Bottlehead Amplifier Discussion / Comparison Thread: Crack, SEX & Mainline
Mar 28, 2019 at 8:44 AM Post #1,846 of 2,108
The Alps I used didnt change the sound at all....all it did was add a really nice volume control that rotates really smooth
and has great low end tracking, mechanically. The stock pot I got was not that good on the lower settings from 8 oclock to 10 o-clock..

You need to use the pcb either the 99 cent one or the more expensive one...no real reason to spend alot of money on that board.

You will need to notch out the wooden case on the pot side...pix are at BH Crack forum.

This is because of the pcb board width.

Alex
 
Mar 28, 2019 at 2:07 PM Post #1,848 of 2,108
@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?
The volume pot is a potentiometer. :)

Same same.
 
Mar 28, 2019 at 2:14 PM Post #1,850 of 2,108
Two things about this bit of this Bottlehead Crack thread:

1. An attenuator can affect the sound quality. Lots of manufacturers work hard to even eliminate the conventional potentiometer or attenuator, removing that device from the signal path because it can affect sonic character - frequency, phase and timing, noise, dynamics, distortion, channel balance. The Crack is a wonderful device. It's designed to a value point and pulls this off well offering excellent performance for the money. The stock volume pot is cheaper than chips. It's as basic as it comes. The one in my Crack works well - it's quiet, tracks well, and feels nice enough. Just precise tracking for precise channel balance can be very important - if you want your system, whether headphones or conventional speakers, to place the played back elements back in the place they were captured in. This will influence imaging and soundstage. And that affects the sound.

2. I agree that it's a good idea to spend some time with the stock Crack without the Speedball. It lets you shake down the Crack to make sure all's well, and lets you baseline the sonics for a reference to see whether the Speedball makes any difference and any difference you might prefer. Some people may like the sound of the stock Crack. The stock Crack may be a good synergy with the rest of your system and your own preferences. Bottlehead recommends this, too.
 
Mar 28, 2019 at 5:17 PM Post #1,852 of 2,108
I have a lot of headphone amps....actually too many!! :):)

I rotate them every week ot two and am always enamored with the "new" amp in rotation.
Today the Schitt Vahalla2 went into semi-retirement and the Crack with Speedball and the new Alp pot came into rotation.

Using a RCA 6AS7G coke bottle and a NOS 5963 .

Listening as I write, with Beyer T1 2nd gens....

In one word "AWESOME"...

Absolutely marvelous soundstage and imaging..holographic...live performances are very realistic...

More than enough power to make the T1's dance...

Said this before and will say it again...this amp the way it sounds right now could easily be the end game to me...

Yeah...its that good....

This amp is a steal!

Alex
 
Mar 28, 2019 at 6:41 PM Post #1,854 of 2,108
I never heard the Crack but I have built a Mainline and it is my primary amp for the past few months.
I have another DIY SS which has been redundant since the Mainline joined, and don't need an additional amp.

But I was curious if the Crack+SB adds any value if I already use the Mainline?
My primary cans are all high impedance, HD650 and most recently a ZMF Aeolus
 
Mar 28, 2019 at 7:14 PM Post #1,855 of 2,108
I have both. I honestly do not think the crack is any better than a Mainline.

Different design and a different sound presentation for sure.

There are times I swear the Crack is "better" sounding but after listening for several days with the Crack and switching to the Mainline
its like wow! This Mainline is even better than the Crack that I like so much.

The Mainline works with a wider range of headphone impedances and has that nice stepped attenuator...

The 6C45Pi's in Mainline are a very very good tube...linear etc...and no need for tube swapping etc...

If you have the bug for diy and soldering etc and have disposable bucks heck go for it!!

Its a neat amp for the price and will make you smile as well...

Alex
 
Mar 28, 2019 at 8:06 PM Post #1,856 of 2,108
The following post if my opinion. Based on my experience with these amps.

I've used Crack, S3X and Mainline with the same DAC/pre-amp the last few months on my desk. Feeding Sennheiser HD800's (SDR) most of the time. Second choice are AKG K340's.
What i do note is that when i use more "hi-fi" tubes with Crack, like the E80CC or 5692 Ayadula mentioned above (also listening to that right now!), it's not that much different from S3X or Mainline. What i mean to say is; i'm not missing anything with Crack. It's all in there, just a different presentation.

Ranked in order of use:
1. Crack (did anyone mention that tube-rolling is fun?)
2. Mainline
3. S3X

Even with Mainline and S3X next to it, my Crack gets most usage.

Ranked in order of sound quality:
1. Mainline
2. S3X
3. Crack

This is a no-brainer, if you are looking for the best. Get a Mainline. It is the best. Period.

Ranked in order of versatility:
1. S3X (it's moving again to a different room, for speaker use only).
2. Mainline
3. Crack

S3X can feed speakers aswel as headphones in all genres. I've listened to it with various efficient speakers, B&W P9's, HD800's and LCD3's and all sound good with S3X.

Ranked in order of learning experience:
1. Crack
2. S3X
3. Mainline

Crack is the most simple circuit, with the most room for improvement. This makes for a lot of opportunity to learn about circuitry and the effect of certain parts on the actual sound.
As the volume-pot mentioned above. The Bottlehead team put in a good basic volume pot and left enough room in Crack to let the builder put in any pot they wish for.

Ranked in order of sheer fun:
1. Crack
2. Crack
3. Crack

For me, the fun in Crack is derived for the majority from the learning experience. The other part is tube-rolling. Crack is made for tube-rolling.

Ranked for ease of build.
1. You can build them. All three.
2. Yes, you read correct. The manual is so good that with determination everyone can build a Bottlehead kit.
3. I build my Crack with 0 experience in electronics (even had to buy my first soldering iron before i could start).

The quality of the manual and support are the most important things about a DIY kit. And Bottlehead in my experience, is brilliant with both. They deliver a very thorough manual, that takes you trough the whole build, step by step. Everything is in there, from the first soldering lesson up to safety instructions on how to check your amp and where to start when you need to troubleshoot.
If you can't figure it out on your own, there's the support forum where the team will stay with you until your problems are all resolved (when needed).
When you buy a Bottlehead kit, your not on your own to build just a kit. You also buy a very complete manual that will guide you and a team that will give advice until you've completed your journey and are 100% satisfied with your build.

Sorry, what was the question? xD
 
Mar 28, 2019 at 9:16 PM Post #1,858 of 2,108
The following post if my opinion. Based on my experience with these amps.

I've used Crack, S3X and Mainline with the same DAC/pre-amp the last few months on my desk. Feeding Sennheiser HD800's (SDR) most of the time. Second choice are AKG K340's.
What i do note is that when i use more "hi-fi" tubes with Crack, like the E80CC or 5692 Ayadula mentioned above (also listening to that right now!), it's not that much different from S3X or Mainline. What i mean to say is; i'm not missing anything with Crack. It's all in there, just a different presentation.

Ranked in order of use:
1. Crack (did anyone mention that tube-rolling is fun?)
2. Mainline
3. S3X

Even with Mainline and S3X next to it, my Crack gets most usage.

Ranked in order of sound quality:
1. Mainline
2. S3X
3. Crack

This is a no-brainer, if you are looking for the best. Get a Mainline. It is the best. Period.

Ranked in order of versatility:
1. S3X (it's moving again to a different room, for speaker use only).
2. Mainline
3. Crack

S3X can feed speakers aswel as headphones in all genres. I've listened to it with various efficient speakers, B&W P9's, HD800's and LCD3's and all sound good with S3X.

Ranked in order of learning experience:
1. Crack
2. S3X
3. Mainline

Crack is the most simple circuit, with the most room for improvement. This makes for a lot of opportunity to learn about circuitry and the effect of certain parts on the actual sound.
As the volume-pot mentioned above. The Bottlehead team put in a good basic volume pot and left enough room in Crack to let the builder put in any pot they wish for.

Ranked in order of sheer fun:
1. Crack
2. Crack
3. Crack

For me, the fun in Crack is derived for the majority from the learning experience. The other part is tube-rolling. Crack is made for tube-rolling.

Ranked for ease of build.
1. You can build them. All three.
2. Yes, you read correct. The manual is so good that with determination everyone can build a Bottlehead kit.
3. I build my Crack with 0 experience in electronics (even had to buy my first soldering iron before i could start).

The quality of the manual and support are the most important things about a DIY kit. And Bottlehead in my experience, is brilliant with both. They deliver a very thorough manual, that takes you trough the whole build, step by step. Everything is in there, from the first soldering lesson up to safety instructions on how to check your amp and where to start when you need to troubleshoot.
If you can't figure it out on your own, there's the support forum where the team will stay with you until your problems are all resolved (when needed).
When you buy a Bottlehead kit, your not on your own to build just a kit. You also buy a very complete manual that will guide you and a team that will give advice until you've completed your journey and are 100% satisfied with your build.

Sorry, what was the question? xD
There are other amps you can roll you tubes like crazy. :)

Then you need to roll headphones and DACs. Way to go! LOL

BTW, the Mainline is the best of the three from the Bottlehead. Period.
 
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Mar 29, 2019 at 11:27 PM Post #1,859 of 2,108
The Aeolus sounds very good with my Crack. Get the speed ball, if you build a Crack.

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.

One of the best upgrades to do once you've maxed out your Crack and thinking of selling is to replace the power rectifier net with Cree diodes on a PCB. https://www.partsconnexion.com/DIODES-68247.html
I like how in this thread Doc goes ahead and suggests you may as well upgrade to a Mainline if your starting to mess with your power supply at this level of quanta. I disagree. Upgrade your crack for a couple bux and see if you like it. The diodes are kind of the building blocks and clean up the PS a lot. IMHO.

IMHO changing the diodes out after you've done everything else will make you hungry for a bit more and maybe Mainline is a good direction after that.
 
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Mar 30, 2019 at 12:35 AM Post #1,860 of 2,108
One of the best upgrades to do once you've maxed out your Crack and thinking of selling is to replace the power rectifier net with Cree diodes on a PCB. https://www.partsconnexion.com/DIODES-68247.html
I like how in this thread Doc goes ahead and suggests you may as well upgrade to a Mainline if your starting to mess with your power supply at this level of quanta. I disagree. Upgrade your crack for a couple bux and see if you like it. The diodes are kind of the building blocks and clean up the PS a lot. IMHO.

IMHO changing the diodes out after you've done everything else will make you hungry for a bit more and maybe Mainline is a good direction after that.
I don't doubt it offers improvements, and the diode and pcb are pretty cheap.

With that said, and IMO, every upgrade past Speedball seems to be a 1-2% improvement in sound. Sure, you can add the diode, pcb, new caps, bypass caps, choke, silver wire, and so on, and so forth... But what are you getting? 10-15% total improvement for 300% to 500% of the original price? Honestly, I don't think the squeeze is worth the juice. I'd rather put the money into better tubes or source. As Doc suggests, a better design will beat out boutique part upgrades every time, so you might as well get Crack-a-two-a or Mainline.

Different philosophies I suppose.
 
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