Ok.
Chinese
PSU not good
Change, with what, what is not god on Shunt regulators!
Those 2 trimers are in outpt stage!
Regards zeoN_Rider
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Hi zeoN_Rider,
It look like series regulator???
Where you bought this DAC and how much? What is the website? Probably you may need to looking for the new DAC.
BR,
Moddang
It look like series regulator???
Where you bought this DAC and how much? What is the website? Probably you may need to looking for the new DAC.
BR,
Moddang
Hi,
I recently purchased a DAC TDA1541A+WM8805 NOS 1.0UI multi-input from raindrop_hui on ebay. I cannot get any signal out from the analog out on the board. I have tried troubleshooting, but I am a novice when it comes to digital electronics. The communications is strained because of a language barrier and the most I've gotten from Mr. Zou is one email a day. I found some troubleshooting tips while scanning the site for Lesha's DAC. There is a voltage table of the TDA1541A pins posted on the site. According to it the voltage on pin 26 of the the DAC should read about - 5.1 volts. It reads -2.211 volts. I informed Mr. Zou of this and have not heard from him since.
Can you trace a digital signal with an oscope?
I recently purchased a DAC TDA1541A+WM8805 NOS 1.0UI multi-input from raindrop_hui on ebay. I cannot get any signal out from the analog out on the board. I have tried troubleshooting, but I am a novice when it comes to digital electronics. The communications is strained because of a language barrier and the most I've gotten from Mr. Zou is one email a day. I found some troubleshooting tips while scanning the site for Lesha's DAC. There is a voltage table of the TDA1541A pins posted on the site. According to it the voltage on pin 26 of the the DAC should read about - 5.1 volts. It reads -2.211 volts. I informed Mr. Zou of this and have not heard from him since.
Can you trace a digital signal with an oscope?
With regards to Raindrop_hui 1865
I notice that the power transformer 18vac is converted to 15vdc and then to +5vdc/-5vdc while the transformer 9vac is comverted to 9.75vdc and then to 5vdc.
So is it ok to substitute the 9vac transformer with a 12vac transformer? And what is the purpose of the dual regulation when the 15vdc and 9.75vdc are not used at all?
I notice that the power transformer 18vac is converted to 15vdc and then to +5vdc/-5vdc while the transformer 9vac is comverted to 9.75vdc and then to 5vdc.
So is it ok to substitute the 9vac transformer with a 12vac transformer? And what is the purpose of the dual regulation when the 15vdc and 9.75vdc are not used at all?
Today I conneced my AD1865 DAC with LL1578XL on the output:
The gain is a little on the lowside,I have now a 200ohm resistor on the output
Will I get higher gain if I use a say,400 ohm resistor?
The sound is a little dark (don´t know how it is with the tube output?)
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
The gain is a little on the lowside,I have now a 200ohm resistor on the output
Will I get higher gain if I use a say,400 ohm resistor?
The sound is a little dark (don´t know how it is with the tube output?)
Quanghao do you have a I/V board,the one with the tubes on,I´d like to buy one.
Or anyone else got a spare one.
Or anyone else got a spare one.
Andrea,
What is the reason for using 200 ohm I/V resistor instead of recommended by AD 1,7 kohm?
What is the reason for using 200 ohm I/V resistor instead of recommended by AD 1,7 kohm?
Yes, you will get 6dB higher output amplitude with 400 ohm I/V resistors. My experience is that the AD1865 will still produce excellent sound with a 400 ohm passive resistor I/V. This is a relatively rare ability, one shared by the PCM56. If, however, you are directly driving a transformer from the AD1865 outputs, the higher I/V resistor value effectively raises the source impedance as seen by the primary, not something to be desired in itself.
If this is a un-equalized NOS (digital filterless) design, then it might indeed sound a little dark, due to the well known -3.16dB @ 20kHz zero'th order hold response roll-off.
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And what for is that 0,015uF cap between grid and cathode?I/V resistor not shown, sound is much better than SRPP (I compared).
it is a low pass filter. If you trust your cap not to short you can use one 1/mu smaller between grid and anode instead.
Today I would recommend a more linear tube with more gain like the 6e6p.
Today I would recommend a more linear tube with more gain like the 6e6p.
Thanks for reply. Instead you can also use a cap in paralell to anode resistor as Thorsten Loesch do.
I'm just working on an oversampling AD1865 DAC with SM5842 digital filter passive I/V and tube gain stage. When I'll finish it I'll post the results and some photos.
I'm just working on an oversampling AD1865 DAC with SM5842 digital filter passive I/V and tube gain stage. When I'll finish it I'll post the results and some photos.
Using the Trim/Offset on the AD1865N
Hi...
I see there's been no post here for a long time....hope I'm not alone out here!! 😱
Question: Has anyone used the L/R TRIM pins on the AD1865N (will be using the K version) and noted a perceived and/or improved sound quality? To test this I imagine it will take a test CD with tones low enough to establish distortion at 60dB down?
Thanks,
Gary
Hi...
I see there's been no post here for a long time....hope I'm not alone out here!! 😱
Question: Has anyone used the L/R TRIM pins on the AD1865N (will be using the K version) and noted a perceived and/or improved sound quality? To test this I imagine it will take a test CD with tones low enough to establish distortion at 60dB down?
Thanks,
Gary
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