I completed my NOIR build earlier in the week. It was a fun build. When I plugged it in and listened to it thru a DIY pair of bookshelf speakers (old Madison design with Vifa drivers) I was totally floored at the articulate and nuanced the sound that emerged (Roon--> RP3 endpoint--> Hifiberry Dig+ Pro Toslink --> Schiit Modi MB --> NOIR -->ACA --> Speakers). I had never heard those speakers sound so good. Same result with Audeze LCD-1. Color me impressed.
Last year when I built my WHAMMY I used a red case with red Riverstone knobs I bought on Amazon at $10 for a pair. I used the other one on the NOIR. I think the red knob on black case looks terrific.
Last year when I built my WHAMMY I used a red case with red Riverstone knobs I bought on Amazon at $10 for a pair. I used the other one on the NOIR. I think the red knob on black case looks terrific.
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Congratulations on a very nice build, bchassy! The red knob does really pop against the black background of Noir. Maybe you'll want to also install a red power on/off LED to complete the look ...?
BTW I just ordered a pair of Audeze LCD-X's myself. Really looking forward to pairing them up with Noir (plus a couple other headphone amps, for comparison)!
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BTW I just ordered a pair of Audeze LCD-X's myself. Really looking forward to pairing them up with Noir (plus a couple other headphone amps, for comparison)!
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Mark:
I neglected to thank you for good work on the Noir and this thread. Really helpful. Thanks.
The red led is a good idea. If I get it done I'll post it. The one I have in there now is more orange than yellow but it's definitely not red enough. Red and black are a great color combo.
I loved my LCD-Xs but sold them off last Spring for reasons I do not remember. I have new LCD-1s. They are extremely light, feel great, and to me at least they ooze quality. The sound is surprisingly close to many higher price planars. To my aging ears at least. That said, I am sure the LCD-X will sound great with the Noir.
I neglected to thank you for good work on the Noir and this thread. Really helpful. Thanks.
The red led is a good idea. If I get it done I'll post it. The one I have in there now is more orange than yellow but it's definitely not red enough. Red and black are a great color combo.
I loved my LCD-Xs but sold them off last Spring for reasons I do not remember. I have new LCD-1s. They are extremely light, feel great, and to me at least they ooze quality. The sound is surprisingly close to many higher price planars. To my aging ears at least. That said, I am sure the LCD-X will sound great with the Noir.
I have a question regarding the grounding of the Noir. In the build guide/images of builds I've seen directly tie the board's ground to the chassis. However, in the Pass/FirstWatt builds Papa Nelson has been pretty adamant about lifting the ground using a CL-60 as shown here:
Firstwatt F5 amplifier v3 - diyAudio Guides
I wonder if in using this as a preamp we might be inviting ground loops?
Firstwatt F5 amplifier v3 - diyAudio Guides
I wonder if in using this as a preamp we might be inviting ground loops?
Home made power amps with line voltage inside need a safety device. Noir is very safe because it uses an isolated external supply. Be sure to use one with the appropriate safety agency certification.
I am not worried about safety with shorts to the case - you are correct that the external supply takes care of that; however, I AM worries about ground loops. I've had issues with mix and match situations of equipment in the past where there were inconsistencies between the device binding it to the case or floating the ground (or using a CL-60). As a solution, I've just started building my devices the same way: 1 single "star" ground point where that ground point is only connected to the case/incoming ground/shield via a CL-60. That seems to keep things consistent and loop-free.
So asking for advice from the community on this approach because who knows, I could be doing something silly or there could be a better way.
So asking for advice from the community on this approach because who knows, I could be doing something silly or there could be a better way.
I empathise with the ground loop topic.
I'm loving my Noir still, it sounds fantastic and is a great value project, however until this week my source for it has been a Shanling portable hi-res player but now I've tried it with a just completed mains powered DAC project and I'm experiencing some hum that I'm going to have to troubleshoot.
I'm loving my Noir still, it sounds fantastic and is a great value project, however until this week my source for it has been a Shanling portable hi-res player but now I've tried it with a just completed mains powered DAC project and I'm experiencing some hum that I'm going to have to troubleshoot.
Sure, feel free to build your D.I.Y. project however you like. If you decide to use the PCB sold in the Store, spend a few minutes "buzzing it out" with the continuity tester / buzzer feature of your DVM. I think you'll find that there is electrical continuity between the ground pads (flywire soldering points) of all four RCA jacks, and also continuity between them and the "ground" terminals of electronic components such as R25. You'll also want to trace the electrical continuity between the PCB mounting holes at the four corners of the board, and RCA ground. Same goes for the "ground" pins of the 6.35mm headphone jack (labeled "G" and "L" on the schematic and on the board).
If you discover that continuity exists where you don't want it to exist, you'll either need to route your external flywires differently, or cut traces on the PCB, or use insulating (nylon) bolts & nuts to fasten the PCB to the chassis floor, or ... (insert additional ideas here). And if you discover that two points are not connected, which you feel ought to be connected, then devise a scheme to hook them together.
If you decide to use the front panel PCB that the Store ships along with the main circuit board, you'll want to buzz out its continuity too. In particular you'll want to check the continuity between the body of the ALPS RK27 potentiometer, and the front & rear shielding planes on that PCB. If it's not what you want, make a modification. Or perhaps decide against using that panel after all. I don't think you'll find anything to modify on the rear panel PCB, because all of the jacks (including the DC barrel jack) are insulated from the panel. That PCB does include shielding planes on both sides, however.
I spend a lot of time listening to my Noir, using a mains powered CD player as a source. I don't hear any hum at all. FWIW.
If you discover that continuity exists where you don't want it to exist, you'll either need to route your external flywires differently, or cut traces on the PCB, or use insulating (nylon) bolts & nuts to fasten the PCB to the chassis floor, or ... (insert additional ideas here). And if you discover that two points are not connected, which you feel ought to be connected, then devise a scheme to hook them together.
If you decide to use the front panel PCB that the Store ships along with the main circuit board, you'll want to buzz out its continuity too. In particular you'll want to check the continuity between the body of the ALPS RK27 potentiometer, and the front & rear shielding planes on that PCB. If it's not what you want, make a modification. Or perhaps decide against using that panel after all. I don't think you'll find anything to modify on the rear panel PCB, because all of the jacks (including the DC barrel jack) are insulated from the panel. That PCB does include shielding planes on both sides, however.
I spend a lot of time listening to my Noir, using a mains powered CD player as a source. I don't hear any hum at all. FWIW.
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Hey Mark, there's no implied criticism of the Noir in my post, as I've said several times it's a great project delivering amazingly good listening. I was just making an observation that ground loops can be an occasional issue with projects that can cause a bit of head-scratching - I certainly wasn't suggesting that the Noir is 'noisy' - it aint!
FWIW, my new DAC uses output transformers, the first time I've used them, so I'm in new territory - I'll start my checking my understanding of the schematic and then start trying to nail down what's causing the hum.
I finished building my Noir about a week ago and I've had some problems. Everything went pretty smooth except a bit of frustration with winding the inductor. So when I powered up, it biased fine. I didn't think the trimmer on the led was working but I just didn't turn it up enough. But when I plugged in some headphones and a source there was a lot of noise. So when the pot is all the way down there is no noise, when there is no source connected there is no noise. Ok so I checked to RCA inputs the headphone output and the Pot connections so see if I got something crossed up, but after looking over that a good half dozen times I don't see an error. So I then tried testing left and right channels, so left channel sums left+right and right does the same. Center channel is a good -30db down. I pulled the pot and put a multimeter on it and it test like the other 10k pots I have. Soldered it back in and still the same behavior. I went to test phase next, I can barely hear the in phase test but out of phase test plays at a normal volume level.
I keep on looking at the wiring of the RCAs pot and output, but would a wiring mistake have the associated noise? I wouldn't think so but.
I keep on looking at the wiring of the RCAs pot and output, but would a wiring mistake have the associated noise? I wouldn't think so but.
I had 2 problems. First I found was cold soldering on the pcb side of the headphone jack flyover leads. I fixed that and then got the amp to work. Then I moved the amp, and then the same issues returned. I was able to manipulate the RCA ins and make it work as expected but any movement would go back to the above issues. Then I found my oh so brilliant mistake. I didn't float signal ground on the RCA's. I have no idea how I made it work by wiggling the RCAs in but anyways it made me look and see what I did.
I pulled it apart reflowed all the flyover wires from the backside of the board and redid the RCA's proper and it works like a charm. Well with the cans it likes, it hates the HE-4xx Drop cans but loves the Fostex T60RP. I tried some Grados too and they worked fine, I just didn't listen for any period of time.
Thanks PRR, you got me started by your post. I appreciate it
I pulled it apart reflowed all the flyover wires from the backside of the board and redid the RCA's proper and it works like a charm. Well with the cans it likes, it hates the HE-4xx Drop cans but loves the Fostex T60RP. I tried some Grados too and they worked fine, I just didn't listen for any period of time.
Thanks PRR, you got me started by your post. I appreciate it
How does that "hate" manifest itself? At 35 ohms and 93 dB/mW, they're certainly not the most sensitive cans ever, but not the least sensitive planars either. (This amp should be good for about 103 dB SPL max.) They have a bit of a reputation for "strident" treble, so that might be bringing out some distortion perhaps?
I would try the "3300-4700 µF in parallel to the three series diodes" mod and see whether that makes it hate the HE-4xx less at least. Simulation indicated something like a 13 dB improvement in distortion. I'm a bit skeptical given the numbers but some people have actually claimed to hear it in the stock design, so it seems worth a shot. Observe polarity. 6.3 V will do.