Tube Rolling w/Crack

Dr. Toobz · 1230478

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Offline Strikkflypilot

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Reply #885 on: June 24, 2014, 07:34:00 AM
Thanks Paul, I thought I had read something like that around here.

Home system:
Sources: Ibasso DX90, Google Chromecast Audio optical out
DAC: Schiit Gumby
Amp: Bottlehead Mainline
http://bottlehead.com/smf/index.php?topic=7463.0
Phones: HD800S

Office:
Sources: Iphone/ Ipod
DAC: Dragonfly Red+Jtrbug
Amp: Crack/Speedball heavily modded
Phones: HD580,HD600 grilles


Offline Strikkflypilot

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Reply #886 on: June 25, 2014, 10:15:17 PM
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?

Home system:
Sources: Ibasso DX90, Google Chromecast Audio optical out
DAC: Schiit Gumby
Amp: Bottlehead Mainline
http://bottlehead.com/smf/index.php?topic=7463.0
Phones: HD800S

Office:
Sources: Iphone/ Ipod
DAC: Dragonfly Red+Jtrbug
Amp: Crack/Speedball heavily modded
Phones: HD580,HD600 grilles


Offline Paul Birkeland

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Reply #887 on: June 26, 2014, 07:54:21 AM
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.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Strikkflypilot

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Reply #888 on: June 26, 2014, 11:16:35 AM
Thank You so much:) That should reduce size and weight a bit!

Home system:
Sources: Ibasso DX90, Google Chromecast Audio optical out
DAC: Schiit Gumby
Amp: Bottlehead Mainline
http://bottlehead.com/smf/index.php?topic=7463.0
Phones: HD800S

Office:
Sources: Iphone/ Ipod
DAC: Dragonfly Red+Jtrbug
Amp: Crack/Speedball heavily modded
Phones: HD580,HD600 grilles


Offline pduk

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Reply #889 on: June 28, 2014, 06:55:16 AM
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.



Offline JamieMcC

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Reply #890 on: June 28, 2014, 07:46:44 AM

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.



Shoot for the moon if you miss you will still be amongst the stars!


Offline Paul Joppa

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Reply #891 on: June 28, 2014, 01:16:06 PM
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.

Paul Joppa


Offline kscwuzhere

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Reply #892 on: July 02, 2014, 09:22:03 AM
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!!


« Last Edit: July 02, 2014, 10:11:26 AM by kscwuzhere »



Offline i luvmusic 2

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Reply #893 on: July 02, 2014, 12:19:52 PM
 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!
« Last Edit: July 02, 2014, 12:38:17 PM by i luvmusic 2 »



Offline hardisondan

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Reply #894 on: July 03, 2014, 01:06:15 AM
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



Offline John EH

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Reply #895 on: July 03, 2014, 02:23:26 AM
What are the markings on the box or tube say.  Probably a Sovtek 6AS7G.  If so that will work fine.



Offline hardisondan

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Reply #896 on: July 03, 2014, 03:23:10 AM
Yes, the box has 6AS7 on it.

Thanks



Offline Joshewah

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Reply #897 on: July 03, 2014, 03:39:26 AM
That's the right tube. It's just the (sexier) ST bottle shape versus the ruggedized shorter bottle of the militarized 6AS7



Offline Paul Birkeland

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Reply #898 on: July 03, 2014, 04:53:21 AM
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.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline i luvmusic 2

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Reply #899 on: July 03, 2014, 12:10:34 PM
I thought it would but that's ok, THANK YOU!