Tube Rolling w/Crack

[kscwuzhere]

Thanks guys. Siemens E80cc ordered

Now that you have your e80cc's, I highly recommend this mod to run it at the correct voltage:

http://bottlehead.com/smf/index.php/topic,5989.30.html

I noticed significant sound improvements when running the tubes at the correct voltages and it also will increase the life of your tube!

 

[Strikkflypilot]

Thanks, I though it was a drop in replacement when the speedball is installed, ref first post.

 

[JamieMcC]

Thanks, I though it was a drop in replacement when the speedball is installed, ref first post.

It basically is and I used mine that way for six months before doing the above mod which tweaks the circuit to a better operating point for the tube so it performs a little better. The mod is easy enough and can be done for well under $10 and well worth the short time it takes to do.

 

[Strikkflypilot]

Sweet. Why stop modding now
By the way, it seems Your resistors are in parallell for E80CC mod and not in series.
Cool way of doing it! I probably would have found a switch between a 237 and 470ohms resistor that alternates between them.

Would this do as a switch? http://www.farnell.com/datasheets/1633279.pdf
Planning on superglueing the base to each of the small speedball boards.

Oh, and these are the Resistors I am getting: http://no.farnell.com/multicomp/mf12-470r/resistor-0-125w-1-470r/dp/9343245
Those are metal film. Anyone prefer carbon composition?

 

[Paul Joppa]

Don't use carbon comp - they are noisy when DC current flows, and they drift in value. Metal film or bulk metal foil ($$) were recommended by the original designer, John Camille.

 

[Strikkflypilot]

Thanks Paul, I thought I had read something like that around here.

 

[Strikkflypilot]

I am asking the tech experts here, the switches that have been applied, and the one I have bought myself are very large.

What are the specs they need to fulfill in order to switch from one 470ohm to two 470ohms in parallell in terms of heat tolerance, voltage and current?

 

[Paul Birkeland]

What are the specs they need to fulfill in order to switch from one 470ohm to two 470ohms in parallell in terms of heat tolerance, voltage and current?

Almost nothing.  3V, 5mA.

 

[Strikkflypilot]

Thank You so much That should reduce size and weight a bit!

 

[pduk]

I got a nice TS 5998 a few weeks ago when a bunch popped up on ebay and have been busy listening and trying to match up 12au7s to it for a while now. I had a bit of an epiphany yesterday... I got a really cheap deal on some tung-sol 6080s (just plain 6080) a while back being the only bidder on an auction from Germany, had installed one and really liked it, but then started with the 5998.

I went back to the 6080 yesterday and... I prefer the sound over the 5998. It's got much more heft on the bottom end, the stereo imagery seems more "wide" somehow, and the top end is less fatiguing. I received two 1964 GE 5814A's today (this ebay habit is getting ridiculous but I couldn't resist trying a valve made one year before I was born, and they were only £13 each) and the match is wonderful, to my ears.

I do know I have a preference for low/mid and don't like too much piercing treble. Perhaps this combination happens to suit my ears, or maybe my 5998 is lacking somehow... or is it a case of the Emperors new clothes with some of the pricier valves? I was wondering whether anyone else ended up settling on something else having tried the 5998 or am I the only one?

Paul.

 

[JamieMcC]

I do know I have a preference for low/mid and don't like too much piercing treble. Perhaps this combination happens to suit my ears, or maybe my 5998 is lacking somehow... or is it a case of the Emperors new clothes with some of the pricier valves? I was wondering whether anyone else ended up settling on something else having tried the 5998 or am I the only one?

Paul.

Paul I don't think your alone here I will often listen to a Mullard or GEC 6080 in preference to the 5998 both cost a quarter of the price and can often still be found for under $15. While the 5998 is the more competent all round tube sometimes depending on the genre listened to certain 6080's can be just glorious with a particular track or album.

 

[Paul Joppa]

I think one of the problems is that a tube in high demand will more likely have gone through several hands before you get it, and the good ones have been weeded out of the pool of available ones.

I also suspect (but can't prove) that an important parameter is the trace chemistry of the oxide coating, which will vary between individual tubes - the tube type and/or manufacturer is correlated but not an infallible indicator. Since it's all proprietary secrets, there are no specs to go by.

 

[kscwuzhere]

I just got an awesome deal on a WE421A yellow/orange label, clear top and this thing is fantastic! I found that compared to my Chatham 5998 the we421a has a slightly smoother and extended top end as well as more perceived timbre in each instrument. I also found mid-highs to sound a little more detailed as I can tell each notes transients better. One hell of a tube!!

 

[i luvmusic 2]

Is it possible to run 6AS7G/6080 as input tube with a external power supply for the tube heater and what are the necessary MOD to run this tube for the CRACK?THANK YOU!

 

[hardisondan]

Is this the right tube for my Crack? In all the photos I've seen of people's completed kits, I don't think I've seen this one..

I like the look of it.. looks a bit like the 300B (in my limited experience), but I hope I've been shipped the right one.

Dan

 

[John EH]

What are the markings on the box or tube say.  Probably a Sovtek 6AS7G.  If so that will work fine.

 

[hardisondan]

Yes, the box has 6AS7 on it.

Thanks

 

[Joshewah]

That's the right tube. It's just the (sexier) ST bottle shape versus the ruggedized shorter bottle of the militarized 6AS7

 

[Paul Birkeland]

Is it possible to run 6AS7G/6080 as input tube with a external power supply for the tube heater and what are the necessary MOD to run this tube for the CRACK?THANK YOU!

This won't work all that well, as the overall gain of the circuit will drop drastically, to maybe something like 5dB with Speedball and maybe 1-2dB without Speedball.  You would also need two of the large Speedball boards to facilitate this.

 

[i luvmusic 2]

I thought it would but that's ok, THANK YOU!