Hello,
Last week I received my 2 new tent boards to add to my 4 deck (old version) DDDAC with blue board.
After installation I was impressed with the sound change with 6 boards. Unfortunately after a few hours of play I am getting issues on the right channel with some parasite sounds of almost complete channel disapearance.
On the blue board I adjusted Rload with a 34 Ohms + a 68 ohms which gives a nice 26,67 Ohms in total on eadch side. Checking the voltages between common and pos/neg I get 2,82 Volts on Left side and 2.92 volts on right side (with right A pos neg at around 4,5V and B pos neg at 4,7V).
With the 4 old bords I had eaxactly the same voltage on each side. Is there something else I should test to help narrow down the problem ?
PS : It seems the problem increases with higher bitrate audio.
Many Thanks,
Lobo.
Last week I received my 2 new tent boards to add to my 4 deck (old version) DDDAC with blue board.
After installation I was impressed with the sound change with 6 boards. Unfortunately after a few hours of play I am getting issues on the right channel with some parasite sounds of almost complete channel disapearance.
On the blue board I adjusted Rload with a 34 Ohms + a 68 ohms which gives a nice 26,67 Ohms in total on eadch side. Checking the voltages between common and pos/neg I get 2,82 Volts on Left side and 2.92 volts on right side (with right A pos neg at around 4,5V and B pos neg at 4,7V).
With the 4 old bords I had eaxactly the same voltage on each side. Is there something else I should test to help narrow down the problem ?
PS : It seems the problem increases with higher bitrate audio.
Many Thanks,
Lobo.
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The fact that you had the same voltages at the I/V resistors with 4-deck and 6-deck DAC boards, and your last statement saying the problem increases with high bit-rates, suggests that you may have a power supply that can not handle the current demand of the tent shunt decks, in addition to what you had previously.
I have a dddac official power supply on which I changed the transformer to a Rcore transformer with a lillte increase in power as from the original transformer.
To what I read so far every board consume 100Mamp each so I "could" go up to 8 boards with one ddac power supply.
Since this new change I can hear a little "hum" coming from the power supply and the big heat sink has a temperature of 65 °C while running. I will check the power consumption this evening.
Thank you Extreme_Boky
The new Ten decks consume around 150mA, or even more. The hum is not a good sign...
The R-core transformer I am using is a 2x15v - 15va -> total of 30 VA. This should be one amp on each line.
Transformateur R-CORE 30VA 2x15V - Audiophonics
For testing purpose only would it be possible to connect the two lines of the Rcore to one power sppply line (to double availablle power) and do the same with the original toroidal transformer on the second line of the dddac power supply like on the drawing provided ?
Transformateur R-CORE 30VA 2x15V - Audiophonics
For testing purpose only would it be possible to connect the two lines of the Rcore to one power sppply line (to double availablle power) and do the same with the original toroidal transformer on the second line of the dddac power supply like on the drawing provided ?
Attachments
I think new tent boards consume 200 mA each, so your total consumption now is more than 800mA - theoretically it should be ok. Check solder joints between top board and motherboard - probably bad joint somewhere. I recently added second board to my dddac with clclc psu - no problems at all.
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After some tests on the power consumption 4 old Dac Board + 2 tent dac boards shows a consumption of 0.850A to 0.950A (I also see 1.147A after init)
What would be the best way to proceed to beef up the DDDAC power supply a bit apart from the below two points?
1) Removing the 1A fuse and add two R-core 30VA transformers (one on each power supply 15v line)
2) Add a fan on the Tip122 heatsink to increase it's efficiency .
3) ...
What would be the best way to proceed to beef up the DDDAC power supply a bit apart from the below two points?
1) Removing the 1A fuse and add two R-core 30VA transformers (one on each power supply 15v line)
2) Add a fan on the Tip122 heatsink to increase it's efficiency .
3) ...
Ok, I had a bit of time to measure the current consumptions on my 4 decker DDDAC.
The motherboard and the 4 (original) decks -> 510mA
The WaveIO -> 380mA (on a separate power supply)
This is with 24/192 material being played.
Your motherboard and 6 decks are drawing around 850 - 950mA, but the transformer and the TIP122 (with original heatsink) should handle this fine, albeit running a bit hot...
... which means that you may have an issue somewhere else...
Check the current draws of each section (analogue and digital) of all DAC IC's by measuring voltage drop at R1, R2, R3 and R4. I am not sure about new Tent decks... but the series drop-down resistors should be very easy to find by comparing their layout with the original DAC decks' layout
I suspect it will all measure okay..., in which case you should check the WaveI/O card signals up to the IC4. If all good, continue by checking the LR, Data and BCK signals on the decks.
I also remember that the early batch of Tent DAC decks had an issue with smd transistors: the fet transistor (2SK208) and one of the transistors in the same package, but around Tent regulator area (I think...), were swapped arround on a PCB, so it's probably a good idea to check that as well.
Good luck,
Nick
Thank you a lot Extreme_Boky for the information. (Some of it is above my knowledge about checking the signal) Voltage I can do but signal ..
So after testing voltage drops I can say everything looks fine.
After removing the connection with WaveIO board and the additional led board from the blue mainboard the power consumption stays at 840 MV with the temperature of the TIP 122 going down to 50 - 54 degrees
Thus there should be something wrong in the way my waveio is connected. (It is powered with a 5v DDAC power supply and uses the 2 ribbon provided in the DDDAC package (one for the i2s and one for the leds board)
To check this further I will reinstall my odroid C2 with I2S out and see if there is a different behaviour of the 12 Volts tip122.
What an adventure for a newbee like me ...
PS : the temperature readings with the temp camera shows the PCM1794 of the new boards running at 50 degrees while turned on (no signal) and the Rload resistors shows the same temperature. It is hard to check the temp of the PCM1794 of the old boards as the newer are on top and these chips are surrounded by caps .. I suppose this is perfectly normal.
So after testing voltage drops I can say everything looks fine.
After removing the connection with WaveIO board and the additional led board from the blue mainboard the power consumption stays at 840 MV with the temperature of the TIP 122 going down to 50 - 54 degrees
Thus there should be something wrong in the way my waveio is connected. (It is powered with a 5v DDAC power supply and uses the 2 ribbon provided in the DDDAC package (one for the i2s and one for the leds board)
To check this further I will reinstall my odroid C2 with I2S out and see if there is a different behaviour of the 12 Volts tip122.
What an adventure for a newbee like me ...
PS : the temperature readings with the temp camera shows the PCM1794 of the new boards running at 50 degrees while turned on (no signal) and the Rload resistors shows the same temperature. It is hard to check the temp of the PCM1794 of the old boards as the newer are on top and these chips are surrounded by caps .. I suppose this is perfectly normal.
Hello,
To change subject I am not sure whet I did but the problem on the DDDAC is gone I would like to give my opinion on the change.
Here is the inital setup : DDDAC blue mainboard with 4 old decks and the cinemags. I was quite happy soundwise with a "bit of harsness" mainly due to the speakers (B&W matrix floor sanding).
The change : addition of 2 new tent boards.
The change is bigger than expected !! The main areas of changes are as follow :
1) Far bigger sound stage with a better 3d imaging of the reproduction. Every instrument has more room, you can easier focus on each of them.
2) There are a lot of added details that I couldn't hear with the 4 decks
3) The lower spectrum is more present and has a bigger weight.
4) The higher spectrum is more defined while being further away and thus giving less harshness to my system.
With such an improvement I will be forced to move to 8 boards even if my bank account doesn't agree
System setup : Odroid C2 -> (with Waveio or without using I2S) ->DDDAC -> McIntosh mc4100 -> B&W Matrix 3 floorstanding Speakers.
To change subject I am not sure whet I did but the problem on the DDDAC is gone I would like to give my opinion on the change.
Here is the inital setup : DDDAC blue mainboard with 4 old decks and the cinemags. I was quite happy soundwise with a "bit of harsness" mainly due to the speakers (B&W matrix floor sanding).
The change : addition of 2 new tent boards.
The change is bigger than expected !! The main areas of changes are as follow :
1) Far bigger sound stage with a better 3d imaging of the reproduction. Every instrument has more room, you can easier focus on each of them.
2) There are a lot of added details that I couldn't hear with the 4 decks
3) The lower spectrum is more present and has a bigger weight.
4) The higher spectrum is more defined while being further away and thus giving less harshness to my system.
With such an improvement I will be forced to move to 8 boards even if my bank account doesn't agree
System setup : Odroid C2 -> (with Waveio or without using I2S) ->DDDAC -> McIntosh mc4100 -> B&W Matrix 3 floorstanding Speakers.
Nice work Alex ! By the way, what part is the heatsink on the blue power supply on the TIP transistor?
The heatsink is made by AAVID and part number 6399BG 50 mm height.
It still does get quite hot running the WaveIO and my I2S splitter but not too hot to touch.
There is a better one available if you don`t mind going up to 65.5 mm height which is: AAVID THERMALLOY*530002B02500G and has a thermal resistance of 2.6 CW.
I will use it because I leave the Dac on all the time and tend to go for lower temperatures if possible.
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