Head-Fi.org › Forums › Equipment Forums › Portable Headphone Amps › JDS Labs C5 portable amplifier appreciation + discussion thread (check 1st post for review)
New Posts  All Forums:Forum Nav:

JDS Labs C5 portable amplifier appreciation + discussion thread (check 1st post for review) - Page 20

post #286 of 1016
2/23/13 at 12:10pm
Quote:
Originally Posted by miceblue View Post

It is strange, but from JDS Lab's C5 blog post:

Looking more closely at the press release photos, all of the C5's have the switch in the up position.

 

The switch position was a choice of performance over aesthetic intuition. I wanted bass boost Up, and normal audio Down also, but that analog path used the longer set of legs on the switch. It's important to keep pathways short in this section of circuitry.


Quote:
Originally Posted by randomkid View Post

Bass boost is hardware from what I know

 

Correct. A switch also yields greatest performance. We did two prototypes with digital pots in place of the toggle switch, but there's no true "off" state. The wiper presents a small amount of resistance even at minimal position. Thus, bass boost could never truly be turned off in the chosen circuit, and you'd experience an extremely small amount of phase and frequency response manipulation. So we went back to a DPDT toggle to control bass boost.

 

We released firmware source code for the benefit of the DIY community. It's not intended to manipulate SQ.

 

 

Quote:
Originally Posted by Bananaheadlin View Post

Are all other JDS products shipping prolonged due to the preorder queue of the new C5?

 

No way! We stay on top of incoming orders. All in-stock orders placed through Friday afternoon have already shipped.

 

25% of C5 preorders have also shipped by now. The remaining 75% will be fully tested and ready to ship as soon as the second round of cases come back from the anodizer (Wednesday).

JDS Labs Insider
» Get the latest news and updates at the JDS Labs sponsor page.
Reply

Head-Fi's Best Sellers

post #287 of 1016
2/23/13 at 3:53pm
Quote:
Originally Posted by jseaber View Post

Quote:
Originally Posted by miceblue View Post

It is strange, but from JDS Lab's C5 blog post:

Looking more closely at the press release photos, all of the C5's have the switch in the up position.

 

The switch position was a choice of performance over aesthetic intuition. I wanted bass boost Up, and normal audio Down also, but that analog path used the longer set of legs on the switch. It's important to keep pathways short in this section of circuitry.


Quote:
Originally Posted by randomkid View Post

Bass boost is hardware from what I know

 

Correct. A switch also yields greatest performance. We did two prototypes with digital pots in place of the toggle switch, but there's no true "off" state. The wiper presents a small amount of resistance even at minimal position. Thus, bass boost could never truly be turned off in the chosen circuit, and you'd experience an extremely small amount of phase and frequency response manipulation. So we went back to a DPDT toggle to control bass boost.

 

We released firmware source code for the benefit of the DIY community. It's not intended to manipulate SQ.

Sounds great! It's cool to hear that you did try it out, but opted out for performance instead of aesthetics.

 

As for re-programming the C5, on the blog it mentions that a 6-pin header and an ISP programmer are needed. The SparkFun webpage that is linked mentions that the 6-pin cable is included with the ISP programmer. I haven't used Arduino before (first time learning experience! :) ), so I'm wondering how does one connect the C5 to the Arduino? I can't really tell from the photo on the blog how it's connected.

Reply
post #288 of 1016
2/23/13 at 3:57pm

It starts to get weird when people are concerning which direction of the switch is bass boost or not :p

Reply
post #289 of 1016
2/23/13 at 8:02pm
Quote:
Originally Posted by ClieOS View Post

It starts to get weird when people are concerning which direction of the switch is bass boost or not tongue.gif

Yeah, we're not particular about things at all here at head-fi are we? ;-)
Reply
post #290 of 1016
2/23/13 at 8:15pm
Quote:
Originally Posted by miceblue View Post

Sounds great! It's cool to hear that you did try it out, but opted out for performance instead of aesthetics.

 

As for re-programming the C5, on the blog it mentions that a 6-pin header and an ISP programmer are needed. The SparkFun webpage that is linked mentions that the 6-pin cable is included with the ISP programmer. I haven't used Arduino before (first time learning experience! :) ), so I'm wondering how does one connect the C5 to the Arduino? I can't really tell from the photo on the blog how it's connected.

 

The 6-pin ISP header is unpopulated. See "JP1", near the bottom left corner of the battery:

 

 

Warning: Off-topic engineering... (Click to show)

 

There are two ways to interface an Atmega chip:

1) ISP, via 6-pin header

2) Serial pins, usually via FTDI (USB-to-serial bridge)

Atmega's latest AT90USB series microcontrollers have onboard USB support for direct programming via USB (no FTDI or ISP required). But, they dropped I2C support pins on the equivalent 16K microcontroller, and we need I2C to interface the digital potentiometers.

Since firmware should never need to be flashed on a C5 amp, we decided not to implement FTDI, as it would be a waste of money to most users.

The 6-pin ISP header had to be omitted on production units due to physical height. A standard 0.1in, 6-pin header simply will not fit in the C5 case. You can still solder in the header; pins can be slightly trimmed to fit. All well within the capabilities of a DIY'er.

 

JDS Labs Insider
» Get the latest news and updates at the JDS Labs sponsor page.
Reply
post #291 of 1016
2/23/13 at 8:40pm
Quote:
Originally Posted by jseaber View Post

Quote:
Originally Posted by miceblue View Post

Sounds great! It's cool to hear that you did try it out, but opted out for performance instead of aesthetics.

 

As for re-programming the C5, on the blog it mentions that a 6-pin header and an ISP programmer are needed. The SparkFun webpage that is linked mentions that the 6-pin cable is included with the ISP programmer. I haven't used Arduino before (first time learning experience! :) ), so I'm wondering how does one connect the C5 to the Arduino? I can't really tell from the photo on the blog how it's connected.

 

The 6-pin ISP header is unpopulated. See "JP1", near the bottom left corner of the battery:

 

 

Warning: Off-topic engineering... (Click to show)

 

There are two ways to interface an Atmega chip:

1) ISP, via 6-pin header

2) Serial pins, usually via FTDI (USB-to-serial bridge)

Atmega's latest AT90USB series microcontrollers have onboard USB support for direct programming via USB (no FTDI or ISP required). But, they dropped I2C support pins on the equivalent 16K microcontroller, and we need I2C to interface the digital potentiometers.

Since firmware should never need to be flashed on a C5 amp, we decided not to implement FTDI, as it would be a waste of money to most users.

The 6-pin ISP header had to be omitted on production units due to physical height. A standard 0.1in, 6-pin header simply will not fit in the C5 case. You can still solder in the header; pins can be slightly trimmed to fit. All well within the capabilities of a DIY'er.

 

Okay I see what you mean now. This sounds like a fun project; I haven't had to solder header pins before, but it looks doable. Thank you for the heads up!

Reply
post #292 of 1016
2/23/13 at 9:48pm
Quote:
Originally Posted by miceblue View Post

Okay I see what you mean now. This sounds like a fun project; I haven't had to solder header pins before, but it looks doable. Thank you for the heads up!

I recommend using an angled 6 pin header rather than straight up making for easier access due to the battery near jp1 and might even be able to fit in the case and might save you the trouble of cutting the pins(even if you do need to cut it up to fit the case it will be easier) since this is your attempt at doing it.
Reply
post #293 of 1016
2/24/13 at 6:59pm

Ordered mine via noisymotel, cant wait.

Reply
post #294 of 1016
2/25/13 at 12:33pm

Anxiously awaiting a comparison review between C5 and C421 w/ 8260 opamp before i can finalize my deision to buy or not.. The wallet will remain on lock down till then.biggrin.gif


Edited by 808Ronin - 2/25/13 at 12:36pm
Reply
post #295 of 1016
2/25/13 at 1:20pm
So, which color has bigger sound stage? Lol

The red is super hot, but the slate is nice and match my Ed.8 better... Hmm tough decision...
Reply
post #296 of 1016
2/25/13 at 1:40pm

The red sounds more intimate if that matters to you. The color may have a placebo on your perception to sound and the slate may well be sounding dark. wink_face.gif

Reply
post #297 of 1016
2/25/13 at 1:45pm
Quote:
Originally Posted by Vanquiz View Post

So, which color has bigger sound stage? Lol

The red is super hot, but the slate is nice and match my Ed.8 better... Hmm tough decision...


The red is more likely to get you tickets, where i hear the slate is rock-solid.  The gray is pretty neutral on things, though it was only implied by gray...

Reply
post #298 of 1016
2/25/13 at 3:10pm

The bass boost sounds pretty rockin' with the K 701, but way too much for a much bassier V-MODA Crossfade M-100 (although it does remind me of a live concert kind of bass).

The volume lever is really smooth, and I mean REALLY smooth. I'm still playing around with it. Having no channel imbalance at low listening levels is great for low-volume listeners such as myself.

The gain toggle takes some time to get used to since it's hard to push in, you have to push it right in the center, but it works well.

 

 

 

 

 

 

 

 

 

 


Edited by miceblue - 2/25/13 at 3:24pm
Reply
post #299 of 1016
2/25/13 at 3:31pm
Quote:
Originally Posted by miceblue View Post

The bass boost sounds pretty rockin' with the K 701, but way too much for a much bassier V-MODA Crossfade M-100 (although it does remind me of a live concert kind of bass).

The volume lever is really smooth, and I mean REALLY smooth. I'm still playing around with it. Having no channel imbalance at low listening levels is great for low-volume listeners such as myself.

The gain toggle takes some time to get used to since it's hard to push in, you have to push it right in the center, but it works well.

I am an image! :D (Click to show)

 

 

 

 

 

 

 

 

 

 

 

 

Red is definitely faster!  Miceblue has his already! :)  Mine is sitting at home waiting for me.  Guess who is clocking out early today?    /me points at himself

Reply
post #300 of 1016
2/25/13 at 3:43pm

Initial comparisons between the C5 and the O2, to me at least, the O2 has a larger soundstage with better instrument separation, the C5 has more bass (though I admit it is hard for me to properly volume match).

Reply
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Portable Headphone Amps

Head-Fi's Best Sellers

Head-Fi.org › Forums › Equipment Forums › Portable Headphone Amps › JDS Labs C5 portable amplifier appreciation + discussion thread (check 1st post for review)