[sdiy] Digital delay memory

[Jay Schwichtenberg]

Tom,

Thanks.

I was dragged kicking and screaming into SMT. Once there I've found it's not
that hard with decent equipment, good lighting, thin solder (helps to keep
amount of solder on a joint low) and a good magnifier. Even with my 63 year
old eyes and hands. Yes, you have to be more critical of how you do things.
For the stuff I do I don't go smaller than 0805 discrete parts unless I have
to and if you want you can even go with 1202s. Clean the board well, use
flux and small solder helps for good joints. It doesn't hurt to have solder
wick handy either.

Good luck with the project and keep us informed.
Jay S.

-----Original Message-----
From: Tom Wiltshire [mailto:tom at electricdruid.net] 
Sent: Wednesday, April 27, 2016 1:12 PM
To: Jay Schwichtenberg
Cc: 'synth-diy DIY'
Subject: Re: [sdiy] Digital delay memory

Personally, I've being trying to out-do the PT2399 - shouldn't be too
impossible, right?!? But it implies a through-hole chip, and as close to a
single-chip solution as I can get. As such, the dsPIC and an external SRAM
isn't a bad fit.

Of course, if I go to SMD there are a million better quality options -
higher powered processors, better codecs, bigger RAMs. But where's the fun
in that?

I'd like to produce a DIYer-friendly digital delay chip that could be used
in stomp boxes and/or synths and which could produce longer, better quality
delays than the PT2399. I think it's doable. I've got some reasonable
hardware on stripboard, and I'm working on the firmware. With a bit of luck,
I can chuck a few extra features at it.

I'll keep you posted.

Tom


On 27 Apr 2016, at 19:29, Jay Schwichtenberg <jays at aracnet.com> wrote:

> I've been thinking about doing some DSP stuff and delay line stuff with
the
> newer MicroChip PIC32MZ series of processors. They're not really cheap but
> have up to 512K bytes of internal RAM and an I2S interface. When start to
> think about putting something together with SPI RAM with your time, board
> space and PCB development then to me the extra cost becomes trivial.
> 
>
https://www.olimex.com/Products/PIC/Development/PIC32-HMZ144/resources/PIC32
> -HMZ144_UM.pdf
>
http://www.digikey.com/product-detail/en/olimex-ltd/PIC32-HMZ144/1188-1160-N
> D/5247127
> 
> We see a lot of little ARM boards come out like the Teensy/Arduino for
> example. I'd like to see something like that with a higher end ARM chip on
a
> bigger board with USB and bootloader, external fast ram and more pins
broken
> out. That to me would be a good basic platform for doing a whole lot of
> stuff. Main problem for hobbyists like us is most ARM chips that have an
> external memory interface are in BGA (Ball Grid Array) packages. These
would
> require some form or reflow soldering. Some people have used toaster ovens
> and hot plates to do that but it sounds pretty tricky for the average
> person. Also the boards would probably have to be more than 2 layers with
> buried and blind vias.
> 
> Good luck.
> Jay S.