DEMO Rock Mania delay pushed to the max - calling PT2399 experts

[JTEX]

Here's a quick demo of Rock Mania's PT2399 delay "overclocked" to about 0.6 seconds. That's about as clean as I could get the repeats at this 2x-out-of-spec delay time. I don't have experience with other PT2399-based delays, so I am wondering if it can get better than this. I kind of doubt it. What do you think?

https://on.soundcloud.com/wFCpr

 

[Paradox916]

Here's a quick demo of Rock Mania's PT2399 delay "overclocked" to about 0.6 seconds. That's about as clean as I could get the repeats at this 2x-out-of-spec delay time. I don't have experience with other PT2399-based delays, so I am wondering if it can get better than this. I kind of doubt it. What do you think?

https://on.soundcloud.com/wFCpr

I’m far from an expert but the hand full of pt2399 delays I have built that sounds about on par for a pt2399

 

[passtheducky]

I think “underclocked” is the word.

To get acceptable results, I think you would need to use companding or preemphasis, like with an analog delay.

 

[JTEX]

I think “underclocked” is the word.

To get acceptable results, I think you would need to use companding or preemphasis, like with an analog delay.

Underclocked is the right word indeed.

Regarding the compander idea, I don't really think so. That would help with BBDs, where the problem is the limited dynamic range (high noise floor), so you're squeezing the signal into a narrower DR, going through the BBD, then expanding it back. Like a noise reduction on a tape machine. PT2399 is not noisy when idle, until you pass a signal through it at too low a sample rate. The noise you hear affects the signal only (not the silence) and is due to quantization error/distortion. Unfortunately you can't fix that with a compander.

I rely wish they made a PT2400 or something with 2 or 3 times the amount of built-in RAM. That would fix it.

 

[Paradox916]

Underclocked is the right word indeed.

Regarding the compander idea, I don't really think so. That would help with BBDs, where the problem is the limited dynamic range (high noise floor), so you're squeezing the signal into a narrower DR, going through the BBD, then expanding it back. Like a noise reduction on a tape machine. PT2399 is not noisy when idle, until you pass a signal through it at too low a sample rate. The noise you hear affects the signal only (not the silence) and is due to quantization error/distortion. Unfortunately you can't fix that with a compander.

I rely wish they made a PT2400 or something with 2 or 3 times the amount of built-in RAM. That would fix it.

Maybe try looking at FV-1 that’s definitely a step up from a Pt2399, and and the foot print really isn’t that much bigger.

 

[JTEX]

Maybe try looking at FV-1 that’s definitely a step up from a Pt2399, and and the foot print really isn’t that much bigger.

I would have, if it didn't draw 40 to 70mA at 3.3V. That doesn't work for my intended use cases. Rock Mania can also be used as a belt or strap pack, or I can just throw it in a gig bag bag with some earbuds and take it to the beach, so battery life is super important. With a PT2399 (undervolted!), the whole pedal draws 12mA with everything on. This is less than just the official PT2399 idle current alone, which seems impossible until it isn't

 

[Paradox916]

Gottcha, yeah didn’t realize power consumption was an issue with what you were doing, makes total sense now.

 

[passtheducky]

Regarding the compander idea, I don't really think so.

I think so. Companding does reduce quantization noise in low bit depth systems. A lot of the *good* digital delays in the early days used companding. The Eventide 910 and some of the Lexicon units had them when the converters were 10 or 12 bit.

But it sounds like you don’t have the power to spare on additional active components so that is probably not the solution for you anyway.

 

[JTEX]

I think so. Companding does reduce quantization noise in low bit depth systems. A lot of the *good* digital delays in the early days used companding. The Eventide 910 and some of the Lexicon units had them when the converters were 10 or 12 bit.

But it sounds like you don’t have the power to spare on additional active components so that is probably not the solution for you anyway.

To my ear, at long delays, PT2399 did not clean up with higher amplitude signals compared with lower ones, so I didn't see how companding could help it. Not that I'd have the power budget to add it, like you said.
Also, louder high frequencies tend to run into slew rate issues, which can sound even more broken than some graininess. There went the pre-emphasizing idea. Basically I think the PT2399 is just not good enough, but couldn't find an alternative in the right power envelope.