Re: Went looking in HK
Hi,
By now you're probably home already. But, just in case you're going back, since Manila is not that far away, as compared to NYC.
You were strolling in the ritzy touristic area. Those audio stores are not the places to look for exotic things like Zhaolus. Sonys, Aiwas, yes, but not the "unheard of" brands among the non-fi folks.
The high-end stoers are not there, but rather in Shum Shui Po (Ap Liu St., Eddie Wu's address?). So, you'd have to take the train to perhaps the Cheung Sha Wan station area. You'll find many such stores. There are also audio stores on I think Sai Yeung Choi St., at the beginning (south end), mostly housed in a couple of high risers.
I used to live in HK, that's how I know. I was last in HK 3 years ago. Since HK transforms itself every second..... But.... Ap Liu St. area still has the audio stores you and I would go, not Tsim Sha Tsui.
I am new as a poster here, so I can't send PMs out. I am looking to mod a Zhaolu 2.5c that I "WILL" be getting soon. Nobody has it in stock here in the U.S. I would hope to be asking the experts in this thread about a couple of simple mods, like inserting the LM 4562. I'm not a technically sophisticated person. I would need a road map to find the spot to do the replacement. I've gotten some pictures already, but, I'm sure I will have questions.
Thanks in advance.
fallen said:
Hi,
By now you're probably home already. But, just in case you're going back, since Manila is not that far away, as compared to NYC.
You were strolling in the ritzy touristic area. Those audio stores are not the places to look for exotic things like Zhaolus. Sonys, Aiwas, yes, but not the "unheard of" brands among the non-fi folks.
The high-end stoers are not there, but rather in Shum Shui Po (Ap Liu St., Eddie Wu's address?). So, you'd have to take the train to perhaps the Cheung Sha Wan station area. You'll find many such stores. There are also audio stores on I think Sai Yeung Choi St., at the beginning (south end), mostly housed in a couple of high risers.
I used to live in HK, that's how I know. I was last in HK 3 years ago. Since HK transforms itself every second..... But.... Ap Liu St. area still has the audio stores you and I would go, not Tsim Sha Tsui.
I am new as a poster here, so I can't send PMs out. I am looking to mod a Zhaolu 2.5c that I "WILL" be getting soon. Nobody has it in stock here in the U.S. I would hope to be asking the experts in this thread about a couple of simple mods, like inserting the LM 4562. I'm not a technically sophisticated person. I would need a road map to find the spot to do the replacement. I've gotten some pictures already, but, I'm sure I will have questions.
Thanks in advance.
Hi Guys,
Can somebody tell me what are the power connector (6 pin header) on the digital board connected to? This is a Digital board so one would expect to have only Vcc +5 and Gnd, but the connector is a 6 pin.
I am planning to move this board into a different case in which I have built a descrete output stage. So, I will have to build the supply neccessary to power the digital board.
The output connector I think is
L+
L-
Gnd
R+
R-
Right?
Thanks,
Dinesh
Can somebody tell me what are the power connector (6 pin header) on the digital board connected to? This is a Digital board so one would expect to have only Vcc +5 and Gnd, but the connector is a 6 pin.
I am planning to move this board into a different case in which I have built a descrete output stage. So, I will have to build the supply neccessary to power the digital board.
The output connector I think is
L+
L-
Gnd
R+
R-
Right?
Thanks,
Dinesh
Member
Joined 2003
The easiest way to find out would be with a multimeter and visual inspection of the PCB traces. I'd have to take mine all apart to know which pin is which, but there's 5V analog and 5V digital supplies with separate grounds, and 2 lines trigger the relays (relay control circuit is on the power supply board).
The output connector you are correct, though I'm not positive of the polarity, but I don't think it really matters.
The output connector you are correct, though I'm not positive of the polarity, but I don't think it really matters.
Dcibel,
Thanks for answering. I did not know there was a 5 V analog. I did measure, and 2 pins came up GND and 2 pins came up +5V and I though they were both the same 5V supply. I did not realize the 2 5V supplies are 2 separate supplies. I could not detect any voltage on 2 pins.
Regards,
Dinesh
Thanks for answering. I did not know there was a 5 V analog. I did measure, and 2 pins came up GND and 2 pins came up +5V and I though they were both the same 5V supply. I did not realize the 2 5V supplies are 2 separate supplies. I could not detect any voltage on 2 pins.
Regards,
Dinesh
Member
Joined 2003
Oh, you don't really want to see that embarrassing sight, do you? I'm not even sure I can show where all the ground track cuts are, as I remember some of them were underneath parts...I can only recommend that you have a close look at the circuit, reverse engineer it a bit, and see what you can do with a scalpel, soldering iron, and some wire to improve it.
My main intention of modifying the Zhaolu was to improve the output filter, and also to replace all the electrolytic caps as the ones that were installed were not the correct voltage rating and so would not withstand the test of time. The extra work of changing the grounding arrangement was just extra work that I thought was a good idea to do "while I was in there".
I may have a look at the Zhaolu board over the weekend, and see if I can take some photos that can at least describe the changes made to the power supply board.
My main intention of modifying the Zhaolu was to improve the output filter, and also to replace all the electrolytic caps as the ones that were installed were not the correct voltage rating and so would not withstand the test of time. The extra work of changing the grounding arrangement was just extra work that I thought was a good idea to do "while I was in there".
I may have a look at the Zhaolu board over the weekend, and see if I can take some photos that can at least describe the changes made to the power supply board.
Member
Joined 2003
Hi I got a zhaolu D3.
It sound great only thing is when I sit an the couch with my computer and there is a static discharche. The Dac produces high frequent digital output and blew two times a tube of my amp. Also when I switch the amp on off or the cd player on of.
I did connect after that a net filter and connected the digital ground to earth. But nothing helps??
Does any one know what to do about that? Thanks Helmuth.
Does any one have a drawing of the circuit of the D3?
It sound great only thing is when I sit an the couch with my computer and there is a static discharche. The Dac produces high frequent digital output and blew two times a tube of my amp. Also when I switch the amp on off or the cd player on of.
I did connect after that a net filter and connected the digital ground to earth. But nothing helps??
Does any one know what to do about that? Thanks Helmuth.
Does any one have a drawing of the circuit of the D3?
BobM said:
The Marants cd17mk2 is connected coax, the philips dvd coax, the tv optical.
The fault occurs when I got a static discharge to my laptop how is connected to the same net voltage.
There is no direct connection to the DAC other then the net voltage, with the laptop. It even seems to me there is a radio frequent pulse from the static discharge how makes the DAC oscillate.
The dac even reacts to switching on the light, with the net filter this is solved till now.
It can stand switching on the CD player but switching it of makes the dac to go into the oscillation state.
My profession is electronics and I work on a R&D of a firm how makes switching power supply's and lamp drivers from 15W to 34kW.
What I need is the solution to the problem, or a a schematic of the DAC to find the solution.
Regards Helmuth
Helmuth said:
Greetings,
I also have a D3 and is having the same problem as you. I didn't know what problem it was until I saw your post.
For my case, things start to go wrong when either 1) A computer PSU from another room is switched on, 2) I switch on the DAC followed by the amp, 3) I plug in the USB harddisk (???)
And for my case it's not a high frequency digital output although it appears to be so, but it's actually a severely clipped and super-loud audio signal. I managed to find out because most of the time I set the source volume at near zero so I can max the amp. It will just get veeeeeeeery loud and clip if I increase the volume from the source by a bit.
Currently looking for ways to solve the problems. I've tried 1) Changing the PSU of the other computers (didn't help), 2) Changing sound cards (helped a bit), 3) Ungrounding the DAC (didn't help), 4) Reversing the polarity of the DAC (didn't help).
You mentioned a net filter, what's that?
wwenze said:
I work at development department of a firm how develops and produces lamp drivers every unit needs a filter to prevent high frequent noise spread on the supply voltage.
They are also sold in this form. To place in series with the supply voltage. Sold in different current ratings. 1 ampere is enough in this case.
An externally hosted image should be here but it was not working when we last tested it.
Recent the problem became worse with my Zhaolu DAC.
Cause I had placed the DAC above the tube amp transformers.
The magnetic interference of the transformers was the cause playing loud or switching things trigged the DAC to oscillate.
So try place the DAC free from other electronics and see if it improves the stability. Try to shield it with a good earth shielding.
Because of this I think it will be use full to clean al screw holes from paint so the bottom and cap of case makes a good contact with earth to shield the electronics of the From from magnetic interference.
Regards Helmuth
You could also effectively implement a "star ground" by running a wire from each screw to a central spot. Ideally you would need to isolate the chassis ground plane for this to be more efficient, but you could probably get away with it even with just running the wires.
There is no central ground location that connects to the ground pin on the incoming AC line, so you will need to connect the ground on the AC to your start ground point as well.
Bob
There is no central ground location that connects to the ground pin on the incoming AC line, so you will need to connect the ground on the AC to your start ground point as well.
Bob
Lucky, I happen to have one of those lying around, and enough diy skills to build one should the need arise, but I try not to play with mains voltage. 
I'll remove the amp from the top of the DAC and see if it helps.
Update: Ok, what I did - Removed the amp to a faraway place, added 2 more ferrite choke rings to the DAC's power cord, used Zhaolu D2.5 as a shield by placing it on top and grounded,
Switch the power of the computer in another room, still *prszzzzzstuztstuztstzust*
Maybe for my case it's just plain bad mains power quality.
I'll remove the amp from the top of the DAC and see if it helps.
Update: Ok, what I did - Removed the amp to a faraway place, added 2 more ferrite choke rings to the DAC's power cord, used Zhaolu D2.5 as a shield by placing it on top and grounded,
Switch the power of the computer in another room, still *prszzzzzstuztstuztstzust*
Maybe for my case it's just plain bad mains power quality.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.