Tube Rolling w/Crack

Dr. Toobz · 1251652

0 Members and 2 Guests are viewing this topic.

Offline larcenasb

  • Full Member
  • ***
    • Posts: 160
Reply #2355 on: August 23, 2021, 04:56:11 AM
...I'm just trying to get a feel for what it is that people like so much about the 5998s (for those who think its the bees' knees at least).

I agree with your impressions--I find my 6AS7G tubes are also "more musical" compared to a 5998. When I turn up the volume...the 6AS7G remains full-sounding and enveloping, while the 5998 sounds brighter and sometimes harsh. I'm listening with 600 Ohm AKG K240 Sextetts.

When I use my brother's Sennheiser HD 600 however... the whole synergy shifts to something more desirable. Compared to my K240, the Sennheiser sounds laid-back, and as Doc speculated I might think, "just sounds dull." I'm talking about the infamous veil of the Sennheisers. As you can imagine, brightness and a little harshness would sound totally different with the Senns, making them sound a little more lively and dynamic. As the Senns + 5998 are popular choices with the Crack, IMO I think that synergy is what many people like so much. Hope this helps.
« Last Edit: August 23, 2021, 04:57:56 AM by larcenasb »

Lowell B.


Offline charnich

  • Jr. Member
  • **
    • Posts: 22
Reply #2356 on: August 28, 2021, 10:37:28 AM
Thanks for your input Larcenasb. I actually use the Senn HD6xx with the the 5998 and still get that bit of harshness. I'll admit though that since I posted I've tried a 12BH7A for my input tube and I have to say I like it a lot better in combination with the 5998 (vs the 12AU7A).Overall the combination is very impressive sounding but now I need to go back and compare to the 6080 which I haven't yet heard with the 12BH7A. I still think the 5998 can be a little harsh with the new input tube but I certainly like it better than with the 12AU7A. One thing's to be said though, the TS 5998 looks absolutely killer... Regardless, with any combination of tubes I've tried yet, all of them sound great with the crack....

Chuck Nicholson


Offline larcenasb

  • Full Member
  • ***
    • Posts: 160
Reply #2357 on: August 28, 2021, 07:31:21 PM
Yeah, I guess we should state the whole audio chain because it all contributes of course haha.

With the Senn HD 600: If I use the S.M.S.L Sanskrit 10th annv. DAC, then the 5998 can sound harsh. If I use my Sylvania grey-plate 12AU7, then the 5998 can sound harsh. But before the Speedball upgrade, the 5998 always sounded controlled and never harsh.

Here's the audio chain for a dynamic sound that isn't harsh for me: AudioQuest DragonFly v1.0 -> Bottlehead Crack + Speedball w/ Tung-Sol 5998 & RCA 6SN7GT (w/ adapter) -> Senn HD 600

Lowell B.


Offline Larpy

  • Full Member
  • ***
    • Posts: 230
Reply #2358 on: August 29, 2021, 08:05:15 AM
I have been immersed in tube audio for 25 years and in that time (mostly early on) I've bought dozens and dozens of NOS and OS tubes.  I've learned that fetishizing any particular tube is pointless.  Given that we all hear differently and have different systems, no one tube is going to be guaranteed to sound either great or horrible.  It all just depends.

Yes, objectively there are better built tubes that will last longer than lesser built tubes, but what's the point if you don't like the way they sound to your ears in the equipment you have? 

It's fun to tube roll, but with prices getting so crazy for the vintage stuff, I don't think it makes sense to spend more than, say, $50-$75 for the kinds of tubes we're talking about here (6AS7s, 6080s, 5998s, 6SN7s, 12AU7s). Chances are slim you'll hear a sonic difference commensurate with the cost.  You might get lucky and buy just the right vintage tube for your sonic taste (and system synergy), but the odds are against it.  I have boxes and boxes of vintage tubes that, although they're fine tubes, they didn't quite give me the sound I was looking for.

It's worth remembering that posts about vintage tubes on the internet from 20 years ago are from a whole other era:  tube audio was still a very small niche market in audio (at least in the U.S.), and the availability of desirable NOS tubes was huge compared to now.  It was so easy to buy tubes then that are now nearly extinct, and often for as little as $10-$20 a piece.  It was cheap to tube roll all sorts of tubes from the 1940s and 1950s.

But that era is gone, and so when we read a 20 year old post on some audio forum that insists we just have to hear tube "X," keep in mind it was written during a time when it was relatively cheap and easy to do so.  That window closed fast (by the mid aughts, as I recall).

Being more specific, vintage Tung Sol 5998s are a well made tube.  5998s have lower output impedance than a 6AS7 or a 6080, so with headphones like many Sennheisers, they sound brighter and faster.  If your system sounds a little dull and sluggish, a 5998 might be just the thing.  But there's no sonic magic lurking inside its glass.

I listen through Sennheiser HD800s (which, granted, are brighter than the 6xx series), and I'm perfectly content listening to a (relatively) inexpensive '60s-era RCA 6AS7 as a cathode follower.  I also have such storied tubes as a TS 5998, a TS 7236, and a Mullard CV2984, but none sound "better" to my ears through my system than the plain Jane RCAs. 

« Last Edit: August 29, 2021, 08:11:21 AM by Larpy »

Larry


Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 19850
Reply #2359 on: August 29, 2021, 08:17:05 AM
I've learned that fetishizing any particular tube is pointless. 
You'll have to let us know how long that took!


I also have such storied tubes as a TS 5998, a TS 7236, and a Mullard CV2984, but none sound "better" to my ears through my system than the plain Jane RCAs.
You're reminding me that I should be selling my 5998s and CV2984s...

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Larpy

  • Full Member
  • ***
    • Posts: 230
Reply #2360 on: August 29, 2021, 11:53:30 AM
You'll have to let us know how long that took!

I'm embarrassed to admit that the lesson didn't fully sink in until early 2020, after I built my Kaiju and bought my first pair of Western Electric tubes: the 396A ('60s vintage).  At last, I had my hands on fabled Western Electric tubes!  Maybe "fetishized" is a bit hyperbolic, but I was prepared to be sonically transported to a land of audio bliss after I installed them and powered up the Kaiju.

Meh.

That was the straw that broke the camel's back.  Call me a slow learner.
« Last Edit: August 29, 2021, 11:56:12 AM by Larpy »

Larry


Offline larcenasb

  • Full Member
  • ***
    • Posts: 160
Reply #2361 on: September 10, 2021, 01:39:33 PM
I just got a new 12AU7 (1950s RCA black plates) that has a faint and constant hiss in the left channel. Switching to other 12AU7s makes the hiss go away. The loudness of the hiss is the same whether the volume knob is turned all the way down or all the way up. When music plays with low volume, I can hear it; with medium-loud volume, I faintly hear it.

Is there a typical cause for this kind of hiss? And is there anything I can do to fix it? Thanks.
« Last Edit: September 10, 2021, 03:46:39 PM by larcenasb »

Lowell B.


Offline Paul Joppa

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 5847
Reply #2362 on: September 11, 2021, 04:30:54 AM
I believe it's usually in the cathode coating, either interface resistance or the cathode is not fully formed. In the latter case, it may go away with the usual 50-100 hours running time. If it's interface, it's a used tube and won't go away.

Paul Joppa


Offline larcenasb

  • Full Member
  • ***
    • Posts: 160
Reply #2363 on: September 11, 2021, 06:04:28 AM
The tube tested 82/80 on a "calibrated Precision 612 vacuum tube tester" where the minimum reading is 46/46. The seller didn't say what a typical new tube would test at, but looking at photos online shows this tester's scale goes up to 100. So, I guess it's a used tube?

But since the tube was just a few dollars, rather than return it, I'll use the opportunity to learn and see if "the cathode is not fully formed." I'll run it for 100 hours and see if the hiss goes away. Thanks, Paul. Always great to hear from you. Cheers

Lowell B.


Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 19850
Reply #2364 on: September 11, 2021, 06:07:19 AM
I have a precision 612.  80 is typically considered the lowest rating you would expect for a new tube.  I've had brand new 12AU7s fresh from sealed boxes only read 80 on the meter, and I've had used Russian 12AU7s peg the meter, so there isn't really much information there beyond there being adequate emission.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline larcenasb

  • Full Member
  • ***
    • Posts: 160
Reply #2365 on: September 11, 2021, 06:19:35 AM
Thanks PB! Always nice to hear from you too! So, hopefully, the tube is new or newish and the cathode is not fully formed. I'm excited for this test, running it for 100 hours to see what happens. I'll report back. Cheers :)

Lowell B.


Offline Doc B.

  • Administrator
  • Hero Member
  • *****
    • Posts: 9676
    • Bottlehead
Reply #2366 on: September 13, 2021, 08:46:13 AM
Larpy is the most excellent voice of reason here. I agree 110%. Re the last two posts, the same historical inflation due to necroposts about "what's best" goes for tube testers. I bought my TV-10 D/U in 1991 for $50. I've sold testers for $750 in more recent years. The very best tube tester is the device you intend to run the tube in, so I wouldn't be too concerned about "80%" etc.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline larcenasb

  • Full Member
  • ***
    • Posts: 160
Reply #2367 on: September 18, 2021, 02:57:29 PM
Here's an update on that 12AU7 I got that had the constant hiss in the left channel. After just 2 hours of running them, the hiss volume went quite low. If it was 6/10 before, it then went down to 2/10. After 3 hours, the left channel started crackling. There would be the slight hiss then a couple seconds of crackle-crackle-crackle, then just slight hiss again, then more crackles. The crackles are like rice crispies and aluminum foil being crumpled in front of my ear. At this point, I turned off my amp and came to check in. Is it safe to keep running the amp, to try and see if the hiss will go away, if there are crackles? Is the tube dying? Thanks so much.

Lowell B.


Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 19850
Reply #2368 on: September 18, 2021, 07:23:10 PM
Crackle is more of what we would expect from oxidized tube pins or possibly a solder joint that isn't quite 100%. 

You can clean the tube pins gently with steel wool and you may find that crackling goes away, just be sure you get any loose fibers off the pins when you're finished.   
« Last Edit: September 19, 2021, 04:24:10 AM by Paul Birkeland »

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline monsterdonkey

  • Jr. Member
  • **
    • Posts: 36
Reply #2369 on: September 19, 2021, 09:29:39 AM
It’s funny. I was reading this thread about a 12AU7 that hisses and I have one of those. It’s a modern Northern Electric 12AU7. Some people review them favourably so I added one to an order of vintage tubes I bought a couple years ago. It was the most expensive and also the worst sounding of the bunch, or so I thought. It hissed loudly enough that I never used it. I just went to set the Crack up in a corner to let it burn in this hissy tube, but I plugged in a GE 6080 I haven’t been getting along with that well so as not to put unnecessary hours on a tube I enjoy. A quick check on the headphones to see how it’s sounding at the beginning of the experiment and the hiss is missing. Could it be that it had a reaction with my other preferred tubes? Maybe whatever I don’t like about the GE 6080 also happens to defeat the hiss noise? Maybe my ears are that much worse since I last tried that tube? Who knows?

Edit: oh wait, there’s a 60Hz hum or something there too.. I’ll let it run all day today but after that I’m done with that tube. I can’t see the point of messing around with it when there are plenty of very good cheap tubes around, several of which I already own. I can accept that sometimes you get a dud. Maybe it could work in a guitar amp.
« Last Edit: September 19, 2021, 10:14:38 AM by monsterdonkey »