Twisted Pear Buffalo Sabre DAC - Page 8

Hey Guys,

I really appreciate the support from all of you in each of your diverse ways. Rodent did not offend me.

Some notes about listening to gear.

Everyone is going to percieve the buffalo a little differently. Some will call it analytical, some warm. Some bright, some laid back. Just like the Opus and the COD. I don't think I have read two reviews that heard it the same way.

This actually makes sense because there are a lot of variables. Even though these are modules there is still a lot for the DIYer to ajdust and create. So it is very likely true that many of the DACs that get built from our modules don't sound alike.

One very cool thing about the modular approach is that you are free to plug in your own implementation of different pieces.

Wan't to use a zero feedback I/V stage? Go ahead!! It will work fine. Want to use your own regulators? Go for it!

So I expect the whole range of experiences an opinions. I just hope everyone has a good time doing this.

Cheers!
Russ

Should I consider getting into this if I don't know very much about audio electronics? I can read basic schematics, have clean soldering skills, but know only the very basics of electricity.
As it's sold pre-assembled, I'm hoping that there's little opportunities to mess up, but I might be wrong.

For example, I'm still not entirely sure how sinusoids represent sound. my understanding is that it represents the voltage fluctuations of alternating current, with the ground plane serving as the base, frequency representing the pitch, and the amplitude.. I suppose affects the magnitude .. volume? I'm eager to learn, but without a proper physics course until I'm able to free up some course hours, I'm not sure where to start.

Russ, you mean you drive a 32ohms load with a lm4562? Or is it a different IVY module you are talking about?

Greetings Gert-Jan

I think he is driving his phones balanced off the THS4131's. I am pretty sure he was powering the 650's off a Ballsie for a while though too, which would be from a 4562 (actually, LME49720).

Quick little question; can I use balanced and unbalanced outputs from IVY without changing anything on the board and at the same time? So I wire up balanced and unbalanced outputs and connect both to my balanced and unbalanced amps respectively and I don't have to change anything, just turn on either amp, correct?

And of course, another little question; approximately when will the next batch of boards be available?

Yes.


In a few weeks.

Thanks Brian, just what I wanted to hear. Oh, and my imaginary psychiatrist agrees completely with your signature

With the THS4131. Of course you won't want to drive that 32 ohm load very hard, but it works much better than I had hoped even for those cans.

Well, somehow the concept of 2-day shipping is lost on the distributor, so the chips are going to take a week to get to me instead of 2 or 3 days requested, so I will not have them until Monday the 5th. I therefore will not be able to ship until at least Wednesday the 7th. Sorry.

Hi James,

We all start somewhere, being eager to learn is the best quality you need in my opinion. Anyways, just a little somehting about sine waves, current and such.

The sinne wave is as you pointed out, it represets the instantaneous fluctiuations a DAC or AMP will preset. This voltage fluctuation, when driving into some load like a speaker, will cause a current to flow. Without going too deep, the current is proportional to the voltage applied across the speaker. (The more knowledgeable, please dont flame me, im assuming the case of resistive load only, to get the basica idea across) The equation is V = IR, where V is the votlage from the DAC (or AMP) and I is the current that the DAC or AMP is driving through the load R. The ground plane is simply the viewing point where your measuring the voltage from. all the current the DAC or AMP pushes (or pulls) through the load uses the ground plane as its return path, back to the power supply.

Frequency is the pitch of the sine wave.
Volume is proportional to the amplitude of the sine wave.

Music is really made up of a bunch of sinewaves at different amplitudes, frequencies and phases. (lets not go into this one for now)

But hopefully that is enough to get a handle on things. Oh and by the way, like you mentioned, the current/voltage are AC signals, which means they change directions. Anyone trying to sell you wires (or cables) with arrows on them saying they need to be installed a certain way, well,........ what can I say,......BS, comes to mind.

Dustin

Heh, you don't need to know squat to build this stuff. Solder this there, this here, and then the casework!

“ESS requires NDA for the datasheet of Sabre DAC for the following reasons:

1. Although we are shipping chips, the datasheet is not yet complete. We do not want to have preliminary information public.

2. NDA is also a way to keep track of who has datasheet (and revision number). An update of the data sheet is in progress. We expect to release this update to all who has signed a NDA and received datasheet.”

Thanks

Dustin

Russ,

Have you considered changing IVY to use single-channel op-amps for summing after the THS4131? I ask because I'd _much_ rather use some of what's available in only single channel than the LM4562/LME49720, which, at least in my opinion, mostly only serves as a decent alternative to the NE5532 rather than the best option for audio.

You and I will simply disagree on the assessment of the device. First, I can say your opinion is not the same as mine in the least, nor that of any of the engineers or users I respect most. I did not pick that part haphazardly. I have many many hours listening and measuring that op amp and others, and made a choice accordingly.

As a practical matter single op amps simply would not fit as well on the board so I did not use them, form factor was a design choice.

Now here is the great news for you! If you really feel like it you can omit the BAL/SE section altogether on the IVY and roll your own. How cool is that! Or you can drop in any other dual you like. AD8620 works very well as do others. the new dual JFET opamp from TI also sounds great! I forget the name of it.

You could even just pop a transformer on the balanced outputs for SE output. A few have done this.

Cheers!
Russ

Let me know if you remember the name of the new TI part. Just curious.