[zlobby]

I am probably going to be buying one of these kits to use with my hd600.  I also listen to grado sr-80s from time to time.  I know this amp isnt supposed to be great for low ohm cans, but can anyone attest to it from personal experience?

 

[HiGHFLYiN9]

This is a bargain priced kit and the sound quality is fantastic with higher impedance cans, but I had a listen to a pair of MS2is with the Crack and it wasn't the best I've heard them. Listening to the same cans with a Millet MiniMAX and M Cubed yielded more dynamic results.
 

 

[Armaegis]

Crack is fantastic with the HD600, not so much with the SR80 (or MS1, or HF-2).

 

[tdogzthmn]

 
Quote:

Crack is fantastic with the HD600, not so much with the SR80 (or MS1, or HF-2).

Hmm, I have been interested in an SR325 but sign's are pointing to this being a poor match.  Also I have new tubes on the way, one being a Tung-Sol 5998 

 

[Armaegis]

Bottlehead designed the Crack for high impedance cans. My experiences seem pretty consistent with that. It's not that low impedance cans sound bad, just... *shrug*.
 
I'd be curious to see someone take one of the Beyers with the 32 vs 250 vs 600 ohm and see how they sound coming out of a Crack.

 

[hypoicon]

The Crack works well with my DT990s (600 ohm) and sounds terrific (as many others have remarked) with my Senn HD-650s. It actually doesn't sound bad with my HF-1 grados, or my RS-1s; but as others have remarked as well, it's not the best match. Other amps I own sound better.

 

[Doc B.]

Quote:

Bottlehead designed the Crack for high impedance cans.

Yes, that was the intended usage from the start and we have gone to some lengths to emphasize this. The amp will make good sound with lower impedance headphones, but it is not going to allow them to give their absolute best bass performance. This is simply going to be a matter of taste in a lot of cases.

 

[Neogeo333]

I want to thanks Doc for this wonderfull amp, using it witha DT 990 600ohm.  One question for Doc, i remember that you said back in the Bottle head forums that if used witha  5998 tube it might  work well with cans low as 70ohm?  I wonder if it can do better with WE 421A?  

 

[Skylab]

Quote:

I want to thanks Doc for this wonderfull amp, using it witha DT 990 600ohm.  One question for Doc, i remember that you said back in the Bottle head forums that if used witha  5998 tube it might  work well with cans low as 70ohm?  I wonder if it can do better with WE 421A?  

The WE 421A and the Tung-Sol 5998 are the exact same tube.  Only Tung-Sol made this tube; the WE 421A is just a rebranded 5998.

 

[Beefy]

And even if the 421A do sound better through some phantasmagorical effect, it is not because of the output impedance which is still the same.

 

[diego]

The output impedance using 5998s is probably lower than 80, depending on the exact operating point which I don't know. As a reference, I have a different amplifier with an output impedance of 65 and it sounds good with my 62 ohm AKG 701. However, the bass is tighter with my 300 or 600 ohm headphones.

 

[tdogzthmn]

The 5998 has a very clean and detailed sound which is what I was looking for.  Mine is branded IBM and I scored it off ebay for $30.  

 

[zlobby]

Just a heads up for those interested in buying one of these.  We are starting a group buy on this forum.  This thread has all the information...
 
http://www.head-fi.org/forum/thread/527004/bottlehead-crack-group-buy

 

[Armaegis]

I just installed the Speedball upgrade last night. Wow. For lack of a better word, the resolution was amazing. The changes were subtle yet not; like little micro details were restored to the music. I'm not even talking about "things I've never heard before" trope... no, more in the sense that I could now hear how each note would sing just a little sweeter, and have just that touch of air and vibrato. For acoustic and vocals, this was simply magical. If you listen to music where the breath between notes is just as important as the music itself, then this is a highly recommended (if not mandatory) upgrade.
 
That said, I couldn't hear much of a difference when playing some heavy and "crowded" music. In these cases, that sense of detail and intimacy was not so much lost as it was obscured. Nowhere to "breath" so to say.

 

[james93]

Quote:

I just installed the Speedball upgrade last night. Wow. For lack of a better word, the resolution was amazing. The changes were subtle yet not; like little micro details were restored to the music. I'm not even talking about "things I've never heard before" trope... no, more in the sense that I could now hear how each note would sing just a little sweeter, and have just that touch of air and vibrato. For acoustic and vocals, this was simply magical. If you listen to music where the breath between notes is just as important as the music itself, then this is a highly recommended (if not mandatory) upgrade.
 
That said, I couldn't hear much of a difference when playing some heavy and "crowded" music. In these cases, that sense of detail and intimacy was not so much lost as it was obscured. Nowhere to "breath" so to say.

Which headphones are you using?
 
I'm on the list for the group buy for the Crack with Speed and my current headphones are Grado SR-60, which I will still use for work.  I'm looking to upgrade to either the Grado HF-2, Senn HD-600 or 650.
 
James