AD797 Output
I need some help.
Please see the attached schematics.
What should be the recommended dual voltage supply?
Do I need a coupling cap for the output to RCA socket?
Where should the Vref connected to?
Is my numbering of opamp inputs correct?
Is the RCA socket connected to analog ground?
I need the single ended portion only
Thanks
Audiohifi
I need some help.
Please see the attached schematics.
What should be the recommended dual voltage supply?
Do I need a coupling cap for the output to RCA socket?
Where should the Vref connected to?
Is my numbering of opamp inputs correct?
Is the RCA socket connected to analog ground?
I need the single ended portion only
Thanks
Audiohifi
Attachments
Everything you need to know is covered in the excellent integration guides.
Twisted Pear Audio Document Repository
Twisted Pear Audio Document Repository
I have several Buffalo-II boards sitting on a shelf, so I decided to offer them as complete DACs. I have them listed on the Parts Bin page.
$199 with the current AVCC module.
$199 with the current AVCC module.
Good to know that there are still some available.
I may have to start saving up for a replacement, as mine seems to have a non-functioning i2c header.
Buffalo II changing the clock
want to change the clock of 80 MHz of my Buffalo II with new clok 100MHz. It's possible ? how should I do. Thank you.
want to change the clock of 80 MHz of my Buffalo II with new clok 100MHz. It's possible ? how should I do. Thank you.
Buffalo II Still Available ?
Dear Brian,
Are the Buffalo II still available ?
Thank you !
Dear Brian,
Are the Buffalo II still available ?
Thank you !
Simplified Build
Dear Brian,
Thank you for the reply. Is it possible to build a simplified Buffalo DAC II and upgrade later ? I understand it is not ideal.
Thinking:
Buffalo DAC II
All the best
Dear Brian,
Thank you for the reply. Is it possible to build a simplified Buffalo DAC II and upgrade later ? I understand it is not ideal.
Thinking:
Buffalo DAC II
All the best
Last edited by a moderator:
yup...
I put a 100 MHz CCHD-575 on my B-II (although he smaller footprint is tricky)
You have to be very careful removing the clock, otherwise you will damage the traces. What I do with just a good temperature controlled iron:
First remove as much solder as possible at each pad using solder wick, but do not overheat things, be patient.
Then, heat the pad while GENTLY prying up on that edge of the clock module. It is important to just pry up very gently, otherwise you will wreck the board. When the solder at that joint releases remove the heat while holding that edge up. Repeat the process for the other three pads.
Then clean the board, and solder in the new clock module, being careful to not overheat it. Solder on pad at a time, and allow the module to cool in between.
Remember, that you do risk wrecking the board if you are not extremely careful, and do not attempt this if you are not certain you can pull it off, or are not prepared to scrap the board if you botch it!
I put a 100 MHz CCHD-575 on my B-II (although he smaller footprint is tricky)
You have to be very careful removing the clock, otherwise you will damage the traces. What I do with just a good temperature controlled iron:
First remove as much solder as possible at each pad using solder wick, but do not overheat things, be patient.
Then, heat the pad while GENTLY prying up on that edge of the clock module. It is important to just pry up very gently, otherwise you will wreck the board. When the solder at that joint releases remove the heat while holding that edge up. Repeat the process for the other three pads.
Then clean the board, and solder in the new clock module, being careful to not overheat it. Solder on pad at a time, and allow the module to cool in between.
Remember, that you do risk wrecking the board if you are not extremely careful, and do not attempt this if you are not certain you can pull it off, or are not prepared to scrap the board if you botch it!
Yes, the noise performance will be dominated by the local linear regulators. Providing them with a cleaner source is always better, but you can do that later.
We really prefer the performance of the Amanero over XMOS solutions.
Caps caps caps
Can't live without them
One of many BIIs I've built stayed too long in the closet and I thought I give it a try once more
After the first power up the AVCC was dead. The guys from TP were kind enough to send me another one freewave but putting the new one didn't solve the problem (leds ok but AVCC volts out of spec). I thought that it destroyed another AVCC and set it aside for some months.
So now, after testing the new AVCC, it seems ok, so I took a close look at the DAC board and after a check I found that C8, C5, C6, C7 caps have "gone fishing". What are the specs of these ?
Can't live without them
One of many BIIs I've built stayed too long in the closet and I thought I give it a try once more
After the first power up the AVCC was dead. The guys from TP were kind enough to send me another one free
wave but putting the new one didn't solve the problem (leds ok but AVCC volts out of spec). I thought that it destroyed another AVCC and set it aside for some months.So now, after testing the new AVCC, it seems ok, so I took a close look at the DAC board and after a check I found that C8, C5, C6, C7 caps have "gone fishing". What are the specs of these ?
After 5 years of use, it seems that the my Buffalo II / Ivy / Placid combo distorts after running for some time, after one hour or so. Sounds then a little bit like a record needle clooged with dust (or power transitor dying). The effect can be worsened by switching digital sources. Then the signal is almost completely gone, very thin and distorted. Same distortion behavior, sounds like you were listening to a record stylus solely without aving the amp turned on or put the volume down.
Switching off the Buffalo / Ivy / Placid combo and having it cooled down helps.
After lets say 10 Minutes, everything comes back to normal again.
Any ideas?
All the best,
Salar
Switching off the Buffalo / Ivy / Placid combo and having it cooled down helps.
After lets say 10 Minutes, everything comes back to normal again.
Any ideas?
All the best,
Salar
If it is heat-related, my best guess is a bad solder joint.
See if you can get it to happen by artificially heating with a hair dryer (gently). You may be able to isolate the source that way. Alternatively, you can try cooling to make it stop.
Most likely areas of interest are wire connections and heat generating components (power supply and Tridents, for example). It could also be a failing electrolytic capacitor, given the age.
See if you can get it to happen by artificially heating with a hair dryer (gently). You may be able to isolate the source that way. Alternatively, you can try cooling to make it stop.
Most likely areas of interest are wire connections and heat generating components (power supply and Tridents, for example). It could also be a failing electrolytic capacitor, given the age.
Hello Brian,
I was writing my post while testing the Buffalo / Ivy / Placid combo, so I have to do a corretion now:
Distortion starts earlier as described, after around 20 min. Could be very likely that the distortion rises linear until it becomes audible, especially in loud music passages. Because I am listening to piano in the moment, distortion could be masked by the pianos harmonics.
Against what i described before, Changing the source does not
alter the distortion. I assume that the described point where the music becomes almost inaudible is just "another step further" Sometimes the Buffalo is switched on for hours before I start to listen to something (or there are long pauses in between)This is why I thought it was a source/clock related Problem. But I have to check on this.
About bad solder Joints:
I remember that I took a lot of time for soldering, taking care for the solder to creep / rest in the upper and lower side of the solder hole. So I assume I did this well but yo´ll never know.
Venting is done fairly well, even though the combo sits in a Nakamichi CD-Player. But I altered the top cover to submit more ventilation. Still around 40 degrees centigrade in the
cabinet during the summer.
Disassembling the Player will be a pain in the ... to check all this.
Could it be a heat related voltage drift in the Placid BP?
All the best,
Salar
I was writing my post while testing the Buffalo / Ivy / Placid combo, so I have to do a corretion now:
Distortion starts earlier as described, after around 20 min. Could be very likely that the distortion rises linear until it becomes audible, especially in loud music passages. Because I am listening to piano in the moment, distortion could be masked by the pianos harmonics.
Against what i described before, Changing the source does not
alter the distortion. I assume that the described point where the music becomes almost inaudible is just "another step further" Sometimes the Buffalo is switched on for hours before I start to listen to something (or there are long pauses in between)This is why I thought it was a source/clock related Problem. But I have to check on this.
About bad solder Joints:
I remember that I took a lot of time for soldering, taking care for the solder to creep / rest in the upper and lower side of the solder hole. So I assume I did this well but yo´ll never know.
Venting is done fairly well, even though the combo sits in a Nakamichi CD-Player. But I altered the top cover to submit more ventilation. Still around 40 degrees centigrade in the
cabinet during the summer.
Disassembling the Player will be a pain in the ... to check all this.
Could it be a heat related voltage drift in the Placid BP?
All the best,
Salar
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