[miceblue]

there is no differences of the output impedance between the C5 & C5D any more ..... and they share now the same 3 position bass boost 

Nice- so ultimately both c5d and the (new) c5 would sound similar?

I say (new) C5 as I had the first generation 2.2 output impedance one with only one bass switch. I sent my C5 to JDS labs for them to add the stepped bass to it. I'm very curious on what the new C5 would sound with my dunu dn-2000s. I'd assume the extra output impedance of the first generation c5 would contribute a bit to its brightness (despite the 16ohm impedance rating it had.) would the lower output impedance of the new C5 remove this brightness (which I do like to an extent)?

Usually the load impedance/output impedance ratio affects the damping factor, which usually contributes to bass control. From my own A/B sessions with the 1st generation C5 and the C5D, the C5D's bass response is a little more extended. The difference isn't huge though, so you're not missing out on much.

 

[canikickit1]

Usually the load impedance/output impedance ratio affects the damping factor, which usually contributes to bass control. From my own A/B sessions with the 1st generation C5 and the C5D, the C5D's bass response is a little more extended. The difference isn't huge though, so you're not missing out on much.

Thanks-
 
Are there things the 1st generation C5 does better than the C5D or vice versa? Or its ultimately the same?

 

[miceblue]

Usually the load impedance/output impedance ratio affects the damping factor, which usually contributes to bass control. From my own A/B sessions with the 1st generation C5 and the C5D, the C5D's bass response is a little more extended. The difference isn't huge though, so you're not missing out on much.

Thanks-

Are there things the 1st generation C5 does better than the C5D or vice versa? Or its ultimately the same?

The only advantage the C5 has over the C5D is a longer battery life (and the price if that's considered, though one has a DAC while the other doesn't). I still have to do the C5D's battery test with the DAC power set to low instead of high, but jseaber replied to an e-mail and said the C5D's battery life as just an "amp" still doesn't have the same battery life as the C5.

 

[Darner]

Hi, I don't have a C5, but am looking for one (used) and have a few questions:
 
* What does it mean that it's good for sensitive headphones? My headphones are Sony 7520's, which really don't require an amp, but I like the way they sound better with one. I use a PA2V2 from an iPod Nano 5th with a Fiio LOD, but can only use a very small portion of the volume dial on the PA2V2 (maybe 20%) before it's too loud. Essentially it seems there is to much power in the PA2V2 for what I'm using it for. This is even with the gain screws on the inside of the PA2V2 set to their lowest settings. Is this the kind of situation the C5 would do better in (aside from being a better amp in general)? Is that what is meant by being good for sensitive cans?
 
* Also, I've read the C5 has no (or much less) channel imbalances at very low volumes. Is this true?
 
* Lastly, I like the idea of being able to program the volume pot to be able to use more of its physical range, given the above-mentioned use scenario. But I don't want to have to invest in the interface and do the soldering, etc (plus the learning curve). Is it possible to have this done free of charge by JDS if I get it second-hand, and would it be necessary? I don't mind maxing out my listening levels with volume at say 50%, but it seems silly to only be able to turn the knob up to 20%, as now. Thoughts?
 
Thank you for any responses! It seems like a great amp.

 

[miceblue]

Hi, I don't have a C5, but am looking for one (used) and have a few questions:

* What does it mean that it's good for sensitive headphones? My headphones are Sony 7520's, which really don't require an amp, but I like the way they sound better with one. I use a PA2V2 from an iPod Nano 5th with a Fiio LOD, but can only use a very small portion of the volume dial on the PA2V2 (maybe 20%) before it's too loud. Essentially it seems there is to much power in the PA2V2 for what I'm using it for. This is even with the gain screws on the inside of the PA2V2 set to their lowest settings. Is this the kind of situation the C5 would do better in (aside from being a better amp in general)? Is that what is meant by being good for sensitive cans?

* Also, I've read the C5 has no (or much less) channel imbalances at very low volumes. Is this true?

* Lastly, I like the idea of being able to program the volume pot to be able to use more of its physical range, given the above-mentioned use scenario. But I don't want to have to invest in the interface and do the soldering, etc (plus the learning curve). Is it possible to have this done free of charge by JDS if I get it second-hand, and would it be necessary? I don't mind maxing out my listening levels with volume at say 50%, but it seems silly to only be able to turn the knob up to 20%, as now. Thoughts?

Thank you for any responses! It seems like a great amp.

* Many headphone amplifiers have large digital volume steps, which makes the volume jump too much for headphones with high sensitivity (basically a change in volume from a given change in voltage; a sensitive headphone will have a large change in volume from a small change in voltage). Likewise, many headphone amplifiers have a channel imbalance region that makes the left or right channels at different volume levels and you would need to increase the volume knob past this region to get the right channel balance (which makes the volume much louder with sensitive headphones). The C5 was meant to help alleviate both of these issues, but I'm not too familiar with the PA2V2 to give you an accurate comparison.

* As just mentioned, the C5 was meant to reduce or eliminate the channel imbalance at low volume levels. JDS Labs actually measured the imbalance here:
http://blog.jdslabs.com/?p=464


* Regarding programming, the digital potentiometer has 63 total steps including the mute step. With simple programming logic (e.g. if attenuation_volume > 31, attenuation_volume = 31), you can probably set a limit for the volume to not increase after 50% of the steps. You should probably contact JDS Labs about that though (contact@jdslabs.com).





[rule]
My C5D review is published now:
http://www.head-fi.org/products/jds-labs-c5d/reviews/10898

 

[Darner]

  ... basically a change in volume from a given change in voltage .... the digital potentiometer has 63 total steps including the mute step. With simple programming logic (e.g. if attenuation_volume > 31, attenuation_volume = 31), you can probably set a limit for the volume to not increase after 50% of the steps. You should probably contact JDS Labs about that though (contact@jdslabs.com).

Thanks for the helpful reply, and the review link too.
 
From this, then, I understand that the 63 steps are absolute (or fixed), and so it's not like you can program it so that the voltage range [ 1 : 62 ] is altered from being [ voltage x : voltage y ] to being [ voltage x/n : voltage y/n ]. Like (attenuation_volume = attenuation_volume / 2)? But setting an absolute limit (if av>31 then av=31) might accomplish the same goal, except that the perceived rate of volume change would be the same as before.
 
I'm at the limits of my technical capacity here, so does this sound right?
 
P.S. Ah, another question: so the volume mechanism is a dial that works like a rocker does, correct? And it doesn't make clicking noises, does it?

 

[miceblue]

  ... basically a change in volume from a given change in voltage .... the digital potentiometer has 63 total steps including the mute step. With simple programming logic (e.g. if attenuation_volume > 31, attenuation_volume = 31), you can probably set a limit for the volume to not increase after 50% of the steps. You should probably contact JDS Labs about that though (contact@jdslabs.com).

Thanks for the helpful reply, and the review link too.

From this, then, I understand that the 63 steps are absolute (or fixed), and so it's not like you can program it so that the voltage range [ 1 : 62 ] is altered from being [ voltage x : voltage y ] to being [ voltage x/n : voltage y/n ]. Like (attenuation_volume = attenuation_volume / 2)? But setting an absolute limit (if av>31 then av=31) might accomplish the same goal, except that the perceived rate of volume change would be the same as before.

I'm at the limits of my technical capacity here, so does this sound right?

P.S. Ah, another question: so the volume mechanism is a dial that works like a rocker does, correct? And it doesn't make clicking noises, does it?

Yes, the steps have a fixed change in voltage that can't be programmed, but the maximum volume limit can be set I believe.

The potentiometer itself is a rocker/swivel (you can move it to the left and right about 45˚ and you can push it in as a button) rather than a dial, and it doesn't make any noise (it's a smooth swiveling action). It springs back to the middle/neutral position when left alone and from that, a "teek" sound can be heard.

 

[r010159]

I just realize what is missing in the C5D. A battery level indicator. Right now I am using it not knowing how much battery is left. For that matter, I do not think discharging the battery to empty is good for the battery.

 

[ThurstonX]

I just realize what is missing in the C5D. A battery level indicator. Right now I am using it not knowing how much battery is left. For that matter, I do not think discharging the battery to empty is good for the battery.

 
I wonder if it flashes at near empty (5-10 min. remaining?), like the C5 does.  Can't believe JDS would overlook that.

 

[jseaber]

   
I wonder if it flashes at near empty (5-10 min. remaining?), like the C5 does.  Can't believe JDS would overlook that.

 
The LED flashes while the battery is low, typically < 30 minutes remaining.

 

[r010159]

John has been helping me with various problems I thought I was having with both my O2 and C5D. The O2 turned out to be a bug in the music player I have been using. The C5D problem turned out to be how the headphone plug was sitting in the jack improperly. This seems to be the fault of the headphone plug. Due to its shape, it does not fit solidly in the jack. But another pair of headphones does.

Once again, the O2 and C5D prevailed with good direction by John of JDS Labs.

 

[ostewart]

Updated 1st post with a bit of a C5D review

 

[maricius]

Can anyone compare an iPod Video 5.5g with the C5 with the C5D (as an amp/DAC) in terms of sound signature and overall resolution? From what I'm reading, the C5 (although not by a large difference) is a better amp than that attached to the C5D. However, I'm curious if the iPod's DAC is at least comparable to that of the C5D. Thanks!!
 
Clarification*: the comparison is between an iPod Video 5.5g/C5 (via LOD) combo vs C5D (as USB DAC AND amplifier)

 

[r010159]

  Can anyone compare an iPod Video 5.5g with the C5 with the C5D (as an amp/DAC) in terms of sound signature and overall resolution? From what I'm reading, the C5 (although not by a large difference) is a better amp than that attached to the C5D. However, I'm curious if the iPod's DAC is at least comparable to that of the C5D. Thanks!!

 
The iPod will not be able to drive many headphones. It does not drive my 250-ohm DT880s well at all. I have read that the DAC on the iPod is good, relatively speaking. So I imaging it is good with earphones. I find the C5D to be a good performer, but a tad lower in SQ compared to the O2/ODAC for instance.
 
Bob

 

[maricius]

   
The iPod will not be able to drive many headphones. It does not drive my 250-ohm DT880s well at all. I have read that the DAC on the iPod is good, relatively speaking. So I imaging it is good with earphones. I find the C5D to be a good performer, but a tad lower in SQ compared to the O2/ODAC for instance.
 
Bob

 
Thanks for the quick reply!! I believe the phrasing of my question wasn't clear enough. I meant the iPod's line-out to a C5 compared to the C5D as a whole. I'm looking for another external amp for the iPod (right now it's stuck to a Fiio E11) as the Duet is rather large and the onboard amp of the iPod Video is recognized to be its bottleneck. If the C5D amp/DAC combo is better than the iPod/C5 combo, I'd get the C5D and just use an Apple CCK with my phone.