Audio on the Pyra : a state of things ?

[Kev2442]

Many of us are planning on using the Pyra as an audio player, and even more care about its audio out in general.

In some of the last news about the subject, you planned on using the TWL6040 with an additional amp instead of the PCM1773 from the Pandora, but still including both on the prototypes for comparison purposes. That was a year and a half ago.

Am I right into thinking you finally adopted the TWL without further testing because of its great results on the first round of audio tests ?

Is the TPA6110A the amp to be used on the Pyra like the Pandora ?
Have you tried the audio yet ? Any comments about the matter ?

Or am I missing news on the subject ?

 

[Xcl4m4t10n]

Very interested on this.

 

[Fixit]

This is an interesting question. I greatly appreciate hardware that can produce lifelike sounds and music. I owned a Zune for a long time until it hit the ground and trashed my HDD. 30GB of music down the tubes...


P.S. @3XCL4M4t10N that GIF in your sig scared the hell outta me. My volume must have been cranked when I clicked that!

 

[Kev2442]

Bump ! Plus more questions :
Are you planning on doing a second round of audio tests to have more official specs concerning the Pyra's specs ?

Oh and, will be be able to crank it up to 192 kHz ? Both in and out ? I don't remember if the headphones out also has a mic in like the TRRS inputs in smartphones...

 

[rygD]

I don't remember if the headphones out also has a mic in like the TRRS inputs in smartphones...

It does.

 

[EvilDragon]

While Pandoras audio circuit is in fact populated on the Pyra prototype PCBs, it requires it's own clock which isn't easy to provide (as it needs to be synced with the audio output), so I'm not sure we can test that

However, the audio from the TWL should be better. The specs and DNR are better than Pandora's chip, and the tests with various measurement tools I did last year also showed that both were almost the same, the TWL was even a bit better.

The DAC used in the Pandora is from Burr Brown, the amplifier is from TI.

Burr Brown has been acquired by TI, so it's the same company that did the TWL and Pandoras audio chip... it could very well be it uses the same or similar hardware inside.

 

[Grench]

While Pandoras audio circuit is in fact populated on the Pyra prototype PCBs, it requires it's own clock which isn't easy to provide (as it needs to be synced with the audio output), so I'm not sure we can test that

However, the audio from the TWL should be better. The specs and DNR are better than Pandora's chip, and the tests with various measurement tools I did last year also showed that both were almost the same, the TWL was even a bit better.

The DAC used in the Pandora is from Burr Brown, the amplifier is from TI.

Burr Brown has been acquired by TI, so it's the same company that did the TWL and Pandoras audio chip... it could very well be it uses the same or similar hardware inside.

I think one of the big things that set the Pandora apart from other audio devices was the sheer amplification power it was capable of providing and that the power was available across the audio spectrum. This isn't just about max volume or signal to noise (those are important too), but being able to maintain perceived tonal balance (EQ) through the volume (dynamic) range.

So - is the TWL's amplifier capable of the same amplification over dynamic ranges that the Pandora had? Can it drive the big fancy audiophile 2ohm headphones as accurately?

Would there be any advantages to using the TWL and running it's output through a dedicated amplifier? Or would that make it worse?

Of all the things Pyra related, getting the audio right should be very high priority - probably a step or two down from making sure the charging circuit works, but still pretty far up the list.

 

[EvilDragon]

Well, putting the amplifier without the DAC before the headset output shouldn't be a big deal (except for a price increase of about 8 EUR)
However, the TWL should work with low impendance speakers / headphones as well, but I'll make sure to test that.

 

[levi]

I assume that versus the Pandora, the Pyra won't have line level in and out any more, because it loses the ext port and none of the new ports added offer analogue inputs or outputs. I've used my Pandora with the TV out cable in the past to digitise analogue sources. I guess if I really cared about audio quality I'd get a dedicated USB sound card, but the Pandora's single unit design certainly has it's benefits in that niche use of recording analogue audio without having a dedicated setup.

 

[Kev2442]

According to rygD, the Pyra will offer a TRRS input. With a proper cable, I'm pretty sure you can plug both a TRS stereo (headphones) line out and a TS mono (mic) line in.
At the very least, RODE makes TRS to TRRS adapters (SC-2 I think), so you should be able to plug a 5V-compatible mic in the headphones out.

 

[rygD]

According to rygD, the Pyra will offer a TRRS input.

For reference: https://www.pyra-handheld.com/wiki/index.php?title=Audio#Jack

I was trying to find one of the posts where ED mentioned it, but there are a lot of posts.

 

[Grench]

Well, putting the amplifier without the DAC before the headset output shouldn't be a big deal (except for a price increase of about 8 EUR)
However, the TWL should work with low impendance speakers / headphones as well, but I'll make sure to test that.

I'm really looking forward to that - and hope to see you brag about the results.

 

[levi]

Yes, but headphone or mic level isn't line level. You can drive consumer line inputs using headphone outputs directly, but a line output is a much simpler beast than a headphone output, having only a low power amplifier and no variable volume control to pass through, so the sound is significantly cleaner. I've never tried connecting line outputs to microphone inputs, but as I understand it levels are way off and impedances are likely to cause problems.

 

[WizardStan]

I've never tried connecting line outputs to microphone inputs

Do not plug line level equipment into microphone jacks. I've never done it either but the one time I almost did I was told that it can literally cause things to explode, since the microphone jacks are powered.
I believe it was an exaggeration, and most likely the worst thing that would happen is distortion, but I still wouldn't chance it.

 

[rygD]

You mean like the beginning of BTTF?!

 

[Kev2442]

Do not plug line level equipment into microphone jacks. I've never done it either but the one time I almost did I was told that it can literally cause things to explode, since the microphone jacks are powered.
I believe it was an exaggeration, and most likely the worst thing that would happen is distortion, but I still wouldn't chance it.

I believe it was because it had Phantom Power (48V) activated, otherwise it's 5V at best.

 

[Eight Bit]

Only the more sensitive condenser microphones and active DI's use phantom power. Some times they can be battery powered too or even have a separate PSU. The 48v is being fed to the microphone from a mixer. Connecting a condenser mic to a regular un-powered dynamic mic jack will result in a non working mic Connecting a dynamic mic to a phantom powered XLR mic connection is usually no problem.
Putting unbalanced line level equipment into a balanced microphone connection (Usually XLR and not Cinch/RCA or Jack) is possible but it would need a special cable with XLR Pin 1 and 3 soldered together on ground and pin 2 to signal of an RCA or mono jack. And I would indeed switch phantom power off in that case because even though the 48V will just end up in ground it could cause some trouble.
Also it would need between 20 and 40 dB padding as the voltage of line level is too high. Some mixers have a small pad button next to the gain knob but better is to use a DI box to make the unbalanced line level signal a balanced mic level and converted to XLR cable.

I've never heard of mics blowing up. I do know of people who have gotten an electrical shock from a broken mic. Nothing severe though.

 

[Kev2442]

As the preorders are open, maybe a little demo of the Pyra's audio capabilities would help get more preorders from audiophile communities. Is it planned in the next videos ?

 

[rygD]

Wouldn't you need some high quality audio files to play, really good audio recording equipment, plus a file format for the recording that won't degrade the audio, then really good equipment on the other end for playback (which the target audience for such a demo would probably have)? Seems like there is a lot in that chain that can go wrong and make a YouTube video fail to show the real quality of audio of such a demo. I am not saying it shouldn't be done, I like the idea and think it might be worth it, I just want to make sure if it is done that it is done correctly. I have very little knowledge of all that stuff as it relates to audiophile interests.

 

[Kev2442]

Well at the very least a video showing it is working
But maybe a second "round of audio tests" would be appropriate. If you can't make them listen to it (and I know most streaming sites - including YouTube - can't) then maybe let the specs talk. At least it will give them an idea.