Oh sorry, I should clarify, I meant as a power amp for headphones, much less power needed. Thanks for the reply, I didn't know that this little amp could even power speakers. If so, I may just build a set, would be a first for me since I'm only a headphone listener.
Considering that the ACP+ PSU has 250mA for each channel, what exactly were you expecting? 😁😁😁
Given any speaker has higher inductance at the low end than a headphone, that is to be expected with lower damping factor and limited current output
I will try using the DAC as a volume control though, that sounds interesting. I thought I read that using digital volume control limited the dynamic range or something like that which is most of the reason I've never bothered with it even though my DAC has a volume knob and a preamp mode.
Yes, it absolutely does. Might affect SNR as well? I'm unsure on that part but digital volume control throws out the bits
Not a particularly big deal if you already are on a 32bit S-D as the real range is more of 24bit but I'm unsure if it cuts off from the real range when using digital volume control
It's not so much that the digital volume control is so good but rather the ALPS volume potentiometers are just ok and the audio quality is improved if you bypass it using digital volume control, that is if your dac is well built and has a quality power supply or even better replace it with a resistor step attenuator. Reading this thread, a step attenuator volume control is a significant upgrade. That's probably my next mod.
1% distortion looks way too high to me. How much bias is your amp running at? What is the voltage before the output cap?
Measure voltages across R12 (Ur12) and R13 (Ur13).
Current through them is Ur12/R12 and Ur13/R13.
What volume attenuator resistance value do you recommend for the ACP? There are attenuators that are made at 10k, 50k, 100k, 250k, 500k.
@ericrosenfield
I watched your video "You Don't Hear Things the Way I Do (on DACs with PecanPi + PecanPi+ vs. SMSL VMV D2R) " and was reminded how I felt about PCM and DSD. Have you experimented with DSD format played through the SMSL D2R? Or do you not hear an improvement? Your pecanPi however converts dsd back to PCM before processing to analog (according to it's website) so I ask about the SMSL.
I watched your video "You Don't Hear Things the Way I Do (on DACs with PecanPi + PecanPi+ vs. SMSL VMV D2R) " and was reminded how I felt about PCM and DSD. Have you experimented with DSD format played through the SMSL D2R? Or do you not hear an improvement? Your pecanPi however converts dsd back to PCM before processing to analog (according to it's website) so I ask about the SMSL.
If I remember the alps was a 20k. I used a goldpoint 25k.
1.0 X V24-2-25K
Goldpoint Stereo V24 Stepped Attenuator, 25K
$165.00 USD
1.0 X V24-2-25K
Goldpoint Stereo V24 Stepped Attenuator, 25K
$165.00 USD
So what's weird is that DSD doesn't seem to work on my D2R despite it claiming that it does. When I try to send DSD to it, it still says "PCM" on the screen and when I tried to use the Colibri DAC DSD Test to only send DSD to it, I get no sound at all. I emailed SMSL about it and they claimed I was doing something wrong and then sent me to generic instructions for Windows. When I explained I was on a Mac they didn't respond. So the short answer is that I have not been able to try DSD on it. I did get DSD working on my Hiby DAP though and played a DSD recorded album put out by PS Audio and it sounded very good, but I'm not sure how to tell the DAP to convert the PCM audio files on the device into DSD (I could try looking again). Anyway, the short answer is that I've not been able to meaningfully compare DSD and PCM on my system.