Any simple volume controller kits?

[TornadoTed]

I am after a simple volume controller to put between my converters and monitors, just something simple like an SPL Volume 2.

https://spl.info/en/products/monitor-controller/volume2/overview.html

I've seen the Sound Skulptor controller and also one offered by a Dutch company whose name escapes me but they both have way more features than I need, are there any simple mastering grade kits out there.

 

[Andy Peters]

I am after a simple volume controller to put between my converters and monitors, just something simple like an SPL Volume 2.

https://spl.info/en/products/monitor-controller/volume2/overview.html

I've seen the Sound Skulptor controller and also one offered by a Dutch company whose name escapes me but they both have way more features than I need, are there any simple mastering grade kits out there.

Funny quote: "In contrast to digital volume controls which reduce the bit resolution at lower listening levels there is no degration in sound with an analog volume control ."

Le Sigh.

 

[ruffrecords]

Funny quote: "In contrast to digital volume controls which reduce the bit resolution at lower listening levels there is no degration in sound with an analog volume control ."

Le Sigh.

Absolutely right. There's that wonderful added Johnson dither for additional resolution below the threshold of hearing. A million times better than some pseudo-random number sequence.

Cheers

Ian

 

[Andy Peters]

Absolutely right. There's that wonderful added Johnson dither for additional resolution below the threshold of hearing. A million times better than some pseudo-random number sequence.

My point is that the "bit resolution" remains unchanged with digital attenuation. A 24-bit word going in is a 24-bit word going out.

 

[abbey road d enfer]

My point is that the "bit resolution" remains unchanged with digital attenuation. A 24-bit word going in is a 24-bit word going out.

You are indeed right academically; however, under attenuation, the resulting 24-bit digital words that hit the D/A are full of leading zeros...
That just shows how a single word can distort the meaning of a sentence; if they had just omitted "bit", or added "useful", they could not have been criticized.
It would really matter if it was audible in normal operating conditions, though...

 

[Andy Peters]

You are indeed right academically; however, under attenuation, the resulting 24-bit digital words that hit the D/A are full of leading zeros...

Under analog attenuation, the signal level decreases whereas the rails remain the same. If you were to digitize after that attenuation, you'd see zeroes in the upper bits.

It would really matter if it was audible in normal operating conditions, though...

Which is my point ...

 

[abbey road d enfer]

Under analog attenuation, the signal level decreases whereas the rails remain the same. If you were to digitize after that attenuation, you'd see zeroes in the upper bits.

That's correct, but we're supposed to listen in analog...or do we?
In their infinite wisdom, the designers of my Tascam 4800 have made the control room level pot analog, but my JBL monitors have DSP's in them... damn!The idea of listening to all these zeros is disturbing

 

[digistu]

I am after a simple volume controller to put between my converters and monitors, just something simple like an SPL Volume 2.

I'm also looking to DIY something like this.  Nothing too complicated - a couple of line level ins, a couple of monitor outs, switching between the two and a mono sum.  Would also be interested in any existing designs.

 

[abbey road d enfer]

I'm also looking to DIY something like this.  Nothing too complicated - a couple of line level ins, a couple of monitor outs, switching between the two and a mono sum.  Would also be interested in any existing designs.

I believe you're not the first one asking for this. There may be a number of threads in this group. When someone undertakes the task, they try to pack as much features as possible so as to please the larger number of users. Sometimes this takes the project way off. For example phase-reverse implies the use of either costly transformers or active electronics.
The big issue with passive solutions is to make sure they will work with all the possible combinations of connections: balanced-in to balanced-out, unbalanced-in to unbalanced-out, unbalanced-in to balanced-out, balanced-in to unbalanced-out. It makes the performance dependant on that of the equipment, in particular the CMRR of the amplifier or active loudspeaker.
Also remember that passive volume controls are not compatible with long cable runs.
I would suggest you buy a dual 5k pot and experiment with it; if you're satisfied, the,n you may add bells and whistles.

 

[Michael Tibes]

I am after a simple volume controller to put between my converters and monitors

There are many very reasonable looking and affordable solutions for that on  ebay or the Chinese auction platforms - potentiometer, chip or relay based. It might be a little hard to find because they sometimes use funny words to describe their stuff, but it is there. I believe with these you don't have to reinvent the wheel unless you want to ;-)

Michael

 

[Rocinante]

I believe you're not the first one asking for this. There may be a number of threads in this group. When someone undertakes the task, they try to pack as much features as possible so as to please the larger number of users. Sometimes this takes the project way off. For example phase-reverse implies the use of either costly transformers or active electronics.
The big issue with passive solutions is to make sure they will work with all the possible combinations of connections: balanced-in to balanced-out, unbalanced-in to unbalanced-out, unbalanced-in to balanced-out, balanced-in to unbalanced-out. It makes the performance dependant on that of the equipment, in particular the CMRR of the amplifier or active loudspeaker.
Also remember that passive volume controls are not compatible with long cable runs.
I would suggest you buy a dual 5k pot and experiment with it; if you're satisfied, the,n you may add bells and whistles.

Yep.
I started with wanting a passive balanced monitor controller. I am nearly finished a good deal later with a daw transport, pga2311 controlled, 4 in 4 out balanced i, unbalanced through to balanced out digital volume controller.

Some of those ebay shops have good stuff and great deals. Some are junk.
You can also hack some of them and modify them to fit your needs. Theres a couple of dudes at diy-audio who have modified some of them to become remote operated highly versatile professional tools. Linux works comes to mind. He makes cool stuff. Theres a few guys on the diy ayudio fb site that have also made some really incredible monitor controllers withmodified ebay boards.

 

[insideout]

https://www.jlmaudio.com/shop/passive-monitor-controller-pcb.html ?

 

[Rocinante]

https://www.jlmaudio.com/shop/passive-monitor-controller-pcb.html ?

That became the foundation of my latest monitor controller. I added a bit more but really its an awesome pcb as it is. I highly recommend it.

 

[Matt C]

https://www.jlmaudio.com/shop/passive-monitor-controller-pcb.html ?

I just built a passive monitor controller based mostly on this article.  Works well

 

[Andy Peters]

Yep.
I started with wanting a passive balanced monitor controller. I am nearly finished a good deal later with a daw transport, pga2311 controlled, 4 in 4 out balanced i, unbalanced through to balanced out digital volume controller.

I will write up and post my IR remote volume control box design and my studio monitor controller design. The former is simple stereo balanced in and out, the latter has four stereo balanced ins and four outs plus headphones. All based on PGA2320. Maybe by the weekend (I had gigs this past weekend and too much travel).

 

[Rocinante]

Andy,
Your controller is a thing of beauty that even the great gods of old would covet. It would really be appreciated.
Fwiw Ive been looking for a volume meter that displays in 7 segment db. Something one could connect to an already made volume controller. Does something like this exist?

 

[abbey road d enfer]

Andy,
Your controller is a thing of beauty that even the great gods of old would covet. It would really be appreciated.
Fwiw Ive been looking for a volume meter that displays in 7 segment db.

Do you mean an alphanumeric display? By essence, loudness varies quite rapidly, so the numbers would change constantly and be utterly illegible.


[/quote] Something one could connect to an already made volume controller. Does something like this exist?
[/quote] There are SPL meters that are used in public places, generally associated with an active SPL limiter. They sample the highest peak about every second and freeze the value for about one second or more. Is it what you want?
http://www.dateq.nl/en/product/spl-d2-2/

 

[Rocinante]

I guess i was unaware of the consistent flux in db that would make it unusuable.
To better explain; if one could get a db reading coming into the monitor controller/mastering switcher instead of a led peak meter.  It would be implementated within the controller possibly before or after the input amps.
But like you said if it was to erratic then that would be useless.

 

[Andy Peters]

I guess i was unaware of the consistent flux in db that would make it unusuable.
To better explain; if one could get a db reading coming into the monitor controller/mastering switcher instead of a led peak meter.  It would be implementated within the controller possibly before or after the input amps.
But like you said if it was to erratic then that would be useless.

The problem is that humans have to read the meter, so you have to pick a display-hold time that humans can handle. What's that time? Dunno. But I guess that a bar-graph LED meter showing instantaneous peaks is more useful, and maybe you can add the numeric display which can be set to show peak/peak-hold/average levels.

A monitor controller with a microcontroller-based switching system might be the ticket. Most micros are available with 12-bit ADCs capable of sampling at hundreds of kilohertz, along with an input mux. Buffer each analog channel, drive an input on the ADC mux, and the micro can do averaging and peak detect and whatever else you'd like to display, as well as driving the meter directly.

 

[Rocinante]

And of course Beis already worked this out.

http://www.beis.de/Elektronik/DPLCM/DPLCM.html

At 110 € for a full kit it aint bad  (especially considering what you get). If one wants to source parts it gets much cheaper. Thats if he still has it. I've enquired.  I think it works for optical spdif only but i asked about analog in.

Joe from JLM also had a really nice digital volume controller a good while back that unfortunately never became a project that i wish he'd sell pcb's for. Ill let you guys know what Beis says.