TheShaman said:
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.
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.asp?page=products_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!
- 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.asp?page=products_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!
jkeny said:
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
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
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
Attachments
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
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
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
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!
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!
jkeny said:
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
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
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
To those who like to try out different power supply designs for the Buffalo/IVY:
Don't dismiss the LCDPS and LCBPS supplies with the LM317 and LM337 too quickly. There is a very interesting thread here at the forum at the "Power Supply Design" section, entitled "Another look at the LM317 and LM337 regulators". There, these regulators are analyzed in depth and some changes from the commony used component values are suggested. The results seem to be very encouraging, a bit better with the LM 337 than the LM317, if I recall correctly. I have not yet studied the thread in detail, but I certainly recommend this to anyone interesting in power supply mods. There is also a conclusion on the sonic improvement, but read for yourself.
It would be highly interesting if someone could try these mods and compare the resulting sonics to those of some of the other favored regulators
The "Power Supply Design" section is a bit hidden, but you'll find it under "Other Stuff".
Kurt
Don't dismiss the LCDPS and LCBPS supplies with the LM317 and LM337 too quickly. There is a very interesting thread here at the forum at the "Power Supply Design" section, entitled "Another look at the LM317 and LM337 regulators". There, these regulators are analyzed in depth and some changes from the commony used component values are suggested. The results seem to be very encouraging, a bit better with the LM 337 than the LM317, if I recall correctly. I have not yet studied the thread in detail, but I certainly recommend this to anyone interesting in power supply mods. There is also a conclusion on the sonic improvement, but read for yourself.
It would be highly interesting if someone could try these mods and compare the resulting sonics to those of some of the other favored regulators
The "Power Supply Design" section is a bit hidden, but you'll find it under "Other Stuff".
Kurt
jkeny said:
No, those traces have to be long, they are not supply traces or routes to decoupling caps.
The only long traces are analog or control (things like LEDs and the I2C). And the analog traces are carefully routed over unbroken GND.
All of the traces that need to be short are short.
The decoupling is actually better than the ESS demo board in terms of length etc.
Cheers!
Russ
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.