PRR, C4 polarity is with its positive(+) side soldered to ground.
So i guess it must be fine.
Will double check it though.
Following, are some PCB photos, but i don't know whether there'll be of any value to actual debugging.
Because the PCB was made by Scotsky and had a few bugs to begin with.
Namely:
-The E-153 diodes marked on the PCB backwards (ameliorated).
-The output capacitors (C27/76) marked on the PCB backwards (ameliorated).
-The resistors (R27,28/77,78) coupled wrongly to the output capacitors, at their joint point with R25,26/75,76 (ameliorated).
Top side thumbnail:
Power supply section closeup thumbnail:
Top side closeup thumbnail:
Bottom side thumbnail:
Bottom side closeup thumbnail:
Bottom side closeup thumbnail:
So i guess it must be fine.
Will double check it though.
Following, are some PCB photos, but i don't know whether there'll be of any value to actual debugging.
Because the PCB was made by Scotsky and had a few bugs to begin with.
Namely:
-The E-153 diodes marked on the PCB backwards (ameliorated).
-The output capacitors (C27/76) marked on the PCB backwards (ameliorated).
-The resistors (R27,28/77,78) coupled wrongly to the output capacitors, at their joint point with R25,26/75,76 (ameliorated).
Top side thumbnail:
Power supply section closeup thumbnail:
Top side closeup thumbnail:
Bottom side thumbnail:
Bottom side closeup thumbnail:
Bottom side closeup thumbnail:
Let me first state, that I made this PCB pure for personal use for a friend and me, and make only a batch of 5.
There was no provit involved. The naming on the PCB, is an inside joke from use.
Next we made a mistake to send the pre-last version to the PCB factory, and not the final, that's why there are faults on the silkscreen.
The junctions you made on the bottemside of the PCB are OK.
Saying that, I send a foto from my working version.
They're big, So I'm not sure how many to send.
First I send the compleet version, and can send, when needed, more detailed verseions if necessary.
Personaly, I think the problem is in de powersupply.
Also I used a silicon isolation for the powerfet.
Try to connect the rest of the power circuit and put a regular powersupply on the input, a normal +/- powersupply.
I hope it helps.
There was no provit involved. The naming on the PCB, is an inside joke from use.
Next we made a mistake to send the pre-last version to the PCB factory, and not the final, that's why there are faults on the silkscreen.
The junctions you made on the bottemside of the PCB are OK.
Saying that, I send a foto from my working version.
They're big, So I'm not sure how many to send.
First I send the compleet version, and can send, when needed, more detailed verseions if necessary.
Personaly, I think the problem is in de powersupply.
Also I used a silicon isolation for the powerfet.
Try to connect the rest of the power circuit and put a regular powersupply on the input, a normal +/- powersupply.
I hope it helps.
Attachments
OK!
Mystery solved!
No need to worry dear Scotsky.
I was sure I'd eventually sort it out with all the help here.
So, thanks to all the folks for the feedback (especially avtech).
He nudged me to focus towards the PSU part.
The issue was not with the chokes actually, but rather with a resistor in series, right before the chokes.
It was forming part of an RC network in the PSU section (had totally forgot about that) and was dropping the voltage rather substantially.
Now I can finally proceed with auditioning the kit.
Mystery solved!
No need to worry dear Scotsky.
I was sure I'd eventually sort it out with all the help here.
So, thanks to all the folks for the feedback (especially avtech).
He nudged me to focus towards the PSU part.
The issue was not with the chokes actually, but rather with a resistor in series, right before the chokes.
It was forming part of an RC network in the PSU section (had totally forgot about that) and was dropping the voltage rather substantially.
Now I can finally proceed with auditioning the kit.
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I have been using the Noir for a few days and I can attest that the amplifier is totally silent, even with the volume pot to the maximum.
And I do not even use a proper enclosure for RF shielding.
Also, the amplifier has enough drive to blow my ears off (I am using a set of Sennheiser HD599 cans).
Regarding the sound signature, it is on the clean side, at least compared to my other head amplifiers.
For example, compared to my Zen-like amp by Marcello, it has better definition in the mid to higher octaves and holds its own in the lower registers, by keeping bass well defined.
However, the tonal character and soundstage presentation of Marcello's amp is more reminiscent of a single-ended tube amp and presents a more relaxed/'fuller' sound overall, which I am more accustomed to. Bass is generally more dominant, although not as well defined as in the Noir.
Depending on the mood, I can switch between the two. For relaxed listening I can use Marcello's amp, while for more critical listening I can use the Noir.
Next thing to try is a different PSU for the Noir. I would like to try a passive CRCRC like I use in Marcello's amp. I think it might be an improvement, taming a bit of the LM337 'hardness'.
Also, I might increase a bit the output capacitors' size. Right now I am using 1000uF.
Maybe doubling that might give it a bit more 'meat'.
And I do not even use a proper enclosure for RF shielding.
Also, the amplifier has enough drive to blow my ears off (I am using a set of Sennheiser HD599 cans).
Regarding the sound signature, it is on the clean side, at least compared to my other head amplifiers.
For example, compared to my Zen-like amp by Marcello, it has better definition in the mid to higher octaves and holds its own in the lower registers, by keeping bass well defined.
However, the tonal character and soundstage presentation of Marcello's amp is more reminiscent of a single-ended tube amp and presents a more relaxed/'fuller' sound overall, which I am more accustomed to. Bass is generally more dominant, although not as well defined as in the Noir.
Depending on the mood, I can switch between the two. For relaxed listening I can use Marcello's amp, while for more critical listening I can use the Noir.
Next thing to try is a different PSU for the Noir. I would like to try a passive CRCRC like I use in Marcello's amp. I think it might be an improvement, taming a bit of the LM337 'hardness'.
Also, I might increase a bit the output capacitors' size. Right now I am using 1000uF.
Maybe doubling that might give it a bit more 'meat'.
Nice you're so fond of it.
It's a very nice delicate amp, I use the HD598 and it's really comfortable/relaxing to listen to.
A good PSU can make the sound more stable, at least that's what I found out.
But did you know the project from Nelson Pass, the H2 ?
https://diyaudiostore.com/collections/newest-releases/products/h2-harmonic-generator
It can give you the warmth what you maybe mis.
I'm collecting the components now, but I'm curious how it wil work.
And there is off course the B1 with Nu-Tube from Nelson.
(Also a project in coming, as soon as I filtert out the BOM from the zilion messages in the thread.)
Enjoy your listening.
It's a very nice delicate amp, I use the HD598 and it's really comfortable/relaxing to listen to.
A good PSU can make the sound more stable, at least that's what I found out.
But did you know the project from Nelson Pass, the H2 ?
https://diyaudiostore.com/collections/newest-releases/products/h2-harmonic-generator
It can give you the warmth what you maybe mis.
I'm collecting the components now, but I'm curious how it wil work.
And there is off course the B1 with Nu-Tube from Nelson.
(Also a project in coming, as soon as I filtert out the BOM from the zilion messages in the thread.)
Enjoy your listening.
Hello,
I started building the Noir headphone amp last year in December. After I received the final component (choke R05034) last week, I finished soldering the PCB.
Before I can put everything together in a case, I like to know if it is possible to use the following SPS for powering the Noir.
MeanWell RS-35-24
Thanks for your help
I started building the Noir headphone amp last year in December. After I received the final component (choke R05034) last week, I finished soldering the PCB.
Before I can put everything together in a case, I like to know if it is possible to use the following SPS for powering the Noir.
MeanWell RS-35-24
Thanks for your help
@Roland968
Thanks for your answer. First I will try to use the RS-35-24, because I got one laying around. I already planned to build an extra case for the power supply and one for the Noir. But I might buy the SPS recommended by you (I bet I will) to test if there is a listenable difference.
When I have finished my work, I will post some pictures.
Thanks for your answer. First I will try to use the RS-35-24, because I got one laying around. I already planned to build an extra case for the power supply and one for the Noir. But I might buy the SPS recommended by you (I bet I will) to test if there is a listenable difference.
When I have finished my work, I will post some pictures.
After one month listening to the Noir all i can say is kudos to mr. Mark Johnson .
Pcb quality is top and it can be easily implemented by beginners as well .
Using a pair of Grado SR-80 i enjoy now music more and more .
Noir is dead silent at any volume level - no hiss or hum just a black veil of silence .
The sound is clean neutral and transparent , bottom and high end are present without causing fatigue , and 6db gain is enough for me .
I had to place a 270R resistor parallel to the led because i had the some problem with @avitkauskas - no big deal .
So yes i highly recommend you to build one have fun and be rewarded with an excellent HPA !
Pcb quality is top and it can be easily implemented by beginners as well .
Using a pair of Grado SR-80 i enjoy now music more and more .
Noir is dead silent at any volume level - no hiss or hum just a black veil of silence .
The sound is clean neutral and transparent , bottom and high end are present without causing fatigue , and 6db gain is enough for me .
I had to place a 270R resistor parallel to the led because i had the some problem with @avitkauskas - no big deal .
So yes i highly recommend you to build one have fun and be rewarded with an excellent HPA !
Attachments
Yep! The cat5 cable will work great.
The long story short is that even a single wire through the ferrite will have some attenuation of the RF that it’s intended to filter, and a few more loops increases the filtering buy a real and measurable amount... The trick being that there are loops through the ferrite. The loops are the thing that increases the filtering, the wire gauge makes essentially no difference in this case.
Also, the ferrite core itself is not a precision doohickey… it’s quite non-linear and has many vagaries of production and manufacturing, which is used intentionally here because those non-linearities increase the filtering of HF and RF. Neat! This means that if every Nior builder removed their ferrite and measured it on an accurate inductance meter, every one would be different, and yet each one would do it’s job as designed.
That’s pretty cool.
Anyway, in this application the difference between the specified 11 loops of 28awg vs. the 24 or 26awg from the cat5 will be functionally identical.
The long story short is that even a single wire through the ferrite will have some attenuation of the RF that it’s intended to filter, and a few more loops increases the filtering buy a real and measurable amount... The trick being that there are loops through the ferrite. The loops are the thing that increases the filtering, the wire gauge makes essentially no difference in this case.
Also, the ferrite core itself is not a precision doohickey… it’s quite non-linear and has many vagaries of production and manufacturing, which is used intentionally here because those non-linearities increase the filtering of HF and RF. Neat! This means that if every Nior builder removed their ferrite and measured it on an accurate inductance meter, every one would be different, and yet each one would do it’s job as designed.
That’s pretty cool.
Anyway, in this application the difference between the specified 11 loops of 28awg vs. the 24 or 26awg from the cat5 will be functionally identical.
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I haven't built a kit since the 1970s. Noir is my reentry into the DIY electronics world. I have a question regarding the thermal pads
for the MOSFETs. The Mouser BOM calls out Bergquist Sil-Pad insulators, but that part is back-ordered. Has anyone used the Keratherm Red insulators from the diyAudio store for this use in the Noir? The thermal conductivity of the Sil-Pad is 0.9W/mK. It's 6.5W/mK for the Keratherm Reds.
for the MOSFETs. The Mouser BOM calls out Bergquist Sil-Pad insulators, but that part is back-ordered. Has anyone used the Keratherm Red insulators from the diyAudio store for this use in the Noir? The thermal conductivity of the Sil-Pad is 0.9W/mK. It's 6.5W/mK for the Keratherm Reds.