RMAA Fuze vs Fuze>10uF Caps>Mini^3, is there something wrong here?
Jan 3, 2012 at 2:56 PM Thread Starter Post #1 of 6

psgarcha92

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Guys, i set out to get the RMAA results of my Fuze (Rockboxed) vs the setup Fuze>10uF Vishay Caps>Mini^3, mainly to see if the caps in the chain were causing some of the notorious behaviour....Basically, sometimes when i plug in my RE0s into this setup, something irritates me. To find if my setup was making some HF noise, i performed RMAA, these are the results. Couls someone please help me read these, as in what might be very wrong here?
 

RightMark Audio Analyzer test report (Fuze at -5db, set on Rockbox)

Testing device Wave mapper
Sampling mode 16-bit, 44 kHz
Interface MME
Testing chain External loopback (line-out - line-in)
RMAA Version 6.2.3
   
   
20 Hz - 20 kHz filter ON
Normalize amplitude ON
Level change 0.3 dB / 0.4 dB
Mono mode OFF
Calibration singal, Hz 1000
Polarity inverted/correct



Summary

Frequency response (from 40 Hz to 15 kHz), dB +0.06, -0.19
Very good
Noise level, dB (A) -81.4
Good
Dynamic range, dB (A) 81.4
Good
THD, % 0.017
Good
THD + Noise, dB (A) -71.2
Average
IMD + Noise, % 0.027
Good
Stereo crosstalk, dB -80.0
Very good
IMD at 10 kHz, % 0.034
Good
General performance  
Good



Frequency response


 
From 20 Hz to 20 kHz, dB -1.04, +0.06
From 40 Hz to 15 kHz, dB -0.19, +0.06



Noise level


 
  Left
Right
RMS power, dB -81.3
-81.2
RMS power (A-weighted), dB -81.4
-81.4
Peak level, dB FS -67.2
-66.7
DC offset, % -0.0
-0.0


 

Dynamic range


 
  Left
Right
Dynamic range, dB +81.4
+81.2
Dynamic range (A-weighted), dB +81.5
+81.4
DC offset, % -0.00
-0.00



THD + Noise (at -3 dB FS)


 
  Left
Right
THD, % +0.0169
+0.0164
THD + Noise, % +0.0241
+0.0239
THD + Noise (A-weighted), % +0.0279
+0.0275



Intermodulation distortion


 
  Left
Right
IMD + Noise, % +0.0272
+0.0273
IMD + Noise (A-weighted), % +0.0256
+0.0258



Stereo crosstalk


 
  Left
Right
Crosstalk at 100 Hz, dB -79
-78
Crosstalk at 1000 Hz, dB -79
-79
Crosstalk at 10000 Hz, dB -78
-78



IMD (swept tones)


 
  Left
Right
IMD + Noise at 5000 Hz, 0.0426
0.0439
IMD + Noise at 10000 Hz, 0.0292
0.0282
IMD + Noise at 15000 Hz, 0.0311
0.0298
 
 
 
 
 

 

 

RightMark Audio Analyzer test report (Fuze>10uF Caps>Mini^3)

Testing device Wave mapper
Sampling mode 16-bit, 44 kHz
Interface MME
Testing chain External loopback (line-out - line-in)
RMAA Version 6.2.3
   
   
20 Hz - 20 kHz filter ON
Normalize amplitude ON
Level change 2.4 dB / 2.9 dB
Mono mode OFF
Calibration singal, Hz 1000
Polarity inverted/inverted



Summary

Frequency response (from 40 Hz to 15 kHz), dB +0.06, -0.19
Very good
Noise level, dB (A) -83.6
Good
Dynamic range, dB (A) 83.6
Good
THD, % 0.023
Good
THD + Noise, dB (A) -69.5
Average
IMD + Noise, % 0.028
Good
Stereo crosstalk, dB -6.7
Very poor
IMD at 10 kHz, % 0.038
Good
General performance  
Average



Frequency response


 
From 20 Hz to 20 kHz, dB -1.04, +0.06
From 40 Hz to 15 kHz, dB -0.19, +0.06



Noise level


 
  Left
Right
RMS power, dB -83.4
-83.2
RMS power (A-weighted), dB -83.6
-83.5
Peak level, dB FS -69.2
-68.7
DC offset, % -0.0
-0.0



Dynamic range


 
  Left
Right
Dynamic range, dB +83.4
+83.2
Dynamic range (A-weighted), dB +83.7
+83.5
DC offset, % +0.00
+0.00



THD + Noise (at -3 dB FS)


 
  Left
Right
THD, % +0.0215
+0.0249
THD + Noise, % +0.0260
+0.0286
THD + Noise (A-weighted), % +0.0315
+0.0352



Intermodulation distortion


 
  Left
Right
IMD + Noise, % +0.0275
+0.0284
IMD + Noise (A-weighted), % +0.0246
+0.0247



Stereo crosstalk


 
  Left
Right
Crosstalk at 100 Hz, dB -5
-6
Crosstalk at 1000 Hz, dB -5
-6
Crosstalk at 10000 Hz, dB -5
-6



IMD (swept tones)


 
  Left
Right
IMD + Noise at 5000 Hz, 0.0483
0.0490
IMD + Noise at 10000 Hz, 0.0294
0.0313
IMD + Noise at 15000 Hz, 0.0327
0.0356
 
 
These are not real world tests, i mean there was no splitter cable and headset/load attached.
My testing device is an Intel HD Sound Card on a Dell Studio 1555.
I like the way my Studio 1555 sounds though, but something about the setup isnt right. i dont know if its the capacitors, i have ordered a few Nichicons & Silmics. The problem sure is not with the RE0s, i like them a lot out of my Computer (Studio 1555), and not that much out of my Rig. its like they become more sibilant. And i dont have a clue if i dont like the Mini^3's sound, or the Fuze's sound itself.
 
Help me here guys.
 
Regards

 


Edit: Ofcourse the Fuze and the Mini^3 were never Volume matched.
 
Jan 3, 2012 at 3:20 PM Post #2 of 6
SomeThing is not right with the crosstalk numbers. Either your methodology is flawed, or there is a problem with your Mini3.
 
I would inspect the soldering on the Mini3 with a loupe. High resistance at the phone jack or ground channel amp could elevate the crosstalk numbers.
 
Jan 3, 2012 at 4:26 PM Post #3 of 6
How do you have the 10uf capacitors connected? With jumper wires? Or are these installed in something?
 
Can you test the Mini3 by itself?
 
Jan 3, 2012 at 5:11 PM Post #4 of 6
Please direct Mini³ questions to AMB DIY audio forum where you'll receive full support from me as well as the members there.

Running RMAA on a Mini³ using a conventional loopback cable should not be done, because the active output ground would become short circuited to the input signal ground through the loop, and therefore your results are invalid.  The amp's output is intended to drive only passive headphones, not the input stage of the sound card which is then connected back to Mini³'s input.  To properly use RMAA on a Mini³ would require special arrangements.

Does the amp pass all its "initial check" steps documented at the Mini³ website?
 
 
Jan 4, 2012 at 4:04 AM Post #5 of 6
@Pars, they are connected in an LOD....like Signal Out from Sansa Fuze>Caps.
 
@amb, yes the Mini^3 i have passes all the Initial tests, i might even check that again when i have a Multimeter with me. I was looking for the FR because i thought maybe the Mini^3 had a spike at HF part of the FR curve. I'd try making a Y splitter cable, would it be ok to check the Mini^3 via RMAA then?
 
 
Regards
 
Jan 4, 2012 at 4:15 AM Post #6 of 6


Quote:
@amb, yes the Mini^3 i have passes all the Initial tests, i might even check that again when i have a Multimeter with me. I was looking for the FR because i thought maybe the Mini^3 had a spike at HF part of the FR curve. I'd try making a Y splitter cable, would it be ok to check the Mini^3 via RMAA then?


No, you cannot use a Y-splitter.  I described why doing a RMAA loopback test is tricky with active ground amps in the reply above, so please try to understand it.
 
If the amp passes all initial checks, then it should function correctly.  The only things I would add is to make sure your solder joints are good on the volume pot and input/output jacks.  Also check your interconnect cable.
 
Rest assured that a properly functioning Mini³ will have ruler flat frequency response from 0Hz into many MHz range.
 
 

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