[37mil]

i burned the v5i for over 100 hours but couldn't bear any more. It was just not working out. It definitely does sound like a chip amp. Compared to discrete, it's left in the dust. The original, yellow, v5 were magnificent followed closely by sparkos.

 

[pelopidas]

Agreed. Compared to the discreet they are just chip opamps. After going discreet it is actually impossible to go back to chips. I am stuck on the V5 and have no upgrade path left.
My next project is to build a better headphone amp. Then what?

 

[Lohb]

Yes, I just did not like the v5i, too thin-sounding/analytic and difficult to fit.
They can bring things back with a V6 though...the best companies pivot fast.
 
Was there any reason the V5 needed that red cover ? Were they that susceptible to EMI or similar ?

 

[palermo]

I did some experiment to my D14 ibasso, swap the stock opamp as LPF (OPA1602) with Muses8920E. It give more separate instrument, forward but warmish sound. D14 turn to darker signature that couldn't please me. Then I look at amp stage opamp, no label on it, so I replace it to AD8599. overall it sounds good for pop and acoustics like stockfish record but lack for metal genre. 

 

[dukefx]

I had the exact same experience with the V5i. It was unbearable at first and took about 40 hours to burn in. I was shocked when someone a few pages back said theirs sounded good right out of the box. Analytical/thin? No, quite the contrary, It was rather tubelike (which I'm not a fan of). I finally settled for the Sparkos which provides the most natural and realistic sound (in the O2 with my K712s).

 

[37mil]

  I had the exact same experience with the V5i. It was unbearable at first and took about 40 hours to burn in. I was shocked when someone a few pages back said theirs sounded good right out of the box. Analytical/thin? No, quite the contrary, It was rather tubelike (which I'm not a fan of). I finally settled for the Sparkos which provides the most natural and realistic sound (in the O2 with my K712s).

exactly my findings as well. Definitely not thin, the bloated bass and reduced treble saw to that. I'm loving the sparkos, been in my dac a long time now.

 

[Charminbaer]

  Hi, 
 
If used in signal path then a capacitor indeed needs to be dedicated for audio use, otherwise you should only care about ripple and noise suppression, so I really don't think it matters much if Elna Silmic or Panasonic FM if used for decoupling (I would care more about the no. of hours that cap was designed to be used for). Basically, a very good low-noise power source is a must in Hi-Fi world, but for opamps decoupling a small and very fast ceramic capacitor of 0.1uF (for fast transients) and a low-ESR 10uF tantalum or 100uF electrolytic should be more than enough for decoupling (http://www.analog.com/media/en/training-seminars/tutorials/MT-101.pdf, http://www.partsconnexion.com/PDF/mulcap-ps.pdf, http://www.capacitorguide.com/coupling-and-decoupling/).
 
If sound is indeed changing when switching between different decoupling caps then using a scope might see this difference, so either the opamp is or is not oscillating anymore, either the ripple and noise on opamp V+/V- is indeed different (depending on the caps used, one specific cap might perform better than another under some circumstances).
 
When used in signal path, then "best cap is no cap", so DC servo and a simple "wire" would be better, if possible. Otherwise, we all need to stick to the best audio cap we can purchase, that means very low: dissipation factor, dielectric absorption, low inductance, ESR etc. ()

 
Exactly my thoughts as well. But in my experience good electolytics with more than 200uf provide better low frequency filtering.
 
As for the signal path no cap indeed is the best cap but unfortunately not always possible. At least not for a manufacturer.
I found NIOB-OXIDE caps to be quite nice in the signal path. Especially if one needs bigger values like 1-50uf, their price to performance ratio is very good compared to PPs or Teflon.

 

[dukefx]

I found NIOB-OXIDE caps to be quite nice in the signal path.

Niob caps tend to have an extremely low Voltage rating, usually <10V

 

[Charminbaer]

  Niob caps tend to have an extremely low Voltage rating, usually <10V

For signalpath use that is no problem. 6V should be sufficient.

 

[raoultrifan]

They really need to be able to block an entire DC-rail, so if your amplifier is operating at +/-12V then the capacitor used in signal path should be able to handle at least 12V, so most likely 16V DC would be the minimum DC voltage for the capacitor you're looking for.

 

[Charminbaer]

  They really need to be able to block an entire DC-rail, so if your amplifier is operating at +/-12V then the capacitor used in signal path should be able to handle at least 12V, so most likely 16V DC would be the minimum DC voltage for the capacitor you're looking for.

Okay i didn´t know that, thanks for the info. I thought it only needed as much as double the signal strength.
 
Isn´t DC Bias normally in the mV range though?

 

[raoultrifan]

You need a capacitor in signal path to filter any possible DC voltage that may come from the input source. Imagine that an opamp, somewhere before the capacitor, will get defective and will get the entire DC voltage to its output pins, then the capacitor needs to handle/filter this DC voltage. http://sound.whsites.net/articles/coupling-caps.htm#p20 would be a good reading.
 
Also, worth reading: www.partsconnexion.com/PDF/mulcap-ps.pdf and http://www.capacitorguide.com/coupling-and-decoupling/ too.
 
Some examples:
- ASUS Essence One DAC has coupling capacitors on it's output RCA and XLR plugs, so in case an internal opamp gets burned, then the DC-voltage will not destroy a possible connected external amplifier. Instead, for its internal headphone amplifier it has no caps in signal path, because it uses DC-servo to get rid of any possible DC-voltage on headphones output.
- Matrix M-Stage HPA-3B amplifier has 4 x input caps, just in case some defective DAC will get connected. Even a DAC having 10mV DC-voltage on its outputs, when connected to a high gain +20dB amplifier will get a 0.1V on headphone outputs, which is quite high DC, even for low-sensitivity cans.
- Objective2 has 2 x input caps too, to protect headphones

 

[ph0n6]

Has anyone bought the LME49600 from this ebay guy before:
http://www.ebay.com/itm/1PCS-LME49600TS-LME49600-ON-DIP-ADPTER-REPLACE-BUF634-/321270074527
Kinda need a pair for replacing mine BUF634 in the P5. The seller have fine ratings, but Chinese ebay are infamous for their counterfeit so......

 

[northendjazz]

@ph0n6 yep I bought some earlier this year from this seller, no problems for me. I enjoyed them in my ibasso p4.

 

[Charminbaer]

  You need a capacitor in signal path to filter any possible DC voltage that may come from the input source. Imagine that an opamp, somewhere before the capacitor, will get defective and will get the entire DC voltage to its output pins, then the capacitor needs to handle/filter this DC voltage. http://sound.whsites.net/articles/coupling-caps.htm#p20 would be a good reading.
 
Also, worth reading: www.partsconnexion.com/PDF/mulcap-ps.pdf and http://www.capacitorguide.com/coupling-and-decoupling/ too.
 
Some examples:
- ASUS Essence One DAC has coupling capacitors on it's output RCA and XLR plugs, so in case an internal opamp gets burned, then the DC-voltage will not destroy a possible connected external amplifier. Instead, for its internal headphone amplifier it has no caps in signal path, because it uses DC-servo to get rid of any possible DC-voltage on headphones output.
- Matrix M-Stage HPA-3B amplifier has 4 x input caps, just in case some defective DAC will get connected. Even a DAC having 10mV DC-voltage on its outputs, when connected to a high gain +20dB amplifier will get a 0.1V on headphone outputs, which is quite high DC, even for low-sensitivity cans.
- Objective2 has 2 x input caps too, to protect headphones

 
Thank you for the informative links.

So it´s more of a safety measure than a purely functional one.
 
I looked up the specifications from AVX which is the manufacturer of my Niob caps. It seems that Niob caps are very hard to short circuit due to dielectric breakdown. It needs greater than 4 times the rated voltage to get it to short circuit.
 
My caps are rated 10V and my power rails +-12V. If I understood this correctly it basically needs approx. 40V of DC to kill anything behind them.
I find that very unlikely in computers since they use no voltage greater than 12V. As for other sorts of equipment that could of course happen.
And I assume it would have a negative impact on soundquality if the dielectric barrier broke down even if not short circuited.
 
 

 As a result the capacitor is not likely to create a short circuit after the main Nb2O5 dielectric breakdown, but keeps a high resistance around 34kOhms typically – see Fig.6 with comparison of resistance after breakdown on tantalum polymer, aluminum polymer and NbO capacitors. It can be noted externally as just a slight increase of leakage current, and otherwise the capacitor keeps working. 
 
Thus within its rated voltage the NbO OxiCapTM capacitor is not likely to fail as a short circuit in applications. The capacitor can be thermally damaged only when used outside the specifications such as over-voltage breakdown (> ~ 4 times rated voltage), reverse voltage, excessive ripple current and high acceleration of temperature with voltage.
 
 
Source: http://www.avx.com/docs/techinfo/New_Tantalum_Technologies.pdf
            Page 4