Messages

1

General Questions / Re: Aion Blueshift

« on: November 20, 2020, 08:19:35 AM »

The signal always passes through a pre/de-emphasis network, while they're supposed to be neutral, they pretty much always audibly impact tone, so that could be what you're hearing?

The signal has to pass through IC2 pin 7 to reach the BBD's and the output of the BBD's is pin 7&8, if your audio probe is definitely working and there's not something weird going on, you can't possibly have any modulation.

Could a bad cap on the compander be the cause? Possibly... I mentioned Tayda tantalum capacitors because last time I tried to use one for digital power filtering it ended up injecting noise rather than removing it and I've avoided them since, I've also heard of their electro's simply being shorts.

Signal comes from IC1 pin 7, goes in to the companders input at pin 6, comes out at pin 7.

2

General Questions / Re: Aion Blueshift

« on: November 19, 2020, 10:33:13 AM »

If you don't have a scope, just audio probe pin 7 & 8 of each BBD while adjusting its bias.

I don't have a scope but I think I've got it dialed in real close.

However, what does it mean when I get zero sound out of pins 7 and 8 of the BBD's, IC's 3 & 9?

That they're not passing signal and you have no effect... when working, you should hear clean undistorted vibrato on each chip there.

3

How Do I? Beginner's Paradise. / Re: How to Convert single supply voltage circuit to Dual +/- voltage supply???

« on: November 19, 2020, 07:06:34 AM »

Pin 4 & R3.

4

How Do I? Beginner's Paradise. / Re: How to Convert single supply voltage circuit to Dual +/- voltage supply???

« on: November 19, 2020, 06:56:32 AM »

I assume you want a split supply for more headroom?

The J-FET is biased off centre through that divider to get more signal swing @9V, but if you're feeding it a split supply, it's probably unnecessary and the 3M3 can indeed just go to ground.

5

General Questions / Re: Aion Blueshift

« on: November 19, 2020, 05:23:10 AM »

If you don't have a scope, just audio probe pin 7 & 8 of each BBD while adjusting its bias.

6

Tech Help - Projects Page / Re: Question on Aquaboy 2016

« on: November 18, 2020, 02:03:28 PM »

The compander is self biasing but to an internal 1.8V reference. The additional resistor is to offset that and provide the most signal swing for the supply voltage.

Don't forget the pedal originally used a battery so optimum isn't always... optimum.

7

General Questions / Re: Aion Blueshift

« on: November 17, 2020, 04:35:14 PM »

Oh, is that what those are for, yeah, that sounds important.

8

General Questions / Re: Aion Blueshift

« on: November 17, 2020, 04:17:17 PM »

It's not as complicated as it looks, no different to any other delay circuit really, just everything's split and doubled but to reach the BBD's, the signal must past through IC2.

I see tantalum capacitors, you didn't get them from Tayda, did you?

9

General Questions / Re: Aion Blueshift

« on: November 10, 2020, 06:45:23 PM »

Sure, post some up of that area.

10

General Questions / Re: Aion Blueshift

« on: November 10, 2020, 04:42:38 PM »

Okay, you've gone a bit off course with your probing.

IC2 pin 7 is where you should listen for audio, should be loud and compressed.
Then, assuming that checks out you can follow to Q5 emitter and then pin 3 of each BBD.

If you get signal at pin 3 of the BBD and it wont pass at pin 7&8 with adjustment of the bias trimmer, might have to consider the BBD or clock again.

IC1 pin 1 voltage reading I'm going to assume is a mistake.

11

Build Reports / Re: Lectric-fx Downtown deluxe octave multiplexer

« on: November 09, 2020, 06:41:30 PM »

Niiiice! Glad I could be of assistance in your endeavor.


Sent from my iPhone using Tapatalk

Thanks Jimi, there are only a couple videos on youtube showing this pedal and your video was more focused in getting the best sounds out of it rather than just showing that it exists. Huge help.

So very clean

For any future readers that may feel there's a little bit of a volume drop, I suggested reducing R4 to 62k here.

That was my frustration also.


Sent from my iPhone using Tapatalk

Did I get you to do the same thing? If so, I'll have to have Keefe change it in the build doc.

12

General Questions / Re: Aion Blueshift

« on: November 09, 2020, 06:40:02 PM »

Do you get any tone change when you adjust the switches?

Just checking the BBD's aren't passing audio but static... best way to check that would be audio probe on pin 7/8 of the BBD.

Otherwise, voltages for IC1, 5, 7 & 12.

13

General Questions / Re: Aion Blueshift

« on: November 09, 2020, 02:04:45 PM »

Bias on IC3 is too low but otherwise, in range.

Next up, companders.

I'm a cruel mistress.

14

Build Reports / Re: Lectric-fx Downtown deluxe octave multiplexer

« on: November 09, 2020, 05:23:47 AM »

So very clean

For any future readers that may feel there's a little bit of a volume drop, I suggested reducing R4 to 62k here.

15

General Questions / Re: Aion Blueshift

« on: November 08, 2020, 10:02:30 AM »

Voltages

   As soon as my wife is done dragging me around looking for 6 cabinet knobs    I’ll get some. Since there are a gabillion IC’s I’m hoping you just want the BBDs or all gabillion?

After that traumatic experience, I'll let you off with just the BBD's to start