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Old 19th February 2021, 03:05 PM   #1051
stew1234 is offline stew1234  United States
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Introducing the Buffalo III-SE-Pro 9028/9038
Quote:
Originally Posted by francolargo View Post
This is an interesting approach and I will be curious about your final configuration and conclusions. I have a few questions.
1. How did you parallel the chips? A purpose-made circuit board, or other surface mount arrangement?
2. Did your circuit include a guard zone for the SET pin (#7)? If so, which board layers?
3. Whoa, 6 chips? That's up to 3 amps, so were they feeding other circuits than just the B3?

I tried a more conservative application of one LT3045 on my most recent project. It supplied the VDD_XO through a relay so that I could remotely switch between synch and asynch DAC operation. At first I set it at 3.3v and used a small passive filter at the B3's VDD_XO input. Not so successful - probably too much wire between the regulator and the B3. I then raised the LT3045 output to about 4.5v and sent that into the VDD_XO trident. In this configuration the SPDIF sources that use the 100MHz onboad clock are sounding very nice. But those are fairly jittery sources so I wouldn't over-sell the experiment and assume that all sources - especially synchronous ones - would benefit as well.

If I'm not mistaken, the LT3045 in an optimal layout should offer about half of the noise of a Trident. I don't have any idea about the PSRR of Trident output. But I would think that with adequate capacitance and enough 3045s for current overhead, the LT3045 could improve the B3Pro performance. But as pages 14 and 15 of the analog devices datasheet suggest, the devil would be in the details.

Please keep us informed if you try the LT3045 for AVCC!

Cheers,

Frank
MPA audio offers boards that have already mounted the LT3045 chips in parallel. I will try with "double" regulation into the tridents and directly feeding AVCC.
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Old 24th February 2021, 02:35 AM   #1052
mjl242 is offline mjl242  Thailand
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I'm wondering if anyone in here can give me some pointers? I have set up a dual mono with 38's and Mercurys. I'm using an spdf input,coaxial, I have a lock but no sound. (Except some squeaks at power off). I have checked voltages, including tridents, and they look good, I have a lock on both boards, but no sound. (I found a link to some firmware for a dual mono setup on github, which gives the lock on both channels as the supplied version only gave a lock on the master. Incidentally that is silent too.)

I had some IVY board so I swapped out a Mercury and tried that...silence. So I think that this may be the analog out on the BIII. I have switch 1 board 1 set to on, but have tried both positions.

I'm not using a volume control so I've just connected the 3.3v pin to PB4. Ive also connected GND, SDA and SCL on both boards. Resets also connected, GPIO pin 1 each board. Also GPIO pin 11 and 12 connected on slave DAC.

All swithces set to ON.

I have some Attiny 85's and can flash with hex files if anyone suggests some firmware.

I'm just not sure where to look next.

Cheers all. I love trawling through this sight for ispiration.
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Old 28th February 2021, 07:18 AM   #1053
laserscrape is online now laserscrape  Ireland
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Quote:
Originally Posted by andrea_mori View Post
Thanks for the tips, I will try to load the unofficial firmware with pure sync mode.

My goal is just to run the Buffalo fed by my FIFO buffer and external oscillators.
Since these oscillators are very low phase noise devices (in the region of the best oscillators on the market) I would avoid the DPLL running, so I think the pure sync mode is the best way to get the best timing performance.

As the I/V converter I'll use transformers, maybe followed by a tube buffer.
Will/Have you tested the 5.6MHz clocks for this?

I only discovered the other day that the 9038 (and possibly other ESS DACs) could work with 5.6MHz clocks for redbook. The PCM179X DACs also allow it, not aware of any other DS DACs that can.
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Old 28th February 2021, 09:14 AM   #1054
andrea_mori is offline andrea_mori  Italy
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Introducing the Buffalo III-SE-Pro 9028/9038
Quote:
Originally Posted by laserscrape View Post
Will/Have you tested the 5.6MHz clocks for this?

I only discovered the other day that the 9038 (and possibly other ESS DACs) could work with 5.6MHz clocks for redbook. The PCM179X DACs also allow it, not aware of any other DS DACs that can.
Not yet tried, I should receive the boards next days.

In pure sync mode I believe it works at 128fs, so with 5.6448 MHz crystal it should play redbooks.
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Old 19th March 2021, 06:18 AM   #1055
francolargo is offline francolargo  United States
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Quote:
Originally Posted by mjl242 View Post
I'm not using a volume control so I've just connected the 3.3v pin to PB4. Ive also connected GND, SDA and SCL on both boards. Resets also connected, GPIO pin 1 each board. Also GPIO pin 11 and 12 connected on slave DAC.

All swithces set to ON.

I have some Attiny 85's and can flash with hex files if anyone suggests some firmware.

I'm just not sure where to look next.
Perhaps look here: Buffalo III SE (Stereo Edition) Pro

If there is a firmware chip in place then you must not connect the reset pin - let it float. If you plan to use I2C for control instead of onboard firmware then you need to manage the reset function in addition to having SDA, SCL, and GND connected to a (preferably isolated) viable controller BUT you will need different addresses for each of the two boards. The two means of control - firmware vs. I2C - are typically mutually exclusive.
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Old 1st April 2021, 02:16 PM   #1056
laserscrape is online now laserscrape  Ireland
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Quote:
Originally Posted by andrea_mori View Post
Not yet tried, I should receive the boards next days.

In pure sync mode I believe it works at 128fs, so with 5.6448 MHz crystal it should play redbooks.
Any follow up impressions on your 9038 DAC?

I got a cheap 9038 based Topping D10S the other day and in stock form it was a really striking example of how objectively bad/incorrect (heavily compressed and unrealistic dynamics) a DAC can sound despite very good measurements
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Old 1st April 2021, 02:30 PM   #1057
andrea_mori is offline andrea_mori  Italy
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Introducing the Buffalo III-SE-Pro 9028/9038
Not yet, the package has arrived just now.
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Old 1st April 2021, 03:00 PM   #1058
francolargo is offline francolargo  United States
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Quote:
Originally Posted by laserscrape View Post
Any follow up impressions on your 9038 DAC?

I got a cheap 9038 based Topping D10S the other day and in stock form it was a really striking example of how objectively bad/incorrect (heavily compressed and unrealistic dynamics) a DAC can sound despite very good measurements
The Topping D10S does indeed test out well.
Topping D10s USB DAC and Bridge Review | Audio Science Review (ASR) Forum

However,
1. Comparing the ES9038Pro to the ES9038Q2M is not apples-to-apples because the latter has only 2 channels while the Pro has 8, which are averaged to create stereo output. https://www.mouser.com/datasheet/2/1..._3-1923484.pdf
2. This is a prime example of the fundamental importance of *how* the DAC IC is implemented - the power quality, the operation mode (current vs. voltage output), the design and linearity of the balanced to SE conversion and output, and perhaps even the benefits of input data reclocking.

As you point out, the objective is nice sound, not nice graphs!
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Old 1st April 2021, 03:03 PM   #1059
laserscrape is online now laserscrape  Ireland
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Ok, you must be quite busy with the group buy and other projects aswell.
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Old 1st April 2021, 03:15 PM   #1060
laserscrape is online now laserscrape  Ireland
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Sorry, didnt mean to imply that the Buffalo was comparable. I bought as D10s as a modding platform and possibly to use with andrea's FIFO+clocks in future, If the impressions of Buffalo were positive then it would give some idea if it's worth pursuing it with D10s.

Definitely some large improvements needed in the power supply of D10S,
Since the op amp I/V wouldn't be loaded as much its possible it has some benefits for SQ of I/V stage with only 2 channels.
Quote:
Originally Posted by francolargo View Post
The Topping D10S does indeed test out well.
Topping D10s USB DAC and Bridge Review | Audio Science Review (ASR) Forum

However,
1. Comparing the ES9038Pro to the ES9038Q2M is not apples-to-apples because the latter has only 2 channels while the Pro has 8, which are averaged to create stereo output. https://www.mouser.com/datasheet/2/1..._3-1923484.pdf
2. This is a prime example of the fundamental importance of *how* the DAC IC is implemented - the power quality, the operation mode (current vs. voltage output), the design and linearity of the balanced to SE conversion and output, and perhaps even the benefits of input data reclocking.

As you point out, the objective is nice sound, not nice graphs!
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