Going back through some posts and saw this. I've had the Umami for a few months now and like it very much, can't really fault it, and can recommend it highly! I find the timbre is very balanced bottom to top and it does a really good job soundstaging. It is not a bright or exciting cartridge, it just lets the music through!
I would put it up there with the best cartridges that I have owned or played with. Some may excel in a few areas but few offer as complete a package.
Will the circuit be noisy, and very susceptible to noise with the lid off?
Yes. Every time, and always.
Put the lid on. Make sure the chassis has connection from ground to all panels.
Yes. Every time, and always.
Put the lid on. Make sure the chassis has connection from ground to all panels.
Does the Spectral DMC-12 have cooling vents/slots in the bottom plate? For good flow of hot air out of the cabinet, good flow of cold air into the cabinet is needed.
I agree with GKTaudio's astute comments.
Have been using the Furman Elite-15 power conditioner for years and have developed an approach that routes media equipment (=P3) to this box and amplifiers to a 20-amp Furman PL-Pro DMC. Using these two, the entire system is quiet and plays together nicely.
My two P3s are quiet in several ways. They produce no hiss or hum unless you turn the preamp volume to the maximum (and then it is just a whisper). More importantly, during play at even very loud levels, inactive space between musical content dies away completely, suddenly, and very much like a CD. Record noise and analog hiss can be present but it sounds separate from the music and can be tuned out -- especially if you are a longterm vinyl aficionado and accustomed to this technique.
@TungstenAudio After thinking about your recommendation to pre out from the HiCap DR I believe that's the "Best" hookup for the SN3/HiCap. IIRC, the DIN connections between the 2 Naim the signal through the HiCap. Unfortunately to try I will need to order a 5 pin DIN, not extremely motivated as I am replacing the Naim as soon as I get my SP14 figured out, or take the plunge for an IP.
I re-did my ground connection as per @GKTAUDIO's suggestion, turned on the Pearl and immediately had a very pronounced 120 Hz hum playing through all inputs with or without mute, though it was several dB louder on the Pearl input. After being on for about 45 sec. the hum dropped significantly in level, still noticeable with my ear to the speaker at a reasonable volume setting.
I certainly appreciate all the help, and would love to determine what is causing the problem. Especially if there is a ground issue in my wiring.
The level increased a bit again, and when I powered down my Aleph and re-started it the hum was present briefly as the Aleph powered up and dissipated. The hum does seem to be the same that I experience until the Caps charge in my Aleph. It's just that it comes and goes!
I certainly appreciate all the help, and would love to determine what is causing the problem. Especially if there is a ground issue in my wiring.
The level increased a bit again, and when I powered down my Aleph and re-started it the hum was present briefly as the Aleph powered up and dissipated. The hum does seem to be the same that I experience until the Caps charge in my Aleph. It's just that it comes and goes!
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Hi Ben,
No, the Spectral board fills almost the entire space in the chassis, so convection inlet slots in the bottom panel would have little effect on cooling the 8 MOSFETs. That's why I used a fully perforated top panel; convection eddies can form at the cooler portions of the PCB, pulling air in down through the panel at those locations and rolling up at the hot rows of MOSFETs.
Bringing it back to the P3, none of mine have cooling slots or holes and seem to generate very little heat even after hours of use. This is opposed to the Iron Pre; I built mine in a chassis with no vents and it was clearly in need of ventilation, which I later provided. For the P3, I don't see the need, but the concern raised was whether any holes in the metal envelope would cause RMI, hum, noise, etc. and I haven't observed that. In fact, my first test chassis (go back to the beginning of this thread) was largely open during testing and had plenty of holes. Ugly, but quiet. Here is my #1 P3 final chassis/build:
Hiss has also been mentioned here, but none of mine display that issue. The only issue I have had is ground-loop related hum. Oh, and the lack of desire to do much op amp rolling, once I landed on what sounded great to me.
No, the Spectral board fills almost the entire space in the chassis, so convection inlet slots in the bottom panel would have little effect on cooling the 8 MOSFETs. That's why I used a fully perforated top panel; convection eddies can form at the cooler portions of the PCB, pulling air in down through the panel at those locations and rolling up at the hot rows of MOSFETs.
Bringing it back to the P3, none of mine have cooling slots or holes and seem to generate very little heat even after hours of use. This is opposed to the Iron Pre; I built mine in a chassis with no vents and it was clearly in need of ventilation, which I later provided. For the P3, I don't see the need, but the concern raised was whether any holes in the metal envelope would cause RMI, hum, noise, etc. and I haven't observed that. In fact, my first test chassis (go back to the beginning of this thread) was largely open during testing and had plenty of holes. Ugly, but quiet. Here is my #1 P3 final chassis/build:
Hiss has also been mentioned here, but none of mine display that issue. The only issue I have had is ground-loop related hum. Oh, and the lack of desire to do much op amp rolling, once I landed on what sounded great to me.
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@ToysforBoys: If I understand correctly, you have P3 plugged into a preamp that produced hum through all inputs, and more when switched to the P3? Do you have a ground wire connected between the turntable and P3? Try it with and without.
I'd go back to first principles.
1. Unplug the preamp, amp and P3.
2. Plug them all into one outlets strip, no power conditioner, etc.
3. If no hum, sounds like a ground loop at the AC supply level.
4. If hum, try different interconnects, or, given your comment about the hum level decreasing after 45 seconds;
5. Pull power to one of the two boards in the P3 and see if there is perhaps a problem with a component on one of the boards.
I've been dropping in here and not reading everything, so please tell me what power supply you are using.
I'd go back to first principles.
1. Unplug the preamp, amp and P3.
2. Plug them all into one outlets strip, no power conditioner, etc.
3. If no hum, sounds like a ground loop at the AC supply level.
4. If hum, try different interconnects, or, given your comment about the hum level decreasing after 45 seconds;
5. Pull power to one of the two boards in the P3 and see if there is perhaps a problem with a component on one of the boards.
I've been dropping in here and not reading everything, so please tell me what power supply you are using.
Thanks, currently a single board from Randy, second board is pending. All solid troubleshooting steps, will try 1 or 2 of your suggestions, already tried some. I am starting to lean towards "a ground loop at the AC supply level."
🤞that I get my SP14 working, I'd be perfectly happy not knowing the why, if its gone!
🤞that I get my SP14 working, I'd be perfectly happy not knowing the why, if its gone!
I'm the exact opposite. I'd be perfectly happy with the ground hum remaining as long as I fully understood what is causing it and can use that knowledge going forward in the future to avoid it.
@Toys4Boys and I bring balance to the universe.
Hi..
I too am I process of making the pearl 3, my question is, is it stupid to skip the piano switch and instead use toogle switches on the chassis rear? I would use a dip16 cable less than 10 centimeter long.
Would be nice not to remove cover to adjust loading.
I too am I process of making the pearl 3, my question is, is it stupid to skip the piano switch and instead use toogle switches on the chassis rear? I would use a dip16 cable less than 10 centimeter long.
Would be nice not to remove cover to adjust loading.
In fact I will have a pretty good idea of what caused it if removing the Naim cures it. The suggestion of taking the pre out from the Naim HiCap vs the pre out from the SN3 could protect against all kinds of nasties as Naim has a somewhat unique method of routing the signal and power through the DIN connecting the 2. Also, Naim gear is prone to inductance issues when used in non-Naim approved configurations.
Now I might be motivated enough to bring my Advent 300 upstairs and try it as a pre.
Now I might be motivated enough to bring my Advent 300 upstairs and try it as a pre.
@amplidude
one idea might be to mount the dip switches on the bottom of the boards and have them accessible via holes in the bottom plate.
just sayin'...
one idea might be to mount the dip switches on the bottom of the boards and have them accessible via holes in the bottom plate.
just sayin'...
one more question, I'm contemplating a copper bar with 4 holes for the jfets to even out heat, I got a nice octet of 2sk170 6.6ma from punkydawgs
Mhenschel arh yes,, also a solution, didnt think of that, I do have a bunch of toogle switches that are getting bored
I'm thinking it would be feasible to super glue the nuts inside the rails so removing the top would just involve removing screws. It would need to be done most carefully, probably 1 nut at a time. One trick for leaving a screw in a nut when using superglue is a little beeswax, or the like on the screw threads.
Matter of fact you could probably get away with just the one screw where the metal has been bared, or a second for good luck.
Matter of fact you could probably get away with just the one screw where the metal has been bared, or a second for good luck.