Arduino based LDR volume and source selection controller

Come on, you can do better than this, zdr. "A friend of mine" and "complete waste of money" ?
It's easy you know to start a flame and I don't feel comfortable with another similar thread. Let's keep it nice in this one.

BTW, did anyone manage to hack to original design so to avoid the mute pop ? I don't usually use mute function but I recently added the remote source change and since it mutes temporary the output (latest firmware) I can't avoid it. It's quite annoying.
 
Come on, you can do better than this, zdr. "A friend of mine" and "complete waste of money" ?
It's easy you know to start a flame and I don't feel comfortable with another similar thread. Let's keep it nice in this one.

I did not mean it as a flame ignition, but as a tribute to Vincent77 who designed this awesome device and on top of that - offered it to community completely free of charge, instead of making tons of money. I'm sorry if you saw it any other way. So agreed, let's keep it nice (and awesome).

BTW, did anyone manage to hack to original design so to avoid the mute pop ? I don't usually use mute function but I recently added the remote source change and since it mutes temporary the output (latest firmware) I can't avoid it. It's quite annoying.

It's not a firmware issue, it's hardware design issue with original boards. All-in-one 4x2 boards have separate dedicated output relays that can mute without pop as they do not switch any DC (unlike calibration relays used for mute in original boards). There had to be a change in firmware to accommodate hardware change though.

The only remaining little annoyance is the volume "bump" when VxD is switching between low and high impedance mode. I compensated it as much as I could in the firmware, but it still can be noticed with white noise.
 
OLED 1602 is perfect fit for F6 châssis from AliExpress:

26495336378_35f305f171_o.jpg
 
I don't mind people making money as long as they do it properly, I'm quite tolerant actually.
We can't go wrong if we stick to the thread's subject, IMHO one of the best contributions in this forum. :up:

Yep, I knew it's hardware related, that's why I mentioned 'hack' but reading your reply, even that seems undoable. I guess we'll have to bite the bullet in this one
 
Hi guys, can this device be used with some form of active linestage to build a full preamp?

That would be an excellent use of it. It have a dual output, so you could even configure it as a two output preamp. Ie one output with gain and one passive output.

I mated this with the Salas DCG3 myself and could not be happier with the sound and function.
Build pics here:
Salas DCG3 by Twst - Google Photos
:)
 
That would be an excellent use of it. It have a dual output, so you could even configure it as a two output preamp. Ie one output with gain and one passive output.

I mated this with the Salas DCG3 myself and could not be happier with the sound and function.
Build pics here:
Salas DCG3 by Twst - Google Photos
:)

Very nice work!

Just wondering what is gain in preamp used for these days? I mean, why do you even need gain in preamp, unless you need a phono stage? I am using my VxD with dedicated headphone amp on one output, and with RMI-FC100 amp on the other.
 
Precerving dynamics and impedance matching.
I think preamps with gain most of the time just sounds more open and alive. Even if it does not usually provide any more gain than the source alone could.

At a minimum I would use a buffer. But I guess that's system dependant and personal taste. :)
 
I found few serious bugs in the code:

1: If you set a volume in upper half and try to set bias, you will notice that lower LDRs (shunts) are way off. It's because the upper half of the volume values set LDRs range to high, causing shunt resistance to fail to be set properly. Workaround is to do bias setting with volume below 20. Fix will be to set the volume to 0 when entering setup menu, and to restore on exit.

2: Power off detect routine triggers saving of IO values into EEPROM. If you play trigger happy with power switch, not only that values might not get saved, it erases the whole EEPROM, and sometimes, even the whole program memory. It happened as often as in 1 attempt out of 10, on two different boards. I'm not sure if this is a problem with some Atmel batch, but I will kill this routine anyway and save values when screensaver kicks in instead. I will also try to rotate EEPROM address locations for IO and volume, to prolong it's lifespan.
 
Last edited: