[adydula]

Ok I will take some tomorrow the larger tube the power 6080 type is a really old RCA large bottle looking type and its looks really cool
 
I am 66yrs old now and grew up with these valves! Ha!!
 
I have built some really complex tube projects over the years, this one is so simple it makes me laugh.....
 
Alex

 

[DDDamian]

I'm amazed when I peer into the innards of my SS amp and see the sheer number of parts. Then I flip the top of the Crack and say "Wow - all that sound out of this??"

 

[Aeolus Kratos]

  @Aeolus Kratos, I recently swapped my ting tingy, actually squeally 5998 out for a new one. If you're in Europe we can try getting my unused tube to you so you can try it out yourself for comparison. No strings attached.
 
PM me if you're interested. 

Hi Moriez,
 
Sorry for replying this late, I'd been traveling for business last week, just came back today.
 
That's very kind of you. I would love to take your offer. Unfortunately, I'm not in Europe, so shipping the 5998 back and forth to my country may take a long time and high cost too.
 
Warm regards,
Kratos.

 

[moriez]

You're welcome and no worries. All is well that ends well. WhiteRaven lives relatively close to me so we have ideal circumstances. Maybe someone else is willing to give you a peek.

 

[adydula]

I found a small hardly perceivable 12AU7 on my signal tube in the crack....but no symbol or marking for a particular manufacturer.
 
The larger tube has nothing I can discern here are some pix if anyone thinks they know what it might be:
 

 

 

 

 

 


 

 

 
Will work on finishing up the case this week.
 
Alex

 

[Whit3Rav3n]

  A very generous offer Whit3Rav3n. The 5998 has a lot of detail. Try seek out a CIFTE (Mazda) 12AU7 to pair it with. My favourite combo so far for detail and a livelier sound. Some of the stock 6080's are a little warm/dull.

Thanks for the tip, maybe I will first try to get an rca clear top tube, they seem to be considered pretty good and they are cheap. The Mazda 12AU7 tubes seem to be hard to get and pretty expensive. Moriez was generous enough to lend me his 5998 so I will be able to test it out and see how it compares to the original tube. 

 

[FunyunBreath]

Just scored a vintage NAD 3020 to go along with my Crack as a solid-state option. The sound signature on this thing is unbelievably close to the Crack, but it seems to do really well with 32 ohm headphones and even 16 ohm IEM's.
 
Picked this thing up on Craigslist for $75 and after a little clean up and Deoxit on the switches/pot it sounds good as new!
 

 

[adydula]

Bottlehead guys told me it is a 6AS7G.....great!
 
Alex

 

[DDDamian]

  Thanks for the tip, maybe I will first try to get an rca clear top tube, they seem to be considered pretty good and they are cheap. The Mazda 12AU7 tubes seem to be hard to get and pretty expensive. Moriez was generous enough to lend me his 5998 so I will be able to test it out and see how it compares to the original tube. 

The clear-tops are well-regarded and much easier to obtain. I'd warn against Mullards if you're finding things a touch dull - they and the ECC82 might be a bit too smooth for your output tube.
 
Hope you like the 5998 - it's a beauty and clear, detailed and lively.

 

[Whit3Rav3n]

  The clear-tops are well-regarded and much easier to obtain. I'd warn against Mullards if you're finding things a touch dull - they and the ECC82 might be a bit too smooth for your output tube.
 
Hope you like the 5998 - it's a beauty and clear, detailed and lively.

Am I correct that this is the RCA clear top that is well regarded?
 
http://www.ebay.com/itm/RCA-12AU7-ECC82-CLEARTOP-VACUUM-TUBE-SINGLE-LOW-NOISE-SUPER-SWEET-WARM-TONE-R04k-/111605051737?pt=LH_DefaultDomain_0&hash=item19fc2df159
 
As far as I have checked the RCA clear top sounds rather clean and bright so it might work well for me.

 

[FunyunBreath]

Yup thats the one, good price too

 

[johnnypaddock]

Great price on that, well worth picking one up. I think I paid $30 for one just a few months ago. It has a nice top end, but I find it slightly lacking in the midrange, kind of a lean sound.

 

[Whit3Rav3n]

Thanks, I ordered one and will see how it sounds. At least it was pretty cheap so it is not a big deal if it is not ideal.

 

[FunyunBreath]

I totally agree with that critique. I picked up a lot of 20 for crazy cheap on ebay and haven't really been using them much. I prefer the fuller mid-centric sound of the Amperex 12au7's.

 

[johnnypaddock]

I'd like to try the Amperex, as well as the Mullard CV4003. I'm currently using a CBS Hytron that seems to match very well.