Slow Danse Macabre—Dimension-P

[chip]

I finally figured out how a Boss Dimension C works and got all excited that I was going to invent a way to do it with PT2399s...only to find out that it had been published at least as early as 2011 as the Dimension P.

It's not exactly how I would have done it (not because I'm an expert—I just only know one way), but I wanted to make this one first to see it go. It uses what Electrosmash calls the "Pin 2 hack," where the modulation is on the reference voltage on pin 2 instead of the VCO on pin 6, like where it was when I built my Pelota modulated delay.

Anyway, it works. It won't stay perfectly motionless at really high depth settings, but it's pretty good for a PT2399 chorus. I'm still going to try it the other way, more like a Pelota. I'm just working up to that, since it's a lot to do on vero for me.

The full writeup is here: https://dunningkrugerfx.com/slow-danse-macabre

 

[chip]

Update:

I finally did it the other way, more like a modulated Pelota delay with all the filtering and stuff (with a fixed delay time, set about as short as a 2399 will go).

It may still need some fine tuning, and maybe doesn't do the Dimension-C thing as well as the first one, but it definitely does something and I'm going to mess with it a bit. It is the most complicated thing I've ever built, and I feel like I learned a bunch, so like the tattoo says, NO RAGRETS.

Full writeup is here: https://dunningkrugerfx.com/another-dimension

Pay no attention to the mess.

 

[Gordo]

Seriously cool artwork there, and really who can resist purple? Very nice work here.

 

[jhaneyzz]

Update:

I finally did it the other way, more like a modulated Pelota delay with all the filtering and stuff (with a fixed delay time, set about as short as a 2399 will go).

It may still need some fine tuning, and maybe doesn't do the Dimension-C thing as well as the first one, but it definitely does something and I'm going to mess with it a bit. It is the most complicated thing I've ever built, and I feel like I learned a bunch, so like the tattoo says, NO RAGRETS.

Full writeup is here: https://dunningkrugerfx.com/another-dimension

Pay no attention to the mess.

View attachment 48966

You sir, are a madman of just the right sort...

bravo...

The sound sample is really nice, except for that nasty last bit with the Emomaster > Toynbee, Had to take a shower after listening to that...

 

[chip]

Seriously cool artwork there, and really who can resist purple? Very nice work here.

Thanks. Rustolem "French Lilac" is as close as I could get to DC-2 color, which is very much the color of this effect to me .

 

[chip]

You sir, are a madman of just the right sort...

bravo...

The sound sample is really nice, except for that nasty last bit with the Emomaster > Toynbee, Had to take a shower after listening to that...

Thanks. Yeah, that Uglyface sound is certainly, uh, something, but it's my go-to for "lets get weird."

 

[swyse]

That's awesome. I wonder if the 6v regulator instead of 5v like some little angel chorus mods would help this. I love the writeups you do on your site and the sound clips are greatly appreciated!

 

[chip]

That's awesome. I wonder if the 6v regulator instead of 5v like some little angel chorus mods would help this. I love the writeups you do on your site and the sound clips are greatly appreciated!

The ideal voltage for a 2399 is 5v, right? I think I've seen some that use 4.5v from a voltage divider making half of the supply voltage instead of regulated power—is that what you mean or is there an advantage in pushing it up to 6v? I think the "absolute max" according to the spec sheet is 6.5v, so it seems like it would be tight, but if there's some advantage to flying close to the sun, I'd be curious. FYI, both of these use 5v regulators and not half of the 9v supply to power the 2399s.

Thanks for checking it out!

 

[swyse]

The ideal voltage for a 2399 is 5v, right? I think I've seen some that use 4.5v from a voltage divider making half of the supply voltage instead of regulated power—is that what you mean or is there an advantage in pushing it up to 6v? I think the "absolute max" according to the spec sheet is 6.5v, so it seems like it would be tight, but if there's some advantage to flying close to the sun, I'd be curious. FYI, both of these use 5v regulators and not half of the 9v supply to power the 2399s.

Thanks for checking it out!

I haven't ever tried it, but I did a bit of research on the little angel when I was prototyping a chorus and I saw some suggestions that the 6v regulator lets you get a lower delay time on the pt2399 and a more lush chorus as a result.

 

[chip]

Huh. The minimum delay time is definitely a limiting factor, especially when you're trying to modulate it, but I don't immediately get how more voltage would change a digital chip. I guess there are analog parts too. I'll have to research it more.

 

[DGWVI]

I haven't ever tried it, but I did a bit of research on the little angel when I was prototyping a chorus and I saw some suggestions that the 6v regulator lets you get a lower delay time on the pt2399 and a more lush chorus as a result.

If you use an HT8970 (pin compatible swap with the pt2399), it can go even lower

 

[swyse]

Huh. The minimum delay time is definitely a limiting factor, especially when you're trying to modulate it, but I don't immediately get how more voltage would change a digital chip. I guess there are analog parts too. I'll have to research it more.

I'm actually not sure either, but I found where I saw the suggestion. https://www.diystompboxes.com/smfforum/index.php?topic=86380.msg723650#msg723650 post 10 if the link doesn't take you there.

 

[chip]

If you use an HT8970 (pin compatible swap with the pt2399), it can go even lower

Oooh, that would be perfect. They just seem impossible to find. I haven't looked that hard, but it seems like mostly "some guy on Ebay" or stuff like this, which appears to include a low-budget AI image generated from the prompt "two DIP-16s mating."

 

[DGWVI]

Oooh, that would be perfect. They just seem impossible to find. I haven't looked that hard, but it seems like mostly "some guy on Ebay" or stuff like this, which appears to include a low-budget AI image generated from the prompt "two DIP-16s mating."

View attachment 48983

The hell kinda parasitic dipswitch fuckery is that?


SmallBear has em ($5?! I bought a ton of em when they were a buck a piece)
Not sure, but if you're in the US, send me a DM

 

[chip]

Oh, shit, buying now. Thanks!

 

[chip]

So, while I wait for these to ship, @DGWVI I see that these have less than half the RAM as a PT2399, and I can imagine what that would do on the "long" end of delay, but not the "short" end. You're used these, right? Is the short end of the delay naturally shorter (i.e., if I were to plug it straight in to an existing circuit, would the delay be shorter?) or does the resistance on Pin 6 also need to be lowered? I assume they have the same latching issue as a PT2399 when you try to make it as short as possible?

I can mess with it. Just curious.

 

[DGWVI]

So, while I wait for these to ship, @DGWVI I see that these have less than half the RAM as a PT2399, and I can imagine what that would do on the "long" end of delay, but not the "short" end. You're used these, right? Is the short end of the delay naturally shorter (i.e., if I were to plug it straight in to an existing circuit, would the delay be shorter?) or does the resistance on Pin 6 also need to be lowered? I assume they have the same latching issue as a PT2399 when you try to make it as short as possible?

I can mess with it. Just curious.

Yes the minimum delay time will be shorter right away

Not at home, so can't record a vid, but here's a
Demo of the Sea Horse with HT8970.
That one uses the 5v regulator- but, 6v up to around 6.5v will reliably give even shorter times.

They do have the same latching issue, and there have been times I've had to audition several HT8970s, the same as with the PT chips

When I get back, I'll try to whip something else up to demonstrate and a/b it with the PT chip

 

[chip]

Awesome, thanks. Don't go to too much trouble on my account, but I appreciate the ideas

 

[chip]

@DGWVI I dropped some HT890s in it. It's hard to do an AB test because the two delay boards are stacked, but the chips definitely work and sound different. I'm not sure if they're really more lush, but I may need to tweak other things.

The following sample is effect off > gradually more and more speed and depth > the big thunk indicates when I turned it down to single delay mode:

https://dunningkrugerfx.com/wp-content/uploads/anotherDimension3.mp3

(I don't really care about single delay mode that much because I already have a Caesar that rocks for that)

Anyway, I may need to mess with it more. I'm pretty sure the "mixer" section is not right, because my math assumed that all the signals were the same and they're not. I also had to juice the resistor in the feedback loop because the whole effect was below unity. It's getting there though. Appreciate the tip on the on the other delay chips.

 

[DGWVI]

@DGWVI I dropped some HT890s in it. It's hard to do an AB test because the two delay boards are stacked, but the chips definitely work and sound different. I'm not sure if they're really more lush, but I may need to tweak other things.

The following sample is effect off > gradually more and more speed and depth > the big thunk indicates when I turned it down to single delay mode:

https://dunningkrugerfx.com/wp-content/uploads/anotherDimension3.mp3

(I don't really care about single delay mode that much because I already have a Caesar that rocks for that)

Anyway, I may need to mess with it more. I'm pretty sure the "mixer" section is not right, because my math assumed that all the signals were the same and they're not. I also had to juice the resistor in the feedback loop because the whole effect was below unity. It's getting there though. Appreciate the tip on the on the other delay chips.

I can definitely hear the shortened delay time, and thicker movement comparing your clips side by side.
Both sound great, though.

What schematic are you working from?