[highfidelity69]

I am currently using my D6 with HighFlights top kit and i-pod touch, which sounds great but the D6 DAC section of the amp can only be used in desktop form through my laptop which sounds fantastic, I was thinking of adding the Cypher Labs Algorhythm Solo to bypass the I-pods DAC section, has anyone done this and what are your impressions.

 

[Allforheather]

you can probably refer to one of the Head-fi tv episodes, where Jude talked about the CL solo quite extensively. Although the amp in the video is SR-71B, your interest should be at the solo anyway, since you  probably know quite well what the d6 is capable of as a amp

 

[highfidelity69]

you can probably refer to one of the Head-fi tv episodes, where Jude talked about the CL solo quite extensively. Although the amp in the video is SR-71B, your interest should be at the solo anyway, since you  probably know quite well what the d6 is capable of as a amp

Thanks for the reply, yes the D6 has a nice amp, but don't wAnt to spend $600 for minimal improvement, and yes I seen Judes video on the Solo, I am sure its a fantastic DAC, buy wanted a non biased opinion.

 

[skip129]

I received my D6, and it's going straight back to iBasso for a refund.
 
When the unit is being used as a DAC, the maximum output of the DAC is only 1.2V peak/0.85V RMS.  With a 10dB gain, this results in 2.68V RMS across the headphones, and for a 32 ohm load, this is 225mW. The specs say 650mW into 32 ohms, so the DAC is not able to get anywhere NEAR this maximum spec.  In my opinion the specs are extremely misleading, because it says quite clearly that the Line Output is 1.5V RMS. If that were true, it would tally nicely with the 650mW specification, but it simply is not anywhere near the truth.  The only way the Line Output can be used is when the unit is used as a USB DAC, because when the unit is being used as an analog headphone amp, that connection becomes a Line Input.
 
On the positive side, the unit works well for low latency ASIO, which is something I was not sure about.  I was able to use an ASIO buffer size of 128 samples @44.1kHz, and I could play software pianos in real time with very low latency. I took a risk with this, and it's unfortunate that I encounterd a completely different and unexpected problem with the output drive capability!
 
It does sound very good (although I'm not a headphone connisseur), and iBasso are at least very responsive, and it is good that they will refund me.
 
Anyway, you have been warned: When used as a DAC, it will only put out 225mW into 32 ohms.
 
Greg.
p.s You can turn the volume up and get a >2.68V RMS level, but it will be clipped. The maximum usable sine wave output is 2.68V RMS.

 

[HiFlight]

I received my D6, and it's going straight back to iBasso for a refund.

When the unit is being used as a DAC, the maximum output of the DAC is only 1.2V peak/0.85V RMS.  With a 10dB gain, this results in 2.68V RMS across the headphones, and for a 32 ohm load, this is 225mW. The specs say 650mW into 32 ohms, so the DAC is not able to get anywhere NEAR this maximum spec.  In my opinion the specs are extremely misleading, because it says quite clearly that the Line Output is 1.5V RMS. If that were true, it would tally nicely with the 650mW specification, but it simply is not anywhere near the truth.  The only way the Line Output can be used is when the unit is used as a USB DAC, because when the unit is being used as an analog headphone amp, that connection becomes a Line Input.

On the positive side, the unit works well for low latency ASIO, which is something I was not sure about.  I was able to use an ASIO buffer size of 128 samples @44.1kHz, and I could play software pianos in real time with very low latency. I took a risk with this, and it's unfortunate that I encounterd a completely different and unexpected problem with the output drive capability!

It does sound very good (although I'm not a headphone connisseur), and iBasso are at least very responsive, and it is good that they will refund me.

Anyway, you have been warned: When used as a DAC, it will only put out 225mW into 32 ohms.

Greg.
p.s You can turn the volume up and get a >2.68V RMS level, but it will be clipped. The maximum usable sine wave output is 2.68V RMS.

You have, of course, considered the fact that DAC output is dependent on the level of the input to the DAC. Perhaps your source input is less than optimum. Also, even in a worst case scenario, an output of 225 mw is about 20x that of the headphone output of most DAPs. This should be adequate to drive nearly any dynamic headphone or IEM to a headbanging level.

 

[qib]

I understand that the pico is double the price of the ibasso but could someone please do a comparison. Either the pico or similarly priced dac/amps. Will be using this to drive the dt150 which is 250 ohms.

 

[skip129]

The plot thickens.
 
It was iBasso that told me the DAC output was 1.2V. They didn't specify peak or RMS. I assumed peak, because it matched my own measurements of the OUTPUT (not the Line Out) quite closely. A 10dB gain applied to a 1.2V peak signal is a but under my measured maximum clean output of about 2.8V RMS. Above 2.8V RMS, the unit clips. 
 
However, they have now said that the 1.2V figure was a mistake, and that the real specification is indeed 1.5V RMS.  It's too late for me to measure mine, because I've sent it back.
 
They have also said that 650mW is not an RMS specification. Let's assume it's a peak power specification then.
 
My peak output voltage is a tad under 4V, and that's still only 490mW  into 32 ohms - not the specified 650mW.
 
2.8V RMS into my headphones (AKG K601) is about 110dB SPL.  This is certainly loud (and they do sound loud), but when listening to music, it is not ear splitting, because typically it's only the transients that reach full scale.  In any case, I have a right to verify that my D6 meets specifications, independently of how loud it may sound with any particular headphones.
 
Greg.

 

[Allforheather]

Just ordered the Topkit, Cant wait !!!

 

[Allforheather]

 
Quote:

The plot thickens.
 
It was iBasso that told me the DAC output was 1.2V. They didn't specify peak or RMS. I assumed peak, because it matched my own measurements of the OUTPUT (not the Line Out) quite closely. A 10dB gain applied to a 1.2V peak signal is a but under my measured maximum clean output of about 2.8V RMS. Above 2.8V RMS, the unit clips. 
 
However, they have now said that the 1.2V figure was a mistake, and that the real specification is indeed 1.5V RMS.  It's too late for me to measure mine, because I've sent it back.
 
They have also said that 650mW is not an RMS specification. Let's assume it's a peak power specification then.
 
My peak output voltage is a tad under 4V, and that's still only 490mW  into 32 ohms - not the specified 650mW.
 
2.8V RMS into my headphones (AKG K601) is about 110dB SPL.  This is certainly loud (and they do sound loud), but when listening to music, it is not ear splitting, because typically it's only the transients that reach full scale.  In any case, I have a right to verify that my D6 meets specifications, independently of how loud it may sound with any particular headphones.
 
Greg.

 
Have you ever tested what is the output level of a iPod Classic lo?? And, when you were testing using the D6 as a dac with its own amp section, after which position on the Pot did you start to get clipping effect??

 

[skip129]

Quote:

 

 
Have you ever tested what is the output level of a iPod Classic lo?? And, when you were testing using the D6 as a dac with its own amp section, after which position on the Pot did you start to get clipping effect??

No, I have never tested an iPod Classic, however a company that makes professional audio equipment told me that it has a high output - 5V RMS.  (not bad!)  
 
I started to hear clipping at about 2 dots under 100%, as shown on the D6's volume dial. I have done other tests to verify that it is the D6 that is clipping, and not something else in the system.  I have also measured another audio interface, and I get a result that is very close to the specs for that audio interface. So, I am quite confident that I am correct that my D6 has audible clipping at about 2.8V RMS. 
 
@HiFlight: Since you sell the "Topkit" for the D6 (yes?), you would presumably have intimate knowledge of the D6. Would that be correct? Have you ever taken measurements? If so, did you measure the peak output voltage on the headphone output, for a full scale digital sine wave on the USB input, at the onset of clipping? (assuming it clipped at all for you) It would be good to have someone like yourself verify my measurement. My unit may have been defective, or I may somehow have made a mistake. (although iBasso aren't suggesting either yet)
 
Greg.

 

[skip129]

@Allforheather: Sorry - I think you were asking about the Line Out of the iPod Classic - is that correct? ("lo" = "Line Out"?). If so, I have no idea what it is. The 5V RMS would be for the headphone output, assuming it has a seperate headphone output. (I'm not familiar with this product)
 
Greg.

 

[HiFlight]

No, I have never tested an iPod Classic, however a company that makes professional audio equipment told me that it has a high output - 5V RMS.  (not bad!)  

I started to hear clipping at about 2 dots under 100%, as shown on the D6's volume dial. I have done other tests to verify that it is the D6 that is clipping, and not something else in the system.  I have also measured another audio interface, and I get a result that is very close to the specs for that audio interface. So, I am quite confident that I am correct that my D6 has audible clipping at about 2.8V RMS. 

@HiFlight: Since you sell the "Topkit" for the D6 (yes?), you would presumably have intimate knowledge of the D6. Would that be correct? Have you ever taken measurements? If so, did you measure the peak output voltage on the headphone output, for a full scale digital sine wave on the USB input, at the onset of clipping? (assuming it clipped at all for you) It would be good to have someone like yourself verify my measurement. My unit may have been defective, or I may somehow have made a mistake. (although iBasso aren't suggesting either yet)

Greg.

I have not tested the D6 for output voltage, and clipping level is dependent on the opamps used and output load, not just DAC input. I have not felt testing was necessary as the D6 has more than enough output to drive any headphone that might be appropriate for portable use, assuming a quality source. I have, however, checked the output of a 20-20K sinewave with my scope and noticed no clipping, but I don't recall what the voltage level of my audio generator was.

It has always been my feeling that measured specifications were of less importance than how a device actually sounds when listening to music, accordingly, my Topkit components have always been chosen on the basis of audio performance rather than datasheet specifications, with the obvious exception of supply voltage requirements.

I have found the D6 to be a well-designed and versatile product, and there have been very few issues reported so far during its production run.

 

[skip129]

Thanks HiFlight.
 
I agree - for headphones that are designed for portable devices, the D6 would be more than ample.
 
However, my interpretation of the D6 specs suggested to me that the D6 would be suitable for moderately hard to drive headphones, that you may use at home connected to mains powered equipment.
I carefully inspected the specifications of a group of iBasso products, and the D6 seemed to stand out as being a bit special - it is very compact, it is battery powered, has a high quality DAC, AND it has a high output headphone amp.  However, if my measurements are correct, it appears that the headphone amp is not as powerful as the specs indicate it should be.
 
I'll see what iBasso say next, in any case.
 
It did sound very good.
 
Greg.

 

[Allforheather]

@Greg,
 
Yes, I'm asking about the Line out level of the iPod Classic. 
Ok, Here is my theory, I'm no expert on electronics and I'm base the below extrapolation on your statement. If it is the output level of the internal dac that causes the output power of the amp section not meeting its specification, what about the aux input then, say if a source, LO from iPod Classic is high enough to let the output power of amp section reach its proposed 650mw. Then, it is not contradicting with the specification advertised on their website anymore. However one still can say it's misleading because buyers might expect the output maximum to be reached under the condition that the unit functioning as a dac and amp combo and the maxima can only be reached when use as a amp only with a powerful enough source device. 
 
Again I'm no electronics experts or I don't really know anything at all.. just my 2 cents

 
The advertised 650mw into 32ohm is crazy though, since the mighty powerful e9 from fiio only rated at 1W into 16ohm....
 
Despite the specs, I'm enjoying my d6 using as a portable amp with my IPC and a dac for my e9. It drives the rs2i beautifully but the same cannot be said for the k701, since, the low end is just gone compare to the e9 and overall the 701 on d6 is very thin sounding. 

 

[skip129]

 
@Allforheather,
I agree with you completely, and in fact, iBasso kind of indicated to me that the maximum is only achievable when using the D6 as an analog amp. However, the reason they gave for that is that the DAC output is only 1.2V. (they didn't specify peak or RMS - I guessed peak, as I said)  They have now backed away from that, and instead said that the DAC is capable of 1.5V RMS (which is what the specs say). If you apply a 10dB gain to that, you get 650mW (and RMS!) into 32 ohms. Yet, they say the power spec is 650mW peak (if it's not RMS, it must surely be peak, but they didn't actually say peak).
So it doesn't all add up.  I have asked iBasso what the actual peak output voltage should be, unloaded, for a full scale digital sine wave input on the USB. 
 
I didn't do any testing of the performance as a purely analog amp.
 
If you think the 650mW into 32 ohms is crazy, what do you think about the iPod Classic? If it can maintain 5V RMS across 32 ohms, that's 781mW.
 
Greg.