Tube Rolling w/Crack

[MIKELAP]

I used a 6sn7 adapter in my Crack for a year or so and rolled a number of 6sn7 tubes and didnt find any that lacked volume using Beyer T1 or HD800 my adapter was essentially plug and play.  So its odds on that its either a problem with the adapter or the tube. Maybe get a inexpensive new 6sn7 to try. I do remember when looking into using the adapter myself that one or two Crack users on headfi were having noise issues with their adapters but mine worked fine from the off.

    Well i found the problem it wasnt with the adapters it was with the tube i used a Russian 6H9C tube and for some reason thats what happened i tested the tube it tested good so i tried the other Russion tube of the pair and same thing happened low volume and it also tested good  weird so after that i tried a Kenrad vt-231 and everything is perfect so i dont understand ill go check data sheet of those Russians probably the  problem is there .Thanks   

 

[Doc B]

Punctuation is always appreciated. It makes posts a lot easier to read.

 

[galyons]

    Well I found the problem.  It wasn't with the adapters.  It was with the tube I used, a Russian 6H9C tube ...

Typo?  A Russian 6H9C is a 6SL7, not a 6SN7.  The Russian common 6SN7 equivalent is a 6H8C.

BTW, I used a 7N7 with a hardwired Loktal socket. Had to enlarge the hole for the Noval socket.  Hate adapters!

Cheers,
Geary

 

[mcandmar]

Was going to ask that too. I have found most 6H8C tubes are noisy with AC heating, you really need to run those on DC.

 

[MIKELAP]

Typo?  A Russian 6H9C is a 6SL7, not a 6SN7.  The Russian common 6SN7 equivalent is a 6H8C.

BTW, I used a 7N7 with a hardwired Loktal socket. Had to enlarge the hole for the Noval socket.  Hate adapters!

Cheers,
Geary

  Your right found that out when i saw the data sheet .

 

[Lawrence Ho]

Our first preamp kit, the Foreplay, offered two dual mono volume control pots as you described.  I built several over they years, and I found it extremely tedious and difficult to ever get the channels balanced, and once they were balanced, I would never really want to adjust the volume because then I would have to start over and rebalance the channels at the new level.

Agreed. It makes adjusting volume a nightmare.
As I remembr, the guy who created the modification had imbalanced hearing.

 

[Lawrence Ho]

Just got myself a chatham 6080wa (black print) from vacuumtubes.net. Their service is excellent btw.

Nevetheless I must say it is a bit disappointing because the website says tung sol chatham 6080, instead of 6080wa.
The structural is visually (also audibly, i suppose) different from 6080.

Sound is fine but sadly not what i expected. My first impression is
it sounds slow, string instruments oustanding, not as airy as mullard cv2984 or the jan rca 6080wa that came with the crack.
*And it is noisy [added 23/03]

 

[elnrik]

Found this site, and thought this article was a good read.  http://www.effectrode.com/signal-tubes/the-6sn7gt-the-best-general-purpose-dual-triode/

Their articles can be found here: http://www.effectrode.com/support/articles/

I also thought the "Tube Family Tree" series to be well done.

Enjoy.

 

[attmci]

Just got myself a chatham 6080wa (black print) from vacuumtubes.net. Their service is excellent btw.

Nevetheless I must say it is a bit disappointing because the website says tung sol chatham 6080, instead of 6080wa.
The structural is visually (also audibly, i suppose) different from 6080.

Sound is fine but sadly not what i expected. My first impression is
it sounds slow, string instruments oustanding, not as airy as mullard cv2984 or the jan rca 6080wa that came with the crack.
*And it is noisy [added 23/03]

They sell used tubes and the quality various.

Return it and try a TS 6080WB.

 

[calmiswar]

Hello everyone, hope everyone's having a nice weekend.


I just snapped up a Tung Sol 6AS7G, what are your thoughts about it? Nice tubes?

 

[attmci]

Hello everyone, hope everyone's having a nice weekend.


I just snapped up a Tung Sol 6AS7G, what are your thoughts about it? Nice tubes?

I belive Nick's recommendations should be the first page of this topic.  Very nice review of various 6as7g  power tubes (not just for crack)

http://bottlehead.com/smf/index.php?topic=663.465

 

[MIKELAP]

What is maximum heater current that it is possible to use with a stock Crack with speedball. Let's say i use a 5998 tube rated at 2.4A. heater current  could i use a 1A. tube without problem .What i wanted to try is a ECC31 NR73/1280type rated at .95A. i know it works with adapters but is it safe longterm. Thanks

 

[Tom-s]

3.5 A. So yes, a 6080 (2.5A) with ECC31 (0.95A) will work.

With the 5998 you're safe.

 

[Lawrence Ho]

They sell used tubes and the quality various.

Return it and try a TS 6080WB.

The postage is going to cost more than the tube itself.
Not sure if they sell 6080wb

 

[Tom-s]

Another safe bet is the 6H13C Svetlana's sold on Ebay.
Does look the better and sounds great.

Buying tubes is mostly like a box of cookies.

 

[attmci]

3.5 A. So yes, a 6080 (2.5A) with ECC31 (0.95A) will work.

With the 5998 you're safe.

The PT-3 power transformer can handle 3.5 amps of AC heating.

Not sure about the PT-10.

 

[attmci]

Another safe bet is the 6H13C Svetlana's sold on Ebay.
Does look the better and sounds great.

Buying tubes is mostly like a box of cookies.

I am not a fan of that tube. And no way it can beat a TS 6080wb carbon plates.

 

[attmci]

The postage is going to cost more than the tube itself.
Not sure if they sell 6080wb

Give them a call. They may still sell 5998 tube too at reasonable price.

 

[ianp]

I finished the stock build in a couple of evenings and have been listening to the stock crack for 5 days now and it was time for some tube swapping.

I had a couple of 12AU7A (Electro-Harmonix and a CONN clear top) tubes in the cupboard and they sound a little better than the stock on my 650s. Listening to the CONN now. It seems add a bit more clarity, a nice sense of airiness to the top end and seems to dig a little deeper for some of the details, but this may be at a little cost to the bass. Ahh, the joys of tube rolling, what you gain on the swings you sometimes lose on the roundabouts 

VALABS pot goes in next and then I'll have to buy a speedball and then look some more into tube rolling.

 

[Lawrence Ho]

Give them a call. They may still sell 5998 tube too at reasonable price.

They don't have any 5998 for over a year.
And it is unlikely they will in short time.