Something strange has happened to my Buffalo. I have completely lost S/PDIF lock and have no sound at all. The automute LED is on.
It was all working fine last night and today I removed my DCB1 from the case to do some adjustments but did not touch the Buffalo other than to remove the connections from the Legato to the DCB1.
I cannot get lock from either the EMU soundcard or the onboard S/PDIF socket. I'm pretty sure the PC is ok, I have re-installed drivers and also tried different RCA connectors on the case and swapped leads to the DAC. Does anybody know what may have happened or what measurement or checks I can take to find out if the signal is going to the DAC. Is there a reset?
I have the S/PDIF input going to the standard connections on the digital terminal block. Would using D1 eliminate a problem?
Thanks
It was all working fine last night and today I removed my DCB1 from the case to do some adjustments but did not touch the Buffalo other than to remove the connections from the Legato to the DCB1.
I cannot get lock from either the EMU soundcard or the onboard S/PDIF socket. I'm pretty sure the PC is ok, I have re-installed drivers and also tried different RCA connectors on the case and swapped leads to the DAC. Does anybody know what may have happened or what measurement or checks I can take to find out if the signal is going to the DAC. Is there a reset?
I have the S/PDIF input going to the standard connections on the digital terminal block. Would using D1 eliminate a problem?
Thanks
Hi Rich, a few thoughts off the top of my head. First, you can reset the firmware by switching the DAC off the on - but I'm sure you've already done that (?). There's also a reset header you can short out - check the schematic and layout from the twisted pear site.
Make sure your iron is turned off. I had a problem losing lock a while back and it turned out to be the field generated by my iron - I could lose and regain lock by moving the soldering station around.
Check the switches on the Buffalo haven't accidentally been set wrong. Measure continuity for the SPDIF lead from the input cable to the DAC. See how you get on.
No joy with the reset unfortunately. I also tried the DAC with the Coax output on a DVD player and it wouldn't lock.
Reading through the TP support forum one guy seemed to have the same problem and Russ suggested that it may be the LMV7239 comparator chip or input section damaged.
Farnell sell the chips but it looks a bitch to desolder. I haven't got a bit that small!
What else in the input section could be damaged?
Reading through the TP support forum one guy seemed to have the same problem and Russ suggested that it may be the LMV7239 comparator chip or input section damaged.
Farnell sell the chips but it looks a bitch to desolder. I haven't got a bit that small!
What else in the input section could be damaged?
You can feed SPDIF directly into the Sabre, without going through the comparator. This will test whether there is a comparator fault. However the SPDIF signal needs to be close to 3.3V, so you could try a few of your digital sources if you are unable to measure. The input pin you need to use will be shown on the Buffalo schematic, it's either D1 or D2 from memory.
Just feed it into "D2", and change the setting of the single switch to "open". Strictly speaking you should also connect a 75 ohm resistor to earth here too, but it should be OK just for testing.
Having said all this, I can't think why the comparator would fail just through messing about with the output stage. My suspicion (from personal experience) is that these things are often down to really daft oversights that one is too embarrased to tell anyone about once figured out.
Just a thought, make sure all the power connections are tight to and from the boards. I recall an intermitant no sound problem a couple of years ago and
discovered that just pressing on the top of the board the sound would cut out.
It would play fine for days then not....
Turns out one of the wires was inserted just under the clamp and looked like it was properly installed. Learned to give every wire a tug to make certain.
Rich
Depending on how you've got the power feeding to the DAC board, you can get a problem with power on if one of the supplies "starts" quicker than the other which gives exactly the inert symptom you have. Trouble is I can't recall whether the digital or analogue rails need to reach operating voltage first - perhaps Russ can remind us.
Just a thought, something to try before more drastic measures...
Mark
Depending on how you've got the power feeding to the DAC board, you can get a problem with power on if one of the supplies "starts" quicker than the other which gives exactly the inert symptom you have. Trouble is I can't recall whether the digital or analogue rails need to reach operating voltage first - perhaps Russ can remind us.
Just a thought, something to try before more drastic measures...
Mark
Yes, I'm agree with Mark, wanted to post the same thing. For example Audio Alchemy's DDE sometimes keep silence. In order to help it sing again I'm doing the following: power supply switched on / unplug wall outlet / wait 10 sek / power supply swirched off / plug outlet / switch on device - miracle!!! It sings again.
But if you use one transformer for all supplies than usual this cannot be happen. Also explore carefully your board with magnifying glass, maybe somewhere a piece of solder friendly shorted track.
Thanks for all the suggestions guys, much appreciated.
Well I didn't have any time yesterday to fiddle with the DAC but today I had another look at things and still can't get a lock. I've tried everything I could think of.
All connections are sound. The supplies to the DAC are Placids run form the same transformer and all have steady outputs. I tried connecting to D2 and got nothing. There are no foreign particles or objects shorting anywhere.
I actually think my DAC is broken somehow.
I'm at a total loss as to how this happened as I did not touch the DAC or any connections to it. The auto mute is on so either the comparator is damaged or the firmware chip maybe. I can get another comparator chip from Farnell but may ask one of the TP boys about firmware replacement.
I will also ask around to see if anybody has a scope that could help in diagnosing the problem.
I have my power amp connected to the analogue outputs of my EMU card and it's actually a very good sounding card like this using the AK4395 DAC. But it's not quite a buffalo.
Well I didn't have any time yesterday to fiddle with the DAC but today I had another look at things and still can't get a lock. I've tried everything I could think of.
All connections are sound. The supplies to the DAC are Placids run form the same transformer and all have steady outputs. I tried connecting to D2 and got nothing. There are no foreign particles or objects shorting anywhere.
I actually think my DAC is broken somehow.
I'm at a total loss as to how this happened as I did not touch the DAC or any connections to it. The auto mute is on so either the comparator is damaged or the firmware chip maybe. I can get another comparator chip from Farnell but may ask one of the TP boys about firmware replacement.
I will also ask around to see if anybody has a scope that could help in diagnosing the problem.
I have my power amp connected to the analogue outputs of my EMU card and it's actually a very good sounding card like this using the AK4395 DAC. But it's not quite a buffalo.
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OK, still one or two things to try.
I take it you are using the SE outputs from the Legato? If so, measure resistance between earth on the Buffalo and earth on your amplifier, with the DAC/amp powered off and the interconnects fitted. It should be close to zero ohms. Once done, try powering up the DAC again. The EMU is transformer isolated, so I'm wondering if the DAC earth is floating.
I take it you are using the SE outputs from the Legato? If so, measure resistance between earth on the Buffalo and earth on your amplifier, with the DAC/amp powered off and the interconnects fitted. It should be close to zero ohms. Once done, try powering up the DAC again. The EMU is transformer isolated, so I'm wondering if the DAC earth is floating.
Hi Richlund,
Have u solved the problem? please do not give up yet. try reverting back to the on-board regulator. its easy, simply solder a wire from C4 (where u connect the 3.3V from the Flea PSU) to the centre tab of REG1. U will likely to get the buffalo working again. Let me know if it works for u.
Have u solved the problem? please do not give up yet. try reverting back to the on-board regulator. its easy, simply solder a wire from C4 (where u connect the 3.3V from the Flea PSU) to the centre tab of REG1. U will likely to get the buffalo working again. Let me know if it works for u.
Brian/Russ... or anyone!!
I'm someone with an early buffalo 1.1...... one of the ones with the lower speed comparator chip so it won't play above 16/48 I think. Anyway, after a couple of years of listening (!) I finally decided to get off my *** and do something. I went and bought the newer comparator (LMV7219) and hoping to fit it in the next day or so.
So, just to be absolutely sure!!!
1. Its IC2, just near the SPDIF switch on the 1.1 board?
2. Any other items need to be changed?
3. Any tips/warnings for removing the old one fitting the new one?
All help gratefully accepted!
Fran
I'm someone with an early buffalo 1.1...... one of the ones with the lower speed comparator chip so it won't play above 16/48 I think. Anyway, after a couple of years of listening (!) I finally decided to get off my *** and do something. I went and bought the newer comparator (LMV7219) and hoping to fit it in the next day or so.
So, just to be absolutely sure!!!
1. Its IC2, just near the SPDIF switch on the 1.1 board?
2. Any other items need to be changed?
3. Any tips/warnings for removing the old one fitting the new one?
All help gratefully accepted!
Fran
Well, let me start by saying I will do the replacement for you if you want.
It is IC2 directly beside the S/PDIF switch.
First, remove the S/PDIF switch; it gets in the way. I usually use soldering tweezers for this, but have done without as well. There should be enough flex in the legs that you can heat and lift one side (very gently), then the other side. If the legs get bent, you can easily straighten them after you get it off.
The easiest way to remove the chip is to cut it off, if you have fine tip cutters (something like these):
You can actually get the tips in there and cut each leg of the chip. Then use a soldering tip to gently drag across each pad to remove the remaining bit of leg from the pads.
If you don't have cutters like that (buy some!
), try heating the 2-pin side pins and lifting that side (very gently) with the tip of an exacto-blade or tweezers. You should be able to do all three pins on the other side with the broad-side of you tip and lift the whole thing off.I then clean all the remaining solder off all the pads with a piece of solder wick.
Add a tiny dab of solder to one of the pins. Press the new chip into place and quickly heat that leg/pad to lock the chip in position. Then go around to the other pins and solder them in place. Very thin solder (0.015") and a fairly fine tip helps (I usually use the corner of a standard 3/32" tip).
Then, just solder the switch back in place.
Job done - thanks Brian.
I removed the switch - made a big diffference. Also, I used a little bit of braid with a drop of solder on it across the 3 legs and then levered the chip back up gently. The chip lifted easily, so I only needed to do the same then for the other side.
The biggest worry was would I drop the chip!! I ordered 2 from farnell, and only 1 arrived in the bag - they had cut the strip short and I reckon the second one fell out! I only bought 2 in case I damaged one....
Fran
I removed the switch - made a big diffference. Also, I used a little bit of braid with a drop of solder on it across the 3 legs and then levered the chip back up gently. The chip lifted easily, so I only needed to do the same then for the other side.
The biggest worry was would I drop the chip!! I ordered 2 from farnell, and only 1 arrived in the bag - they had cut the strip short and I reckon the second one fell out! I only bought 2 in case I damaged one....
Fran
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