Tube Rolling w/Crack

[Nathan]

This tube gets a double thumbs up!

So, to date- here's the whole deal

HD600's with Cardas cable
Crack with Speedball
Padded down volume control
Teflon caps to bypass audio caps
Last power supply cap bypassed with Mundorf film cap
Diy power cable- Belden 19364 with Wattgate male plug and Schurter right angle iec
Cardas input jacks

Tubes are the CV4003 and a 5998

 

[JamieMcC]

The Mullard CV4003 is one of the few 12au7 I have kept. Its a nice tube

 

[Thebb]

Can someone with experience with tubes comment on which would be a better tube paired with a 5998:
- 12au7 RCA Clear Top
-12au7 Mullard

Thanks.

 

[Paul Birkeland]

Can someone with experience with tubes comment on which would be a better tube paired with a 5998:
- 12au7 RCA Clear Top
-12au7 Mullard

Which Mullard?  There are several variants.

 

[Thebb]

Which Mullard?  There are several variants.

12au7 Mullard B Code

 

[Nathan]

Can someone with experience with tubes comment on which would be a better tube paired with a 5998:
- 12au7 RCA Clear Top
-12au7 Mullard

Thanks.

Mullard- but if I couldn't get a Mullard an RCA clear top is my 2nd choice. The best Mullard imo is a CV4003 which is a military version of a 12au7. Clear tops are available inexpensively.

 

[i luvmusic 2]

Another tube that works  with the CRACK is the C3g.

 

[Jimb0]

How would you compare them to lets say the 5998?

 

[Paul Birkeland]

Another tube that works  with the CRACK is the C3g.

No.

 

[Adrian]

Here are a couple valve combinations I've found enjoyable:

Mullard 6080 (rebranded Phillips - Mitcham Plant) with Mullard CV4003 (military) - very good with Beyerdynamic HPs.

GEC 6as7G with RCA 12AU7 Cleartop - excellent with HD600s (the Cleartop adds a little "sparkle" to the top end).

 

[Jimb0]

Very nice tubes Adrian. Been dreaming about owning the GEC 6AS7G one day.

I wonder how those would sound with the 7119's. I can only imagine.

 

[i luvmusic 2]

How would you compare them to lets say the 5998?

I don't think if that is possible i used the C3g to replaced the 12AU7.
Sorry!

 

[i luvmusic 2]

Hi Paul,
  Since i don't understand much  about electronics i can't explain why the C3g's are working well with the CRACK.
I used it to replaced the 12AU7.I really like the sound of these tubes,Someone mention that the C3g have more gain than the 12AU7 Is there any MOD i can do to run the C3g efficient?

THANKS!

 

[Paul Birkeland]

The C3G is a pentode in a different base.  To adapt one for use in a Crack, you would have to build that adapter and triode strap the tube.  Adapters are notorious for being noisy and unreliable, and when you have loose wires going into pins, somewhat dangerous. 

In the Crack circuit, two C3G's in place of the 12AU7 will not hit the target plate voltage, and will lead to excessive dissipation in the output stage's loading devices.

-PB

 

[i luvmusic 2]

The C3G is a pentode in a different base.  To adapt one for use in a Crack, you would have to build that adapter and triode strap the tube.  Adapters are notorious for being noisy and unreliable, and when you have loose wires going into pins, somewhat dangerous. 

In the Crack circuit, two C3G's in place of the 12AU7 will not hit the target plate voltage, and will lead to excessive dissipation in the output stage's loading devices.

-PB

Hi,
  Thanks for your reply!Both tubes are strapped and so far they are quiet no hum at all.Is there anything i can do to hit the target plate voltage?


Thanks!

 

[PLZ7]

So I finished building my BH Crack 3 weeks ago and I'm going to install the Speedball soon as well as interested in upgrading the stock tubes.

I don't really want to change any circuitry either to accommodate new tubes...unless its absolutely worth it cause I WILL be attaching the speedball anyway so I could do it at the same time.

I have HD650's and mostly listen to harder rock (ambient music and classical are up there also)

In the limited research I've done I've seen the NOS RCA 12AU7 Clear Top, Tung Sol 5998 and CV4003 Mullard mentioned a decent amount.

Recommendations anyone? Thanks.

 

[Jimb0]

All of those are good tubes and what most people would recommend. I would check out the JHY-CBS Hytron 5814a's as well. They are a variant of the 12AU7 and you do not need to modify anything to use them. One of the best I've heard paired with the Tung Sol 5998. Great separation of instruments, warmth, good sound stage, and clarity. The JHY-CBS Hytron 5814 are also much cheaper than the Mullard's (I can't compare the two because I haven't heard the Mullard's although I've heard they sound better than them). Make sure you get the one with flat black plates as those sound the best. These are the ones listed on eBay.

http://www.ebay.com/itm/HYTRON-JHY5814-12AU7-ECC82-6189-NOS-1950-BLACK-PLATE-TUBE-D-GETTER-/161549676801?pt=LH_DefaultDomain_0&hash=item259d1c7101
http://www.ebay.com/itm/PAIR-CBS-HYTRON-JHY-5814a-BEST-12AU7-Made-Blk-Plt-D-Getter-Vacuum-Tubes-8-V54-/231451459914?pt=LH_DefaultDomain_0&hash=item35e395014a

There's also this vintage one which is more expensive but I'm not sure if you'll get a better sound. All have flat black plates.
http://www.ebay.com/itm/RARE-CBS-Hytron-JHY-5814-12au7-ECC82-BLACK-plates-tube-Test-NOS-/171631998987?pt=Vintage_Electronics_R2&hash=item27f610780b

The other 12AU7 I tried were the Amperex Bugle Boys (very sweet, vintage sound) which also sounds great with the Tung Sol 5998 but the CBS Hytron 5814a's takes the cake.

James

 

[Paul Birkeland]

$50 for the CBS 5814 is insane.  We shipped many of that exact tube in Crack kits last year.

 

[Jimb0]

I know Paul. Most of highly sought after tubes are marked up so high these days.  :-\

 

[Paul Joppa]

Like Uber's "surge pricing"... fashion has its costs!