Buffalo Tweaking

[Spartacus]

Originally posted by TheShaman

In addition, I'm a bit troubled by the lack of load-regulation on the SuperTeddys.. They'd match well with the constant-current draw of the Counterpoints but I'm not so sure about VD (VA is negligible) or alternative I/V stages like the IVY II implemented in Buffalo 32S (to which I might upgrade at some point).

The digital supply for the Sabre will need low Z at RF frequencies, and as such will be dominated by the Z of the local decoupling caps and track inductances. In other words, the TeddyReg would be fine here.

The analog supply will need a low Z at audio frequencies, particularly if you are using an I/V stage. But that should be taken care of by the LM4562 if you are planning to keep it.

[jkeny]

Here's an idea that might sound crazy but is not as daunting as it first seems:
- why not do your own tweakers Sabre DAC board using a prototyping board designed so hand soldering of smd parts is easy (I have to admit Rolls reminded me of this company that i had looked into years ago but had forgotten about): http://www.schmartboard.com/index.as...ucts_qfp&id=72

So for $60 Sabre32 DAC chip & $10 prototyping board & lots of room to solder in your own flavour of PS supplies, etc & SPI or I2C control from a uC such as Arduino (see here http://hifiduino.blogspot.com/ - it ain't so difficult - all the code is pretty much done already for the Opus DAC - probably simpler for the Sabre DAC). Just sign an NDA with ESS and you're ready to go!

I suggested this over on the TP vendors thread (cheeky I guess) but was told it had been thought of before & their tweakers board was just about ready - I asked when & how much & got no further reply!

[Russ White]

Originally posted by jkeny
I asked when & how much & got no further reply!

You asked a question I simply couldn't answer yet. Patience. Here is your answer if you must have one - I really don't know.

Feel free to use a prototyping board, but it is going to far from ideal routing wise. And RF/decoupling and GND considerations will be very bad.

So while you could likely get music out of it, it would be a shame to waste a $60 chip on such an application.

If you feel like it, go for it, and have fun.

Cheers!
Russ

[jkeny]

Ok Russ, now that I have your attention - what ground topology are you applying to the tweakers board? Most of the ancilliary components will be off-board according to your rough sketch of the up-coming tweakers board.

[jkeny]

All I see on your board is surrounding PS bypass caps & clock - all of which could be accommodated on this prototyping board:

I also have a notion that the improved PS & clock which could be applied to this would more than offset any small sub-optimal issues there might be with this prototyping board

[Russ White]

When did you not have my attention? Would you rather I leave you to yourself?

You need to think about the GND plane.

Also that pic I posted was a very rough sketch, it has changed since then.

Read the ESS design guidelines and then you tell me how you could come close to complying.

Also bypass caps need to be very close to the pins and directly connected to the plane.

You then need to route all outputs along an unbroken GND plane.

There is simply no way you can do that using a protoboard.

Anyway have fun. That's all that counts.

Cheers!
Russ

[jkeny]

Thanks for your reply - I'm not being contentious here just teasing out DIY possibilities as it is a DIY forum! From the description of the board

6 ground holes are connected a copper plane on the bottom side.

Also, as reported here, a number of tweakers have reported better sound with off board PS & IV stages which hardly qualifies as optimal, tight layout!

Apart from clock & PS bypass caps, I don't think anything else should be included on this minimal board?
Thanks for the good wishes - fun it will be then!

[Spartacus]

Originally posted by jkeny
Here's an idea that might sound crazy but is not as daunting as it first seems:
- why not do your own tweakers Sabre DAC board using a prototyping board designed so hand soldering of smd parts is easy (I have to admit Rolls reminded me of this company that i had looked into years ago but had forgotten about): http://www.schmartboard.com/index.as...ucts_qfp&id=72

So for $60 Sabre32 DAC chip & $10 prototyping board & lots of room to solder in your own flavour of PS supplies, etc & SPI or I2C control from a uC such as Arduino (see here http://hifiduino.blogspot.com/ - it ain't so difficult - all the code is pretty much done already for the Opus DAC - probably simpler for the Sabre DAC). Just sign an NDA with ESS and you're ready to go!

I suggested this over on the TP vendors thread (cheeky I guess) but was told it had been thought of before & their tweakers board was just about ready - I asked when & how much & got no further reply!

Hi John,

It's an interesting idea. As Russ says I think the biggest issue will be getting routing and earthing optimal. Tricky, but I don't think impossible - with the proviso that you really know what you are doing and have the measuring equipment to back you up.

Me, I'm still waiting for an ESS9018 to turn up in the post. I'll be grafting it onto my Buffalo mark 1 board.

Thanks for the link to the AOS forum by the way - interesting reading about Leo and Roll's experiments.

Dan

[Russ White]

Hi Jkenny,

I know it has a GND plane, the problem is that the supply traces are going to be far too long and thin.

Give it a go, just warning you that there will be some very significant design compromises that will effect the final result.

You simply have to design for the application you want from the start to get the best results. This involves careful deliberate design and layout.

Remember you are dealing with an 80mhz clock (if you want to do 192/32 SPDIF/AES). This requires better layout then you will get on a protoboard.

Glad your having fun.

Cheers!
Russ

[jkeny]

Originally posted by Spartacus
Me, I'm still waiting for an ESS9018 to turn up in the post. I'll be grafting it onto my Buffalo mark 1 board.
Dan

Hi Dan,
What you're attempting there is much more risky then this protoboard concept - are you des-soldering a ES9008 & then soldering on a ES90018 onto the same board - all in smd?