[howdy]

I had looked into these two DAPs and was coming to a decision on which to get until I read this thread!

Has anyone tried them with a pair of HD25s (my primary out and about headphones)? Their 70 Ohm impedance hasn't been covered by anyone yet.

Either one can power 70 ohm with no problem, the choice for you is weather you like a warm sig or a slightly bright sig. I have both and will keep both, they have there positives and negatives. I switch between them every week.

 

[Hellkitchen]

I'm still insecure about which one buy. Tomorrow I'm going to meet a guy that has an iBasso and I will try his device.
I'm going to sell my TripleFi to him and with the money I'll buy an iBasso or an X3.
 
For iBasso I must wait longer since I live in Italy and I should buy it from USA.. The X3 instead can be bought directly in my country..

 

[howdy]

I'm still insecure about which one buy. Tomorrow I'm going to meet a guy that has an iBasso and I will try his device.
I'm going to sell my TripleFi to him and with the money I'll buy an iBasso or an X3.

For iBasso I must wait longer since I live in Italy and I should buy it from USA.. The X3 instead can be bought directly in my country..

What ear/headphones will you be using? What genre of music do you prefer? You will be happy with either one.

 

[ClieOS]

Just sat down and listened to my AD8620 mod'ed X3, Nano 7G and DX50, volume matched to within 0.5dB of each other (it is impossible to match any closer since all three has digital volume control). Here are some quick impression:
 
Soundstage (wide -> close): DX50 > X3 > Nano 7G
Texture (thick -> thin): X3 > Nano 7G > DX50
Control / tightness: X3 > DX50 > Nano 7G
 
One thing that struck me early on is that DX50 sounds more gainy and bright than most DAP I have. The three way comparison really explains why - it is because DX50 is really thin on the mid and upper bass, which in effect emphasizes more on the treble in the overall presentation and makes it more edgy than it should. On the other hand, the slight hollowness also gives DX50 an excellent soundstage. IIRC, these are kind of opposite to what I have heard on the stock X3. I think I still prefer my mod'ed X3 the most. Though it is easy to tell that Nano 7G isn't quite as good as DX50, I think it actually has better balance as well. If only DX50 has a thicker mid, it would have been really great. Just wonder what opamp DX50 has on the headphone-out and maybe they are worth modding as well.

 

[T.R.A.N.C.E.]

^ Mod the DX50 then compare to Moded X3 

, someone in china apparently already moded the DX50 with AD8620 as LPF and 2x AD797 as gain stage, and Elna capacitors. now those 797's would definitely fix the thin mids for you 

 

[ClieOS]

^ Mod the DX50 then compare to Moded X3 

, someone in china apparently already moded the DX50 with AD8620 as LPF and 2x AD797 as gain stage, and Elna capacitors. now those 797's would definitely fix the thin mids for you 

 
Those are exactly the opamp I'll avoid in those positions. WM8740 doesn't need a LPF, the opamp is for differential-to-single-ended conversion. Here are a few reasons why AD8620 is a poor choice: (1) DX50 is running on +/-4.5 but AD8620 is +/-5V minimum. (2) AD8620 isn't rail-to-rail. Given it is going to be underpowered, not being rail-to-rail further cut into its dynamic performance. There is a chance the AD8620 might clip the signal when it is on full line-out. The only good news is that iBasso limits the full line-out to 1.5Vrms so you might get away with it. But it certainly is not a good opamp to use. AD797 isn't fair very well either. First, it isn't rail-to-rail either (in fact, voltage swing is worst than AD8620) and it is underpowered as well. While it does have excellent low output impedance, It doesn't actually deal particularly well with capacitance load and can be a big problem since DX50 has a massive 440uF of output caps, beside what the headphone will add to it. In fact, you will need to add some resistors to AD797 output to make sure it will be stable.
 
There is a tendency for people to just randomly put in well regarded opamp into a circuit and be happy about it. IMO however, those two are only making each other worst than they would have been individually. As for Elna caps - if they are really going for higher transparency, OxiCaps would have been a better choice. Better yet, iBasso should have avoided caps on the output all together, given the benefit of no needing to worry about corner frequency or coloration. That should be well within their capability and not difficult to implement since they already have a +/- voltage rail.

 

[Hellkitchen]

What ear/headphones will you be using? What genre of music do you prefer? You will be happy with either one.

I listen mainly metal and rock with UE900, TF (for sale) and a pair of HD598. Anyway I've bought the DX50 with the R3 on MP4 Nation. 
After 2 second of listening with the DX50 I've understand that every mp3 player I've listened since now was crap This player is simply stunning. I've found that the UI and the responsiveness of the front buttons are not perfect but the SQ was amazing!!!
 
In other words I loved DX 50 immediately 

 

[goodvibes]

   
Those are exactly the opamp I'll avoid in those positions. WM8740 doesn't need a LPF, the opamp is for differential-to-single-ended conversion. Here are a few reasons why AD8620 is a poor choice: (1) DX50 is running on +/-4.5 but AD8620 is +/-5V minimum. (2) AD8620 isn't rail-to-rail. Given it is going to be underpowered, not being rail-to-rail further cut into its dynamic performance. There is a chance the AD8620 might clip the signal when it is on full line-out. The only good news is that iBasso limits the full line-out to 1.5Vrms so you might get away with it. But it certainly is not a good opamp to use. AD797 isn't fair very well either. First, it isn't rail-to-rail either (in fact, voltage swing is worst than AD8620) and it is underpowered as well. While it does have excellent low output impedance, It doesn't actually deal particularly well with capacitance load and can be a big problem since DX50 has a massive 440uF of output caps, beside what the headphone will add to it. In fact, you will need to add some resistors to AD797 output to make sure it will be stable.
 
There is a tendency for people to just randomly put in well regarded opamp into a circuit and be happy about it. IMO however, those two are only making each other worst than they would have been individually. As for Elna caps - if they are really going for higher transparency, OxiCaps would have been a better choice. Better yet, iBasso should have avoided caps on the output all together, given the benefit of no needing to worry about corner frequency or coloration. That should be well within their capability and not difficult to implement since they already have a +/- voltage rail.

I don't mind output caps quite as much though it's hard to get it right at those values in those sizes required for a DAP. They become part of the voicing and other ways of eliminating DC can have it's own problems though I agree it's preferable to avoid them if you can get it right. I totally agree about the amateur silly fascination with parts. They're not plug and play and better isn't better everywhere. Not too uncommon to go for infinite and unnecessary bandwidth only to have it become unstable and ring. Even the excellent caps you mentioned won't always sound better in a circuit. Sometimes neutral doesn't voice right.

 
I know you changed the output device in the X3 but you chose something that is a replacement drop in from the same family, understood the trade offs and did it for a voicing preference, not because it's absolutely better. What FiiO chose actually has a higher capability An understood trade off for the voicing you wanted and nothing you'll run up against in use.. Most probably prefer FiiOs often slightly warm sig and greater drive ability but I suspect I'd opt for your take.

 

[goodvibes]

  Just sat down and listened to my AD8620 mod'ed X3, Nano 7G and DX50, volume matched to within 0.5dB of each other (it is impossible to match any closer since all three has digital volume control). Here are some quick impression:
 
Soundstage (wide -> close): DX50 > X3 > Nano 7G
Texture (thick -> thin): X3 > Nano 7G > DX50
Control / tightness: X3 > DX50 > Nano 7G
 
One thing that struck me early on is that DX50 sounds more gainy and bright than most DAP I have. The three way comparison really explains why - it is because DX50 is really thin on the mid and upper bass, which in effect emphasizes more on the treble in the overall presentation and makes it more edgy than it should. On the other hand, the slight hollowness also gives DX50 an excellent soundstage. IIRC, these are kind of opposite to what I have heard on the stock X3. I think I still prefer my mod'ed X3 the most. Though it is easy to tell that Nano 7G isn't quite as good as DX50, I think it actually has better balance as well. If only DX50 has a thicker mid, it would have been really great. Just wonder what opamp DX50 has on the headphone-out and maybe they are worth modding as well.

Maybe some SILMIC II in the output if I want to try something. Probably a couple 220mf with a 1mf bypass, squeeze a 3rd 200mf in if I could. Polar, neg out as I suspect they're using now. There's probably enough voicing available in the output caps to not worry about the opamps etc.

 

[howdy]

I listen mainly metal and rock with UE900, TF (for sale) and a pair of HD598. Anyway I've bought the DX50 with the R3 on MP4 Nation. 
After 2 second of listening with the DX50 I've understand that every mp3 player I've listened since now was crap This player is simply stunning. I've found that the UI and the responsiveness of the front buttons are not perfect but the SQ was amazing!!!

In other words I loved DX 50 immediately 

I know someone who bought the same deal you did from mp4nation but he cannot get the R3s to fit properly and is wanting to sell them to me, have you tested these with the DX50? I agree the sound is amazing, did you update the FW yet.

 

[ClieOS]

With the leanness of the current DX50, a more transparent caps are probably a bad match, I would imagine. BTW, the stock caps are UTSJ Jauial series from Toshin Kogyo (TK) Japan, said to be the best audio caps they made (linky). Dimesion of the caps will be a big factor on what caps can be used since it has to be 220uF 6.3x11 10V for a direct replacement and I don't think there is a lot of room inside for something bigger.

 

[Hellkitchen]

I know someone who bought the same deal you did from mp4nation but he cannot get the R3s to fit properly and is wanting to sell them to me, have you tested these with the DX50? I agree the sound is amazing, did you update the FW yet.

Not yet, I should recive my in one or two weeks! I'll test the r3 than but having the ue900 I doubt that I'll use the R3

 

[T.R.A.N.C.E.]

   
Those are exactly the opamp I'll avoid in those positions. WM8740 doesn't need a LPF, the opamp is for differential-to-single-ended conversion. Here are a few reasons why AD8620 is a poor choice: (1) DX50 is running on +/-4.5 but AD8620 is +/-5V minimum. (2) AD8620 isn't rail-to-rail. Given it is going to be underpowered, not being rail-to-rail further cut into its dynamic performance. There is a chance the AD8620 might clip the signal when it is on full line-out. The only good news is that iBasso limits the full line-out to 1.5Vrms so you might get away with it. But it certainly is not a good opamp to use. AD797 isn't fair very well either. First, it isn't rail-to-rail either (in fact, voltage swing is worst than AD8620) and it is underpowered as well. While it does have excellent low output impedance, It doesn't actually deal particularly well with capacitance load and can be a big problem since DX50 has a massive 440uF of output caps, beside what the headphone will add to it. In fact, you will need to add some resistors to AD797 output to make sure it will be stable.
 
There is a tendency for people to just randomly put in well regarded opamp into a circuit and be happy about it. IMO however, those two are only making each other worst than they would have been individually. As for Elna caps - if they are really going for higher transparency, OxiCaps would have been a better choice. Better yet, iBasso should have avoided caps on the output all together, given the benefit of no needing to worry about corner frequency or coloration. That should be well within their capability and not difficult to implement since they already have a +/- voltage rail.

 
Is it possible that the DX50 doesn't use +/-4.5 though? I read somewhere that it uses a single ended 9v supply (which I guess implies use of voltage doubling circuit) , which is also why they used a high capacitance. If it does actually use a single 9v supply, does that change the 8620 and 797 being bad ideas, or is it still not good?

 

[goodvibes]

  With the leanness of the current DX50, a more transparent caps are probably a bad match, I would imagine. BTW, the stock caps are UTSJ Jauial series from Toshin Kogyo (TK) Japan, said to be the best audio caps they made (linky). Dimesion of the caps will be a big factor on what caps can be used since it has to be 220uF 6.3x11 10V for a direct replacement and I don't think there is a lot of room inside for something bigger

One of the biggest issue with using output caps in portable devices. The best ones tend to be bigger or wrong form factor.

 

[goodvibes]

   
Is it possible that the DX50 doesn't use +/-4.5 though? I read somewhere that it uses a single ended 9v supply (which I guess implies use of voltage doubling circuit) , which is also why they used a high capacitance. If it does actually use a single 9v supply, does that change the 8620 and 797 being bad ideas, or is it still not good?

I don't think you're following along. The capacitance discussed isn't part of the power supply. They are strictly dc blocking output coupling caps. 
 
If it used a voltage doubling circuit, it probably wouldn't need the output caps in the first place. Done properly, you can keep the rails perfectly balanced which allows you to eliminate DC offset without blocking it. It's more likely a buffered voltage splitter circuit. I'm sure CleiOS will fill in the blanks.