I have to agree. You should also be happy you got a reply from hypex, I don't think they are obligated to help out when you're mixing and matching. I'm just upset they haven't replied to me and i'm using all their stuff and installing it as per their datasheet.
The first thing to try is one from each of both differential inputs to ground. No need to do both amps until you know it helps.
Hold on - 40 or 63 V to the buffer? Both Vsig and Vdr are specified as max 25 V.
So one from pin 3 to pin 1 and another from pin 2 to 1?
Essentially one across the hot and one across the cold to ground?
Nonsens it is for sure the voltage for the output section. I AM the only one who understand this.
No sorry 40 V for the output section. Over ca 63 V it stops working. They must have done something wrong when adjusting it at Hypex. Now I am going to mount one bridge more in each mono amp.
I understand roughly why like gentleman with the transformer based supply is having trouble.
But Robbby, something is wrong with yours and you installed everything as per the instructions? Can you please explain to this layman what you are having problems with so I can maybe anticipate it if it happens also to me?
But Robbby, something is wrong with yours and you installed everything as per the instructions? Can you please explain to this layman what you are having problems with so I can maybe anticipate it if it happens also to me?
Nothing is really wrong per se, it still plays music and everything fine, there is just a lot more DC on the output then their should supposedly be.
I installed everything according to the datasheet in the "preferred" setup and my wiring was also verified by people here.
They claim there is a bug that may show some DC on the output but that is only when using unbalanced, which I am not. I even tried the 47k resistors like they say for the rca connections but it is possible I may have the resistors installed incorrectly?
OK, lets try this,
1) measure outputs with your meter, then reverse leads and measure again, same except sign?
2) what are you using to measure, ie what quality of meter are you using?
(grasping at straws here)
Yup, just changes between positive and negative DC and it shows a difference of only 1 or 2 hundreths of a volt.
I though it may possibly be my meter, it definitely is not the best, it's a mastercraft (canadian tire brand) multimeter so I grabbed my ideal meter which is more of an electricians meter and sure enough it shows the same thing. 0.5VDC with proper polarity and -0.4 when it is revered, obviously there is a few hundreths difference and the ideal meter only read in tenths. But nonetheless, same thing.
I'm thinking maybe I should try removing one of the resistors? Maybe just leave the one on the hot and remove the cold? With both installed (pin 2 to ground and pin 3 to ground), if I measure resistance from pin 2 to ground I only get 35k ohm, if I measure pin 3 to ground it is the same, 35k ohm. Before installing them I verified the value with my meter and they were dead on 47k.
I though it may possibly be my meter, it definitely is not the best, it's a mastercraft (canadian tire brand) multimeter so I grabbed my ideal meter which is more of an electricians meter and sure enough it shows the same thing. 0.5VDC with proper polarity and -0.4 when it is revered, obviously there is a few hundreths difference and the ideal meter only read in tenths. But nonetheless, same thing.
I'm thinking maybe I should try removing one of the resistors? Maybe just leave the one on the hot and remove the cold? With both installed (pin 2 to ground and pin 3 to ground), if I measure resistance from pin 2 to ground I only get 35k ohm, if I measure pin 3 to ground it is the same, 35k ohm. Before installing them I verified the value with my meter and they were dead on 47k.
Apologies if this question has already been answered in the prior 300+ pages.
Bruno, for use in an all-active system, what method of DC blocking at the speaker terminal do you think is superior? Would you recommend capacitors?Or something else entirely?
You have indicated that the ncore has meaningful DC offset, so for a guy like me who operates on the speaker and amplifier monogamy principle (one driver, one amplifier), this DC blocking issue is relevant.
thanks --
Brandt
Bruno, for use in an all-active system, what method of DC blocking at the speaker terminal do you think is superior? Would you recommend capacitors?Or something else entirely?
You have indicated that the ncore has meaningful DC offset, so for a guy like me who operates on the speaker and amplifier monogamy principle (one driver, one amplifier), this DC blocking issue is relevant.
thanks --
Brandt
Hi Erlend, how are you measuring this 63 Volt? Are you using a Multimeter or an Oscilloscope? In case you are using a Multimeter you will measure the average voltage. The peak voltage might go higher than the 75 volt in which case the amplifier shuts down. By using an oscilloscope you can see the peak voltages.
Still I would recommend to buy a SMPS600. This power supply matches the NCore very well..
That is exactly the concern I expressed earlier - especially if using a single-bridge circuit.
Yes, doing the resistors one at a time is the next logical step. Careful with measuring the resistors when in-circuit, the input circuitry of the nc400 might not like the voltage from the meter when measuring resistance.
Just a terminology issue - there really isn't a "hot" and "cold" in a fully balanced circuit. One input is non-inverting, the other inverting. But anyway, try with just one resistor, first from one input to ground, and then from the other to ground, and see if there is a difference in output voltage.
That's good to hear!
OK, to check - so what you have now is a power supply with two secondary windings on the transformer, but only one diode bridge? So the secondary windings are connected to form one winding with a centre tap, and the ends of the combined winding is feeding the bridge? The bridge produces the + and - outputs, with ground derived from the centre tap point?
Such a circuit is very sensitive to inbalance in load - so add the ripple from an unregulated supply, and you could possibly be hitting the overvoltage limit on one half.
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While I agree, we have already established that that isn't an option, as Erlend has serious ethical, moral or philosophical objections against a SMPS. Personally I would argue that a class D amplifier in itself is a form of SMPS (albeit a continously variable one), but that's just me.
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