• Please note that Audiokarma will be offline briefly for updates early on Monday morning, September 28th.

Recap Schiit Mani with higher-end caps to reduce noise?

.. a little late to the party here but I had some hiss with my Mani so I contacted Schiit. they replied that I could experiment with the gain settings on the bottom of the unit.. and this relieved the hissing sound. at first I was L on 1 and 2, then I went H/L on 1/2 respectively, then switched it around and the sound stopped.

I've read about others getting 'RF interference' but also read replies from forums about this with guys saying they're right next to several stations and get nothing.. your cables should be fine but everything breaks down and sometimes, gear has defects. it may make sense to try another pair of RCA interconnects.

the other option, smart is to sell it, get something else. I've been coveting the Parks Audio Puffin for the last few weeks.. and have decided to get one, the next time funds, price and availability collide-- check out the videos- it's a pretty amazing unit, imho. http://parksaudiollc.com/
 
Tweaking the gain setting just gives a false feeling of less noise. but actually, if the output signal is normalized to the same level as the higher gain output, the background hiss level is basically the same. I did this test with audacity. Mani is 3db noisier than my NAD1130.
 
rothwellaudio said:
This is absolutely correct. In fact, all phono preamps hiss to some extent - and getting the hiss as low as possible has been a challenge for electronic engineers since electronics was invented. However, I wouldn't expect the hiss to be a problem with a modern mm phonostage. Maybe the noise is power supply related and due to the use of a switch mode power supply. The Mani takes 16VAC in and looking at a picture of the circuit board on Shiit's website I don't see the sort of components I would expect to see for a conventional power supply, so I suspect they're using a switching regulator. Maybe that's the problem :dunno: If so, just swapping a few caps won't do any good.
Click to expand...

Maybe, a better filtered & regulated power supply? I'm currently using an industrial grade 3.5amp one on my Pro-ject Phono tubed pre-amp. It is much quieter than the OEM one.

MeanWell medical & industrial grade power supplies are very, very stable DC supplies. Quietest, I've measured with less than 3mVAC riding on top of the DC. If you can get one in your voltage range and can use ~1-amp supply.

https://www.meanwellusa.com/webapp/product/search.aspx?prod=GS15A
 
Last edited:
The Mani comes with a 16v AC wall wart. Internally the unit has the diodes and caps to complete it's linear 23v (ish) power supply. That goes to a 12v regulator which then goes to two 5v regulators which power the opamps.

My personal Mani is powered with 23v DC (yes you can use a DC adapter with your factory AC powered Mani) from a lab supply through a large choke filter then 50,000uf of capacitor storage. The low level "hiss" is still present with DC power but no more low level 60 HZ noise of any kind on DC power vs a small amount (60 dB - 70 dB down) with the AC wall wart.

I have also recapped it internally along with bypassing the output coupling caps. (residual output DC is only 1.6 mv and it goes directly to an AC coupled Topping TP60 in my second system)

The Mani is not difficult to work on and is built to a higher quality than the super-cheapo Chinese stuff. It is not built to the level of my Conrad Johnson and Quicksilver units, but better than I expected for $129.

https://1drv.ms/u/s!AifPgmX0tWO8g7dWqJNutUuzyMWDLg?e=FWA9uP
Preview compressed in your browser or download for full quality.

Rather than talking about sound, here is a capture via Technics Sp25, EPA 150 tonearm, Stanton 881S with D50E .4 x .7 elliptical stylus to Mani, to a little Focusrite Scarlet usb interface. Raw capture, no EQ or processing whatsoever other than to normalize. You can judge for yourself if the clarity, punchiness, openness, separation, etc. was worth a few hours of soldering. That capture is used on my radio show along with pure digital files and mostly direct vinyl to broadcast.

Pat
 
Mr Boochie said:
Maybe, a better filtered & regulated power supply? I'm currently using an industrial grade 3.5amp one on my Pro-ject Phono tubed pre-amp. It is much quieter than the OEM one.

MeanWell medical & industrial grade power supplies are very, very stable DC supplies. Quietest, I've measured with less than 3mVAC riding on top of the DC. If you can get one in your voltage range and can use ~1-amp supply.

https://www.meanwellusa.com/webapp/product/search.aspx?prod=GS15A
Click to expand...
Please see my other response. Wall wart is 16v (18v unloaded) AC transformer. Rectification and filtering are inside the Mani.
 
dahoo said:
i confirm my mani has the same pink noise at high volume. it is definitely noisier than my nad1130. you would not notice it through speakers unless putting your ear next to them.
i listen to my needledrops with headphones so the noise is more evident. i am sure it is not buzz or clicks from radio interference.
i am also interested in solutions.
Click to expand...
I dont think there is a solution, or at least not a practical one. Please see my other post. Personal Mani is DC powered from a lab supply to large choke filter and 50,000uf of capacitance. Internally the unit has been recapped with Nichicon Muse. TO my ears there is an obvious improvement in the sound and noise using the lab supply and from the recap but It would take a much deeper dive than what I did to reduce the residual hiss, if it is even possible with that particular design.
 
psemeraro said:
I dont think there is a solution, or at least not a practical one. Please see my other post. Personal Mani is DC powered from a lab supply to large choke filter and 50,000uf of capacitance. Internally the unit has been recapped with Nichicon Muse. TO my ears there is an obvious improvement in the sound and noise using the lab supply and from the recap but It would take a much deeper dive than what I did to reduce the residual hiss, if it is even possible with that particular design.
Click to expand...

Just out of curiosity, have you checked the VAC riding on top of that lab supply with the extra filtering? Just curious.

For an example, I have two hospital grade MEAN WELL 18VDC supplies. One has 2.8mVAC and the other 2.2mVAC riding out top of the 18.18VDC (very steady voltage). Both are 1.2 amp supplies. Typical OEM 18VDC external PSU I've tested can run anywhere from 3.4mVAC to 15mVAC. Some are very unstable. Fluctuating between 18.2 to 18.9 VDC range, even after a 5 minute warmup.

Still, the quietest, by headphone test, is that 3.5 amp unit. It has 3.4mVAC riding on top. Rock steady 18.32 VDC.
 
Mr Boochie said:
Just out of curiosity, have you checked the VAC riding on top of that lab supply with the extra filtering? Just curious.

For an example, I have two hospital grade MEAN WELL 18VDC supplies. One has 2.8mVAC and the other 2.2mVAC riding out top of the 18.18VDC (very steady voltage). Both are 1.2 amp supplies. Typical OEM 18VDC external PSU I've tested can run anywhere from 3.4mVAC to 15mVAC. Some are very unstable. Fluctuating between 18.2 to 18.9 VDC range, even after a 5 minute warmup.

Still, the quietest, by headphone test, is that 3.5 amp unit. It has 3.4mVAC riding on top. Rock steady 18.32 VDC.
Click to expand...
AC measurement does not work correctly on my DMM and no scope at the moment but I have to believe there is not much AC after a large choke and 50,000uf of capacitance. The steady state current draw of the Mani is 50 milliamps.
 
You must log in or register to reply here.
Back
Top Bottom