, indentical issues
Post by: DGWVI on February 13, 2023, 10:46:09 PM
Quote from: jimilee on February 13, 2023, 07:11:35 PM
Thank you, that's counterintuitive for sure.


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Yep!  ;D
Totally threw me at first too
Title: Re: Two Retrogrades, indentical issues
Post by: DGWVI on March 07, 2023, 05:27:29 PM
With the amount of issues I've had with various transistors lately, I really need to get a transistor tester.

I popped the 4401s out for for some 5088s, and BAM. Fuzz to my skull