Dear Rooners,
I am building new “vintage” tube amplifier and I want to add to it some basic functions, like remote control and DAC+ Roon endpoint.
I want to use Arduino as amplifier controller (remote control → volume, mute, on/Off, source selector) and as DAC Im considering using raspberry pi + audio hat+rpieee . In this case, I would like to be able to use Roon volume control → Arduino → analog device… does any one has any expertise with diy system to control analog hardware by Rpi+ropieee ? Is there any audio HAT with an analog output (for example 0-5V…) for the volume level control (or digital vol + and vol -), analog input for volume level feedback, digital output to On and digital input feedback On/Off. Or maybe I should try other solution/ system?.
Any tip or advice more than welcome;)
I Look forward to hearing from you.
Cheers!
Sam
Hi!
Sounds like a fun project! Synchronator will probably be useful to you. If not the actual software, at least the inspiration on how it uses a virtual device in Linux to catch roon’s device volume commands. I’m using it on two different systems to control the hardware volume from roon with RPI endpoints and it works quite well.
You might need to get a plain distro and install roon yourself however, I’m not sure roopiee will have everything you need to get that running.
http://therealmuffin.github.io/synchronator/
On one system I control the amp volume via a usb connected infrared LED. On the other system, I control the DAC/pre using a IR LED connected directly to a header pin of the RPI.
Seb
It does sound like a great project.
Before spending a lot of time on the remote analogue volume control - take a look at this paper by @DrCWO The final truth about DSP Volume Control in Roon | Audio Science Review (ASR) Forum.
I expect you could safe yourself a lot of hassle by just having an old fashioned volume control in the amp circuit - perhaps one per channel in case your tubes aren’t a perfect match - so you can match the levels to the range you want, and then just use roon’s digital volume control.
Hi Seb… I need to study a bit to understand how to use synchronator… ill definitely check it. Thank you!!
Hi Greg. Thank you for the reply!! I have nothig against dsp volume control but this solution has some consequences… in my proect (and actually in most vintige tube amps) tube preamplifier is the main/bigest noise generator in the system. Using dsp volume will require high volume of analog preamp = high noise level all the time… of course i can skip tube preamp but than ill change sound characteristic…
Now im considering to use i2c protocol… but first i need to learn how to use it… 
I also use a tube pre-amp for my main roon zone.
I set the level so it’s just a little louder than I usually listen - so for serious listening my DSP is usually doing less than -6 db.
So I’m not adding much extra noise.
Of course YMMV!