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Hardware Parametric EQ like APO

alto

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Are there any hardware parametric EQs out there which you can somehow chain with your dac and amp?

The use case I have is that I have two computers (work and personal) and I dual boot between Linux and Windows on my personal computer, i.e. I have 3 operating systems where I have to change PEQ settings if I move between these systems and change headphones. So I got to wondering if there is a hardware solution for this out there, basically like having Equalizer APO in a box, perhaps with a USB or web interface. This would allow me to have the EQ as an external device and not have to keep updating settings when switching between systems.
 
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alto

alto

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I took a look at MiniDSP and at first glance it looks like it fits the bill nicely.
I do have some follow up questions, and I realize I have to elaborate on my requirements a little bit, for which I apologize in advance:
  • I'm about to receive a Topping A90D+D90LE stack, so I would like to keep the EQ component balanced as well I suppose, I guess MiniDSP Flex with balanced TRS connectors is the (only?) device from MiniDSP that fills this requirement?
  • The EQ software in MiniDSP seems to have some limitations, like you can't have more than 10 presets, and you have to manually insert each value of the EQ profile. Most importantly though it has limitations for the values, like Q has a minimum of 0.5 but EQ profiles can have lower values than that. This kind of irks me, but I'm not sure how much that really matters?
  • The cost of a MiniDSP Flex with balanced IO is 570USD, which is a lot since I only need the PEQ while the device does a lot more than that, it seems quite overkill for my use case. Are there any other cheaper alternatives that focus more on just the PEQ functionality so I don't have to shell out for Bluetooth, Dirac etc?
 

Chrise36

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I took a look at MiniDSP and at first glance it looks like it fits the bill nicely.
I do have some follow up questions, and I realize I have to elaborate on my requirements a little bit, for which I apologize in advance:
  • I'm about to receive a Topping A90D+D90LE stack, so I would like to keep the EQ component balanced as well I suppose, I guess MiniDSP Flex with balanced TRS connectors is the (only?) device from MiniDSP that fills this requirement?
  • The EQ software in MiniDSP seems to have some limitations, like you can't have more than 10 presets, and you have to manually insert each value of the EQ profile. Most importantly though it has limitations for the values, like Q has a minimum of 0.5 but EQ profiles can have lower values than that. This kind of irks me, but I'm not sure how much that really matters?
  • The cost of a MiniDSP Flex with balanced IO is 570USD, which is a lot since I only need the PEQ while the device does a lot more than that, it seems quite overkill for my use case. Are there any other cheaper alternatives that focus more on just the PEQ functionality so I don't have to shell out for Bluetooth, Dirac etc?
Can't you use one system as input for the other with the right soundcard?
 

staticV3

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@downhouse
What will your D90LE be plugged into? A PC? TV?

If software EQ is not an option and you're fine with inputting audio via S/PDIF or Toslink, then you can potentially get an inline DSP with higher transparency than the Flex Bal, at a much lower cost, using a Raspberry Pi running CamillaDSP. See here:



Edit: USB in->DSP->USB out works too!
 
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alto

alto

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@downhouse
What will your D90LE be plugged into? A PC? TV?

If software EQ is not an option and you're fine with inputting audio via S/PDIF or Toslink, then you can potentially get an inline DSP with higher transparency than the Flex Bal, at a much lower cost, using a Raspberry Pi running CamillaDSP. See here:



Edit: USB in->DSP->USB out works too!
The D90LE will be connected to my work and private computers, I switch USB devices between them with a USB peripheral switch, i.e. mouse, keyboard, audio interface and soon the D90LE, so it will be connected to one of the computers at any given time.

I'm not familiar with the pros and cons ov S/PDIF and Toslink as I've never really used those interfaces before.
With USB in -> DSP -> USB out, do you mean that it would be possible to put a CamillaDSP before the D90LE in the chain, i.e. CamillaDSP -> D90LE -> A90D?

I had a quick look at the CamillaDSP github page but I didn't see a mention of support for PEQ profiles like you would get from AutoEq or oratory1990, is that supported?
 

staticV3

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With USB in -> DSP -> USB out, do you mean that it would be possible to put a CamillaDSP before the D90LE in the chain, i.e. CamillaDSP -> D90LE -> A90D?
Yes.
I had a quick look at the CamillaDSP github page but I didn't see a mention of support for PEQ profiles like you would get from AutoEq or oratory1990, is that supported?
You can definitely apply PEQ profiles from AutoEQ or oratory using CamillaDSP, but you have to copy the values over manually (takes like 30 seconds).
 
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alto

alto

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Yes.

You can definitely apply PEQ profiles from AutoEQ or oratory using CamillaDSP, but you have to copy the values over manually (takes like 30 seconds).
It looks very interesting and I like that you can access it through a web UI. Are there any apparent downsides to using CamillaDSP in the USB chain, other than having to go through the setup which I don't think I'll have much issues with since I use Linux anyway, though the guide for the RPi you linked was very hefty.
 

ezublab

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The D90LE will be connected to my work and private computers, I switch USB devices between them with a USB peripheral switch, i.e. mouse, keyboard, audio interface and soon the D90LE, so it will be connected to one of the computers at any given time.

I'm not familiar with the pros and cons ov S/PDIF and Toslink as I've never really used those interfaces before.
With USB in -> DSP -> USB out, do you mean that it would be possible to put a CamillaDSP before the D90LE in the chain, i.e. CamillaDSP -> D90LE -> A90D?

I had a quick look at the CamillaDSP github page but I didn't see a mention of support for PEQ profiles like you would get from AutoEq or oratory1990, is that supported?
FusionDsp in Volumio allows to import directly headphone PEQ from Autoeq ;-)
1667215276264.png
or a txt file with PEQ (from REW)
1667215872875.png
 
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LTig

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Are there any hardware parametric EQs out there which you can somehow chain with your dac and amp?

The use case I have is that I have two computers (work and personal) and I dual boot between Linux and Windows on my personal computer, i.e. I have 3 operating systems where I have to change PEQ settings if I move between these systems and change headphones. So I got to wondering if there is a hardware solution for this out there, basically like having Equalizer APO in a box, perhaps with a USB or web interface. This would allow me to have the EQ as an external device and not have to keep updating settings when switching between systems.
Behringer Ultracurve Pro DEQ2496. It has no USB input but both balanced analog IO and digital IO. I used one many years as DAC with EQ in my main system.
 
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alto

alto

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Does CamillaDSP introduce any noticeable latency when it's chained as a RPi USB gadget?
 

mdsimon2

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Does CamillaDSP introduce any noticeable latency when it's chained as a RPi USB gadget?

I would expect 20-30 ms. I haven't measured latency in gadget mode but the default CamillaDSP chunk size results in a delay of 22 ms. Gadget mode seems like a good solution for your use case and is very easy to implement with the latest version of Ubuntu.

Michael
 
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alto

alto

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I would expect 20-30 ms. I haven't measured latency in gadget mode but the default CamillaDSP chunk size results in a delay of 22 ms. Gadget mode seems like a good solution for your use case and is very easy to implement with the latest version of Ubuntu.

Michael
That seems very reasonable. Since you're here I might as well ask regarding the RPi CamillaDSP in gadget mode, is it mandatory to have the data/power splitter as mentioned by DeLub in his thread? I.e. this one https://thepihut.com/products/usb-c-data-power-splitter

Also, since I take it you're quite familiar with running CamillaDSP on the RPi, have you had any issues with instability or unexpected behaviors, or have you experienced it running without hickups as if it was a boxed appliance like the MiniDSP?
 

mdsimon2

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I haven't used a data / power splitter, I just power it from the pin header. I have noticed that if you remove the power from the pin header the RPi will draw power from the USB host which probably isn't ideal.

I haven't had any hiccups with CamillaDSP and have been using it on my everyday system for over a year with an Okto dac8 pro. Previously I used a miniDSP OpenDRC-DA8 and would occasionally need to reset it, I have had no such issues with CamillaDSP.

At this point the only criticism I can offer of CamillaDSP is that it needs to run at a constant sample and if you want to use different input sample rates you need to restart CamillaDSP to match. Fortunately in gadget mode implementing rate switching is rather trivial.

Michael
 
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alto

alto

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I haven't used a data / power splitter, I just power it from the pin header. I have noticed that if you remove the power from the pin header the RPi will draw power from the USB host which probably isn't ideal.

I haven't had any hiccups with CamillaDSP and have been using it on my everyday system for over a year with an Okto dac8 pro. Previously I used a miniDSP OpenDRC-DA8 and would occasionally need to reset it, I have had no such issues with CamillaDSP.

At this point the only criticism I can offer of CamillaDSP is that it needs to run at a constant sample and if you want to use different input sample rates you need to restart CamillaDSP to match. Fortunately in gadget mode implementing rate switching is rather trivial.

Michael
What did you use in order to power the RPi from the pin header?
Also the sample rate thing when running as a gadget, how is that solved, do you restart the systemd service based on sample rate changes?
 

mdsimon2

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I use the female half of these -> https://www.amazon.com/gp/product/B01J1WZENK/ with a 5 V power supply that fits (2.1x5.5) with female to male dupont wires -> https://www.adafruit.com/product/826. But this is really stuff I had laying around and did not buy it specifically for this purpose.

@phofman's gaudio_ctl utility referenced in @DeLub's tutorial will automatically restart CamillaDSP with a new configuration for the appropriate sample rate, you can see that tutorial to see how the service configured but it runs gaudio_ctl pointing to a configuration file where you can specify the sample rate "camilladsp-{R}.yml".

Michael
 
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