Tube Rolling w/Crack

[Bubbatwoa]

I'll also suggest that people stop paying stupid money for tubes. I buy tubes on ebay all the time. Not the overpriced ones. IME about half the sellers know jack shit about what they are selling. Caveat emptor. The law of diminishing returns applies heavily. If you see some 6080/6AS7 variant for $400 on ebay, run the other way. It might sound better to you, but it won't sound 26.66 times better than a $15 one. If we all start paying $400 for a 6080 tube pretty soon a Crack kit will be a grand.

I've been wondering for a long time whether NOS tubes really sound better than new production tubes of the same type and specifications, or if the popularity of NOS tubes is more about the fun and pride of owning antique tubes, similar to how people enjoy owning antique furniture.  It seems just about everybody wants NOS tubes but I have my doubts as to whether the hysteria is really justified with respect to sound quality.

[monsterdonkey]

Yes, it’s a funny thing NOS vs New. A couple decades ago I bought a used Fender Deluxe Reverb II and when I looked in the back I found a bunch of old tubes. Imagine! So I ordered a complete set of new JJs and popped them in. I still have those old tubes and now that I’m reading all of these tube rolling forums I wonder if I made a horrible mistake all those years ago, and I consider rolling them back in to see.

One thing I like about tubes is that they are shiny.

[Wplchou]

Hi Doc. B, glad to hear from you.

I agree with you on many levels. While I do hate the sound of RCA 6AS7G and RCA 6SN7, I do find some folks like them, especially those mainly on vocal albums, sometimes Jazz albums. So I stated the reason why I dislike them. I also agree with you on the tube prices. The NOS tube prices were kind of going wild recently. A pair of Tung Sol 6AS7G's were selling for $300+ weeks ago, I was just stunned when seeing the winning bid. People were going crazy, out of rationale, propelled by the tube-mania from head-fi. I got my TS 6AS7G's for $20 a pop just couple of years ago.

BTW, I am using Senn HD800 headphones with my Crack w/ Speedball.

I just finished up my Crack w/Speedball and running them on a pair of 6XX and ZMF Verite C , sounds great on the stock tubes, its my first tube amp, so I went out and got a pair of RCA 6AS7G which was on sale. I didnt change the stock 12AU7 just the stock 6080, and Im not sure if I know how to describe the difference, but for me the stock tube sounds a lot better, clearly wider stage and more "exciting", and on a side note I feel like I had to turn the volume knob more to get more volume from the 6as7g which im not sure why.

Aside from the Tungsol 5998 and mullard , any other tubes would anyone here kindly recommend me both pwer and input. I have scrolled thru lots and lots of threads and fail to find some consolidated post on this matter.

Thanks a lot

[Doc B.]

 I have scrolled thru lots and lots of threads and fail to find some consolidated post on this matter.

Thanks a lot

That's a good thing. It tells you that there is no consensus. We all get to choose a tube that suits our own unique taste.

[attmci]

I just finished up my Crack w/Speedball and running them on a pair of 6XX and ZMF Verite C , sounds great on the stock tubes, its my first tube amp, so I went out and got a pair of RCA 6AS7G which was on sale. I didnt change the stock 12AU7 just the stock 6080, and Im not sure if I know how to describe the difference, but for me the stock tube sounds a lot better, clearly wider stage and more "exciting", and on a side note I feel like I had to turn the volume knob more to get more volume from the 6as7g which im not sure why.

Aside from the Tungsol 5998 and mullard , any other tubes would anyone here kindly recommend me both pwer and input. I have scrolled thru lots and lots of threads and fail to find some consolidated post on this matter.

Thanks a lot

Here you go: https://forum.bottlehead.com/index.php?topic=663.465

[Welderboy]

Got a Thomson 6080WA - worked for a day and now I can only hear a very faint sound if I crank the amp up quite a bit. If I put the original tube in that came with the kit everything works just fine again.

Did I get a dud or is there anything I should try to diagnose?

[Paul Birkeland]

Did I get a dud or is there anything I should try to diagnose?

I would send it back. 

[Welderboy]

I would send it back.

Seller is in the UK and I'm in the US, so hopefully I won't end up paying $20 for the privilege of using it once.

Luckily these aren't super rare, definitely improved the sound a bit so I'll see if they send a replacement or if I find another vendor.

Thanks!

edit: seller already replied (less than 20 minutes) and will send a replacement.

[David Joiner]

Hey All,

Finished my BH Crack months ago, May 2020, and purchased some tubes to roll in (RU 6H13C and a Philips 5914A) and I'm enjoying it immensely. Listened without the SB upgrade for sometime then installed it a couple months back, as well as some Audyne caps (man those suckers are big, 400V? Kinda overkill; barely squeezed them in along with the SB upgrade).

Came back to this topic for ideas on more tube rolling a few days ago, and came across the post with info on a Taiwanese site with lots of tubes. The poster had mentioned that they carried some Thomson 6080WA, lots of them, (and I also read many posters like their sound), and, too, right now they are at a reduced price of ~$US15, so I was thinking of making a purchase, but, there is a "PS" with the tube description that says,

"This tube need soft start of high voltage. if your amplifier does not have a rectifier tube for soft start, do not buy this tube. NO RETURN of this item if your amplifier do not have a rectifier tube . Please pay ONLY IF you agree ."

What does that mean? And, does that mean it won't work in my Crack? If not, why are Thomson 6080WA tubes recommended by other BH Crack posters? The description also mentions to not use them in "Chinese" made headphone amplifiers; what's with Chinese headphone amps, or is the site making a "political" statement?!

Here's the link: http://tubes.tw/shop/product_info.php?products_id=1279

Also, PB in a post sometime in the past mentioned new input tubes are a waste of time (paraphrasing) over NOS or used even? Why? Is it price to value ratio? Or other reasons?


Thanks for any insight!

Happy Rolling!

[Paul Birkeland]

There have definitely been a lot of posts about people having problems with that particular seller, so take that for what it's worth.  That seller also doesn't understand that a directly heated rectifier will put out full voltage within a couple of seconds after being powered on, so even that statement is a little peculiar. 

[Colonl_Charisma]

I've been using the Thomson 6080WA for a few months now in my Crack. No issues to report, and I definitely did not do anything special to it. Just popped it in haha.

[cddc]

There have definitely been a lot of posts about people having problems with that particular seller, so take that for what it's worth.  That seller also doesn't understand that a directly heated rectifier will put out full voltage within a couple of seconds after being powered on, so even that statement is a little peculiar.

Wow, there are even directly heated rectifier tubes, first time to hear it  I thought there are only directly heated power tubes, like 300B or 2A3.

But that seller's comments on needing a soft start from tube rectifiers also confused me, why would a 'hard' start prevent Thomson 6080WA from performing? It just doesn't make sense to me.

[mcandmar]

There have definitely been a lot of posts about people having problems with that particular seller, so take that for what it's worth.  That seller also doesn't understand that a directly heated rectifier will put out full voltage within a couple of seconds after being powered on, so even that statement is a little peculiar.

I wonder if those tubes were more susceptible to arcing on start up.  I know of a certain "Chinese made" amplifier with 6080s that has a daft 3000uf of capacitance in the power supply, maybe they didn't get along.

[Paul Joppa]

...

But that seller's comments on needing a soft start from tube rectifiers also confused me, why would a 'hard' start prevent Thomson 6080WA from performing? It just doesn't make sense to me.

The 6080 can draw excessive current - enough to damage the cathode - if the cathode warms up before the bias kicks in. There is a warning about that in the data sheet, including a minimum cathode bias resistance.

In Crack, the 6080 is operated as a cathode follower, and has a 3000 ohm cathode resistor - about ten times greater than the minimum.

[cddc]

Thanks PJ, I've never noticed that warning in tube data sheet (at least not in the RCA 6080 data sheet that I have).

Is this a specific problem to the Thomson 6080WA tube? Or the seller is selling duds?

I've never heard such problem on other 6080/6AS7G family tubes. Also, you mentioned the cathode resistor in Crack is large enough to shield the impact.