Maybe this is covered before but search did not come up with anything.
In my experience with various kinds of dsp crossovers with various kinds of volume controls I have come to te repetitve conclusion that in my case, as I often listen to levels at -65dB at night to -10dB occasionally at daytime full digital volume control isn't working.
I have tried digital volume control of Roon, digital volume control of a ESS9028Pro dac, digital volume control of a Wolfson dac and various other dacs of which I don't know the chipset. All work fine up to a cetain point (around -30dB) where they start loosing dyamics and detail. This never happened with any form of analog volume control I have used. What the cause of this is is not intersting to me, the fact that it has been repetetive so far is reason enough for me to be looking for a 8 channel volume control.
Besides, and maybe even more important, having an 8 channel volume control gives me the ultimate freedom of using whatever DAC, combination of DAC's, dsp processors, PC crossovers, soundcards or whatever in front of it because the biggest hurdle of all, volume control, has been covered.
My ideal volume control would have the following parameters.
1) 8 channels ganged that can be used either balanced or unbalanced
2) Remote controlled
3) Volume leveling preset per channel
4) if needed buffered outputs
Is there anything like this in existance? If so, I'd like to know it?
Anyone know of any designs, complete kits or a complete device?
In my experience with various kinds of dsp crossovers with various kinds of volume controls I have come to te repetitve conclusion that in my case, as I often listen to levels at -65dB at night to -10dB occasionally at daytime full digital volume control isn't working.
I have tried digital volume control of Roon, digital volume control of a ESS9028Pro dac, digital volume control of a Wolfson dac and various other dacs of which I don't know the chipset. All work fine up to a cetain point (around -30dB) where they start loosing dyamics and detail. This never happened with any form of analog volume control I have used. What the cause of this is is not intersting to me, the fact that it has been repetetive so far is reason enough for me to be looking for a 8 channel volume control.
Besides, and maybe even more important, having an 8 channel volume control gives me the ultimate freedom of using whatever DAC, combination of DAC's, dsp processors, PC crossovers, soundcards or whatever in front of it because the biggest hurdle of all, volume control, has been covered.
My ideal volume control would have the following parameters.
1) 8 channels ganged that can be used either balanced or unbalanced
2) Remote controlled
3) Volume leveling preset per channel
4) if needed buffered outputs
Is there anything like this in existance? If so, I'd like to know it?
Anyone know of any designs, complete kits or a complete device?
Hi, A bit of a problem for sure. My musing on the subject would be to use 8 op amps in non inverting mode and control the gain at the inverting input. Either by a voltage from a single pot or perhaps all tied together with a single variable resistor to ground. Let us know what you end up with as it is an interesting problem.
I have used motorized pots for this, but only for 6 channels (stereo 3 way) but gave up and used digital because my volume range was only ever 10dB and digital was fine for that, better than analog.
Certainly someone here will have an idea.
Certainly someone here will have an idea.
Sadly there is no simple 'perfect' voltage controlled amplifier.
The studio standard was dBx, now THAT Corp.
THAT Corporation 2181-series Trimmable Voltage Controlled Amplifier ICs
At lower price and less excellent performance, the V2164 is four good VCAs in one chip.
V2164 Quad VCA – Electric Druid
The studio standard was dBx, now THAT Corp.
THAT Corporation 2181-series Trimmable Voltage Controlled Amplifier ICs
At lower price and less excellent performance, the V2164 is four good VCAs in one chip.
V2164 Quad VCA – Electric Druid
Crafting an 8 channel volume control
The problem with doing volume control in the digital domain, is that you do it by throwing away bits of resolution. If you wait until the signal is in the analog domain, you attenuate the volume by reducing the overall voltage swing. In the analog domain resolution is consistent no matter what the volume is.
If I were looking to craft an 8 channel (or more) volume control, I'd use either the TI PGA2320 or MUSES attenuator chips. The TI includes an internal opamp. The MUSE chip is $2 more expensive and does not include an opamp. The MUSE chip requires a buildout circuit adding cost. Both chips are easily controlled via Arduino. You could add an inexpensive display to show attenuation in dB. You could also add an IR receiver for a couple of dollars and make it all remote controllable. You would have a have a slick solution that works well and sounds very good!
Just my 2 cents worth.
The problem with doing volume control in the digital domain, is that you do it by throwing away bits of resolution. If you wait until the signal is in the analog domain, you attenuate the volume by reducing the overall voltage swing. In the analog domain resolution is consistent no matter what the volume is.
If I were looking to craft an 8 channel (or more) volume control, I'd use either the TI PGA2320 or MUSES attenuator chips. The TI includes an internal opamp. The MUSE chip is $2 more expensive and does not include an opamp. The MUSE chip requires a buildout circuit adding cost. Both chips are easily controlled via Arduino. You could add an inexpensive display to show attenuation in dB. You could also add an IR receiver for a couple of dollars and make it all remote controllable. You would have a have a slick solution that works well and sounds very good!
Just my 2 cents worth.
If you really want to diy it:
relay switched pi attenuator @ 2K constant impedance with your choice of front and back end op amps. 1, 2, 4, 8, 8, 8, 8, 8 dB each for 47dB range. use 8 from single 10 pin ribbon.
Arduino controlled.
Bluetooth controlled (android phone ) and/or IR remote
Or quadrature input ( like wheel of mouse ) (I used a stepper motor )
You would have to balance / unbalance / balance or design balanced relay switched attenuator.
mine just 2 ch
relay switched pi attenuator @ 2K constant impedance with your choice of front and back end op amps. 1, 2, 4, 8, 8, 8, 8, 8 dB each for 47dB range. use 8 from single 10 pin ribbon.
Arduino controlled.
Bluetooth controlled (android phone ) and/or IR remote
Or quadrature input ( like wheel of mouse ) (I used a stepper motor )
You would have to balance / unbalance / balance or design balanced relay switched attenuator.
mine just 2 ch
Attachments
"...TI PGA2320 ... Neat device...will put it on my list to do someday."
And they can sound really good too! I am aware of some very expensive and well respected audiophile gear that have them in the critical analog path.
And they can sound really good too! I am aware of some very expensive and well respected audiophile gear that have them in the critical analog path.
Crafting an 8 channel volume control
The Cirrus CS3318 is another possible. The part is $25 but handles 8 channels. They can sound pretty good but every channel needs to be buffered IN/OUT.
The Cirrus CS3318 is another possible. The part is $25 but handles 8 channels. They can sound pretty good but every channel needs to be buffered IN/OUT.
Thanks for your replies guys,
I have been looking at the PGA series of chips also but to be honoust I don't want to DIY it so far as that solution. That would mean designing my own circuit and PCB from scratch. I'm more into loudspeaker building and point to point tube amps. I was hoping there was something like a 8 channel PGA2320 allready available with pre programmed operating control. I didn't expect such a thing to be widely available but I can't imagine it doesn't exist and I just haven't find it yet.
I did find something like this 8-channel relay attenuator: RA8 which sound very promising but it seems to be an unfinished thing but it is something I'm looking for.
I have been looking at the PGA series of chips also but to be honoust I don't want to DIY it so far as that solution. That would mean designing my own circuit and PCB from scratch. I'm more into loudspeaker building and point to point tube amps. I was hoping there was something like a 8 channel PGA2320 allready available with pre programmed operating control. I didn't expect such a thing to be widely available but I can't imagine it doesn't exist and I just haven't find it yet.
I did find something like this 8-channel relay attenuator: RA8 which sound very promising but it seems to be an unfinished thing but it is something I'm looking for.
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It is all what you mentioned in post # 1. No Bluetooth, but wireless.
Only not balanced.
The controller runs on a rechargeable battery so you can control all from the listening position.
The actual level channels can be placed out of sight if you want.
I designed and build it.
Jan
Only not balanced.
The controller runs on a rechargeable battery so you can control all from the listening position.
The actual level channels can be placed out of sight if you want.
I designed and build it.
Jan
It is 8 channels, each receiver box has 4 channels, so it is capable for stereo 4-way. Isn't that what you need?
Jan
Jan
Ah, I see I didn't look good enough at the pictures. I thought it where three the same units, one showing on the front, two on the back but it's two 4 channel receivers with one remote unit. Neat
What the basis of the volume control? PGA chip?
What the basis of the volume control? PGA chip?