I am finally building a pedalboard

[xtian]

Yeah, I received the amp itself in short order, but am waiting on the PSU.

In the mean time I built a two button footswitch based on an Arduino Nano to send MIDI program change messages to my Helix board. Works great. Less than $20 in parts.

[JazzGuitarGimp]

I've taken a different approach; i run a little app called Set List Maker on my iPad. It can do a crap ton of stuff, but what I use it for mostly is to send midi patch change messages for each song in the set list. It can send multiple patch changes, all on different midi channels, so you can reconfigure a whole rack of effects with a single touch.

[roberto]

Arduino is a very easy way to control midi racks, both sending midi commands, inserting them or reading and control more things.
I've posted something here around one year ago, on how to control rythm patterns, and IIRC also how to send 8 CCs from pots, to control the parameters of some Fxs (my main rack unit has 5 midi Fxs, one midi looper and a midi tube preamp; my second one has 4 midi Fxs).

[roberto]

Good save, Roberto

English is not my first language, can I ask you to explain what's the right meaning of "good save"?

[xtian]

I've taken a different approach; i run a little app called Set List Maker on my iPad. It can do a crap ton of stuff, but what I use it for mostly is to send midi patch change messages for each song in the set list. It can send multiple patch changes, all on different midi channels, so you can reconfigure a whole rack of effects with a single touch.

How do you get from iPad to MIDI out?

[pompeiisneaks]

Good save, Roberto

English is not my first language, can I ask you to explain what's the right meaning of "good save"?

good recovery. good save means you just barely saved something from failure

~Phil

[JazzGuitarGimp]

I've taken a different approach; i run a little app called Set List Maker on my iPad. It can do a crap ton of stuff, but what I use it for mostly is to send midi patch change messages for each song in the set list. It can send multiple patch changes, all on different midi channels, so you can reconfigure a whole rack of effects with a single touch.

How do you get from iPad to MIDI out?

You start with the Apple Camera Adaptor, which gives you a USB port, then you plug in a MIDI interface. The interface I am using is no longer available. It was sold by Meritline.com I learned about the interface on the VGuitar forum (VGuitarforums.com), and they guys over there made it pretty clear that some MIDI interfaces work with iPad, while others do not. I bought the one they recommended as known to work. Since it is no longer available, a bit more research would need to be done to find a suitable replacement for the Meritline interface.

[xtian]

Lou, I finally received my PSU from China. Did you ever get your amp(s)?

[JazzGuitarGimp]

Hi Aaron,

Yes, they came last week, but not without filing a case and ebay intervention. 49-days from order to delivery!! But they are here and although I've not listened to them yet, I've done some testing on the bench with a signal generator, oscilloscope and dummy load. They're putting out just over 100 watts each into 8-ohm dummy loads. They run surprisingly cool, and take just baby-sips of current from the PSU. I am currently working on the second version of the preamp design; once it's up and running, I'll feed its outputs into the power amps and have a listen.

How are you lking yours!

Cheers,
Lou

[xtian]

Just powered up last night. The white noise at idle is much higher than my parts-express amp, but then, that one is running with 36v, and this new one is running with 132v. So I imagine the noise floor (and overall power) would be lower with lower voltage supply. This new amp, then, will be useful for on-stage only, not quiet, at-home practice. Too bad, because I love the size and weight in this ABS enclosure.

Any suggestions for throttling the voltage for a high/low output switch option?

OJcCcZ7+QRelVr9VeOrUkA.jpg

[xtian]

Let me revise my observation on white noise. The self noise from the amp is, in fact, very low. The white noise only became obvious when I plugged in my pedalboard. So the amp is not the issue, it's just the greater amplification that makes the noise floor obvious. I measured ~250 watts clean into a 4R7 resistive load.

My wiring could use a safety check. Because my chassis is plastic, and because there is nowhere to connect an Earth ground to the PSU, I just used a 2-conducor power cord. The grounds of my input and output jacks are connected together because they are connected on the amplifier board. So as long as the rest of my gear is safely Earthed, everything is A-OK.

HOWEVER, if I do NOT connect this amp's input jack to anything, I can measure 100vAC between the jack's ground tab and Earth, or just a couple of volts, depending on which way I insert the power cord into wall service. Is this a concern I should address? If so, how?

[JazzGuitarGimp]

Hi Aaron,

Two of the mounting holes (they have vias circling them) on the power supply board have connections to the amps' circuitry, and are intended to be earthed. One of them goes to the two, small, chunky blue disc capacitors; not sure what the other one connects to, but I wouldn't be surprised if it connects to DC GND. Also, IIRC, the AC Mains input connections are marked Line and Neutral, and these connections should be observed. Why the choice in plastic enclosure? Just curious. I have a new Hammond 1590DE aluminum enclosure I am not using, and could sell if it's large enough to house everything.

Cheers,
Lou