Tube Rolling w/Crack

[Paul Birkeland]

on eBay some tube sellers will include multiple tube identifying numbers for a tube that's obviously only one of those.

Yes, this allows someone searching for a 6080 to see the CV2984.  The opposite will also be true though, where someone selling a garden variety 6080 will also add CV2984 in the title to appear in the results for searches of CV2984 (there is 1 legit CV2984 on eBay at the moment, but plenty of other listings that pop up when you search for them).

 

[Jake1]

In my limited experience researching tubes and buying a few: on eBay some tube sellers will include multiple tube identifying numbers for a tube that's obviously only one of those. Not necessarily trying to deceive but rather including the identifiers of tubes that can usually substitute for each other with only modest differences between then. The issue is that what a seller might thing is a reasonable substitute might not be in your own particular application so you have to do a little more homework.

I'd love for someone more expert to respond to my interpretation of the situation.

Yeah that makes a lot of sense.  That's what confused me in the first place because I thought all of those different labels meant different things.

 

[loz_the_guru]

Hi all,

Anyone have any suggestions for purchasing tubes in the UK? There's a limited selection on ebay, and all seem a little more expensive than prices i've seen quoted elsewhere. A quick google search wasn't particularly revealing either!

Any UK based crack fans help me out?

 

[Chris65]

Not in the UK, but can suggest https://www.langrex.co.uk. Not necessarily the cheapest, but they do have a large stocks, and prices can be reasonable.

 

[Deluk]

I'm in the UK and Langrex are only about 65 miles from me. I have bought a couple of valves from them via eBay, no problems. Mullard CV2984 (£30) and Svetlana 6AS7G (£12). Both new and work well. Currently, have the 6AS7G in. Small differences with both compared to the original 6080 supplied with the kit with the 6080 may be coming out top for me. I'm using a Mullard CV4003 with them. Found that one in a box of sundry tubes I had in my stash.
Crack with Speedball to fit sometime, maybe this winter.

 

[Banzaiburrito]

I had the same trouble until I stopped searching for tubes and looked for valves instead  lol  : Have you tried Watford Valves? I’m tempted by their Cryo range...

 

[loz_the_guru]

Thanks guys, i'll take a look at those two. The cryo valves do look interesting I agree.

 

[attmci]

https://www.ebay.com/itm/1pc-Gold-plated-6F8G-6C8G-TO-ECC82-12AU7-ECC83-12AX7-tube-Converter-adapter-6-3V/191186388446?hash=item2c8398c5de:g:NCwAAOSwu4BVwu6v

This one adapter should work.

6C8G is much cheaper than 6F8G.

 

[dkazakoff]

Hey there, I was fortunate enough to get my hands on a Tung-sol 6AS7G, and wonder if there is an ideal pairing brand of 12AU7?  Any ideas?  I was thinking of using a Tung-Sol 12AU7 from (the tube store) online

 

[attmci]

Hey there, I was fortunate enough to get my hands on a Tung-sol 6AS7G, and wonder if there is an ideal pairing brand of 12AU7?  Any ideas?  I was thinking of using a Tung-Sol 12AU7 from (the tube store) online

If you wanna to use TS 12au7, find/try a smoke-glass one.

 

[Sonic_dreamer]

I've been digging through this particular post for quite some time, but I do have a quick question regarding tube pairings:

I've got a Winged "C" 6H13C and a Gold Lion ECC82, and it just seems a bit 'off'. I love the bass, but the mids are a bit too forward, and the treble is slightly recessed but is harsh and slightly sibilant at the same time (in the lower treble region, but I can't pinpoint it with EQ, somewhere in the 2k-6k range?).


Has anyone used this pairing with the same results? I'm not sure if I should solve this with a new 6080 or 12au7, as when I roll either tube the sound is too different to really understand which tube was causing either issue. This is, however, my favorite pairing so far from my current, small, collection of the stock JAN 6080WC, EH Gold Pin 12AU7, and Tung-Sol 12AU7. I apologize if this has been answered earlier, and thank you in advance.

 

[LolNole]

I've been digging through this particular post for quite some time, but I do have a quick question regarding tube pairings:

I've got a Winged "C" 6H13C and a Gold Lion ECC82, and it just seems a bit 'off'. I love the bass, but the mids are a bit too forward, and the treble is slightly recessed but is harsh and slightly sibilant at the same time (in the lower treble region, but I can't pinpoint it with EQ, somewhere in the 2k-6k range?).


Has anyone used this pairing with the same results? I'm not sure if I should solve this with a new 6080 or 12au7, as when I roll either tube the sound is too different to really understand which tube was causing either issue. This is, however, my favorite pairing so far from my current, small, collection of the stock JAN 6080WC, EH Gold Pin 12AU7, and Tung-Sol 12AU7. I apologize if this has been answered earlier, and thank you in advance.

While I have not used this pairing myself, I have read similar comments from people who have. The following quote is from page 103 of this thread:

Hey fellas,
I'm running the Svetlana 6H13C winged C + Gold Lion 12AU7 and I'm loving the slam it gives music. Definitely makes it more exciting.

But I'm looking for a tube that mellows out music as the aforementioned combo can make it sound harsh. So I'm looking for something that gives that liquidy tube sound. I hear the Mullard CV4003 counteracts the power the Winged C gives. Would one be a good choice?

Anyone who's had both the Gold Lion and Mullard that can give any inputs?

I also have the Mullard 12AU7/ECC82 which I'm liking with the Winged C as it's not as harsh as the Gold Lion.

I personally thought the Gold Lion 12AU7 made the mids more forward than most 12AU7s. Therefore, I suggest rolling the 12AU7.

 

[Sonic_dreamer]

While I have not used this pairing myself, I have read similar comments from people who have. The following quote is from page 103 of this thread:

I personally thought the Gold Lion 12AU7 made the mids more forward than most 12AU7s. Therefore, I suggest rolling the 12AU7.

Yeah I did see that, seems like the Mullard is the way to go. I'll give that a go and see how it turns out. I also got a Tung-Sol 7236 so I'll try all the different combos and report back.

Thanks!

 

[m17xr2b]

Would the ECC33 work without any changes? I see pins are compatible using a 6SN7 adaptor and heater current is within spec.

 

[Tom-s]

Well. I didn't know yet.

Based in this table https://www.tubeworld.com/ecc32ecc33.htm it should work.

The datasheet also looks ok for Crack https://frank.pocnet.net/sheets/129/e/ECC33.pdf, a bit more amplification.

But i have succesfully used the ECC32 type tube in my Crack.

So i just now plugged in the ECC33 and they sound fine, so i'd use them.

For a Crack with speedball, go ahead and try.

I don't have time to measure voltages at 1 and 5, do that to determine if it's working ok.

PS: it replaced a 7N7 tube in my Crack. Also a very nice tube to try (and cheap).

Edit: Nice tube actually. Good layered soundstage. Mullard sound. Loving it with Hd800's.

 

[Paul Birkeland]

Would the ECC33 work without any changes? I see pins are compatible using a 6SN7 adaptor and heater current is within spec.

The 22.1K resistors in the stock circuit should be changed to 47K.

The 237 ohm R1 resistors in the Speedball board should be changed to about 350 ohms.

The extra gain from these tubes will not be welcomed by most.  The load line for this tube looks terrible just plugging it into the stock Crack.

 

[Tom-s]

Crack is made for rolling tube's!
I still use it more than my Mainline (they are next to each other!)

Tonight i had a fun experiment.

https://ep1.pinkbike.org/p5pb16745694/p5pb16745694.jpg

 

[manther]

Hey, another new builder checking in. I have about 4 days of listening in on my new crack. I'm holding off to install the speedball so I can get used to things first.
But... I do want to try a few inexpensive tubes. I've read a bunch of this thread but not nearly all.
2 questions.
1. Does the Input tube up have a more noticeable effect on the sound?
2. How do these two guys look for an intro into rolling? (See attached screenshot)

**Edit, pretty sure I found the answer to my first question.

The general rule of thumb (IMO) is that the more gain, the more influence.

Since the 6080 is wired for unity gain, the 12AU7 should have a vastly greater influence on the sound, though there are some special 6080 variants that may suggest otherwise.

 

[gregr]

Hi Group,
I misread some of the comments here and plugged my VT-231 into the output socket and listened away. I actually had a few hours on it before I figured it out. Nothing exploded and it sounded OK to me except a very slight flange effect sound in the mids, but I figured it's old, actually a really old sample. Anyway, I'm wondering what's the harm in continuing to use it as the output from time to time? I've since rolled my 6as7's in and out and the amp's fine.
-Greg

 

[adydula]

I would say the "Crack" is made for "intelligent" tube rolling!!
:>)

http://www.diyparadise.com/tubeloadline/tubeloadlines.html

When I was in tech school, back with the dinosaurs (who were still smoking Lucky Strikes)....we had to draw countless load lines in our vacuum tube labs
and final exams!!

I think I have forgot most of this stuff, but when you start stuffing those glass bottles in those sockets lots of stuff is happening...and if your not really
sure of how the circuit is put together..you may have a very unpleasant surprise!!

Alex