Author Topic: alternative to rpi3a+  (Read 805 times)

cuder

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alternative to rpi3a+
« on: October 01, 2022, 08:41:43 PM »
Hi, i couldn't get in time another rpi 3a+ for my pi stomp 1.x. So there is alternative? or should i buy the pi stomp core?

Randall (Admin)

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Re: alternative to rpi3a+
« Reply #1 on: October 02, 2022, 12:10:34 AM »
You never ordered a pi, or you need an extra?  I could send you a 3A+ for $30 (USD) plus shipping $16 to Chile.  I was fortunate to get some back-stock from the RPi foundation.  Could probably send other parts too if you missed out on any.  You have a v1 enclosure, correct?

BTW, v1 and v2 (core) use the same code base.  v1 has more flexible I/O.  v2 has the color LCD.  Sonicly they should be virtually identical.

cuder

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Re: alternative to rpi3a+
« Reply #2 on: October 02, 2022, 05:21:07 PM »
can you? that would be awesome. Yep i don't order a rpi, because i had one but, it got damage i couldn't use anymore.

Erajer

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Re: alternative to rpi3a+
« Reply #3 on: January 02, 2023, 12:32:02 PM »
Hello I extend the question to the last generation of rpi  :)

What about the rpi4 and even the 400 ? Is the processing power step up in the pi stomp worth it ?
What about the 4 or 8 gb ?

Should I expect less latency too ?

Randall (Admin)

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Re: alternative to rpi3a+
« Reply #4 on: January 02, 2023, 01:34:43 PM »
Pi's with faster clocks or more RAM can surely help with performance.  That doesn't mean a given pedalboard will suddenly sound or perform better, or have less latency if you upgrade your pi.  Just that you have more options to make it do more before incurring dropouts.

As a point of reference, I currently have two pi-Stomp core systems that I use for testing.  One has the standard 3A+ w/ 512MB RAM,  the other a CM4 with 2GB RAM on a B-format carrier.  Here's what I saw when loading the same pedalboard on each...

Pedalboard3A+ CPU/RAMCM4 CPU/RAM
AmpBud26%/60%12%/16%
Grungy45%/60%23%/17%
Playground (All FX enabled)59%/63%30%/18%

Each pedalboard "performed" the same on either.   But you can see that the CM4 definitely had more CPU headroom on tap.  It used about half as much for each pedalboard.  And used about 1/4 the amount of RAM (since it has 4x as much)

So with the more powerful system, you're less likely to incur dropouts (XRUNS).   With that extra power and without the worry of dropouts, you could choose to add more plugins, use more CPU intensive plugins or change your sample rate to reduce latency.  For my systems shown above, I run 48k/128 Frames, so 5.3ms Latency.  Because my most hoggy pedalboard, "Playground" is pushing 60% CPU, that's a good configuration compromise for me using the 3A+.  But, with the CM4, if I wanted less latency, I could bump up to 96k to get 2.7ms latency and probably still not incur dropouts.

All that said, the form factor of anything but a 3A+ will not fit well with a pi-Stomp v1 or v2 ("core") into an enclosure.  v3 however, will be designed to accommodate "B" form factor boards.