DAC performance of an old Yamaha

[skinnyq]

Hey guys, I've recently got my hands on two old Yamaha AVRs: The rx-v1200 and the rx-v659.

The RX-V659 is using a Burr-Brown PCM1803 DAC.
The older RX-V1200 is using an AKM AK4527B DAC.

I'm currently using the RX-V1200 as it seems my rx-v659 does not output sound in Stereo/Pure Direct/Straight when using a digital input (although the internet says it should work).

My question is this:
1. Which of these DACs are better and just how much better are we talking?

2. Will I hear an audible difference in SQ if I buy a modern recent DAC compared to these?

 

[ZolaIII]

The performance is more limited and related to power amplifier output than by DAC itself. Unfortunately nothing changed much regarding AVR's and their DAC's most of them even now using old Burr Brown's or eventually made a switch to first gen of Sabre 32. PC space doesn't look much better either which translates to trouble when you need a one supporting bit stream Dolby's decoding support and a high performance DAC in one.

1. They are just a bit better than what you get integrated on broad consumer electronics this day's rest is up to implementation.
2. Most probably not in real content dB range. Maybe some related to Dolby processing but not really related to DAC.
Eventually with headphones and if you try really hard. Rest is more up to futures I guess.

 

[skinnyq]

The performance is more limited and related to power amplifier output than by DAC itself. Unfortunately nothing changed much regarding AVR's and their DAC's most of them even now using old Burr Brown's or eventually made a switch to first gen of Sabre 32. PC space doesn't look much better either which translates to trouble when you need a one supporting bit stream Dolby's decoding support and a high performance DAC in one.

1. They are just a bit better than what you get integrated on broad consumer electronics this day's rest is up to implementation.
2. Most probably not in real content dB range. Maybe some related to Dolby processing but not really related to DAC.
Eventually with headphones and if you try really hard. Rest is more up to futures I guess.

I see.
Well, the RX-V659 should have more power than the RX-V1200. That's why I'm trying to get it to work in Pure Direct/Stereo with a TOSLINK input (unsuccessfully). So technically speaking there should not be an audible difference between the AKM chip and the TI Burr-Brown one?

 

[Chrispy]

What is the digital signal from that you're having issues with? Sounds odd that you can't use it the way you want, altho I forget what Yamaha means by "straight". I doubt the difference in dac would be noticeable, and the newer avr isn't very much more powerful....about 1 dB different.

 

[ZolaIII]

Well they reused and refined Brown now Ti the most. Point is that DAC doesn't have a sound signature in the first place if implemented right and if it covers 16 bit SINAD range it covers theoretical peak (while less in reality) of 98% ever digitaly created music recordings. While real limit lies in power amplifier output.
Try switching to PCM instead direct digital (another name for bit stream) for stereo PCM in options on either end (sender or AVR, preferably AVR if possible).

 

[skinnyq]

My current state:
- RX-V1200 works with digital input (optical) from my PC, TV. In Processor-Direct mode and in normal 2ch mode.
- RX-V659: Straight mode - no sound in digital nor analogue. Pure Direct - Sound only when using analogue. My digital input only works when some DSP is activated. I'm not sure if it's faulty because it works fine with analogue (except the Straight button).

The RX-V659 is set to PCM...
I'm not sure if the RX-V659 is faulty somehow and I don't know how to test for it. Any ideas?

 

[Chrispy]

Might try and see if a full reset might fix it.

 

[ZolaIII]

Put the optical out on TV side to PCM and use it like that with RX-V659.

 

[skinnyq]

Might try and see if a full reset might fix it.

Put the optical out on TV side to PCM and use it like that with RX-V659.

Both done... no-go.
I'm wondering if it might be the cable? but its working fine with the RX-V1200... PCM is set on the TV and AVR.
I can't believe the RX-V659 is faulty because sound is working fine with analogue but with digital input only the Hifi Dsp modes work.

 

[Chrispy]

Sounds broken to me if it can't process digital signals properly.....