DREAM on

[Mark Hammer]

I just received the new Keeley Octa-Psi in the mailbox.  Thank you, Robert!

Still working my way through the various options. but I just HAD to open it up.  The fuzz side is analog, but the pitch-shfting is obviously digital.  Robert had told me a few years ago that he was moving away from the FV-1 and on to another platform.  So no big surprise when I didn't see one inside.  The unit employs a DREAM 5504B DSP chip.  Any experience with these or comments to offer?

[MetalGuy]

I've only heard about those but they look like a major overkill for just a pitch shifter.

[ElectricDruid]

I've only heard about those but they look like a major overkill for just a pitch shifter.

More than somewhat! 14 audio channels in and out and four 24-bit DSP cores does seem a *little* OTT!! 

I remember reading some datasheets for the DREAM stuff some years ago and thinking that it'd be fun to play with, but it's not the sort of stuff you just order from Farnell/Mouser/whatever so it's "hard to get" in that sense.

[Mark Hammer]

It may well be overkill for this pedal.  But I imagine that when one switches to a different DSP platform, you commit. That means you learn, over time and applications, what it can and can't do, and what it makes easier or precludes; something that will make itself known over the course of multiple pedal designs/intentions.

[ElectricDruid]

Totally agree.

And if you can, it makes sense to re-use the hardware too. JHS did their 3-series pedals and they all use the same enclosure with the same drilling. I bet several of them use the same FV1-based PCB too. Only the screenprint and the firmware changes. That's *such* a saving that it can make it make sense to waste a lot of apparent DSP power just to hit the next price break on chips/boards/whatever. You don't want to order a few hundred of several different things. You want to order a thousand of one thing. Or ten thousand, if you can!

The 3-series isn't the only example either. Some other builder did a similar thing, but I can't remember which right now.

[Mark Hammer]

Plenty of pedal-makers use the same form factor on their enclosures.  If not for all of them, then for most, or at least enough of them to make bulk purchase/contracting of the same enclosure and machining.  Boss, DOD, and Chase Bliss have stuck to the same physical form for years now.  And sometimes, the feature set is almost driven by how many holes there are to fill in the enclosure, and how they might be filled! (Hmm, we could put a rotary switch in there, or a dual concentric pot...).  And of course, many of us have seen PCBs that had legended "blanks", such that the same board could be stuffed in several different ways to make different pedals.

[Sweetalk]

I talked to Robert a couple years ago in a interview I made with him about the FV1 and told me that they were moving away of the FV1 to the Dream family of DSP. Like Mark said, when choosing a DSP family you commit to it, learning its ways, how to program it, how to make the PCB for it, circuit, etc, it's not something you like to have different types of DSP for each product.

[Digital Larry]

I just looked at the Dream website.  Not that I want to dive back into all that again but they do have a graphical tool for patch development which helps a lot.  Looks like there was a pedal dev board with 1/8" connectors but no idea where/if you can actually get one other than directly.

[MetalGuy]

Here's one from Profusion:
https://gb.profusion.uk/uk/sam5504fx-ek
And another one here:
https://www.corona-tech.com/en/product-page/5704gtfx2-ek