I do have a problem with the standard Hypex setup though, I have:
Hypex Softstart - Hypex 500VA - Hypex HG PS - 2xHypex UcD400 V1.1
When the amp is "cold", I mean turned off for a few hours, I have a nasty click in the speakers at turn on.
The Softstart limits inrush about a second (maybe shorter) then goes full power. At that moment the HG PS "unmutes" the amps, and a second later I get a click. Turn off is quiet.
Turn off/turn on right after that, no more click in the speakers, perfectly quiet.
I simulated a longer "cold turn on" softstart time (turn on, and off before the relay click, then after a second, on again) - I get no click.
Hypex is ***fantastic*** in support, as they have sent me a few caps to solder on the UcD400 to delay the "unmute" a bit more.
Unfortunatly i'm a bit scared about soldering these tiny SMD's. I asked them if I could delay the SS a bit more but they asked me to try the UcD's first.
Maybe it's something specific about my setup, but it's strange to see that an all-hypex setup has this behaviour. But again, fantastic support! 😀
Hypex Softstart - Hypex 500VA - Hypex HG PS - 2xHypex UcD400 V1.1
When the amp is "cold", I mean turned off for a few hours, I have a nasty click in the speakers at turn on.
The Softstart limits inrush about a second (maybe shorter) then goes full power. At that moment the HG PS "unmutes" the amps, and a second later I get a click. Turn off is quiet.
Turn off/turn on right after that, no more click in the speakers, perfectly quiet.
I simulated a longer "cold turn on" softstart time (turn on, and off before the relay click, then after a second, on again) - I get no click.
Hypex is ***fantastic*** in support, as they have sent me a few caps to solder on the UcD400 to delay the "unmute" a bit more.
Unfortunatly i'm a bit scared about soldering these tiny SMD's. I asked them if I could delay the SS a bit more but they asked me to try the UcD's first.
Maybe it's something specific about my setup, but it's strange to see that an all-hypex setup has this behaviour. But again, fantastic support! 😀
Infact I asked if the Hypex power supply have silent TURN ON but you have experienced that this isn't.
I don't know if the new capacitors can solve the problem because actually in my setup ( diy power supply) the click on the drivers are immediatly after the turn on, if the problem was just more delay one second should be sufficient no need for more time.
I don't know if the new capacitors can solve the problem because actually in my setup ( diy power supply) the click on the drivers are immediatly after the turn on, if the problem was just more delay one second should be sufficient no need for more time.
I have also a click after muting turns on (DIY), it is not nasty but good audible. No sound at turn off. I thought it might be a grounding problem, as my test setup is not optimized and I feed a unbalanced signal to the UCDs. After the specs it is supposed to be dead silence. I will further look into that topic when I install my real setup.
I hoped to be able to eliminate the cap in the tweeter path in my tri-amped system but don't dare at the moment.
stephan
I hoped to be able to eliminate the cap in the tweeter path in my tri-amped system but don't dare at the moment.
stephan
The MUST switch on without any click, I will ask our support to contact you.
We recommend 2-3 seconds delay to let the bootstrap capacitor fully charge, when they are not fully charged you will hear this thick.
Jan-Peter
Jan-Peter,
Your support dept. has already given me a solution, they sent me some caps to make the UcD's start up time longer, but i'm still considering if I should solder these SMDs.
The SS takes about 1 second before I hear the relay click, then right after that (about half sec to full sec) the blue lights on the modules come up.
Before the Hypex SS/transformer I used to do this manually, first turn on the AC power to the transformer, after a second or three I turned on the modules (simple switch between gnd and on) and I barely heard a click.
Maybe the SS startup time is good to avoid the inrush, but at that time the main PS caps are still charging when the power goes to full and the modules turn on at this time?
If I prolong the inrush limitation (see method higher in the thread) there is no "pop" in the speakers. The pop is "midrange", no nasty DC or anything.
PS. I have 2.5mm² cable between PS and modules for power, about 15 to 20cm, maybe this causes the problem? Cable capacitance?
Your support dept. has already given me a solution, they sent me some caps to make the UcD's start up time longer, but i'm still considering if I should solder these SMDs.
The SS takes about 1 second before I hear the relay click, then right after that (about half sec to full sec) the blue lights on the modules come up.
Before the Hypex SS/transformer I used to do this manually, first turn on the AC power to the transformer, after a second or three I turned on the modules (simple switch between gnd and on) and I barely heard a click.
Maybe the SS startup time is good to avoid the inrush, but at that time the main PS caps are still charging when the power goes to full and the modules turn on at this time?
If I prolong the inrush limitation (see method higher in the thread) there is no "pop" in the speakers. The pop is "midrange", no nasty DC or anything.
PS. I have 2.5mm² cable between PS and modules for power, about 15 to 20cm, maybe this causes the problem? Cable capacitance?
Yves,
No I guess the combination of the Power supply and V1.1 of UcD400 is the problem. We have increased the delay time in the UcD400 in later revisions.
Can you ship the UcD400 back? We will change the caps immediatly, to avoid too long no music at home ... 😉
Jan-Peter
No I guess the combination of the Power supply and V1.1 of UcD400 is the problem. We have increased the delay time in the UcD400 in later revisions.
Can you ship the UcD400 back? We will change the caps immediatly, to avoid too long no music at home ... 😉
Jan-Peter
Jan Peter, the dc protection in the power supply is activated just when you have dc or few hz before? How fast is it? If I'm not wrong lower the frequency the protection came in longer the time you have for the disconnection.
Patriz,
The DC protection is: 47K + 10uF to ground, and two zeners of 3.3V each.
The timing is 47K + 10uF and the voltage will be +/-7V minimum.
Regards,
Jan-Peter
The DC protection is: 47K + 10uF to ground, and two zeners of 3.3V each.
The timing is 47K + 10uF and the voltage will be +/-7V minimum.
Regards,
Jan-Peter
Jan-Peter,
I've just been told by support that my modules will be replaced. Once again, this proves Hypex is doing absolutely magnificent support towards all customers, small or large.
Heel hard bedankt Jan-Peter!
Yves
I've just been told by support that my modules will be replaced. Once again, this proves Hypex is doing absolutely magnificent support towards all customers, small or large.
Heel hard bedankt Jan-Peter!
Yves
Hello.
How close together can i put the speaker output and DC power cable in the udc module ?
Thanks.
How close together can i put the speaker output and DC power cable in the udc module ?
Thanks.
I have them running together (well kind off, they are in close proximity) and have absolutely no hum or anything in the speakers.
Chassis grounding question.
I have XLR inputs on my amp and I thought a few posts back that I read Bruno saying that the correct wiring is to take the earth tab on the XLR sockets directly to pin 1 (earth) on the XLRs? This seems a bit peculiar because a) we are then grounding to the chassis at two points and b) we are sticking chassis noise into the signal ground
Surely something like taking the XLR grounding tabs directly to the chassis earth is better?
The rest of the amp uses something which should be a star earth with a single tap from the powersupply to a screw in the chassis and from there to the mains inlet earth pin
I don't have any hum at this stage, but could someone confirm the "correct" wiring for these things. I don't have control of the source wiring - it's an embedded plug in an RME pro audio PC soundcard - however it's a balanced source
I have XLR inputs on my amp and I thought a few posts back that I read Bruno saying that the correct wiring is to take the earth tab on the XLR sockets directly to pin 1 (earth) on the XLRs? This seems a bit peculiar because a) we are then grounding to the chassis at two points and b) we are sticking chassis noise into the signal ground
Surely something like taking the XLR grounding tabs directly to the chassis earth is better?
The rest of the amp uses something which should be a star earth with a single tap from the powersupply to a screw in the chassis and from there to the mains inlet earth pin
I don't have any hum at this stage, but could someone confirm the "correct" wiring for these things. I don't have control of the source wiring - it's an embedded plug in an RME pro audio PC soundcard - however it's a balanced source
Sorry if this question has been asked before, but after searching I haven't found it.
In the UcD400/700 datasheet, it says that, if current limit condition is hold during more than 40ms, the module enters "STOP MODE". Please could anyone explain what does this mean? Is the module shut down? How to reset that condition?
It is only a DIYer curiosity. I would like to have some references for my home amp current protection.
Best regards,
Pierre
In the UcD400/700 datasheet, it says that, if current limit condition is hold during more than 40ms, the module enters "STOP MODE". Please could anyone explain what does this mean? Is the module shut down? How to reset that condition?
It is only a DIYer curiosity. I would like to have some references for my home amp current protection.
Best regards,
Pierre
Of course you will have TWO groundings in this way, but the UcD amps are having a fully symmetrical balanced input (instrumental op amp!), so all common noise or hum is cancelled out.
The length of the input wire (pin1 to ground) is with the Neutrik connector the shortest what is possible so all common noise/hum or RFI is put away from the input and goes thru the chassis ground. When you work with a central ground by the power supply all this common noise goes inside the amplifier, and we don’t wants to have this inside the amp!
With the UcD700 we will introduce a new type of short circuit protection. The amplifier limits the maximum current to 28Apiek, when the current goes above these limit after 40mS the amp will shut down for 2-3 sec. In this way the amplifier can always deliver the full power in a very low impedance (<2 ohm) without going in a shut down protection. By normal music signals you will hardly have a signal what takes more as 40mS.
Jan-Peter
Indeed!
But...we DON'T recommend to connect a RCA in parallel with a XLR. Use the XLR and make the cables asymmetrical whereby the shield goes to -sym at the cinch side, the XLR side stays symmetrical. In this way the signal stays symmerical from the XLR at the amplifier till the cinch connector.
But you don't have to do it in this way, it's our recommondation, everybody is of course free to do it in their own way!
Jan-Peter
But...we DON'T recommend to connect a RCA in parallel with a XLR. Use the XLR and make the cables asymmetrical whereby the shield goes to -sym at the cinch side, the XLR side stays symmetrical. In this way the signal stays symmerical from the XLR at the amplifier till the cinch connector.
But you don't have to do it in this way, it's our recommondation, everybody is of course free to do it in their own way!
Jan-Peter
It's also recommended by Bruno to use a three core signal wire when using RCA and tie ground and pin 3 together at the source (using an XLR on the amp side of course). I guess the idea is then at least you get the second wire which carries a copy of the noise out of phase and hence provides some noise immunity (clever really)
However, I do agree - surely if you put an RCA jack on the back of the box then it's going to be pretty noise wired like this? RCA jacks are normally insulated from the chassis, what we are essentially doing here is tieing the RCA shield directly to the chassis
Curious...
Ed W
Edit: my reply crossed with that from Jan-Peter. The explanation for why it works is still valid though I think..?
However, I do agree - surely if you put an RCA jack on the back of the box then it's going to be pretty noise wired like this? RCA jacks are normally insulated from the chassis, what we are essentially doing here is tieing the RCA shield directly to the chassis
Curious...
Ed W
Edit: my reply crossed with that from Jan-Peter. The explanation for why it works is still valid though I think..?
Jan-Peter,
You emphasize in the description of the UCD700 the low ESR of the bypass electrolytic caps,lowered even further by there being several in parallel,while at the same time warning against using too low a value in the 180/400 modules.What is different about the 700 modules which allows the use of low ESR components?
Also could the DC offset adjustment circuitry of the 700 be adapted for use on the 180/400 modules?
Curious,
Bob Lewis
P.S. Excellent service by the way,the 4x 400AD modules puchased recently arrived only two days after ordering!
You emphasize in the description of the UCD700 the low ESR of the bypass electrolytic caps,lowered even further by there being several in parallel,while at the same time warning against using too low a value in the 180/400 modules.What is different about the 700 modules which allows the use of low ESR components?
Also could the DC offset adjustment circuitry of the 700 be adapted for use on the 180/400 modules?
Curious,
Bob Lewis
P.S. Excellent service by the way,the 4x 400AD modules puchased recently arrived only two days after ordering!