Introducing the Buffalo III-SE-Pro 9028/9038
The Buffalo-IIIse Pro (Stereo Edition) 2-Channel DAC
Brian and I have had access to samples of the ES9028/38 DAC chips for over a year and half now. Of course - we were very excited to give them try. And we did - but we found that early samples from ESS had a significant defect that made evaluating it very difficult on our current platform, thankfully those issues were soon resolved by ESS and new samples were obtained. We then began design/prototyping in earnest. In the meantime we have been getting questions daily about when we will release new modules designed around the new DACs. The answer is we are releasing one now - but please read on because how we got from there to here is important.
There is a lot of greatness in these two new chips. First the over-sampling filters and IIR filter are much improved over the ES9018 - and I am not overstating this - you will absolutely hear the difference between the various filters and you can select the one that work the best for your particular application or taste. The new DACs have the following filters:
8X FIR filters:
You can see the responses and read more about the filter in the datasheets. We expose all of the built in filters in the current on-board firmware. So you can experiment and see what you like for yourself.
The ES9028/38 “Jitter Eliminator” technology itself has undergone some very important changes in regard to how it can be configured - including a new sync mode feature. It also has some interesting configuration around trade-offs like initial lock speed and DPLL bandwidth that are completely new compared to the ES9018.
We also realized that there is a lot that the current Buffalo III-SE module delivers that we have found DAC builders really like. We wanted to keep those features - they include:
The digital and control aspects of the ES9028/ES9038 DACs are in some ways similar to the ES9018 - but in many more ways are a significant departure from the venerable (and still excellent) ES9018. Quite simply the ES9028/ES9038 could never be considered drop-in replacements for the ES9018. Still - what Brian and I wanted to do was present a module that could both allow reuse of already excellent I/V stages like the IVY-III and the Legato when using the ES9028 while still allowing the user to opt for the ES9038 when paired with the new Mercury output stage. Yes - you are reading correctly we have an output stage that will absolutely handle all of the current of even a mono ES9038 - in current mode! So users have nice DAC upgrade path without ditching what they already have.
It is true (as I have stated in other threads) that the ES9038 in particular presents some particularly interesting design challenges because of the sheer amount of current it pumps out to the I/V stage. Presenting a virtual ground (so that the DAC operates as a current rather than voltage source) to that much output current is no small challenge. One of the reasons we have held off releasing a new module based on these chips was precisely because of the demands of the ES9038. The good news is that what we discovered actually benefits all of the ESS9018/28/38 DACs (yes - even the ES9018) and our patience has been rewarded in a solution we can truly be proud of.
So what we are presenting to our users is the ability to use existing excellent output stages with the ES9028 - variety is good! As well as a new output stage that is also suitable for the ES9038.
The ES9028 and ES9038 are practically identical except for the analog output section - which is duplicated 4 times and connected in parallel in the ES9038. The ES9038 was clearly designed first and foremost for 8 channel operation - but works well in stereo and mono mode as long as you have an output stage that can handle its copious current. We have tried two approaches to the ES9038 and will actually be supporting both eventually. First you can sum channels at the DAC - this is what the B3SE-Pro does. Second you can take all 8 outputs and sum them after I/V. This we have also tried and it also works quite well - but is also very expensive and huge! Also, after trying both we found to our (pleasant) surprise that compared to summing at the DAC and I/V with Mercury the result of summing after I/V was almost identical!!! There is no compromise in summing at the DAC as long as your I/V stage is up to the challenge. Now if you want a compact 8 channels of bliss - the ES9038 is indeed awesome - so at some point soon we will release a new 8 channel DAC call Buffalo IV based on the ES9038. It however will be a completely new design and thus will not be as simple to integrate with existing I/V stages etc. That DAC module will also allow you to sum after I/V if you so desire.
So there you have it. After much testing and designing a whole new output stage to meet the challenge we are ready to present to you the Buffalo III-SE-Pro. We are taking orders now for the module along with a new series AVCC and Tridents which are redesigned to take on the rigors of the increased current demand of the ES9028/9038. We also made the new trident available in a broader range of voltage output. This is important because in cases like running the ES9038 in mono at high sample rates, you want to run VDD at a slightly increased voltage than the nominal 1.2V). The ES9038 recommends 1.3V when running high sample rates in stereo/mono and we offer that voltage. I actually found that the ES9028/38 all seem to operate better at 1.3V VDD. We also found the running the AVCC module at 3.6V is desirable (because it increases the output swing slightly) - so we configure it for that voltage.
Please ask any questions you have about the new DAC modules and the Mercury - I am sure I forgot to mention something - though keep in mind I will be opening a new thread when Mercury is ready for us to open orders. Mercury is actually finished and is only awaiting final testing of the production PCBs - the circuit itself is finalized. We have just received the production Mercury PCBs and we will be testing them this week. Mercury is the spiritual sibling of CounterPoint - and is essentially the same idea - it is exactingly purpose built to maximise the potential of the ES9018/28/38 I can’t wait to introduce it to you in more detail.
I am working on the datasheets for the new modules and I will make them available very soon. They are very similar to existing modules so most users should be able to hit the ground running. The most important thing to remember is that the voltage input should be right at 5V - please don’t exceed that by more than a half volt because of the relatively low maximum voltage of the ADM7151 regulators in the Trident-SR and AVCC-SR that we recommend for this module.
Things we created to get ready for B3SE-Pro
Cheers!
Russ
The Buffalo-IIIse Pro (Stereo Edition) 2-Channel DAC
Brian and I have had access to samples of the ES9028/38 DAC chips for over a year and half now. Of course - we were very excited to give them try. And we did - but we found that early samples from ESS had a significant defect that made evaluating it very difficult on our current platform, thankfully those issues were soon resolved by ESS and new samples were obtained. We then began design/prototyping in earnest. In the meantime we have been getting questions daily about when we will release new modules designed around the new DACs. The answer is we are releasing one now - but please read on because how we got from there to here is important.
There is a lot of greatness in these two new chips. First the over-sampling filters and IIR filter are much improved over the ES9018 - and I am not overstating this - you will absolutely hear the difference between the various filters and you can select the one that work the best for your particular application or taste. The new DACs have the following filters:
8X FIR filters:
- Brickwall
- Hybrid fast roll-off minimum phase
- Apodizing fast roll-off linear phase
- Slow roll-off minimum phase
- Fast roll-off minimum phase (default)
- Slow roll-off linear phase
- Fast roll-off linear phase
- 1.5874fs - 70K
- 1.3605fs - 60K
- 1.1338fs - 50K
- 1.0757fs - 47.44K(default)
You can see the responses and read more about the filter in the datasheets. We expose all of the built in filters in the current on-board firmware. So you can experiment and see what you like for yourself.
The ES9028/38 “Jitter Eliminator” technology itself has undergone some very important changes in regard to how it can be configured - including a new sync mode feature. It also has some interesting configuration around trade-offs like initial lock speed and DPLL bandwidth that are completely new compared to the ES9018.
We also realized that there is a lot that the current Buffalo III-SE module delivers that we have found DAC builders really like. We wanted to keep those features - they include:
- A simple consumer level SPDIF input option by incorporating an on-board comparator
- Simple intuitive stereo/mono PCM/DSD inputs - no summing or remapping required
- All of the configuration inputs are exposed on a header so that switching of certain features can be done either with the DIP switches on board or remotely - say at the front or back panel or via a second controller.
- Optional ADC driven volume control for precise but simple operation.
- Easy stacking integration with existing and new output stage modules like (Mercury, IVY-III, Legato) which are using the current module form factor and spacing. Individual independent voltage regulation for the Clock, Digital, and Analog sections of the DAC - designed for Trident and AVCC modules.
- The ability to reuse your existing power supplies (as long as they can supply a steady 5VDC) like the Placid-HD or the LCDPS.
- Improved digital input scheme (no more ES9018 style remapping and summing)
- Added GPIO support from the DAC including mapping them as various inputs
- Output gain calibration for multi-DAC use cases including Mono operation
- Exposing the new Hyperstream II sampling modes (sync/async)
- Exposing the capability to run the DAC in either master or slave mode.
- Support for remote clock and data I/O using uFL connectors.
The digital and control aspects of the ES9028/ES9038 DACs are in some ways similar to the ES9018 - but in many more ways are a significant departure from the venerable (and still excellent) ES9018. Quite simply the ES9028/ES9038 could never be considered drop-in replacements for the ES9018. Still - what Brian and I wanted to do was present a module that could both allow reuse of already excellent I/V stages like the IVY-III and the Legato when using the ES9028 while still allowing the user to opt for the ES9038 when paired with the new Mercury output stage. Yes - you are reading correctly we have an output stage that will absolutely handle all of the current of even a mono ES9038 - in current mode! So users have nice DAC upgrade path without ditching what they already have.
It is true (as I have stated in other threads) that the ES9038 in particular presents some particularly interesting design challenges because of the sheer amount of current it pumps out to the I/V stage. Presenting a virtual ground (so that the DAC operates as a current rather than voltage source) to that much output current is no small challenge. One of the reasons we have held off releasing a new module based on these chips was precisely because of the demands of the ES9038. The good news is that what we discovered actually benefits all of the ESS9018/28/38 DACs (yes - even the ES9018) and our patience has been rewarded in a solution we can truly be proud of.
So what we are presenting to our users is the ability to use existing excellent output stages with the ES9028 - variety is good! As well as a new output stage that is also suitable for the ES9038.
The ES9028 and ES9038 are practically identical except for the analog output section - which is duplicated 4 times and connected in parallel in the ES9038. The ES9038 was clearly designed first and foremost for 8 channel operation - but works well in stereo and mono mode as long as you have an output stage that can handle its copious current. We have tried two approaches to the ES9038 and will actually be supporting both eventually. First you can sum channels at the DAC - this is what the B3SE-Pro does. Second you can take all 8 outputs and sum them after I/V. This we have also tried and it also works quite well - but is also very expensive and huge! Also, after trying both we found to our (pleasant) surprise that compared to summing at the DAC and I/V with Mercury the result of summing after I/V was almost identical!!! There is no compromise in summing at the DAC as long as your I/V stage is up to the challenge. Now if you want a compact 8 channels of bliss - the ES9038 is indeed awesome - so at some point soon we will release a new 8 channel DAC call Buffalo IV based on the ES9038. It however will be a completely new design and thus will not be as simple to integrate with existing I/V stages etc. That DAC module will also allow you to sum after I/V if you so desire.
So there you have it. After much testing and designing a whole new output stage to meet the challenge we are ready to present to you the Buffalo III-SE-Pro. We are taking orders now for the module along with a new series AVCC and Tridents which are redesigned to take on the rigors of the increased current demand of the ES9028/9038. We also made the new trident available in a broader range of voltage output. This is important because in cases like running the ES9038 in mono at high sample rates, you want to run VDD at a slightly increased voltage than the nominal 1.2V). The ES9038 recommends 1.3V when running high sample rates in stereo/mono and we offer that voltage. I actually found that the ES9028/38 all seem to operate better at 1.3V VDD. We also found the running the AVCC module at 3.6V is desirable (because it increases the output swing slightly) - so we configure it for that voltage.
Please ask any questions you have about the new DAC modules and the Mercury - I am sure I forgot to mention something - though keep in mind I will be opening a new thread when Mercury is ready for us to open orders. Mercury is actually finished and is only awaiting final testing of the production PCBs - the circuit itself is finalized. We have just received the production Mercury PCBs and we will be testing them this week. Mercury is the spiritual sibling of CounterPoint - and is essentially the same idea - it is exactingly purpose built to maximise the potential of the ES9018/28/38 I can’t wait to introduce it to you in more detail.
I am working on the datasheets for the new modules and I will make them available very soon. They are very similar to existing modules so most users should be able to hit the ground running. The most important thing to remember is that the voltage input should be right at 5V - please don’t exceed that by more than a half volt because of the relatively low maximum voltage of the ADM7151 regulators in the Trident-SR and AVCC-SR that we recommend for this module.
Things we created to get ready for B3SE-Pro
- Trident/AVCC-SR Local Regs for B3/B3SE/B3SE-Pro Trident and AVCC headers - Trident-SR
- B3SE-Pro Module
- Mercury Output Stage
Cheers!
Russ
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