[JamieMcC]

It would be great if you let me know what you think of the sound, because it looks great, but that doesnt really meam much about its sound. And I guess it is a good idea to rather get it from the actual supplier.

I am still curious about a good place to get great condition 5998 tubes that isn't from EBay. I would rather pay a bit more and get a tube that I know will work for a while, or is reliability not a problem for the Tung-sol tube? This question is obviously directed at everyone.

 
 
Firstly I will comment of the RN55 Dales they are the only type of resistor I have tried so far that I am unable to tell if they change the sound of the amp through my headphones often using other less expensive resistors you can make out subtle differences/characteristics after fitting or removing them from the signal path. 
 
Comparing my Valab attenuator against the attenuator with RN55's the differences are very subtle and perhaps even subjective but I like what I am hearing (or should that be what I am not hearing) with RN55 the Valab is around $20 and imo is a one of the best value upgrades for the Crack you can get.
 
The Valab in comparison to the stock pot is increased resolution and clarity and low level listening is balanced. The draw back of fitting the Valab is the amount of steps is limited to 23 so you do not have the fine tuning of the volume level the stock pot or a 36 step attenuator would give.
 
But If you are running a pc based system and can attenuate the level of the music you listen to with your software volume slider on the media player you use then finding the sweet spot with the Valab's 23 steps should not be a problem.
 
One of the things to consider is that if fitting a high quality attenuator how much benefit will it give you in your system and is the rest of your system going to limit the perceived performance of the new attenuator.
 
Something like the Alps blue velvet or Valab is going to bring a noticeable improvement over the stock pot for not much outlay the savings made with going for these less expensive but still very good options is that there will be money left over for say the 5998, film output caps etc .These I suspect in combination will give a greater improvement than just a more expensive attenuator on its own.

 

[Doc B.]

Clarification: number of steps does not = how "fine" you can tune the level. That is determined by the amount of attenuation per step. As an example a 23 step attenuator with 1.5dB steps will have double the step resolution of a 36 step attenuator that is 3db per step.

 

[JamieMcC]

  Clarification: number of steps does not = how "fine" you can tune the level. That is determined by the amount of attenuation per step. As an example a 23 step attenuator with 1.5dB steps will have double the step resolution of a 36 step attenuator that is 3db per step.

 
Yes of course you are right doc and there needs to be a balance found between individual step resolution and the total range of resolution available and this is a consideration when using the stepped attenuators. But if a 24 and 36 step attenuator are both equal in their total range of attenuation it is highly probable the 36 step will offer finer increments. Which was what I was trying to get across in my ham fisted way.

 

[NightFlight]

  I did exactly that.  I LOVED the HD600 + Crack but I wanted the bigger sound stage and more detail.  
 
I know I am in the minority here, but I hated the HD800's and the Crack (Speedball, Mundorf caps, Blue Velvet Pot, Telefunken ECC83, Tung Sol 5998).  I was actually going to return the HD800's because I 100% preferred the HD600 to the HD800's.  A fellow head-fi'er talked me out of it.  The HD800's have rich blood and to sound right (to me) they something pretty major behind them.  My analogy (despite it not being perfect) is the HD800's are like a Ferrari F60.  It's really an amazing thing.  But put the wrong tires, fuel and oil on/in it, however, and it's a mess.  You're better off with a less expensive car with the right tires, fuel and oil.  It wasn't until I upgraded my amp that I fell in love with the HD800's.  Having lived with both setups for a long time now the HD600 + Crack still very well holds its own and it has lost nothing when it come to an enjoyable listed.  What you already have is a really special combination.
 
But that's me, IMHO, YMMV, etc etc etc.  Many others here would strongly disagree and that's okay, to each their own.  But that was my experience.  

 
Thanks, that gives me much hope for the Mainline.  
 
I for one have tried the HD600's and HD800's side by side with my amp and another at a meet last year. The meet worked out that myself and Greyhorse got to be the bottlehead table.  Also, I brought a bunch of tubes to try.

  In our case we both agreed that the 5998 was the biggest change overall in terms of tube and for the better. We also both preferred the 800's, but more so with the 5998. The HD800 seems to (sort of) slurr with the RCA 6080.  Greyhorse really wanted to buy my 5998 on the spot. I had to say no a few times... and even keep a close eye on it (jokingly of course!) I'm convince someone sprinkled pixie dust on mine because the WE-421A at least to my ears... had nothing on it but a bit of screech.
 
Having started out with the 800's the test of the 600's was kind of a shock for me. Like a bit of a step backward. 
 
So while having found different preferences as you stated above, I still think the Mainline is likely to bring out more of the best out of the 800s. That's the hope anyhow. 

 

[NightFlight]

My brother also gave me this Alps pot with the bag of goodies the Khozmo came in (wire/caps/pots/heat shrink). I just noticed it's a switched pot as well.. I'm guessing its supposed to be okay too.
 

 

 
 
Not certain what all the pins are.
 
Edit: Wait. Bottom row(in) is Left, Ground Right Ground. Top row is out. 
Edit: Hey, it IS a blue velvet. That's what I get for posting without googling first.

 

[Mich4lle]

 
 
But If you are running a pc based system and can attenuate the level of the music you listen to with your software volume slider on the media player you use then finding the sweet spot with the Valab's 23 steps should not be a problem.
 

 
Oh Okay, I didn't realise that if you are running the crack through a PC that the balance issues at low volumes is not a problem. So does this mean that if I run my Crack through a DAC then I don't necessarily have to spend money on a fancy Attenuator? Will I see any improvement over the stock volume pot at all?

 

[JamieMcC]

   
Oh Okay, I didn't realise that if you are running the crack through a PC that the balance issues at low volumes is not a problem. So does this mean that if I run my Crack through a DAC then I don't necessarily have to spend money on a fancy Attenuator? Will I see any improvement over the stock volume pot at all?

I doubt you will see any improvement in sonics if using stock pot but you should be able to over come low level channel imbalance this way that is if you are experiencing any in the first place.

 

[Jeb Listens]

Hi all!

I've had a Crack kit in the top of my wardrobe for a couple of months now. When I received it I was pretty busy and still enjoying my other amps so tucked it away for calmer times.

When I received it I was very enthusiastic. Over the last few weeks i guess I've become a bit daunted by the thought of undertaking the build. I don't have any DIY electronics experience. Just wondering if other people felt this way and how they found the process?

Jeb.

 

[bigfatpaulie]

   
Thanks, that gives me much hope for the Mainline.  
 
I for one have tried the HD600's and HD800's side by side with my amp and another at a meet last year. The meet worked out that myself and Greyhorse got to be the bottlehead table.  Also, I brought a bunch of tubes to try.

  In our case we both agreed that the 5998 was the biggest change overall in terms of tube and for the better. We also both preferred the 800's, but more so with the 5998. The HD800 seems to (sort of) slurr with the RCA 6080.  Greyhorse really wanted to buy my 5998 on the spot. I had to say no a few times... and even keep a close eye on it (jokingly of course!) I'm convince someone sprinkled pixie dust on mine because the WE-421A at least to my ears... had nothing on it but a bit of screech.
 
Having started out with the 800's the test of the 600's was kind of a shock for me. Like a bit of a step backward. 
 
So while having found different preferences as you stated above, I still think the Mainline is likely to bring out more of the best out of the 800s. That's the hope anyhow. 

 
 
The Mainline is a top shelf amp and anyone would be lucky to have it.  The Mainline has a very different in signature VS the Crack, however.  The Crack is warmer sounding and what one would more expect from an OTL amp.  The Mainline is much more transparent a neutral and leaves the Crack in the dust in virtually every technicality you can imagine.  It's just fantastic with the HD800's and it will certainly elevate your HD800's by leaps and bounds.  

 

[dsound]

Hi all!

I've had a Crack kit in the top of my wardrobe for a couple of months now. When I received it I was pretty busy and still enjoying my other amps so tucked it away for calmer times.

When I received it I was very enthusiastic. Over the last few weeks i guess I've become a bit daunted by the thought of undertaking the build. I don't have any DIY electronics experience. Just wondering if other people felt this way and how they found the process?

Jeb.

Hey there.  The documentation is top notch so I wouldn't worry.  Just remember to go slow and make sure you have good solder-joints.  Also, the Bottlehead forum members are extremely helpful with troubleshooting should the need arise.

 

[bigfatpaulie]

Hi all!

I've had a Crack kit in the top of my wardrobe for a couple of months now. When I received it I was pretty busy and still enjoying my other amps so tucked it away for calmer times.

When I received it I was very enthusiastic. Over the last few weeks i guess I've become a bit daunted by the thought of undertaking the build. I don't have any DIY electronics experience. Just wondering if other people felt this way and how they found the process?

Jeb.

 
Just take your time and you'll be fine  

 

[JamieMcC]

Hi all!

I've had a Crack kit in the top of my wardrobe for a couple of months now. When I received it I was pretty busy and still enjoying my other amps so tucked it away for calmer times.

When I received it I was very enthusiastic. Over the last few weeks i guess I've become a bit daunted by the thought of undertaking the build. I don't have any DIY electronics experience. Just wondering if other people felt this way and how they found the process?

Jeb.

 
I felt the same way when my kit first arrived when you haven't done any soldering or even used a multimeter before it can very daunting.  I practised my soldering first on a few scraps of wire I had lying around which helped get my confidence up along with watching Tyll Hertsens Crack build video for help full tips I actually stopped mid build a couple of times to watch the video again.
 
Because each step of the build is covered not only by written instructions but also with lots of pictures having the visual reference makes following any confusing bits much easier.   
 
Take your time read and check each step before going to the next and before you know it you will be enjoying the build and have a great sounding Crack at the end. If you get stuck or just want a little confirmation on anything just post a message on the Bottlehead forum and the Bottlehead team will soon get back to you.
 
Good to see another UK based builder.

 

[Jeb Listens]

Thanks for the encouragement and suggestions, guys - I'll give it a go soon.
 
 I think in part it was all the safety stuff at the start of the manual that gave me cause to worry a bit!  Obviously - that's probably the point (to really make you stop, take note and think about consequences) and it's vitally important stuff.   I'm very cautious and like to be very precise, so I'll just go very slowly and try and enjoy the process.
 
Jeb.

 

[JamieMcC]

 
Thanks for the encouragement and suggestions, guys - I'll give it a go soon.
 
 I think in part it was all the safety stuff at the start of the manual that gave me cause to worry a bit!  Obviously - that's probably the point (to really make you stop, take note and think about consequences) and it's vitally important stuff.   I'm very cautious and like to be very precise, so I'll just go very slowly and try and enjoy the process.
 
Jeb.

 
Hi Jeb I would also suggest breaking the build down into sections and not trying to hook it all up in a marathon session.

 

[Jeb Listens]

   
Hi Jeb I would also suggest breaking the build down into sections and not trying to hook it all up in a marathon session.

Cool, thanks Jamie, I will do just that.   My current headphones are LCD-2s, which I understand are not really suitable for the Crack.  So as well as a soldering iron i'll need to get some headphones too! -  I guess it just comes down that that age-old choice between the HD600 and HD650 -  any pointers there? HD600 more neutral and 650 a bit warmer - correct?  
 
Jeb.