DSD output mod for Denon 1940?

[InSides]

So I've read through the several ESS Sabre threads, and one of them mentions that ESS themselves used a modified Denon DVD-1940 to send a DSD signal to the DAC.

Obviously, it can be done.

Can anyone point me to a resource with more information regarding this?

I would like to get in line for the next batch of Buffalo DAC's from Twisted Pear, and seeing I need a transport, this would be a wonderful option if possible to do.

[roger jons]

Yeah, I'm interested in this mod too, anyone who got an idea how to perform it?

/Roger

[tubesguy]

I think that if you do a thorough search of those threads, you'll come upon more info, including pictures, of how the signal is taken from the Denon, from vias that are fairly clearly identified and seem to be very accesible.

[francolargo]

Some information is in the ESS Sabre reference DAC thread.

http://www.diyaudio.com/forums/showt...41#post1497241

http://www.diyaudio.com/forums/showt...92#post1523392

In this mod, Russ steals PCM from vias near the on-board DAC. I assume that the ESS mod fed DSD to the Sabre chip, but that they obtained it similarly - by soldering into circuit board vias.

For me, the allure of SACD is in decoding multichannel recordings. Russ mentioned that rather than use the Buffalo in 8 channel mode for 5.1 program material, he would prefer 3 DACs each receiving stereo PCM. However, the options for this mod may be in question. It now appears that there will be down time while TP switches the Buffalo over to the new ESS9018. That chip will automatically decode DSD or PCM and preliminary plans at TP are reportedly to offer a bare-bones 8 channel board in addition to a stereo implementation. I have a Denon DVD-1930 waiting for mods, but won't do anything until more is known about the ESS9018. ...in particular, each channel's digital filtering make the chip a candidate for a digital crossover, but how that squares with being a multi-channel DSD decoder remain to be worked out...

Best,

Frank in Mpls.

[DECKY999]

I have just finished this mod yesterday. You have to steal 3 signals and one ground as close as possible to the signals - as shown in the previous post. Signals are DSDMXR, DSDMXL and DSDCLCK which correspond to DSD1, DSD2 and DCLCK on the buffalo input. The first image is from Denon 1920 service manual with high-lighted signal pins.

All three signals have to pass thorugh a hex inverter to bring them to required TTL level signal (SPDIF3 or DSD is a 75ohm terminated TTL level signal). They are too weak as taken from the chip. The circuit that I used is also attached. In addition to this you would need a regulated 5V PSU for the hex inverters. You can run all three of them from a single supply. I hope this helps

[hy2a3]

Decky999,

Nice info for someone without much electronics knowledge, yet wishing to mod a SACD CDP for Twisted Pear's Buffalo DAC application. May I ask about your experience with the posted 74HC04 driver circuit ? Are you still using it and time tested to work (Buffalo locks in the DSD signals). Reading, the digital signal from the Sony DSD decoder chip is too low in level ~.5v, and the 74HC04 driver circuit will bring the signal to ~ 5v ttl level. This ttl level would make the DSD signals compatible with the Buffalo DAC input requirements. Just thinking out loud.

Thank, Henry
USA

[SoNic_real_one]

All of the Denon universal DVD players use the same Sony DSD decoder, so that mod is possible in any of them.
Also, I have a Toshiba universal player that has a Phillips DSD decoder that sends the DSD to a TI DAC (DSD1608 with accesible traces) and that makes it usable for the same task too...

[crazyfrog]

Very useful information for me. I intend to try that mod in a Theta compli (old model) to get a real DSD output. However, I see it can only "fit" in the Buffalo DAC.

[SoNic_real_one]

What do you mean? TI's DAC's can accept DSD directly too. Something like PCM1792A, PCM1798, DSD1796...

[crazyfrog]

You're right.
What I meant is...
With my limited knowledge in this area I don't know what to do with my DA converter when a DSD signal is coming if it's built to throw a PCM signal to a PCM1794 DAC onboard.