HI
If this topic is not at is right place please move it.
That’s said, I would like to change the DAC I currently use SLSM M100 linked via USB to one connected to RPI3 via GPIO port.
The new dac must be Hardware volume control compliant to volumio.
My question, concerns how the Hardware volume control is implemented.
I understood software is a calculation on the bits with the pb of quality… OK
So how the harware volum control works ? for me hardware means at the output of the DAC there a hardware component that control the volume, like would do a potentiometer, or any chip specilized like (PGA2311, CS3318, etc.)
When see the description of DAC, hifiberry, allo, for exemple this is not eplained what technology is used.
So is Hardware volume control really hardware ? or a mix ?
Thanks if someone can clarify this ?
before buying a new one how check I do the right choice ?
georges
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Hardware control means that inside the the DAC, a set of components or logic are in charge of modifying the output level. Most of the time, manufacturer does not really document how it is done. Search the internet for that. But when the Alsa device detect an HW implementation, it is available in volumio.
I already saw hardware providing HW control but with no effect due to a bad/wrong implementation. In that case, only software volume control allows to change it. In volumio it’s done in 24b calculation to keep quality as best as possible…
Thanks Balbuze. So is there a way to select which DAC to buy and be sure it supports the true HW control ? I assume that this is not allowed here to list the oppropriate dacs, but put 60-100$ and discover it does not fit the requirements, it’s a same.
in the most advanced DAC chips, the dedicated circuit for setting the volume is inside the chip itself.
the linux kernel driver gets the new volume value to be set, and translate this value into a command sent to the DAC chip via I2C.
inside the DAC chip, this value is used to apply the proper gain or attenuation to the analog output signal.
to make it simple, it’s like if the PGA2311 or CS3318 or similar is inside the DAC chip, controlled by the Raspberry Pi with a digital command.
if you want a DAC with such a feature, just look for “Hardware Volume Control” in the spec-sheet. If you have doubts about a specific model, you can write it here and we can help you with checking it
The topping D10s has served me well for many years.
it has hardware volume control thats fully compatible with Volumio
Very neutral sounding.
One of the features I like about it, is the hardware volume also passes back out the optical/ coax spdif so you can connect another DAC/Amp and both get controlled by Volumio Ideal for multiple sets of headphones and one source. But thats just my use case
HI Damur
As you suggested, here is the list (price sorted) of the dacs compliant RPI3 & 4 I have the possibiliy to get.
To drive the discussion, here are some comments.
I use Qobuz and chromcast audio (limited to 24bits 96khz) the dac via toslink is SMSL M100 everything works fine.
I would like to have plenty use of the Hres (192khz), for that I installed volumio and connected the dac via USB to the RPI3. That works but have noise, plops etc often in 192khz, sometimes on 96. I assume this is a pb with the USB.
So I assume if I use a DAC directly connected to the RPI, this will solve the issue. Two key points would motivate the acquisition :
-Better sound rendering that the SMLM100
-Hardware volume control (set by volumio) to connect it directly to the Class A amplifier.
Your help will be appreciated.
(45€) AUDIOPHONICS I-Sabre DAC ES9023 TCXO Raspberry Pi
(54€)HIFIBERRY DAC2 PRO Module DAC PCM5122 pour Raspberry Pi Burr Brown 24bit 192kHz
(99€) ALLO BOSS V1.2 DAC PCM5122 32Bit / 384kHz
(99€) AUDIOPHONICS DAC I-Sabre ES9038Q2M Raspberry Pi / I2S & SPDIF / PCM DSD Alimentation USB-C
to reply to your question, if you use a DAC connected directly to the RPi GPIOs you will solve the plop/noise problems, even with hi-res playback (96kHz, 192kHz)
from the products you listed, here the response if they have or not HW volume control
AUDIOPHONICS I-Sabre DAC ES9023 → it does not have HW volume control
HIFIBERRY DAC2 PRO → it does have HW volume control
ALLO BOSS V1.2 → it does have HW volume control
AUDIOPHONICS DAC I-Sabre ES9038Q2M → it does have HW volume control
the PCM5122 is one of the DAC chips with HW volume control, and the linux driver of the HIFIBERRY DAC2 PRO and ALLO BOSS V1.2 makes use of this capability
I had the HifiBerry DAC2 pro and was pretty happy with it. The D10S was a significant upgrade. Both very good value, but the Topping is amazing at that price. Plus you get orange numbers!
We connected an RPI4 to a Devialet Expert 200 via USB and unfortunately got really, really bad results.
Then we used an Allo DigiOne (RPI3) and connected it to the same Devialet Expert 200 with coax. The sound was massively better - fantastic! It really was worlds apart!
I would like to test the same thing with a Topping E50 DAC. (with an Allo Nirvana for RPI and DAC) But I won’t get to it until the weekend / next week. I’ll be happy to share my experiences later when I’m ready.
But yes, you have to use the software volume. With 24bit resolution in Volumio this shouldn’t be a problem.
Please don’t forget that a USB DAC might have problems if connected to a RPi3, due to the poor implementation of that part (those problems have been solved on RPi4).
According to me, on a RPi2/RPi3 the best option to avoid problems is still a HAT DAC connected to the RPi GPIOs
