JDS Labs C5/C5D (pg96) portable amp/amp+DAC
Apr 4, 2013 at 10:35 PM Post #811 of 3,417
Quote:
 
Bass boost of C5 is actually stronger. Neither amp's bass boost curve is centered at 80Hz; c421's "peak" was below 80Hz. You can find the curve on our release article.

 
John, how does 14dBu translate to dB?  I'm assuming it's the unloaded voltage measurement?  It would be cool to see a typical or "standard" dB graph.
 
Apr 4, 2013 at 10:39 PM Post #812 of 3,417
If that's right, and the c421 page is also correct in saying "
Bass Boost, +8dB peak"
, then that means the C5 bass boost is less aggressive than the C421's?  Is that right?  I quite like the bass boost on my c421, I leave it on almost all the time and rarely find it too powerful, so I'm not sure I'd like the 1.5dB reduction.  John, is the c421 centered at 80Hz as well?


EDIT:  replaced "dac" with "opamp" above.


Bass boost of C5 is actually stronger. Neither amp's bass boost curve is centered at 80Hz; c421's "peak" was below 80Hz. You can find the curve on our release article.


Hm if that's true, might I suggest updating the C5's description then? It can be deceiving. I pointed out that the bass boost wasn't centered at 80 Hz on the Facebook announcement post, nor is the bass boost at 80 Hz a +6.5 dB gain if I'm reading the graph correctly.

 
Apr 5, 2013 at 5:43 AM Post #813 of 3,417
Listening to Nirvana - In Utero (in remembrance of Kurt Cobain's death 19 years ago) through ODAC > C5 > Sunrise Audio Dragon2
 
sounds beautiful, really does Kurt's voice justice, aggressive and very very raw.
 
Apr 5, 2013 at 2:08 PM Post #814 of 3,417
Quote:
Hm if that's true, might I suggest updating the C5's description then? It can be deceiving. I pointed out that the bass boost wasn't centered at 80 Hz on the Facebook announcement post, nor is the bass boost at 80 Hz a +6.5 dB gain if I'm reading the graph correctly.


 
Bass boost is frequency dependent here, so the only way to further clarify is to plot the curve (either visually as we've done, or mathematically). A frequency dependent spec without a given point is useless. How would you clarify?
 
We'll post another bass plot in dB with our next update. There've been quite a few requests and I'd like to lump all of these numbers and curves into another article.
 
Apr 6, 2013 at 12:21 AM Post #815 of 3,417
Quote:
Quote:
Hm if that's true, might I suggest updating the C5's description then? It can be deceiving. I pointed out that the bass boost wasn't centered at 80 Hz on the Facebook announcement post, nor is the bass boost at 80 Hz a +6.5 dB gain if I'm reading the graph correctly.


 
Bass boost is frequency dependent here, so the only way to further clarify is to plot the curve (either visually as we've done, or mathematically). A frequency dependent spec without a given point is useless. How would you clarify?
 
We'll post another bass plot in dB with our next update. There've been quite a few requests and I'd like to lump all of these numbers and curves into another article.

Hm I see. I think it would be better to list the center frequency of the bass boost, and how much gain it has there, similar to what James of FiiO mentioned for the E12 amp.
 
 
 
Quote:
Originally Posted by jseaber /img/forum/go_quote.gif
 
Quote:
Agreed. +8db does seem like that's a lot of boost. Most people that would buy a amp at this price point would simply buy Sony XB700s if they wanted their headphones to sound like that
smily_headphones1.gif

 
Hope I didn't start this rumor! Bass boost is +6.5dB at 80Hz and diminishes from there.
 
We tried a 1-band bass EQ in an early prototype (64 steps), and I wasn't pleased. Everyone preferred the on/off switch. Mechanical switches perform best in measurements as well. This experiment gave us the opportunity to try as few or as many levels as we wanted. At +3dB/+6dB/+8dB, the go-to level was still around +6dB. Real-world users simply desired +0 or +6dB, so that's what we built.

^ from "diminishes from there", I was thinking the bass boost was centered at 80 Hz and there has a +6.5 dB gain at that frequency
 
Quote:
Bass boost of C5 is actually stronger. Neither amp's bass boost curve is centered at 80Hz; c421's "peak" was below 80Hz. You can find the curve on our release article.

^ from this, my initial impression that the bass boost is centered at 80 Hz was wrong and that the bass boost is actually higher than +6.5 dB somewhere.
 
Apr 6, 2013 at 3:04 AM Post #816 of 3,417
i am curious, has anyone had a chance to compare C5 to Tralucent T1?
 
Apr 7, 2013 at 8:38 PM Post #818 of 3,417
Quote:
Has anyone tried the C5 with the Soundmagic HP100?

Since the C5 is still a fairly new product, you're probably not going to find someone who has heard that specific pairing, yet.
 
My headphone impressions with the C5 are limited to the K 701, V-MODA M-100, and Shure SRH940, but my observations between the C5 and Objective 2 have all been pretty consistent with my previous statements:
  1. O2 gives the sense of a larger soundstage with more air between instruments; C5 sounds more boxed-in
  2. O2 sounds a bit more dynamic; C5 sounds a little duller (not boring dull, but instruments don't sound as "full")
  3. O2 has a smoother treble (I don't think smoother is the right word for this, nor is rolled-off, but it's not as fatiguing compared to the C5); C5 sounds a tad bit brighter
  4. C5 has a midrange that is is a tad bit more forward and engaging; O2 sounds more laid-back
^ those last two points are probably what the Headfonia review was talking about, maybe.
 
Apr 7, 2013 at 9:09 PM Post #819 of 3,417
I have both. The HP100 is one of my favorite cans right now, and sounds great with the c5, however it doesn't handle the bass boost so well. These cans have enough bass as it is so they can become overly exaggerated and bloaty with the c5 bass boost and electronica.

The FA011 handles the c5's boost more naturally. I prefer the HP100 on the WA7, but prefer the FA011 (with boost) on the C5, and the HP100 (no boost) on the C5.

Confusing I know, but hopefully helpful. Happy to answer any other specific questions.
 
Apr 7, 2013 at 9:20 PM Post #820 of 3,417
Quote:
Thanks a lot for the response.
smily_headphones1.gif


If I remember correctly, John's calculations assumed a sensitivity of >100 dB. The DT880/250 is less efficient at 96 dB. And from what I understood, the sensitivity plays a major role in the amp's ability to perform with a particular pair of headphones. From what I've read in this thread, the HD800, although having a higher impedance of 300 ohms, has a higher sensitivity of >100 dB.

So, this sensitivity issue is what has me worried about the capability of this amp to perform well with the DT880/250. It would be great if someone who has experience with the combo can chime in.

 
Can anyone elaborate on the sensitivity issue of the DT 880s in the context of the C5?
 
 
My transportable rig is: laptop --> ODAC -->line OUT / Line IN  --> O2 --> DT 880 (250 Ohm; 2005 Edition)
I'm very happy with the ODAC and O2 as two separates, but I want to explore more (under $300).
 
I am considering the Meridian Explorer, UHA-6S MKII, DACport LX (dac only), and of course
tongue_smile.gif
 the C5.
 
Apr 7, 2013 at 9:55 PM Post #821 of 3,417
Quote:
Quote:
Thanks a lot for the response.
smily_headphones1.gif


If I remember correctly, John's calculations assumed a sensitivity of >100 dB. The DT880/250 is less efficient at 96 dB. And from what I understood, the sensitivity plays a major role in the amp's ability to perform with a particular pair of headphones. From what I've read in this thread, the HD800, although having a higher impedance of 300 ohms, has a higher sensitivity of >100 dB.

So, this sensitivity issue is what has me worried about the capability of this amp to perform well with the DT880/250. It would be great if someone who has experience with the combo can chime in.

 
Can anyone elaborate on the sensitivity issue of the DT 880s in the context of the C5?
 
 
My transportable rig is: laptop --> ODAC -->line OUT / Line IN  --> O2 --> DT 880 (250 Ohm; 2005 Edition)
I'm very happy with the ODAC and O2 as two separates, but I want to explore more (under $300).
 
I am considering the Meridian Explorer, UHA-6S MKII, DACport LX (dac only), and of course
tongue_smile.gif
 the C5.

Ah, I've heard a lot of good things about the UHA-6S MKII, another worthy competitor to the O2 from what I've read. Unfortunately I don't know too much about the DT880. It seems like the DT880 and K 701 have their issues with their "age over time". People are so often confused between newer and older models that it makes reading reviews, and recommendations difficult. I've had my share of confusions between the 7-bump K 701, 8-bump K 701, K 702, Q 701, and K 702 65th Anniversary Edition.... -.-''
 
Quote:
I have both. The HP100 is one of my favorite cans right now, and sounds great with the c5, however it doesn't handle the bass boost so well. These cans have enough bass as it is so they can become overly exaggerated and bloaty with the c5 bass boost and electronica.

The FA011 handles the c5's boost more naturally. I prefer the HP100 on the WA7, but prefer the FA011 (with boost) on the C5, and the HP100 (no boost) on the C5.

Confusing I know, but hopefully helpful. Happy to answer any other specific questions.

Ah, even better then.
 
Yeah the bass boost is a hit or miss depending on personal preferences and headphones. I don't recall reading such experiences with the CMoyBB oddly enough.
 
Apr 7, 2013 at 10:40 PM Post #822 of 3,417
Quote:
 
Can anyone elaborate on the sensitivity issue of the DT 880s in the context of the C5?
 
 
My transportable rig is: laptop --> ODAC -->line OUT / Line IN  --> O2 --> DT 880 (250 Ohm; 2005 Edition)
I'm very happy with the ODAC and O2 as two separates, but I want to explore more (under $300).

 
I have the same O2 and ODAC you do. And the C5.
 
I'm getting an AudioQuest DragonFly and an HRT microStreamer in the next week or two and will try to do a test between them all (ODAC/O2, ODAC/C5, and then the DragonFly and the microStreamer.)
 
The DragonFly and the microStreamer are both below $300 and should be in your considerations.
 
Apr 7, 2013 at 10:55 PM Post #823 of 3,417
you know what would be great if they revised O2 and made it with the same shape format as the C5. What is stopping me from carrying O2 around is the odd placement of the volume knob.
 
Apr 7, 2013 at 10:59 PM Post #824 of 3,417
Quote:
you know what would be great if they revised O2 and made it with the same shape format as the C5. What is stopping me from carrying O2 around is the odd placement of the volume knob.

But that is precisely why I like the C5, hahaha. It has a very pocket-friendly interface. The important things are where they should be, in my opinion. One improvement I have for the C5 is that the potentiometer stick out a little more since I find it hard to adjust in my pocket sometimes (or maybe it's just due to my long fingernails....). Once I do get access to the potentiometer on the other hand, volume and gain adjustments are really smooth.
 
And to bring this up again, another improvement would be a gain toggle LED indicator.
 
Apr 7, 2013 at 11:42 PM Post #825 of 3,417
As much as I like the digital volume control on C5 I do like a large volume knob. I dont listen to music that low and I never had balance problem with any of my amp.
As far as the gain goes I was wondering would it be possible to have a three gains setting progammed on C5?
Quote:
But that is precisely why I like the C5, hahaha. It has a very pocket-friendly interface. The important things are where they should be, in my opinion. One improvement I have for the C5 is that the potentiometer stick out a little more since I find it hard to adjust in my pocket sometimes (or maybe it's just due to my long fingernails....). Once I do get access to the potentiometer on the other hand, volume and gain adjustments are really smooth.
 
And to bring this up again, another improvement would be a gain toggle LED indicator.

 

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