[miceblue]

Any plans to allow users to update firmware of their C5D or does it have to be sent back?

Technically users can update the firmware. You need to solder-in some header-pins, or something similar, and have an ISP programmer circuit.

I can't find my soldering iron and silver solder, so I haven't had a chance to get the C5D hooked up to my computer, but I did exactly the same thing for the C5 as explained in my review.
http://www.head-fi.org/products/jds-labs-c5-headphone-amplifier/reviews/9198

 

[AzrinRain]

   
All correct!
 
That firmware should not have shipped, by the way. I'll inform our production staff to ensure it doesn't happen again with the remaining C5Ds in this batch. It's a minor inconvenience, so let me know if you'd like to exchange it.
 
Edit: For those interested, the behavior Vemon and dbdynsty25 have described is firmware dated December 13th, v1.1.0. The final C5D code was published on December 14th, v1.2.0. The current shipping batch of C5D is machine assembled with v1.1.0 code, and we're manually loading code v1.2.0 at JDS Labs. It seems that someone in production had a mixup while loading code. Fortunately, this is a minor usage tweak. We'll double check inventory on Monday.

 
Ah! That explains why my bass boost switch is being funny. Thanks for the clarification, John!

 

[jseaber]

  Any plans to allow users to update firmware of their C5D or does it have to be sent back?

 
Yes, this has always been possible if you happen to have an Arduino programmer. Code and instructions are published on Github:
https://github.com/jdslabs/C5D_Firmware
 
No further firmware updates are planned. Since this update is limited to a handful of users, I'm sure we could ship loaner programmers to anyone interested.
 

Technically users can update the firmware. You need to solder-in some header-pins, or something similar, and have an ISP programmer circuit.

I can't find my soldering iron and silver solder, so I haven't had a chance to get the C5D hooked up to my computer, but I did exactly the same thing for the C5 as explained in my review.
http://www.head-fi.org/products/jds-labs-c5-headphone-amplifier/reviews/9198

 
It's no longer necessary to solder; we use spring loaded pins instead. The process takes about 10 seconds total.
 

   
Ah! That explains why my bass boost switch is being funny. Thanks for the clarification, John!

 
What do you mean? Bass boost is entirely mechanical and unrelated to firmware.

 

[AzrinRain]

What do you mean? Bass boost is entirely mechanical and unrelated to firmware.

John, based by the way @Vemon's question was answered, i had the impression it was.
Was the bass boost intentionally configured that way (low>high>mid), or was it supposed to be naturally progressive (low>mid>high)?

 

[jseaber]

John, based by the way @Vemon's question was answered, i had the impression it was.
Was the bass boost intentionally configured that way (low>high>mid), or was it supposed to be naturally progressive (low>mid>high)?

 
Vernon correctly described the bass boost switch. It's wired this way to achieve maximum performance, rather than maximum intuitiveness. Please see here for further confirmation:
http://www.jdslabs.com/pdf/Instructions_C5D.pdf

 

[teohouse88]

which headphone impedance the C5D can drive up to?? (100,200,300 ohm)
Is the C5D able to drive a Beyerdynamic DT880 Pro 250 Ohm?

 

[AladdinSane]

Possible to add the additional bass boost increment to an older C5?

 

[jseaber]

  which headphone impedance the C5D can drive up to?? (100,200,300 ohm)
Is the C5D able to drive a Beyerdynamic DT880 Pro 250 Ohm?

 
There's no exact answer to this question. It's possible to drive any headphone impedance with any amp. Maximum output volume depends on headphone's sensitivity and the output power of the amp at a specific impedance. Example:
 
DT-880 Pros have sensitivity of 96 db/mW @ 250 ohms, so they need < 40 mW to exceed 110dB output. C5D can deliver more than 40 mW into 250 ohms, so this is a reasonable match.
 

Possible to add the additional bass boost increment to an older C5?

 
Yes, the switch can be upgraded for the cost of parts + shipping. These switches are backordered until next month. 

 

[chengsta]

Has anyone here paired this amp (bass boost max) with the new jh roxanne?  I know its a bit early, but I'm hopeful.

 

[zeppu08]

Does anyone here tried this combo..

iPod classic 7th gen + c5d

How does the SQ of the DAC part change? Stock vs C5D dac..

And how does as a whole goes?

Thank you!

 

[ostewart]

You cannot use the DAC part with an iPod classic. But just the amp section. So you're better if getting just the C5. Using the classic with it sounds great. Very flat and neutral.

 

[zeppu08]

You cannot use the DAC part with an iPod classic. But just the amp section. So you're better if getting just the C5. Using the classic with it sounds great. Very flat and neutral.

Ohh. Really I thought the ipod 7th gen is bypassable? Or just the c5d is not compatible for the ipod to bypass it? Sorry im new in using dacs.. ^_^

 

[Varoudis]

Ohh. Really I thought the ipod 7th gen is bypassable? Or just the c5d is not compatible for the ipod to bypass it? Sorry im new in using dacs.. ^_^

Not compatible, but sounds amazing! As an amp

 

[zeppu08]

Not compatible, but sounds amazing! As an amp

Ah. Now i get it! Thanks for the feedback!

 

[Zorander]

HI,

I just noticed this thread in my search for a DAC/Amp combo for my Samsung Note 2. How does it match with the AT CK100Pro? Also, I am using the Neutron MP player; is there any issue between this software and the C5D?

Thanks.