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Messages - madbean

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Tech Help - Projects Page / Re: Rust bucket Voltages way off
« on: September 20, 2017, 05:07:46 PM »
I spot checked some voltages on my build and what I have on the chart seems to be pretty much correct (I did not check all possible pins).

Like GovtL said, IC8 is one of your problem areas but IC9 is also causing an issue. You've got 5.6v across the board where you should be having a lot of 0v (or near 0). But then, you have several other problem IC's as well. Whether or not those all trace back to one root cause is very hard to say (with so many ICs).

Here is what I do in these situations (and believe me, it will suck). You need to start testing these chips individually. I would start by pulling IC7, 8, 9 and 10 then do comparisons with the remaining chips and the reference voltage chart. If things start to check out then start popping those pulled ICs back in one at a time while comparing voltages to the chart again.

There is no easy or fast way to solve a problem like just have to get in there and isolate the chips that are screwing up the build and replace them or look for something that might be causing good chips to go bad. I remember that I actually had a similar problem when I was putting this project together - actually completely unprecedented in all my building: I had three bad ICs in one build. It wasn't the design or my build but three different ICs that were bad (I think one CA3080, an LM311 and one other one).

Also, please upload a pic of the top of the board - I'll look it over for anything that jumps out.

General Questions / Re: Non madbean/affiliate board help?
« on: September 17, 2017, 02:29:03 PM »
Of course. Tech help is the right place.

Tech Help - Projects Page / Re: Rust bucket Voltages way off
« on: September 16, 2017, 06:19:09 PM »
I'm sorry - I got distracted by other things the last couple of days. I will get mine out tomorrow and look at the voltage chart.

General Questions / Re: 2N5457 and J201 replacements
« on: September 16, 2017, 06:17:45 PM »
MPF102 can be an excellent replacement. Not sure on the availability though. I bought my last batches of all of them when the EOL was announced.

VFE Projects / Re: Tractor Beam update
« on: September 14, 2017, 05:46:39 PM »
Huh - 8mm. That is a bit long (though they could be made standing). Here are two 6mm ones (still a bit long):

Thanks for posting that. I forget which one I used...I'll have to look.

General Questions / Re: Dirtbaby Dry/Wet
« on: September 13, 2017, 12:10:18 PM »
Do it this way:

Remove T1 and wire a 50kB pot to it instead. Remove C38 and put a 10k in its place. Jumper pads 3&2 of the Blend pot on the PCB (but don't solder pad2 yet - you need to connect something else there.

Remove R47. Solder lug3 of a 50kA pot to pad1 of the Blend pot on the PCB. Connect lug1 of the new 50kA pot to ground. Solder a wire to lug2. On the other end of that wire, solder a 10k resistor. Now solder the other end of the resistor to pad2 of the Blend pot on the PCB (the one I told you not to solder before).

Illustration below. This still isn't perfect because the two 10k resistor act as voltage dividers when one pot is grounded but it will get you much closer to what you want. You could make R2 a 22k or 47k instead to reduce this just depends on how high you set that Level control (BTW - you don't need to remove or fix the Level control for any of this). Also, you can use a 50kA for pot1 as's just a matter of preference. A 50kA will allow for more subtle blends of the wet into the dry signal.

General Questions / Re: Dirtbaby Dry/Wet
« on: September 13, 2017, 11:54:28 AM »
Can anyone tell me why this isn't giving me individual control over the wet and dry signal and they are still interactive with one another?  Is there a better way to accomplish what I am going for?

Because you are grounding the signal when you turn one of the volume pots down. You need resistors to prevent this. Use a 10k off the wiper of each volume pot, and connect the other end of each resistor to R6 (or skip R6 and connect them both to OUT).

VFE Projects / Re: Tractor Beam update
« on: September 12, 2017, 08:50:01 AM »
Here is the draft of the Tractor Beam BOM/Shopping list. I have a bit of debugging to do on my build but I believe this list is accurate.

Global Annoucements / International orders are delayed
« on: September 12, 2017, 06:05:42 AM »
It looks like most of the international orders I've dropped off at USPS in the last 7 days are not being updated through the USPS tracking system (they show as 'awaiting receipt'). This is likely due to Hurricane Irma. Virtually all international orders go from Nashville to Miami before departing to their destination. And, I expect Miami hasn't been productive these last several days. But all packages have been dropped off here in Nashville so they do have them.

Anyway, if you received shipping notification in the last week and USPS is not updating your package, don't panic. It's just a matter of waiting for normal operations to resume which will hopefully be soon.

Tech Help - Projects Page / Re: naughty fish sounds like a distortion??
« on: September 10, 2017, 06:51:00 PM »
There's not enough information provided to give any sort of help. Without knowledge of any part substitutions used, voltages on the build, pictures, etc I can't offer much advice.

Tech Help - Projects Page / Re: Rust bucket Voltages away off
« on: September 10, 2017, 01:03:25 PM »
It's possible I wrote down incorrect voltages (I've certainly been known to do that). I can dig mine out and double check.

Open Discussion / Re: The strangest commercial you'll see today
« on: September 10, 2017, 12:53:18 PM »
The only thing it needed was Howard the Duck.

Build Reports / Re: Reverse Engineered Centaur
« on: September 10, 2017, 10:09:59 AM »
That's not very surprising, honestly. But...I mean...c'mon. Do the Reverse Centaur.

Open Discussion / Re: Bertrand is out to play
« on: September 10, 2017, 09:58:54 AM »
Kinda gassing hard on a Starfire IV electric now. I love the bass so much it seems like the perfect compliment. Anyone own one of these? Not into the Bigsby but the fixed bridge version seems right for me.

Tech Help - Projects Page / Re: Excel Calculator
« on: September 08, 2017, 06:54:22 PM »
Here's an updated version of the Formulas Excel sheet. I've added the following:

LC Filter (inductor/cap filter)
Resistor Drop (for finding the correct resistor value and wattage it requires for a specific voltage drop)
LM317 (for outputting specific voltages based on two resistors with the LM317)

Examples for each in the first row.

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