[Arttx]

Anybody experiencing audio dropouts with his JDS Labs C5D amp/DAC?
I have had from the first moment although I have maxed the PC performance. What a shame, I thought this would be a solid piece of gear, but seems not to work very well.
So I get audio dropouts by just scrolling a web page. DPC latency is generally <<500 us but occationally jumps higher.
My PC is a Lenovo X240 laptop with i5 @1.9 GHz.

Any pointers, please?

 

[s0ckpupp3t]

Anybody experiencing audio dropouts with his JDS Labs C5D amp/DAC?
I have had from the first moment although I have maxed the PC performance. What a shame, I thought this would be a solid piece of gear, but seems not to work very well.
So I get audio dropouts by just scrolling a web page. DPC latency is generally <<500 us but occationally jumps higher.
My PC is a Lenovo X240 laptop with i5 @1.9 GHz.

Any pointers, please?

I had a similar issue with my Dell laptop and the C5D.   Turns out for whatever reason my laptop wasn't playing nice with the C5D in USB asynchronous mode (no problems with my wife's Macbook).  JDS sent me a software update to reconfigure the C5D to USB adaptive mode which completely fixed the problem.  I recommend emailing JDS on this.
 
My posts on this issue around here:
http://www.head-fi.org/t/647838/jds-labs-c5-c5d-pg96-portable-amp-amp-dac-appreciation-discussion-thread/2355

 

[ThurstonX]

This is a bit of a cross-post of something I just posted in an HE-500s thread, but since the C5 is half the experiment, I figured it might interest this crowd.
 

---

 
So, received and have been burning in my third pair of HE-500s.  Since I'd measured the resistance of my other HFM cans, I did the same for these.  32.4 & 33.9 are what I get.  Compare that to the ~50 ohms for my HE-560s.  At that low rating, I decided to see if my li'l JDS Labs C5 portable amp could drive the HE-500s.  I tried it with a previous pair (the first, I think, which I never measured), and it was partial success.  Some things didn't clip - hot masters, I reckon - while others couldn't get loud enough to enjoy without clipping.  While I've only tested one song thus far, the C5 drove them very well, not just from a volume perspective, but quality, which that little amp definitely has.  Sadly, the HE-500s still aren't really portable 

 
Then I plugged in the 50-ohm HE-560s.... annnnnd quickly took them off.  It just wasn't on, which was predictable.  With the volume max'd on high gain, I could barely hear it.  OK, not that bad, but nowhere near enough power.  I know HFM products vary widely, and even within a particular model, but didn't they say the HE-560s would be easier to drive?  Maybe I'm not remembering that correctly.  Thankfully, my Lyr packs more than enough quality power to make those babies sing.
 
So, while I'm not recommending the C5 for the HE-500s, esp. considering my earlier tests, it'll certainly do in a pinch, if your HE-500s have a relative lower resistance.

 

[miceblue]

This is a bit of a cross-post of something I just posted in an HE-500s thread, but since the C5 is half the experiment, I figured it might interest this crowd.

[rule]
So, received and have been burning in my third pair of HE-500s.  Since I'd measured the resistance of my other HFM cans, I did the same for these.  32.4 & 33.9 are what I get.  Compare that to the ~50 ohms for my HE-560s.  At that low rating, I decided to see if my li'l JDS Labs C5 portable amp could drive the HE-500s.  I tried it with a previous pair (the first, I think, which I never measured), and it was partial success.  Some things didn't clip - hot masters, I reckon - while others couldn't get loud enough to enjoy without clipping.  While I've only tested one song thus far, the C5 drove them very well, not just from a volume perspective, but quality, which that little amp definitely has.  Sadly, the HE-500s still aren't really portable 

Then I plugged in the 50-ohm HE-560s.... annnnnd quickly took them off.  It just wasn't on, which was predictable.  With the volume max'd on high gain, I could barely hear it.  OK, not that bad, but nowhere near enough power.  I know HFM products vary widely, and even within a particular model, but didn't they say the HE-560s would be easier to drive?  Maybe I'm not remembering that correctly.  Thankfully, my Lyr packs more than enough quality power to make those babies sing.

So, while I'm not recommending the C5 for the HE-500s, esp. considering my earlier tests, it'll certainly do in a pinch, if your HE-500s have a relative lower resistance.

Interesting to note. A touring HE-560 unit will be making its way to me in the upcoming weeks, so I'll be sure to give those a try with the C5D as well.

HiFiMAN rates the HE-560 at 90 db/mW, which is slightly more efficient than the HE-500. I usually calculate power ratings at 90 dB SPL RMS and + 15 dB SPL for any peaks with average dynamic music (I accounted for music with a dynamic range rating of DR15 in this case), for a total of 105 dB SPL. The C5D can output 1.182 VRMS at 32 Ω, or 43.5 mW. The HE-560 requires 32 mW at 50 Ω to reach the 105 dB peaks, so the C5D is cutting it pretty close.

Actually, I have this post bookmarked.
http://www.head-fi.org/t/647838/jds-labs-c5-c5d-pg96-portable-amp-amp-dac-appreciation-discussion-thread/450#post_9233131

It looks like the C5 can approximately output 50 mW into a 50 Ω load, so it should be sufficient for the HE-560 at a fairly loud volume level (90 dB SPL RMS is pretty loud for listening to music).

 

[ThurstonX]

Interesting to note. A touring HE-560 unit will be making its way to me in the upcoming weeks, so I'll be sure to give those a try with the C5D as well.

HiFiMAN rates the HE-560 at 90 db/mW, which is slightly more efficient than the HE-500. I usually calculate power ratings at 90 dB SPL RMS and + 15 dB SPL for any peaks with average dynamic music (I accounted for music with a dynamic range rating of DR15 in this case), for a total of 105 dB SPL. The C5D can output 1.182 VRMS at 32 Ω, or 43.5 mW. The HE-560 requires 32 mW at 50 Ω to reach the 105 dB peaks, so the C5D is cutting it pretty close.

Actually, I have this post bookmarked.
http://www.head-fi.org/t/647838/jds-labs-c5-c5d-pg96-portable-amp-amp-dac-appreciation-discussion-thread/450#post_9233131

It looks like the C5 can approximately output 50 mW into a 50 Ω load, so it should be sufficient for the HE-560 at a fairly loud volume level (90 dB SPL RMS is pretty loud for listening to music).

 
Given my results, I'm very interested to hear about your results.  The resistance seems to play a big part in it.  If you remember to, measure the drivers using a DMM and post the numbers when you post your general results/impressions.

 

[miceblue]

Given my results, I'm very interested to hear about your results.  The resistance seems to play a big part in it.  If you remember to, measure the drivers using a DMM and post the numbers when you post your general results/impressions.

How does one measure the drivers' impedance?

 

[PFULMTL]

Anybody experiencing audio dropouts with his JDS Labs C5D amp/DAC?
I have had from the first moment although I have maxed the PC performance. What a shame, I thought this would be a solid piece of gear, but seems not to work very well.
So I get audio dropouts by just scrolling a web page. DPC latency is generally <<500 us but occationally jumps higher.
My PC is a Lenovo X240 laptop with i5 @1.9 GHz.

Any pointers, please?

Plug it into another available USB port. I had that problem when plugged into the rear, but it is gone when plugged into the side port.

 

[mark5hs]

I'm almost sold on the C5D. Is it worth the extra cost over FiiO E17/18?

 

[ThurstonX]

How does one measure the drivers' impedance?

A Digital Multi-meter (DMM) set to measure resistance.  Black (COM) probe on the Sleeve portion of the TRS plug, then the red probe to Tip and Ring.  No biggie if you don't have a DMM, but it's a good investment at $7.

 

[miceblue]

I'm almost sold on the C5D. Is it worth the extra cost over FiiO E17/18?

I haven't tried the E18, but I much prefer the C5D over my friend's E17 when I listened to it. The C5D sounds much more airy and transparent in comparison.

How does one measure the drivers' impedance?

A Digital Multi-meter (DMM) set to measure resistance.  Black (COM) probe on the Sleeve portion of the TRS plug, then the red probe to Tip and Ring.  No biggie if you don't have a DMM, but it's a good investment at $7.

Oh that's all you need to do? That's pretty simple to do then. : D
I though you meant measure directly across the wires on the driver as opposed to the cable.

 

[PFULMTL]

This is my portable setup that I bring with my laptop. I need the tablet for work to multitask, and don't even bother bringing my phone.  Don't want to use the laptop for music since it lasts less than 5 hours.
The DAC sounds much better this way than when plugged into the laptop or even desktop.
I need a cable like this, but shorter http://www.ubersignal.com/micro-usb-to-mini-usb-charging-cable-for-wilson-sleek-859967.html

 

[mark5hs]

OK I think I'll get the c5d! Thanks!

 

[Chickamauga]

C5D or Ibasso D42? Thoughts? Experiences? 

 

[WilliamLeonhart]

Has anyone do a a/b comparison between C5D and O2/ODAC too? The difference in price is quite a lot.
Oh and is it worth it to upgrade from C412 to C5 (I have Grados only)? I used to have the C421 and still remember it fondly. 

 

[Nicolas L]

  Has anyone do a a/b comparison between C5D and O2/ODAC too? The difference in price is quite a lot.
Oh and is it worth it to upgrade from C412 to C5 (I have Grados only)? I used to have the C421 and still remember it fondly. 

 
Oooh, finally a question that I'm able to answer, since I've auditioned both the C5, C5D and O2/ODAC with the HD598s. In my opinion, I prefer the O2/ODAC, since it's able to take advantage of the 598's open design for the sound stage, and for complicated pieces such as Sultans of Swing, the instrument separation and clarity is superior than the C5D. On the other hand, the C5D's sound signature is towards the 'dark' side, which personally I'm not a fan of, but I do admit, the light bass boost is sometimes fun for pieces by Daft Punk and Eagles. The high-bass boost is simply not my cup of tea and gives me migraines when I use it. 
 
Feel free to ask more questions!