In the Buff-alo

[Werd]

32bit dac at 1.4v unity? Something wrong here.  Where is the 2 volt line level? What am I missing here?

[richidoo]

32bit dac at 1.4v unity? Something wrong here.  Where is the 2 volt line level? What am I missing here?

You're not missing anything.  2V isn't mandatory. Bit depth is not related to output voltage. The designer aims for best SQ and specs rather than obeying convention. The instructions describe how to make more gain if needed in the out put stage, but it has been enough for me with the standard build. Many designers are easing off the traditional gain standards to avoid having too much gain which equals too much noise. It would be nice to have the full 2V sometimes. 

[Werd]

Awe, this is a single bit dac no MSB. Supports up to 32 bit but is not a 32 bit dac. I get it now

[richidoo]

Their trademark is "Sabre32" because it is a 32 bit DAC. It can also render single bit DSD directly.
Fact Sheet:
http://www.esstech.com/PDF/ES9018%20ES9012%20Product%20Brief.pdf
White paper with all the technical details:
http://www.esstech.com/PDF/sabrewp.pdf
Nope, it's not MSB.


Twisted Pear Audio has just released a new master clock product called Cronus. It provides master clock to digital source, then reclocks the stream directly, then sends the clean I2S to Buffalo 2 and 3, and any I2S input DAC.

[Werd]

I think it modulates a 32 bit signal into a single bit output.  If there is no MSB than its a pulse modulator or single bit output. The advertising is deceptive.

Or I could be completely wrong.

[richidoo]

Hell if I know 

[Werd]

Hell if I know 

😂 it is I took digital in college with my technician course. Nonetheless what you've done achieving  zero gain output using transformers is more than I've ever done or thought of.

[richidoo]

Capacitor-phobia is a good motivator!

The ESS9018 DAC has some DC offset so cap or tranny is needed to stop that. The new Legato uses trim pots to null out the DC so no caps or trannies needed.

[Nick B]

Yeah, you're right. The more DACs in parallel, the more current you can source. But an active output stage buffers current so no shortage of power to the load. So a Buffalo uses ESS 9018 DAC chip which has 8 separate DAC channels in it, so Buffalo PCB can do either 4+4 stereo, or 8 in parallel for a mono channel per board, but then you need two Buffalos, for left and right. I guess a few peeps have done that. The ESS DAC can source 3mA per DAC, or 12mA stereo, or 24mA mono, so I was able to drive stereo 10kOhm loads with only a 1:1 tranny, non active output. I lived with that for 2 years. When i sold my old Buffalo32 to Nick I tested it and heard awesome bass and solidness that I missed with my tranny version, so I added the active output to mine and it is much better than the trannies. Now I use an active output stage which provides a nearly dead short load to the DAC to keep it in current mode where it sounds best, and then the output stage provides gigantic current to any load, like 150mA iirc. But the active output stage is unity gain, so the DAC is a little shy for voltage, only 1.4Vrms. There is a way to up the gain on the output stage, but I haven't done that yet. I have a preamp so no biggie.

The trannies runthe DAC in voltage mode, it sounds better in current mode, so you need an active I/V converter to show the dac a low impedance load, then change the current to a voltage output. That's what makes it sound good. Not all ESS9018 DACs do this.

The Buffalo 3SE is a great DAC. With Legato output stage, and Placid bipolar power supply, plus a USB input like Amenero or diyinhk makes a really great stereo DAC for <$1000

Rich,
That Buffalo dac you sold to me is a great dac. I was shocked at the performance. Being a McCormack enthusiast, I bought their DAC 1 recently and put a $1,000 in as a beginning upgrade. It would cost another $1,500 to $2,000 to bring it to their Platinum level. Right now I'm on hold with everything audio as we have medical bills to pay. But I am seriously considering just putting your TPA dac in a nicer box and just enjoying it
Nick