Yes.
It's very nice and can be used for many other projects, you'll love it.
Yes.
If you intend to use the SMPS DC filter from the store, in a Noir application,
beware that the store board assumes negative ground but Noir assumes positive ground. Study both of the schematics and verify or refute this claim yourself. Then apply your ingenuity and cleverness to figure out a way to make these two dangerously incompatible things, suddenly become compatible.
A snippet from post #1 of this thread:
_
beware that the store board assumes negative ground but Noir assumes positive ground. Study both of the schematics and verify or refute this claim yourself. Then apply your ingenuity and cleverness to figure out a way to make these two dangerously incompatible things, suddenly become compatible.
A snippet from post #1 of this thread:
_
Attachments
I guess i will abandon the smps line filter then and proceed with the default implementation ..only substituting choke SU9V-R05034 with SU9VF-05030 .
Thanks for the input .. i assume the wall wart needs to be regulated ..
I will report when i am done with pictures and leave feedback ... looking forward to a nice build and a nice sounding HPA ..🙂
Thanks for the input .. i assume the wall wart needs to be regulated ..
I will report when i am done with pictures and leave feedback ... looking forward to a nice build and a nice sounding HPA ..🙂
Hello,
I am in the process of building Mark's Noir headamp (sourcing parts and waiting for PCB).
I am thinking of powering it with a linear PSU. Something simple, like a regulator followed by filtering or even an unregulated power supply with enough RC filtering stages to remove ripple and noise. Will be referencing V+ to ground since it needs negative power.
I like simplicity of unregulated power supplies but i would like to hear your thoughts.
Also, are R24 (1K) and R30 (330R) values critical? I have some spare 300R 5% and several 1K 10% that might be not exact values.
Thanks!
I am in the process of building Mark's Noir headamp (sourcing parts and waiting for PCB).
I am thinking of powering it with a linear PSU. Something simple, like a regulator followed by filtering or even an unregulated power supply with enough RC filtering stages to remove ripple and noise. Will be referencing V+ to ground since it needs negative power.
I like simplicity of unregulated power supplies but i would like to hear your thoughts.
Also, are R24 (1K) and R30 (330R) values critical? I have some spare 300R 5% and several 1K 10% that might be not exact values.
Thanks!
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Those resistor values should not be changed. Fortunately they are included in assortment kits which you can purchase inexpensively.
at Amazon France: Link 1
at Amazon UK: Link 2
at Amazon Deutschland: Link 3
at Amazon Netherlands: Link 4
Remember that Noir requires a power supply that gives negative 24 volts, with positive ground. It needs a DC power supply with either (A) no connection to protective earth {like 98% of all SMPS wall warts in the US}, or else (B) a connection from protective earth to POSITIVE DC OUTPUT.
If you erroneously attempt to connect Noir to a DC power supply having a connection from protective earth to NEGATIVE DC OUTPUT, you'll almost certainly damage both Noir and the signal source which provides its input. So don't do that.
If you don't understand the above then you shouldn't attempt the experiment, it is too dangerous for you.
at Amazon France: Link 1
at Amazon UK: Link 2
at Amazon Deutschland: Link 3
at Amazon Netherlands: Link 4
Remember that Noir requires a power supply that gives negative 24 volts, with positive ground. It needs a DC power supply with either (A) no connection to protective earth {like 98% of all SMPS wall warts in the US}, or else (B) a connection from protective earth to POSITIVE DC OUTPUT.
If you erroneously attempt to connect Noir to a DC power supply having a connection from protective earth to NEGATIVE DC OUTPUT, you'll almost certainly damage both Noir and the signal source which provides its input. So don't do that.
If you don't understand the above then you shouldn't attempt the experiment, it is too dangerous for you.
OK.
Thanks.
I'll probably use an LM337 based PSU with -24VDC output, leftover from a previous Germanium transistor project.
One more question.
Is it fine to use a 50k ALPS stereo potentiometer that have spare, instead of 10k?
Thanks.
I'll probably use an LM337 based PSU with -24VDC output, leftover from a previous Germanium transistor project.
One more question.
Is it fine to use a 50k ALPS stereo potentiometer that have spare, instead of 10k?
The original build schematic, should work good with any 24V DC powersupply.
There is enough filtering, for that.
Personally, I prefer a conventional lineair powersuply.
I made mine with a LM337K.
Edit:
I mistake, I use a LT1083CP
There is enough filtering, for that.
Personally, I prefer a conventional lineair powersuply.
I made mine with a LM337K.
Edit:
I mistake, I use a LT1083CP
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So, I tried to put together the Noir, using the PCB from Scotsky.
Unfortunately, it did't work.
Had one part mislabeled (apart from a couple of other faults that Scotsky warned me about).
In particular, the E153 current regulating diode was marked the other way around and didn't notice until power up...
When i did, BC516 Darlington transistors started overheating almost immediately.
And when checking voltages, bias voltage was zero and remained zero even when turning the pot clockwise.
Also, a weird symptom was a pretty serious drop in supply voltage.
Instead of measuring -24VDC right at the NEGPWR spot, I was getting something like -14VDC instead.
Even after reversing the E153 current regulating diode to match the schematic correctly, little changed.
I suspect because of the CRD being mislabeled i've fried the Darlingtons and possibly the E-153 too.
Hope the Mosfets are OK though.
Anyway, would you please let me know what you think folks?
Should i try it once again with fresh BC516 and E-154?
Or get a couple of STP16NF06 just to be sure?
Unfortunately, it did't work.
Had one part mislabeled (apart from a couple of other faults that Scotsky warned me about).
In particular, the E153 current regulating diode was marked the other way around and didn't notice until power up...
When i did, BC516 Darlington transistors started overheating almost immediately.
And when checking voltages, bias voltage was zero and remained zero even when turning the pot clockwise.
Also, a weird symptom was a pretty serious drop in supply voltage.
Instead of measuring -24VDC right at the NEGPWR spot, I was getting something like -14VDC instead.
Even after reversing the E153 current regulating diode to match the schematic correctly, little changed.
I suspect because of the CRD being mislabeled i've fried the Darlingtons and possibly the E-153 too.
Hope the Mosfets are OK though.
Anyway, would you please let me know what you think folks?
Should i try it once again with fresh BC516 and E-154?
Or get a couple of STP16NF06 just to be sure?
Just finished my Noir build but have a problem. It powers up fine but there’s almost no volume through headphones. I have to strain to hear it’s playing anything. Any ideas where I can start troubleshooting?
Thanks.
Thanks.
Firstly, do some checks regarding bias voltage across R27/R77.
It should read around 5.10VDC.
Check also the supply voltage, right at the NEGPWR spot.
It should read around -22VDC.
Then check if your source feeding the Noir is capable of supplying a healthy voltage swing.
If i'm not mistaken, it should have a nominal line level of at least 250mV RMS.
Also, I believe that Noir is a a medium-low gain amplifier.
It should be better suited for headphones that are specified medium-low impedance with medium-high sensitivity.
So, do check whether your headphones are high impedance and/or low sensitivity.
It should read around 5.10VDC.
Check also the supply voltage, right at the NEGPWR spot.
It should read around -22VDC.
Then check if your source feeding the Noir is capable of supplying a healthy voltage swing.
If i'm not mistaken, it should have a nominal line level of at least 250mV RMS.
Also, I believe that Noir is a a medium-low gain amplifier.
It should be better suited for headphones that are specified medium-low impedance with medium-high sensitivity.
So, do check whether your headphones are high impedance and/or low sensitivity.
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I'm so sorry to hear about that. Must have missed that.
It was our own first try to make a PCB. And because you have to make a minimum of 5 PVB's, it become to expensive to make another batch for only two persons.
Did you compare the parts orientation with the foto's I sended to you?
Those are from my working amp and the same PCB. All components from mouser.
My friend made the same with same positioning and components.
I wil try to measure the voltage's you mention. (If I have the possibility, I wil try today).
Also, you're sure the input voltage is stable enough and can deliver the Amperage?
It is single end klasse-A, so the rendement is only 12,5%.
I'll let you know.
Btw, I made my first mistake with this amplifier, by using a wrong power supply what costed my filter trafo.
After that I used a conventional non switching power supply, and luckely nothing was broken.
But it is working fine with my Sennheiser HD-598.
By the way, i reorder the Darlingtons and E-153 diodes that were probably damaged as explained at my previous post (#388) and also reordered the Mosfets, just in case.
I've traced the PCB by Scotsky point by point, have identified the defected points and made sure the rest of it follows the actual schematic.
Hope i haven't missed anything and will go smoothly this time.
I really want to build this amp since i really like the results from my other discreet, solid-state amp (Tortello's ZEN-like).
Tortello's amp is a single-stage design while Mark's is two-stage of course.
But both follow a minimalist, Class A Mosfet approach, which makes it interesting to me.
I've traced the PCB by Scotsky point by point, have identified the defected points and made sure the rest of it follows the actual schematic.
Hope i haven't missed anything and will go smoothly this time.
I really want to build this amp since i really like the results from my other discreet, solid-state amp (Tortello's ZEN-like).
Tortello's amp is a single-stage design while Mark's is two-stage of course.
But both follow a minimalist, Class A Mosfet approach, which makes it interesting to me.
In my case, i left out the and shorted FL1 (wich I blow, and is actually only needed for filtering unwanted noise from switching powersuply's), and you could check F2.
I'll come back to it.
I'll come back to it.
No worries Scotsky.
Will make it work. 🙂
Regarding PSU requirements, I think Noir draws a total of around 350mA.
So I decided to use an LM337BT, to provide clean -22VDC to NEGPWR I have handy.
I've used it in the past, to provide negative power to a past Germanium transistor amplifier.
It's a pretty typical, datasheet configuration, with additional RC filtering before the regulator IC and LC filtering following the IC.
LM337BT should be fine for providing the 350mA needed to power Noir, since it's specified for a maximum 1.5A load.
Thanks for the reply. I’m a total novice at this, so I’ll have to figure out how to check the bias voltage.
I am getting the proper supply voltage.
I’m using a Bifrost DAC. Can’t find the spec you’re referring.
I’m using 20 ohm Audeze, so it seems like those should be easy-enough to drive.
What's your specific headphone model?
If it's a planar magnetic with a relatively low-sensitivity, things can get pretty hard for any given headphone amp.
Bitfrost has a maximum line level of 2.0V RMS, in single ended output mode.
It should be enough.
If it's a planar magnetic with a relatively low-sensitivity, things can get pretty hard for any given headphone amp.
Bitfrost has a maximum line level of 2.0V RMS, in single ended output mode.
It should be enough.
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I have the Audeze LCD-X.
I tried testing the bias voltage but not sure if I’m doing it right - I’m touching a probe to the blue stripe side of the resistor and the other to the grounding lug connection. I get reading at R27 of 4.47 VDC, and at r77 4.14 VDC
I tried testing the bias voltage but not sure if I’m doing it right - I’m touching a probe to the blue stripe side of the resistor and the other to the grounding lug connection. I get reading at R27 of 4.47 VDC, and at r77 4.14 VDC
https://cdn.shopify.com/s/files/1/1006/5046/files/Noir_HPA_build_instructions_rev_F.pdf?361
Page 33 has the bias instructions.
You are measuring a voltage drop across the resistor, so one probe attaches to one side of the resistor, and the other probe to the other side of the same resistor.
Page 33 has the bias instructions.
You are measuring a voltage drop across the resistor, so one probe attaches to one side of the resistor, and the other probe to the other side of the same resistor.
Thank you. I adjusted the bias as instructed. But the issue remains. I’ve built a few of these DIY projects and this is my first total failure. I appreciate everyone’s help.