Guys im going to jump on the bandwagon here and mod my xfi xtreme music.
I have 3 of the op-amps en-route from NS, I am still up in the air about changing out the power cap or not.
If I do Im looking at probably a
470Uf 16v FK Black Gate (polarized)
or a
470Uf 16v N Black Gate (non polarized)
Im still trying to determin the effects of a larger cap and if it lead to any of the problems I read about on page 25 of this thread, also the effects of polar vs non-polar.
I have like 8 more pages to read before I have read the whole thread but I wanted to post this up in the mean time.
I am concerned with this:
Quote:
Ok, I've looked at the data.
Input voltage is matched, pins are matched, output voltage is almost matched (LM4562 a little higher), LM4562 itself uses a little more power (few mA).
On the plus side:
LM4562 has 20V/us slew rate vs 3V/us of the old opamp. Distortion, noise rejection, etc.: it's all better. BUT...
On the minus side:
LM4562 is capable of delivering 23mA, while the old opamp can do 70mA. Also, the old opamp can handle low resistance loads better than the LM4562 (though it does lead to higher distortion).
The NJM4556 is specificly made for directly driving headphones, while the LM4562 is the better "preamp". My conclusion: it's close enough to use as a drop-in replacement, provided you know what you're doing. If you want to plug in your headphone without amplification, it's possible the original opamp is a better choice. |
So this applies to me directly, I run my soundcard to a splitter one goes to my sterio to amp for my speakers when I want to play loud or watch a movie. The other side goes to my headphones for when I want max SQ or have to be quiet. Note that I dont have both plugged in at the same time, I always unplug my headphones when not in use as to not actually have the signal running to two sources at once.
Here is the specs on my headphones.
Audio Technica A700's
Type: Closed Dynamic
Driver Unit: 53mm, CCAW voice coil
Magnet: Neodymium
Frequency response: 5-35,000 Hz
Impedence: 64Ω
Max. Input Power: 500mW
Sensitivity: 102dB
They drive quite nice directly from the sound card wich was a priority of mine when I was buying them since I didnt want to have to buy an amp and also maybe use them with somthing like an Ipod down the road if need be.
50% volume on the creative panel is about perfect for me, so based on what I quoted above, what do I need to expect to happen with my direct soundcard ==> headphone connection after I do the mod?
(line-in and surround chans) Pm@c: yeah some get them for free from National, not me 
but Analog sent them free of charge, maybe cause I used my uni address there and didn't with National. I'll probably try a few different ones on the line-in position to see which works best (my turntable tends to be hooked upto it and guitars), ill record some samples of each and compare and report if there are any notable differences.
