Twisted Pear Buffalo Sabre DAC

[pabbi1]

No updates?

[BrianDonegan]

There was a bit of a mixup with the chips. ESS sent me a batch that was not vapor sealed (they are moisture sensitive), but they are sending new ones, so I am just waiting at the moment. I should know tomorrow when the replacements will be here.

[johnsonad]

Soon, very soon I've got a case and parts ready to go

Any impressions from the 20 or so people that have them already? I know Nebby is busy in the sandbox at the moment. How about the other 19?

[Beefy]

After a significant amount of research I'm pretty much set on the idea that a Sabre DAC will be my next DIY project. Yes, it must be exciting for you all, but you'll have to wait until later for autographs. Anyway, I've done as much reading as my poor little brain could manage without exploding but still have a couple of minor questions - mostly around the power power supply.

I intend to use the LCDPS and LCBPS and was thinking of using two 15VA 15+15 that Twisted Pear sells for convenience. But to get the 5VDC and 6.6VDC for the Sabre, that is a BIG voltage drop across the regulator considering the voltage coming from the toroid.... more than the drop when normally used at 7.5VDC for the Opus. Are those toroids still OK?

I would like to add a TOSLINK module and a DPDT switch to be able to use both TOSLINK and coax. No problems there, but I was hoping to power the TOSLINK module from the same LCDPS. Is this OK? Would it be better to tap the supplies for the digital or analogue section?

Lastly, I assume the IVY tune-up will be completed and shipped in the correct config to get the most out of this kit?

Cheers for the help folks! My money is sitting here ready to go, and it is all down to who can refresh the Twisted Pear site at just the right time to place an order........ let the games begin!

[Russ White]

Originally Posted by Beefy

After a significant amount of research I'm pretty much set on the idea that a Sabre DAC will be my next DIY project. Yes, it must be exciting for you all, but you'll have to wait until later for autographs. Anyway, I've done as much reading as my poor little brain could manage without exploding but still have a couple of minor questions - mostly around the power power supply.

1) I intend to use the LCDPS and LCBPS and was thinking of using two 15VA 15+15 that Twisted Pear sells for convenience. But to get the 5VDC and 6.6VDC for the Sabre, that is a BIG voltage drop across the regulator considering the voltage coming from the toroid.... more than the drop when normally used at 7.5VDC for the Opus. Are those toroids still OK?

2) I would like to add a TOSLINK module and a DPDT switch to be able to use both TOSLINK and coax. No problems there, but I was hoping to power the TOSLINK module from the same LCDPS. Is this OK? Would it be better to tap the supplies for the digital or analogue section?

3)Lastly, I assume the IVY tune-up will be completed and shipped in the correct config to get the most out of this kit?

Cheers for the help folks! My money is sitting here ready to go, and it is all down to who can refresh the Twisted Pear site at just the right time to place an order........ let the games begin!

Hi Beefy,

1) Yes its just fine. We have actually revised the power supply numbers a bit. Buffalo. I would suggest 7-9V for both VA and VD.

2) Sure powering the TOSLINK module from the same supply as you use for the buffalo VD supply should work just fine.

3) Yes, we ordered some new IVY PCBs which implement the latest recommended filtering approach. they should be here by the time we are ready to start shipping the next herd of buffaloes.

We apologize for the wait. But this is a brand new chip with lot of lessons to be learn on how to get the IVY dialed in to our liking. Also we have had some supply issues with ESS failing to send sealed parts etc... Joy Joy.

In the end I hope you agree It will be worth the wait.

Cheers!
Russ

[Beefy]

Originally Posted by Russ White

Hi Beefy....

..... We apologize for the wait.

Thanks for the prompt reply, Russ

No problems at all with the wait... even if I do miss out on this next round of boards. You guys are doing fantastic work for the DIY community!

[Clutz]

Originally Posted by Russ White

We apologize for the wait. But this is a brand new chip with lot of lessons to be learn on how to get the IVY dialed in to our liking. Also we have had some supply issues with ESS failing to send sealed parts etc... Joy Joy.

If the chips are that sensitive that being shipped with a broken vapor barrier damages them, how can they ever be operated outside that vapor barrier? I perhaps am incorrectly assuming that the vapor barrier is a sonically welded plastic bag that the chips in the trays are placed in, and not something done to the chips themselves?

Cheers,
Brad

[BrianDonegan]

The problem with moisture is only when you heat the chips, such as in the reflow oven. any moisture that the chip has absorbed expands and can kill the chip. They need to be "baked" at 110C for 4 hours to remove moisture before reflowing (or any high heat exposure). this is part of the reason I am hesitant to sell kits, as it is not unlikely that a good chip will be killed when mounting it if it has not been properly baked. I also want to be sure people get a working module, as the chips are not exactly cheap.

I should add that this is only a problem for us because I was looking at having an assembly house build some boards for us to help meet demand. I got a great price from one place, but they don't do baking. Another place does the baking, but the per board charge is twice as much, and I want to keep the price as low as possible. My current plan, however, is to just start building and make them available as I can. I will try the outsourcing later, when ESS can supply the sealed chips.

[fierce_freak]

The Buffalo is awesome and a clear step up from the WM8740 Opus for me, but it looks like Russ has mentioned in the thread on the other site that he can't choose a favorite between the Buffalo and the WM8741 Opus. Did the upgrade to WM8741 make that "big" of a difference?

[soloz2]

Originally Posted by fierce_freak

The Buffalo is awesome and a clear step up from the WM8740 Opus for me, but it looks like Russ has mentioned in the thread on the other site that he can't choose a favorite between the Buffalo and the WM8741 Opus. Did the upgrade to WM8741 make that "big" of a difference?

I hope so cause I've got an Opus on the way!

[Russ White]

In a word, yes. The WM8741 sounds very different to me from WM8740 I think the new filter (especially response #2) is the real reason. Its a completely new beast. Not simply a reworked WM8740. The only thing it really seems to share is the pin out.

Where you can really hear the difference is in high def (192khz 24bit) content. Where the WM8740 seems most happy at around 96khz the WM8741 happily extends to 192khz.

Now I would not say its any better than the ESS chip, its certainly much much closer than one would expect.

What I think is great, is that it is so simple to get wonderful sound out of it. No heavy duty analog filtering required. This chip does its own analog filtering at a frequency calculated to help remove quantization noise.

To be honest I was really peeved with Wolfson for taking so long to get us the chip. But now I am very happy we can get it.

Cheers!
Russ

[fierce_freak]

Thanks Russ. I figured it must have been somewhat more than an incremental update, and it's good to hear that the filters have been so improved.

[Beefy]

Originally Posted by Russ White

Now I would not say its any better than the ESS chip, its certainly much much closer than one would expect.

Good to know that I can 'resort' to the Opus if I get desperate

The desirability of the Sabre though is the integration...... no need for receivers, Metronome etc. Some people might like the ability to customise; I just want something easy, regardless of cost

[penger]

Originally Posted by Russ White

In a word, yes. The WM8741 sounds very different to me from WM8740 I think the new filter (especially response #2) is the real reason. Its a completely new beast. Not simply a reworked WM8740. The only thing it really seems to share is the pin out.

Where you can really hear the difference is in high def (192khz 24bit) content. Where the WM8740 seems most happy at around 96khz the WM8741 happily extends to 192khz.

Now I would not say its any better than the ESS chip, its certainly much much closer than one would expect.

What I think is great, is that it is so simple to get wonderful sound out of it. No heavy duty analog filtering required. This chip does its own analog filtering at a frequency calculated to help remove quantization noise.

To be honest I was really peeved with Wolfson for taking so long to get us the chip. But now I am very happy we can get it.

Cheers!
Russ

Would it still be wise to put the WM8741 through the Metronome?

[Russ White]

Originally Posted by penger

Would it still be wise to put the WM8741 through the Metronome?

Yes, I definitely like it in there.

I have only taken the metronome out when I have listened to 192K material.

Cheers!
Russ