[captouch]

 

In my build, the Speedball was the first upgrade and made by far the biggest improvement.

Have you tube swapped at all?

 

[Beefy]

 
Quote:

Have you tube swapped at all?

I have tried several 12AU7/12BH7 options for the driver, and a couple of 6AS7/5998 for the power tube.
 
Swapping the driver tube makes very little difference, while the 5998 offers a small additional improvement over 6080/6AS7 - but not nearly as much as the Speedball.

 

[BmWr75]

Quote:

 

In my build, the Speedball was the first upgrade and made by far the biggest improvement.

I built my Crack with the Speedball from the get go, so never heard it without the Speedball upgrade.
 

 

[RingingEars]

The speedball will be the next upgrade to go in mine.
I just love huge caps and the cheap stereo pot had to go so now that I have that out of my system I'll do the speedball.
I do notice a small sonic improvement in the cap/pot upgrade I did last night. It brought the mids forward a little more on the DT880 and made the highs clearer.
I hear a lot about the DT880 highs being a little overwhelming, but I have never noticed it. They always sound smooth to me paired with the stock crack and now with the upgrades even more-so. I'm loving it so far. I would like to try other tube or even some SS amps with the Beyers just so I can have some comparative notes, but so far I don't see any reason too.

 

[tdogzthmn]

Are any Crack owners looking to get a Smack amp?  I wonder if it would make a good compliment.

 

[Armaegis]

I should have a Smack coming in as soon as they get their first run of their kits finished up.

 

[Oberst Oswald]

I built the SEX 2.1 and am more than happy with it.  The sound is excellent with the 3 dynamic headphones that I have.  Bottlehead is on a roll with the 3 headphone amps and should be interesting reading to compare the 3 amps with, lets say, Senn HD 800 with is in the middle at 300 ohms to be fair.

 

[tdogzthmn]

I fully agree that a threesome review of these amps is a must. I would be more than willing to do such a review but it will take some time for me to get all three in my possession. I would also say the HD600 would make a good can to use due its popularity and that most of these amps were built using the HD600 as a reference point.

 

[RingingEars]

It would be nice to try the Smack(or have the Smack along side the Crack) since there are so many great lower impedance cans out there...

 

[Aart]

On my quest to eliminate annoying background noise, I have tried swapping output tubes. Next step is to swap driver tubes, which driver tube would you guys recommend me ? (I use a tung-sol 5998 as output tube).
 
 

 

[tdogzthmn]

Quote:

On my quest to eliminate annoying background noise, I have tried swapping output tubes. Next step is to swap driver tubes, which driver tube would you guys recommend me ? (I use a tung-sol 5998 as output tube).
 
 

For me the 5998 was noticeably quieter than the other tube types I tried.  The other tube I use is the E80CC which is very detailed followed by the 5814 blackplate and 6189 which I also enjoy alot.

 

[captouch]

Just ordered my kit including Speedball.

In terms of tubes, I have some 12au7's on hand to try out (Amperex Bugle Boy, Full Music that came with my EF5), but the power tubes are pricey.

It sounds like some are saying a 5998 or 421A makes a pretty big improvement, even with Speedball. However, cheapest I've seen is $80 used, and who knows how long a used tube will last.

Anyone done any comparisons between a 5998/421A and a Cetron 7236??? These are available NOS for a little over $40. I've read they're computer rated 5998A's and I've also read the 5998A's are inferior to true 5998's. Any comments would be appreciated - I don't know if I want to go down this path, but if it does make a big improvement, knowing me, it's just a matter of time before I do it.

Also, I've seen several people doing the Axon 91uF caps - it seems the effect of these are more subtle.

Roughly, does the stock Crack and Speedball get you at least 80% to the potential of the amp, or is it a no brainer, if you can afford it, to replace the power tube and caps? I don't want to chase diminishing returns, but am willing to spend some more for noticeable (not really subtle) improvements.

Thanks!

 

[RingingEars]

I did the pot and cap upgrade at the same time so I don't which one made the biggest difference, but there is a definite improvement. I dropped in a set of the AXON 91uF caps and an Alps Blue Velvet on Sat. The difference wasn't subtle at all. It really brought the mids forward.

 

[captouch]

I did the pot and cap upgrade at the same time so I don't which one made the biggest difference, but there is a definite improvement. I dropped in a set of the AXON 91uF caps and an Alps Blue Velvet on Sat. The difference wasn't subtle at all. It really brought the mids forward.

No Speedball in yet, right? I understand the role of larger caps, but would the pot improve SQ as well, or just L/R balance?

Were both upgrades very easy, or quite a bit more complicated than the base build?

 

[Beefy]

 
Quote:

It sounds like some are saying a 5998 or 421A makes a pretty big improvement, even with Speedball. However, cheapest I've seen is $80 used, and who knows how long a used tube will last.

They do sound a bit better, but that price is ridiculous. I picked up two lightly used 5998 for $80 shipped when I built mine, which was pushing it - so $80 for one is downright silly.
 
If I were you, I would do all the other easy upgrades instead, and forget the 5998 power tubes. Grab a couple of NOS RCA 6AS7 for $15 a pop and they will keep you going for years.