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post #16861 of 27693
Quote:
Originally Posted by JamieMcC View Post
 

 

If you do a google image search "270 ohm 5w resistor" you will see both types they do the same thing just transfer the heat generated differently. 

 

Four white cement ones are used in the standard Crack when the speedball upgrade is add two are removed and two large heat sinks are used instead.

 

The gold ones are wire wound but in=cased in alloy to transmit the heat to the case. Crack case is open underneath with vent in the top plate for air circulation. 

 

Here's a pic of a standard Crack and then with speedball note the extra circuitry and the two large black heatsinks which replace the two long white cement resistors shown in the lower half of the first pic.

 

                

 

Thanks very much for explaining the resistors and heat vent.

 

BTW, I saw some pictures of your crack with speedball...very neat and nice. Wondering how the holes were cut on the carbon fiber around the vent?

 

I am also quite curious to know how the huge capacitors and the resistor cylinder that you added can improve the Crack with speedball? What do they do?

 

Carbon Fiber

 

Large Capacitors and Resistor Cylinder

post #16862 of 27693
Quote:
Originally Posted by cddc View Post
 

 

Thanks very much for explaining the resistors and heat vent.

 

BTW, I saw some pictures of your crack with speedball...very neat and nice. Wondering how the holes were cut on the carbon fiber around the vent?

 

I am also quite curious to know how the huge capacitors and the resistor cylinder that you added can improve the Crack with speedball? What do they do?

 

Carbon Fiber

 

Large Capacitors and Resistor Cylinder

 

I used a dremel with different attachments to cut out the slots and holes in the carbon using the holes in the alloy top plate which is stuck to it as a guide.

 

The capacitors can have quiet a effect on the sound, generally speaking for this application the higher the quality of capacitor the easier it is for the audio frequencies to pass through with the least amount of degradation to them, hopefully resulting in a truer more detailed sound. The difference is kind off like looking through a clean window compared to a dirty one. You get a clearer sonic picture.

 

The two small capacitors are Valab polypropylene in oil film capacitors 47uf each and the larger one on top is a high quality 10uf RTI Teflon capacitor which is used as a bypass for the two 47uf film ones.  These replace the stock electrolytic coupling capacitors.

 

The resistor cylinder is a 23 stepped attenuator (volume control) simply it again provides a shorter less resistive path for the signal to travel, less resistance means more details get through.

 

There are more details on the mods in the link

 

http://bottlehead.com/smf/index.php/topic,5284.0.html


Edited by JamieMcC - 4/13/14 at 5:11pm
post #16863 of 27693
Quote:
Originally Posted by JamieMcC View Post
 

 

I used a dremel with different attachments to cut out the slots and holes in the carbon using the holes in the alloy top plate which is stuck to it as a guide.

 

The capacitors can have quiet a effect on the sound, generally speaking for this application the higher the quality of capacitor the easier it is for the audio frequencies to pass through with the least amount of degradation to them, hopefully resulting in a truer more detailed sound. The difference is kind off like looking through a clean window compared to a dirty one. You get a clearer sonic picture.

 

The two small capacitors are Valab polypropylene in oil film capacitors 47uf each and the larger one on top is a high quality 10uf RTI Teflon capacitor which is used as a bypass for the two 47uf film ones.  These replace the stock electrolytic coupling capacitors.

 

The resistor cylinder is a 23 stepped attenuator (volume control) simply it again provides a shorter less resistive path for the signal to travel, less resistance means more details get through.

 

There are more details on the mods in the link

 

http://bottlehead.com/smf/index.php/topic,5284.0.html

 

Thank you very much for the introduction of capacitors and stepped attenuator! Checked the link...it was like holy smoke...Fantastic modding! And thanks a lot for sharing.

 

It seems lots of fun modding the Crack with Speedball, not to mention the additional fun from tube rolling. Planning to get one :beyersmile:

post #16864 of 27693
Quote:
Originally Posted by JamieMcC View Post

... simply it again provides a shorter less resistive path for the signal to travel, less resistance means more details get through.

 

?

post #16865 of 27693
Quote:
Originally Posted by connieflyer View Post
 

I would not worry about the essence, it can do a really nice job with the 650's.  I have the stx version , same thing really, and used it with the 650's for two years before upgrading to a Garage 1217 Ember amp last year.  It was a very nice upgrade, I had been looking at outboard dacs, but the specs are not much better uptil you hit close to $8 or $900.00.  The specs on the dac for the essence series is right up there with the better dacs.  Use what you have in the essence until the fever hits you at the same time as your wallet is flush with cash, and then look into an amp.  Check this link for the essence........http://www.tomshardware.co.uk/high-end-pc-audio,review-32894-5.html....the whole article......http://www.tomshardware.co.uk/high-end-pc-audio,review-32894.html.  When I am not using the Ember, I use optical out to a Harman Kardon avr 510 to Electro Voice Sentry V speakers and it sounds really great.  You may need a better amp than what you are using to drive speakers, but the onboard Dac is really quite good.

 

Thanks for your response. I will be using the built in amp of the essence for a long while as i'm spending the entire budget on the HD650. If i decide to upgrade the amp in the future i heard the Matrix M-Stage HPA2 is a very good amp for the price.

post #16866 of 27693

One more question about Crack with speedball - what DAC can unlock the full potential of Crack with SB? 

 

Is Modi enough? Or Uber Bifrost would be much better? Or other recommendations? 

 

Thanks a lot.

post #16867 of 27693
Quote:
Originally Posted by jimmers View Post
 

?

 

Take a look at Rasmus Sørensen crack build blog for a illustrated explanation. 

 

http://diy.koenigs.dk/2014/03/18/stepped-attenuator-legendary-g-e-c-cv-2523-tube/


Edited by JamieMcC - 4/14/14 at 1:06am
post #16868 of 27693
Quote:
Originally Posted by JamieMcC View Post
 

 

Take a look at Rasmus Sørensen crack build blog for a illustrated explanation. 

 

http://diy.koenigs.dk/2014/03/18/stepped-attenuator-legendary-g-e-c-cv-2523-tube/


What he says is OK, he doesn't say

"... simply it again provides a shorter less resistive path for the signal to travel, less resistance means more details get through."

post #16869 of 27693
Quote:
Originally Posted by cddc View Post
 

One more question about Crack with speedball - what DAC can unlock the full potential of Crack with SB? 

 

Is Modi enough? Or Uber Bifrost would be much better? Or other recommendations? 

 

Thanks a lot.

 

I have the modi and bifrost on my desk currently. Short answer, if you can swing the money get the bifrost. 

post #16870 of 27693
Quote:
Originally Posted by Zorrofox View Post

Thanks for all the suggestions folks. I wet for the Slappa because it's the most similar to my V-Moda case. Of course, £25 here! Thanks everyone.

Good choice.

 

I have one and it fits my HD600's like a glove, is well made and feels like it should offer good protection...although I've not put that aspect to the test much!

post #16871 of 27693
Quote:
Originally Posted by jellofund View Post

Good choice.

I have one and it fits my HD600's like a glove, is well made and feels like it should offer good protection...although I've not put that aspect to the test much!

Yes, it looks the part. Headphones manufacturers would do well to look to V-Moda for its packaged accessories. Second to none.
post #16872 of 27693
Quote:
Originally Posted by Zorrofox View Post


Yes, it looks the part. Headphones manufacturers would do well to look to V-Moda for its packaged accessories. Second to none.

 

Mine took a tumble down the stairs, and you can't even see signs what a calamity it went through (BTW, my wife is no longer allowed to touch my headphones :rolleyes:)

post #16873 of 27693
Quote:
Originally Posted by jimmers View Post
 


What he says is OK, he doesn't say

"... simply it again provides a shorter less resistive path for the signal to travel, less resistance means more details get through."

 

I think the statement is basically correct, I could have worded it better like a shorter path with less resistive elements in the signal path,  but was pushed for time as on my way to work, It was intended as a short simple reply not a in depth technical explanation, Perhaps you would care to provide a more comprehensive explanation yourself?

 

Below an extract from the Goldpoint website

 

http://www.goldpt.com/compare.html

 

"A few notes on stepped attenuators.


Stepped attenuators offer distinct sonic advantages over common potentiometers. This is due to their use of discrete resistors and the purest method of signal attenuation: resistor voltage dividers. Discrete resistors typically have better low noise characteristics than the carbon or cermet resistor elements used in potentiometers.
The total measured resistance for each position of a stepped attenuator remains constant throughout years of use. This is because the wearing (rubbing) parts in stepped attenuators are low resistance switch contacts, not resistive elements with wipers sliding on them as in potentiometers.

Potentiometers can add clicks, pops, and static sounds due to wear.
Stereo potentiometers used as volume controls often produce different volume levels for each channel, and the amount of  mismatch can vary as the potentiometer is turned up or down. The channel-to-channel tracking specification for stereo potentiometers, even very expensive ones, is typically 5% to 20%. With stepped attenuators you can easily achieve stereo signal levels matched to within one half of one percent (0.5%).
With stepped attenuators, the signal level has been pre-determined for each step, so front panel calibration markings can represent actual signal levels."


Edited by JamieMcC - 4/14/14 at 11:01am
post #16874 of 27693
Quote:
Originally Posted by ButtUglyJeff View Post

Mine took a tumble down the stairs, and you can't even see signs what a calamity it went through (BTW, my wife is no longer allowed to touch my headphones rolleyes.gif )

That's good to know because I do not want to lose these babies. My wife has no desire to go anywhere near my headphones. She thinks I'm a bit weird but what's really weird is that she can listen to the same song on my PX100II's and then on my HD650's and hear a difference, but not see why this difference matters. And now I have to sneak some Schiit into this room somewhere without it being too obtrusive.

I've been off work for the last 10 weeks due to an accident at work and today was my first day back. I spent all day yesterday designating a room for this hobby. I got it all set up before work except for a monitor which would be delivered from Amazon at work. All I had to do was come home, install a monitor, boots off & slap the 650's on. It works.
post #16875 of 27693

Nice!  Put your feet up and put the tunes on.  :beerchug:

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