[KcMsterpce]

I have a Bottlehead Crack with Speedball and a Mainline. I love both.

I'm still working on a bunch of mods to my Crack to include separating the power supply into a separate enclosure, adding a Schotky diode rectification circuit, upgrading caps (Daytons), input selector 2 pair RCA in, output selector (rca pre and head), dual mono black velvet attenuation, vu meters, and more. I'll try to post Pics when done.

I think it's pretty cool that you like to tweak/upgrade the Bottlehead. I wouldn't mind doing that, but for me, I wouldn't stop tweaking and fiddling. It's better that I don't engross myself into yet another time and money sink hobby. I plan on getting another OTL some time soon. I've had several years with my Bottleheads now. I'm ready to move "up".

I love the Crack w/Speedball for its price to performance ratio. Insanely good.
The Mainline is spendy, but it is so much more refined, revealing, and pleasant to listen to. Where the Crack is pronounced, and likes to show off (Speedball), the Mainline kind of creeps up on you and doesn't have to show off. The Speedball is the hare, and the Mainline is the tortoise. It takes more time to get really familiar with the Mainline, but it just grows on you, whereas the Crack hits you right away, and demands your attention.

 

[Tom-s]

Sex would be my choice of the bottlehead headphone amps for best bang for your buck for sure.

I'm with Jamie on this one.
Especially while it's on sale!

I always thought Crack was most bang for buck. But now that i own Crack, S3X (with C4S) and Mainline my perspective changed.
Use S3X with Klipsh Heresy III speakers and HD800 / AKG K340 headphones, really shines with all.

 

[SilverEars]

I just installed the Speedball upgrade on the crack. I had the Speedball soldered and ready to go, and thought it would be a quick install, but no. It took quite a bit of time to get the speedball wired up.

As far as soldering, I got it to work on the first go, which I was happy with. Because for the regular crack build, I had to trouble-shoot the headphone jack, and took me awhile to figure out the headphone jack needed good soldering, which isn't visually obvious. Speedball needs more precision soldering, and I'd recommend using a sharper point soldering iron for it.

What really puzzles me is why the headphone jack is so sensitive to soldering job (and the symptoms were quite interesting). Speedball is as I expect for the soldering job, no trouble with it.

I do notice improvement in sound with speedball. The treble seem to have gotten smoother (more detailed sounding), lower-mids warmth subsided a bit (tighter bass response), more clarity, and probably the most noticeable change is the imaging, and it's more apparent with something like HD800S.

In general with the HD6XX, I think without the Speedball, Crack is warmer, and with speedball, sound gets less warm with greater clarity. I like how crack sounds, particularly with Speedball. Definitely worth getting if you have high impedance cans like Sennheiser 300 ohm.

The improvment seems most obvious with HD600. Like previous posters that pointed out the HD600 sounding great. I can wholeheartedly agree that Speedball upgrade brings out the greatness ouf of the HD600.

 

[Thenewbie76]

Has anybody tried the ZMF aeolus with the bottlehead crack? I got a THX 789 AMP powering the Aelous and they sound great but I just wanna know how they sound with the Aeolus . Also I might use it with my hd 600

 

[SilverEars]

Has anybody tried the ZMF aeolus with the bottlehead crack? I got a THX 789 AMP powering the Aelous and they sound great but I just wanna know how they sound with the Aeolus . Also I might use it with my hd 600

It's an OTL so output impedance is quite high (120 ohms), but interestingly, it sounds good with Sennheisers 300 ohms, notably the 6 series. Interesting how well the 300 ohm 6 series matches up with crack.

Look into what ohms those ZMF headphones are and if high enough, Crack is worth trying out if they are high impedance dynamic drivers I say. It's a different kind of sound than you get with solid-state. One issue I can foresee is if ZMF headphones are already a bit warm due to the wood because the OTL provides a bit of low-end warmth to the Sennheisers, but still sounding clear as Sennheisers are not as significantly warm as the ZMF headphones. Best way to know is trial.

Sex is not as warm as Crack, so sex might be the better fit for ZMF, and also it has low output impedance of 4 ohms. The thing is Crack's OTL creates an interesting thicker sound(but, not muddy) to the Sennheisers and also imaging is interesting for it as well. Sex is slightly more precise with slightly more texture peaks to the images with less low-end warmth, seemingly more neutral response, but I don't know about morr interesting...

I find Crack's imaging so damn interesting with HD600/6XX/650.

 

[Thenewbie76]

It's an OTL so output impedance is quite high (120 ohms), but interestingly, it sounds good with Sennheisers 300 ohms, notably the 6 series. Interesting how well the 300 ohm 6 series matches up with crack.

Look into what ohms those ZMF headphones are and if high enough, Crack is worth trying out if they are high impedance dynamic drivers I say. It's a different kind of sound than you get with solid-state. One issue I can foresee is if ZMF headphones are already a bit warm due to the wood because the OTL provides a bit of low-end warmth to the Sennheisers, but still sounding clear as Sennheisers are not as significantly warm as the ZMF headphones. Best way to know is trial.

Sex is not as warm as Crack, so sex might be the better fit for ZMF, and also it has low output impedance of 4 ohms. The thing is Crack's OTL creates an interesting thicker sound(but, not muddy) to the Sennheisers and also imaging is interesting for it as well. Sex is slightly more precise with slightly more texture peaks to the images with less low-end warmth, seemingly more neutral response, but I don't know about morr interesting...

I find Crack's imaging so damn interesting with HD600/6XX/650.

Thx for the insight but I don't think I'm prepared to take up the sex as my first audio D.i.y project. I feel like taking baby steps . Also it's pretty much this or the Little dot mk3 I will get. Lastly I don't think the Aeolus is too warm for me. If it does end up getting too warm can't I just get 'bright' sounding tubes to shift the sound signature?

 

[omniweltall]

It's an OTL so output impedance is quite high (120 ohms), but interestingly, it sounds good with Sennheisers 300 ohms, notably the 6 series. Interesting how well the 300 ohm 6 series matches up with crack.

Look into what ohms those ZMF headphones are and if high enough, Crack is worth trying out if they are high impedance dynamic drivers I say. It's a different kind of sound than you get with solid-state. One issue I can foresee is if ZMF headphones are already a bit warm due to the wood because the OTL provides a bit of low-end warmth to the Sennheisers, but still sounding clear as Sennheisers are not as significantly warm as the ZMF headphones. Best way to know is trial.

Sex is not as warm as Crack, so sex might be the better fit for ZMF, and also it has low output impedance of 4 ohms. The thing is Crack's OTL creates an interesting thicker sound(but, not muddy) to the Sennheisers and also imaging is interesting for it as well. Sex is slightly more precise with slightly more texture peaks to the images with less low-end warmth, seemingly more neutral response, but I don't know about morr interesting...

I find Crack's imaging so damn interesting with HD600/6XX/650.

Zmf is 300ohm. I have a feeling it will sound good with the crack.

But most people use the crack with senns 6-series. I heard many times that they are match made in heaven. I think hd600 might be an even better match than hd650/6xx.

 

[ProfFalkin]

Has anybody tried the ZMF aeolus with the bottlehead crack? I got a THX 789 AMP powering the Aelous and they sound great but I just wanna know how they sound with the Aeolus . Also I might use it with my hd 600

The Aeolus sounds very good with my Crack. Get the speed ball, if you build a Crack.

Compared to my Jotunheim: Sound stage widens a bit, and it takes on a buttery smooth and rich sound. Bass extension is ok, but not what you will find in the Jotunheim. With that said, it still kicks like a mule where called for. Treble extension and detail are perfectly acceptable, but again, the Jotunheim seems to extend more but ends up sounding a little brittle in this area. I prefer the Crack here. Mid range is rich, mesmerizing, and so much better than my Jotunheim.

I've had the little dot loaned to me, and I don't care for it. It had no soul. I've owned the MCTH, Lyr 3, Jotunheim, Element, and other $300 - $600 amps, and the Crack is the only one I've kept. The MCTH sounds too soft, the Lyr 3 is quite good but not as truly "tubey" sounding, the Jotunheim pulls preamp duty for my studio monitors but doesn't get headphone time at all, and the Element is neutral but lifeless in comparison.

The Crack is a rule breaker. Measurement objectivists need not apply. Subjectively, the Crack brings soul and feeling to the music. A sit down and get lost in the music for hours kind of experience.

Don't get crazy with capacitor upgrades and all that. An Alps pot upgrade, the Speedball, and a good tube selection are all I would suggest. Putting more $ into it than that, and you might as well get the CrackATwoA or Glenn OTL if you want better sound.

Hope that helps.

 

[adydula]

Agree with that.....speedball and the ALPS pot upgrade. The low end tracking was abit off with the stock pot, the real Alps replacement made this go away and its perfect now.

Alex

 

[Thenewbie76]

@SilverEars thx for the insight. But I agree with what you say. Thin

The Aeolus sounds very good with my Crack. Get the speed ball, if you build a Crack.

Compared to my Jotunheim: Sound stage widens a bit, and it takes on a buttery smooth and rich sound. Bass extension is ok, but not what you will find in the Jotunheim. With that said, it still kicks like a mule where called for. Treble extension and detail are perfectly acceptable, but again, the Jotunheim seems to extend more but ends up sounding a little brittle in this area. I prefer the Crack here. Mid range is rich, mesmerizing, and so much better than my Jotunheim.

I've had the little dot loaned to me, and I don't care for it. It had no soul. I've owned the MCTH, Lyr 3, Jotunheim, Element, and other $300 - $600 amps, and the Crack is the only one I've kept. The MCTH sounds too soft, the Lyr 3 is quite good but not as truly "tubey" sounding, the Jotunheim pulls preamp duty for my studio monitors but doesn't get headphone time at all, and the Element is neutral but lifeless in comparison.

The Crack is a rule breaker. Measurement objectivists need not apply. Subjectively, the Crack brings soul and feeling to the music. A sit down and get lost in the music for hours kind of experience.

Don't get crazy with capacitor upgrades and all that. An Alps pot upgrade, the Speedball, and a good tube selection are all I would suggest. Putting more $ into it than that, and you might as well get the CrackATwoA or Glenn OTL if you want better sound.

Hope that helps.

that is so good to know coming form another aeolus owner. I just wanna say that I might hold off on getting the speedball first just to see how it sounds without it and then get the speedball . But how do I find this ALPS pot upgrade? What is it? Where do I find it because I don't see it under the bottlehead headphone amp website

 

[adydula]

https://www.parts-express.com/alps-...MI8OfW2YTr3wIVlODICh0kKA6GEAYYASABEgInUfD_BwE

 

[ProfFalkin]

@SilverEars thx for the insight. But I agree with what you say. Thin

that is so good to know coming form another aeolus owner. I just wanna say that I might hold off on getting the speedball first just to see how it sounds without it and then get the speedball . But how do I find this ALPS pot upgrade? What is it? Where do I find it because I don't see it under the bottlehead headphone amp website

https://www.parts-express.com/alps-...MI8OfW2YTr3wIVlODICh0kKA6GEAYYASABEgInUfD_BwE

^^^^^^ Yep.

What he said.

https://bottlehead.com/smf/index.php?topic=11314.msg102859#msg102859

Some people have put audio note potentiometers in there instead. I think the Alps is just fine.

If you're completely bereft of reason, you can put a Khozmo or Gold Point pot in there.

 

[adydula]

There is also a 99 cent PCB you need to mount the pot to.....I cant find the link but its in the Crack Forum at bottlehead.com

You could ask Paul for the info, he posted it awhile back..

Alex

 

[itsikhefez]

A bit pricier but I've found this one useful in the past:
https://www.amb.org/audio/epsilon27/

 

[Thenewbie76]

@ProfFalkin Can I just ask. Just to confirm a audio potentiometer is to help with the volume pot right and won't offer any difference in sound right?