[Tom-s]

I can only comment on the Schiit Modi 2U. It's a great DAC. It plays perfect with my Crack running from my macbook.
And it looks cool next to the aluminum macbook. Best spend dollar i'd recommend a Modi 2U or multibit.
Looking second hand is always a good idea. I found a Gustard X20 for cheap that way and use it till today (price of a new Bifrost).
The only reason i sold the Modi and kept the X20 is the fact that the modding bug got me so hard i just needed to play around with that DAC.

 

[Allanmarcus]

I've used various DACs with my crack, and all work well. Differentiation between DAC is usually subtle unless you have really good ears, and or are trained.

I have a modi multibit on order, and will be getting it next week. I'll try to post comments and impressions with the crack.

You can usually find pre-made cracks used for decent prices. I know of one for sale on another site for $500, and it comes with many tubes, and many upgrades. I've heard it personally, and it sounds good. PM me if interested.

For $300 I would get a modi multibit, a PeachTree DAC-it2, or a used Bifrost.

 

[adydula]

mrravioli...
 
You could take the odac apart from the amp but thats a chore for most....best just get a new one...they arent that expensive. The ones out now are REV B sonically no real difference.
 
I have used several headphones with the ODAC and other amps, for what its worth the ODAC is just ...well a very good dac that doesnt do much except do what its designed to do very well at a great price. I have compared to others and its as good as many others costing much more.
 
Headpones I use, Audeze LCD2's, AKG 701/2's, AudioTechnica ATH M50's, MSR7's, Beyerdynamic T90's, 1350's, Senn 650's...
 
All work well with the O2 and ODACand all can be driven to painful levels. The Crack amp is a great option for your higher impedance cans! Sound is different than the O2.
 
Music style is many different styles, but I like stuff that is very well mastered and recorded. I dont try to fix bad recordings of artists I like by finding a set of headphones or amps to "fix" crappy recordings. I look for neutral electronics, that allow me to hear what headphones can and can not do. The ODAC will allow you to do this.
 
I like jazz, rock, instrumentals, check out this link I started that has many of the BEST recordings out there.....all kinds of stuff:
 
http://www.audiocircle.com/index.php?topic=63936.0
 
Best of Luck and Enjoy!!
Alex

 

[Doc B.]

 You can usually find pre-made cracks used for decent prices.

 
One thing I would caution buyers of used kits - find out if the seller guarantees that the amp will work when you receive it. There are some very skilled builders out there, and yet we see a fair number of amps sold used coming across our repair bench. Seems sometimes to be due to damage from poor packing. Other times it seems due to less than stellar construction by a maybe less than very skilled builder. We're happy to repair them, it pays my tech's wages. But as a buyer you probably don't want to have to ship an amp to us to get it fixed before you can use it. 
 
This has been an issue with kits forever. I remember buying Dynaco Stereo 70s that were stunningly crafted underneath (usually by engineers) and Stereo 70s that were a nightmare bird's nest underneath. All built from the same set of instructions.

 

[mrravioli]

mrravioli...

You could take the odac apart from the amp but thats a chore for most....best just get a new one...they arent that expensive. The ones out now are REV B sonically no real difference.

I have used several headphones with the ODAC and other amps, for what its worth the ODAC is just ...well a very good dac that doesnt do much except do what its designed to do very well at a great price. I have compared to others and its as good as many others costing much more.

Headpones I use, Audeze LCD2's, AKG 701/2's, AudioTechnica ATH M50's, MSR7's, Beyerdynamic T90's, 1350's, Senn 650's...

All work well with the O2 and ODACand all can be driven to painful levels. The Crack amp is a great option for your higher impedance cans! Sound is different than the O2.

Music style is many different styles, but I like stuff that is very well mastered and recorded. I dont try to fix bad recordings of artists I like by finding a set of headphones or amps to "fix" crappy recordings. I look for neutral electronics, that allow me to hear what headphones can and can not do. The ODAC will allow you to do this.

I like jazz, rock, instrumentals, check out this link I started that has many of the BEST recordings out there.....all kinds of stuff:

http://www.audiocircle.com/index.php?topic=63936.0

Best of Luck and Enjoy!!
Alex

Definitely concur with the 'neutral electronic' concept. Actually not only to the extent of recordings, even to the 'real sound' territory. I'm a classical fan and go to concert as often as I can (fortunately we have a world class orchestra here). IME, the 'true' acoustic sound is no way 'perfect', but definitely perfectly 'detailed'. When I sit in the front rows, I can hear the conductor humming, stomping and even world-class singers have sibilance (which many audiophiles spend thousands of dollars to eliminate)

 

[adydula]

You know I agree with you. When I go to a live concert or band I really listen to what the instruments sound like....when you listen to a trumpet up close or a drum whack....its brutal in real life....I want stuff that allows this to be recreated as best possible. Every once in awhile you get the right material with the right downstream stuff and am amazed. But often than not its a compromise compared to the real world "listening" event.
 
Alex

 

[jamesino]

How loud of a volume do you guys use when comparing amps? Does the DAC have an impact on how loud you need to turn your amp?
 
I have a Modi 1 > BHC + SB > HD 650 and listen to music with the knob at 9 o'clock. 

 

[buke9]

How loud of a volume do you guys use when comparing amps? Does the DAC have an impact on how loud you need to turn your amp?

I have a Modi 1 > BHC + SB > HD 650 and listen to music with the knob at 9 o'clock. 

There might be some differences between some dacs but I doubt very large. If I were comparing between two I would just try to volume match between the two or I could break out the calibrated mic and get the exact volume. 9 o'clock is very loud for my HD 700's from the Crack feed by my Yggy.

 

[Tom-s]

Listening levels on Crack differ with tube's gain and headphone dB SPL / mW. 
When using a crack with lets say a ecc40 and 5998 it will be way louder at same potentiometer position compared to the standard ecc82 and 6080.
 
For more useful volume range FAQ #3 helps a lot.

 

[buke9]

Listening levels on Crack differ with tube's gain and headphone dB SPL / mW. 
When using a crack with lets say a ecc40 and 5998 it will be way louder at same potentiometer position compared to the standard ecc82 and 6080.

For more useful volume range FAQ #3 helps a lot.

Using a 5998 now I know way it's louder now thanks.

 

[HOLLOWCOW]

So I finally got the CRACK+SB amp and the MODI MULTIBIT combo to pair with my Beyer T90's.
 
It is a solid upgrade over the JDS Element (same components as O2+DAC combo).
the sound is better and more alive than the JDS,
however with the stock tubes I still find the treble too fatigue, and the sound to be a little digital and too much clarity. 
I'm a total noob to tube amps. I had someone assemble it for me. 
I understand the Crack have two types of tubes. the big one is the sound signature and the small one is the power, is this right?
 
 
MY QUESTION IS:
I'm looking for a new set of tubes to give it a more "tuby" "lush/warm" sound with nice roll-off to the trebles.
the bass can also be improved. (maybe less in your face and more slow like sennheiser bass. maximum budget of 350$. preferably less.
Ive read some recommendation on the rca 6AS7G and the Tung Sol 5998. but those comments werent about the crack with speedball upgrade and the T90's
 
 
I would really appreciate your recommendation based on your personal experience with this setup.
I would also be really greatfull if you can provide a link to a reliable eBay seller or web store. as all the parameters and brands are very unclear to me.
I could easily buy something else.
THANK YOU!

 

[Tom-s]

From the new tubes i'd recommend the following combination (sub 50$):
 
- Genalex Gold Lion new production ecc82  (that's the small one)
- Svetlana 6H13C (not new as you ask but cheap all over the bay, and big bottle shaped*)
 
The Svetlana gives a very strong bass foundation and more air to the music compared to the average 6080wb (i prefer it to my 6AS7G RCA's).
The Gold Lion is a great little tube with a nice balanced tubey sound. I prefer it by far over the other new production ecc82 tubes i tried and to the most NOS.
 
*It excels in real audiophile quality => because big bottles look better.

 

[JamieMcC]

  So I finally got the CRACK+SB amp and the MODI MULTIBIT combo to pair with my Beyer T90's.
 
It is a solid upgrade over the JDS Element (same components as O2+DAC combo).
the sound is better and more alive than the JDS,
however with the stock tubes I still find the treble too fatigue, and the sound to be a little digital and too much clarity. 
I'm a total noob to tube amps. I had someone assemble it for me. 
I understand the Crack have two types of tubes. the big one is the sound signature and the small one is the power, is this right?
 
 
MY QUESTION IS:
I'm looking for a new set of tubes to give it a more "tuby" "lush/warm" sound with nice roll-off to the trebles.
the bass can also be improved. (maybe less in your face and more slow like sennheiser bass. maximum budget of 350$. preferably less.
Ive read some recommendation on the rca 6AS7G and the Tung Sol 5998. but those comments werent about the crack with speedball upgrade and the T90's
 
 
I would really appreciate your recommendation based on your personal experience with this setup.
I would also be really greatfull if you can provide a link to a reliable eBay seller or web store. as all the parameters and brands are very unclear to me.
I could easily buy something else.
THANK YOU!

 
Another option you could try would be bypassing the Cracks 100uf output capacitors with some Russian 250v 1uf K75 10 capacitors they are only a couple of dollars each and should add bags of character, think full rich juicy mid centric sound with bags of texture plus you should get the roll off you are after. Cheep to try anyhow so thought I would throw the idea out there for consideration..
 
http://www.enjoythemusic.com/diy/0411/capacitor2.htm
 
http://www.ebay.co.uk/itm/1uF-250V-Hybrid-PIO-Capacitors-K75-10-Matched-Pair-2-x-0-947uF-/201719646854?hash=item2ef76d8a86:g:HykAAOSwiONYK-Tr

 

[buke9]

[COLOR=454434]So I finally got the CRACK+SB amp and the MODI MULTIBIT combo to pair with my Beyer T90's.[/COLOR]

[COLOR=454434]It is a solid upgrade over the JDS Element (same components as O2+DAC combo).[/COLOR]
[COLOR=454434]the sound is better and more alive than the JDS,[/COLOR]
[COLOR=454434]however with the stock tubes I still find the treble too fatigue, and the sound to be a little digital and too much clarity. [/COLOR]
[COLOR=454434]I'm a total noob to tube amps. I had someone assemble it for me. [/COLOR]
[COLOR=454434]I understand the Crack have two types of tubes. the big one is the sound signature and the small one is the power, is this right?[/COLOR]


[COLOR=454434]MY QUESTION IS:[/COLOR]
[COLOR=454434]I'm looking for a new set of tubes to give it a more "tuby" "lush/warm" sound with nice roll-off to the trebles.[/COLOR]
[COLOR=454434]the bass can also be improved. (maybe less in your face and more slow like sennheiser bass. maximum budget of 350$. preferably less.[/COLOR]
[COLOR=454434]Ive read some recommendation on the rca 6AS7G and the Tung Sol 5998. but those comments werent about the crack with speedball upgrade and the T90's[/COLOR]


[COLOR=454434]I would really appreciate your recommendation based on your personal experience with this setup.[/COLOR]
[COLOR=454434]I would also be really greatfull if you can provide a link to a reliable eBay seller or web store. as all the parameters and brands are very unclear to me.[/COLOR]
[COLOR=454434]I could easily buy something else.[/COLOR]
[COLOR=454434]THANK YOU![/COLOR]

To me the stock tubes were unusable. It might be the fact that it was used so can't say for sure. I'm also pushing it a bit with HD-700's at 150 ohms but with Tung Sol 5998 and Telefunken 12au7 it is quite nice definitely tamed the highs on the 700's. I have a pair of Tung Sol 6080 Chathams that had a more lush sound but the bass was a bit too boomy I'm thinking this could be from the lower impedance of the 700's don't know will have to wait to try it out on the HD-6xx's sometime around Christmas. I haven't had too much luck with RCA tubes as I have another tube amp that came stock with them and it was just too bright for me switching out the RCA 1626 for a Tung Sol VT-137 and all was right in the world for me.

 

[HOLLOWCOW]

Thank for your replays, I'm going with the ts 5998 nos from the 60s and mullard ECC82.
Hope it will last long enough.