[Lickumms]

Around $230. The Tung Sol is going to cost you $150+ and the Mullard will cost about $70.

 

[bmilcs]

  Around $230. The Tung Sol is going to cost you $150+ and the Mullard will cost about $70.

Jeeeeeesus. I didn't realize it would be that much.

 

[bmilcs]

Better yet, will it make a sizeable difference?

 

[Lickumms]

  Better yet, will it make a sizeable difference?

I am not sure if the 5998 will make a big difference of not. I know the 7236 made a pretty noticeable difference over the stock 6080. The 7236 improved the sound stage and tightened the bass up quite a bit. I would maybe start with a 7236 like a Cetron or a Sylvania. I really like the Cetron it is a great starting place for tube rolling and it a very good tube and will only put you back $40. Another option for a power tube would be 6AS7G/Russian 6H13C they are pretty cheap, less than $30, and do increase the over all tube sound.
 
I bought my Cetron off of eBay.: http://www.ebay.com/itm/7236-CETRON-BID-USA-NOS-Balanced-sub-for-5998-6520-421A-6080-6AS7-No-Reserve-/252572540429?hash=item3ace7f1e0d:g:dOEAAOSwCGVX2e0E
 
Though the biggest sound difference will come from changing out the input tube. I personally found the stock tube on the crack to be far to bass heavy and sloppy. I'm not really sure what to recommend because they all change the sound so much it really comes down to what you personal preference is. I would probably start off by buying a RCA 12au7 or any 12au7 that is around $20. Even at the lower price you will notice a pretty large difference.
 
 
For other tubes you can use check out this forum: http://bottlehead.com/smf/index.php?topic=663.0

 

[bmilcs]

 
I am not sure if the 5998 will make a big difference of not. I know the 7236 made a pretty noticeable difference over the stock 6080. The 7236 improved the sound stage and tightened the bass up quite a bit. I would maybe start with a 7236 like a Cetron or a Sylvania. I really like the Cetron it is a great starting place for tube rolling and it a very good tube and will only put you back $40. Another option for a power tube would be 6AS7G/Russian 6H13C they are pretty cheap, less than $30, and do increase the over all tube sound.
 
I bought my Cetron off of eBay.: http://www.ebay.com/itm/7236-CETRON-BID-USA-NOS-Balanced-sub-for-5998-6520-421A-6080-6AS7-No-Reserve-/252572540429?hash=item3ace7f1e0d:g:dOEAAOSwCGVX2e0E
 
Though the biggest sound difference will come from changing out the input tube. I personally found the stock tube on the crack to be far to bass heavy and sloppy. I'm not really sure what to recommend because they all change the sound so much it really comes down to what you personal preference is. I would probably start off by buying a RCA 12au7 or any 12au7 that is around $20. Even at the lower price you will notice a pretty large difference.
 
 
For other tubes you can use check out this forum: http://bottlehead.com/smf/index.php?topic=663.0

Thank you for the advice.
 
Tightening up the bass would definitely be appreciative. I have to say the more I listen, that's the one place where I feel improvement could be had.

 

[buke9]

The RCA 6080's aren't the best for lower impedance headphones at all the bass is for sure flabby. Chatham 6080's much better and for me the 5998 better still. I'm not allowed to buy anymore tubes at the moment as I bought a new tube amp that works better with my Planars . I'll have to wait till Christmas bonus time to get anymore and maybe some higher impedance cans that will pair better with the Crack.

 

[bmilcs]

I went ahead and purchased that CETRON tube
 
I have a hard time finding the right input tube on ebay. What am I looking for? NOS isn't all that important; just as long as it's tested and working well.

 

[Lickumms]

  I went ahead and purchased that CETRON tube
 
I have a hard time finding the right input tube on ebay. What am I looking for? NOS isn't all that important; just as long as it's tested and working well.

I mainly look for tubes that test new or at least good. Personally I would start off with a cheap good tube to see if you notice a sound difference like a  RCA 12AU7 Clear Top. They are usually less that $15. It was the first tube I bought and I noticed that while it didn't change the sound sig that much it really cleaned up the bass a lot. Though your ears are different than mine and you might notice a bigger or smaller difference.
I would get something like this: http://www.ebay.com/itm/RCA-12AU7-Clear-Top-Vacuum-Tube-Tested-New-On-Calibrated-Hickok-/331979425620?hash=item4d4b840754  Or any other one that test well.
 
After trying out that tube, if you wanted to move up to a more expensive tube, I would maybe read some threads about different tubes and see if you can find one that may better suit your preference. Or try out different brands and models of tubes around the $20 range.

 

[bmilcs]

 
I mainly look for tubes that test new or at least good. Personally I would start off with a cheap good tube to see if you notice a sound difference like a  RCA 12AU7 Clear Top. They are usually less that $15. It was the first tube I bought and I noticed that while it didn't change the sound sig that much it really cleaned up the bass a lot. Though your ears are different than mine and you might notice a bigger or smaller difference.
I would get something like this: http://www.ebay.com/itm/RCA-12AU7-Clear-Top-Vacuum-Tube-Tested-New-On-Calibrated-Hickok-/331979425620?hash=item4d4b840754  Or any other one that test well.
 
After trying out that tube, if you wanted to move up to a more expensive tube, I would maybe read some threads about different tubes and see if you can find one that may better suit your preference. Or try out different brands and models of tubes around the $20 range.

 
The problem I have when it comes to these things is the lack of organization. There are 100 forum pages at Bottlehead in a single thread on tube rolling. I have two kids, 8 and 12, a wife, and am very busy. 
 
Is there an organized means of checking out my options?

 

[Lickumms]

   
The problem I have when it comes to these things is the lack of organization. There are 100 forum pages at Bottlehead in a single thread on tube rolling. I have two kids, 8 and 12, a wife, and am very busy. 
 
Is there an organized means of checking out my options?

Sadly, not really.
If you wanted to go with a more expensive tube you could look into getting a Philips SQ E82CC. I would describe it as a warm tube with its clean and balanced sound and very tight, accurate, bass. It is an excellent tube though it can be rather hard to find.
 
This site does give you a general idea of how different tube brands sound. http://www.audiotubes.com/12au7.htm

 

[bmilcs]

I have both of your tube recommendations plugged into my Crack .
 
It definitely cleared things up. Treble seems to be much more forward, but where'd my bass go?
 
I imagine breaking them in will make a difference yes?

 

[Lickumms]

Which input do you have? The RCA clear top? If it is the clear top it is a more treble focused tube.
It is pretty much the polar opposite of the stock input tube and one of the better tubes you can get for under $20. Though it should still have some bass. Not nearly as much as the stock tube but still some.
 
The bass should increase over time as the tube is burned in. Though combined with the 7236 the RCA can end up being a bit bass lite. I find that with NOS tube it tends to take 10-20 hours of use before it is properly burned in.
 
If the RCA ends up not being to your liking I would check out a Genalex Gold Lion 12AU7.
It is a new production tube. It is a very mid focused tube with tight, accurate, bass and decent overall detail. Though, compared to the RCA it will have almost no highs and may sound a bit dull.
 
Or you could try the Philips SQ E82CC. It is probably my favorite tube but is a bitch to find.

 

[Quadfather]

The problem I have when it comes to these things is the lack of organization. There are 100 forum pages at Bottlehead in a single thread on tube rolling. I have two kids, 8 and 12, a wife, and am very busy.

Is there an organized means of checking out my options?

I have a 24 year old daughter, 18 year old quadruplets, a wife, two dogs, and a cat and I find the time. I love audio that much! This hobby is as addictive as heroin. LOL