New to Hi-fi, Questions about Set-up

[jamclear276]

I've had KRK Rockit 6s for some time, and wanting better sound quality I did a bit of googling and learned about lossless audio. Most of it still goes far over my head, but after some googling I found that I'd be able to do a pretty rudimentary setup with items I already owned. I suppose I should describe the setup before I get into the issues which have arisen:

First, I set my Macbook Pro's Built-in Output to 2ch 24-bit Integer 96.0 kHz, and downloaded ALAC tracks which I play in Vox; I ran a digital optical cable from the Macbook's 3.5 mm headphone output to a Digitial to Analog Audio Converter; the DAC output had both RCA and 3.5 mm headphone, and the only cable I had was a 3.5 mm to RCA chord, which I plugged into an American Audio M822FX mixing console that controls the KRKs/headphone output.

Now I'm sure someone with knowledge of lossless audio will (hopefully) be able to spot any glaring issues with what I have described. I have successfully played these tracks over the KRKs with no major sound problems; I just don't really have a way of knowing if any data loss is occurring anywhere in the system. I tried listening to a few tracks using a pair of Sony MDRXB950N1 headphones connect to the mixing console by the 3.5 mm cord that came with the headphones and a quarter inch male adapter; the volume was very quiet, and when I tried various combinations of levels across the different volume controls (Vox volume control, the channel volume on the M822FX, the control room volume for the headphones, and the master volume) I found that when the track became comfortably audible I noticed some pops and cracks, and with the volume turned even higher I noticed consistent rattling on bass kicks or similar impactful sounds. I'm sure that the headphones are not blown, as I tested them on my iPhone on a louder volume, but using a standard mp3 track, without any noise distortion.


To summarize, I suppose my concern: is there a point in my setup where I am losing data that could be causing the unpleasant playback in my headphones, as I would like to avoid these pops and cracks during playback on my KRKs.

like the title says, this is all new to me, so I hope my descriptions/terminology is adequate

 

[droidlike]

I ran a digital optical cable from the Macbook's 3.5 mm headphone output to a Digitial to Analog Audio Converter; the DAC output had both RCA and 3.5 mm headphone, and the only cable I had was a 3.5 mm to RCA chord, which I plugged into an American Audio M822FX mixing console that controls the KRKs/headphone output.

Am I the only one missing your exact DAC brand name and model number ?

 

[BlueWizard]

"Pops and Crackles" sound to me more like a bad cable or poor connection. Any device in your signal path that is adding "pops and crackles" is a defective device.

Also, why such a convoluted signal path?

You apparently have a Headphone amp that most likely has a DAC in it. It has RCA which can go to the KRK and the 3.5mm that can go to the Headphones.

If the Headphone Amp has a Volume Control which it most reasonably does, the perhaps that control is dirty. Try rotating the control up and down, and see if that produces the 'pop and crackle'. If it does, then, with not signal, move the Volume Control up and down rapidly and repeatedly, and that should wipe the contacts clean.

Also try wiggling or moving your interconnecting cables and see if that produces noise. That might help you find a bad cable or a bad connection.

Steve/bluewizard

 

[jamclear276]

Am I the only one missing your exact DAC brand name and model number ?

Apologies. It's just a cheap thing I grabbed from Amazon:
https://www.primecables.com/en/p-31...m_pla=google&gclid=CN6QsZqupNQCFQ6saQodMjUEfA

"Pops and Crackles" sound to me more like a bad cable or poor connection. Any device in your signal path that is adding "pops and crackles" is a defective device.

Also, why such a convoluted signal path?

You apparently have a Headphone amp that most likely has a DAC in it. It has RCA which can go to the KRK and the 3.5mm that can go to the Headphones.

If the Headphone Amp has a Volume Control which it most reasonably does, the perhaps that control is dirty. Try rotating the control up and down, and see if that produces the 'pop and crackle'. If it does, then, with not signal, move the Volume Control up and down rapidly and repeatedly, and that should wipe the contacts clean.

Also try wiggling or moving your interconnecting cables and see if that produces noise. That might help you find a bad cable or a bad connection.

Steve/bluewizard

So if I ran a 3.5mm to RCA from my Macbook to the M822fx I could bypass the DAC without using the TOSLINK cable I have? As I said I'm entirely new to this so I had a possibly unfounded inclination that the analog output from the headphone jack of the MacBook couldn't handle 24 bit audio, which is why I opted for the TOSLINK cable.

As for the popping/crackling as a result of low volume; I have been downloading my lossless audio files from bandcamp and it struck me that although these are offered as lossless audio files they may not be truly lossless. I found a program called Spek that checks the audio quality of files, and although I don't know exactly what I'm looking at, I can deduce by some wave forms the quality of certain tracks over others.

The "Gunshots" track has excellent playback on speakers and no pops/cracks in my headphones, whereas the "Hey" track seems to cutoff around 12kHz, again I don't know but I assume this difference is affecting my audio playback.


Alex

 

[Jampot90]

The link you provided at Prime cables is for an analogue to digital converter which is the wrong way round. Did you mean this one? -

https://www.primecables.com/p-31145...link-to-rl-stereo-audio-converter-primecables

You could connect the mac to the mixer but then the mac will be doing the digital to analogue conversion - not ideal.
Optical out to a modest dac should provide what you are looking for. If you can afford one with a volume control and headphone output it would allow you to leave the mixer out of the loop and (probably) have better results. Like this -

Amazon.com: SMSL SD793-II PCM1793 DIR9001 DAC Digital Audio Decoder Amplifier, Black: Electronics

What you have heard about lossless being more satisfying is correct - it will be worth the effort.

Jim

 

[jamclear276]

The link you provided at Prime cables is for an analogue to digital converter which is the wrong way round. Did you mean this one? -

https://www.primecables.com/p-31145...link-to-rl-stereo-audio-converter-primecables

You could connect the mac to the mixer but then the mac will be doing the digital to analogue conversion - not ideal.
Optical out to a modest dac should provide what you are looking for. If you can afford one with a volume control and headphone output it would allow you to leave the mixer out of the loop and (probably) have better results. Like this -

Amazon.com: SMSL SD793-II PCM1793 DIR9001 DAC Digital Audio Decoder Amplifier, Black: Electronics

What you have heard about lossless being more satisfying is correct - it will be worth the effort.

Jim

Ah, yes, thanks for correction. This is the info I was looking for; I figured the pops I was hearing during playback was something along the line unable to keep up with the higher quality audio playback.

Although cutting the mixer out of the loop for headphone playback is preferable, I need the mixing board to control the input to the KRKs; does the DAC you posted have Analog L/R RCA output (it only shows the front view), and if it does, is it alone adequate to moderate the KRK monitors?


Alex

 

[Jampot90]

It appears to have L & R rca jacks on the rear -

SMSL SD-793II PCM1793 DIR9001 DAC Digital Audio Decoder + Headphone Amplifier - Shenzhenaudio.com

but in the faqs (scroll down the page) it says the volume control is only effective on the headphone out, which is a blow.

More expensive, but this one seems to and plays files from an sd card or usb -

Amazon.com: SMSL DP1 3 in 1 Headphone Amplifier Portable,Headphone Amplifier DAC,High Resolution Music Player: Electronics

I'm quite tempted by that one if I can find it here in UK

Jim

 

[jamclear276]

Yeah, that's not the best that it's limited to just the headphone output, but thanks for the links and the clarification, the DP1 doesn't look too bad at all; the fact it has its own playback is even better.

Alex