Tube Rolling w/Crack

[Paul Joppa]

Your calculations are correct, should be no problem.

FWIW, we did play around with 7233 triodes a few years ago. Kind of halfway between 6080 and 5998.

[howzz1854]

Thanks for the info Paul

[Doc B.]

We are always happy to hear that people are experimenting. And when they do I am reminded to mention that in trying this kind of thing the builder takes full responsibility for their actions. The guys are advising you as they can with the info provided, but we can't guarantee the result. My advice is do not test whatever you cook up with your HD800Ss. Use a set of headphones you can live with sacrificing first, to make sure it all works the way you want.

[howzz1854]

THanks Doc, will keep that in mind.

[Coldplayer]

Hey guys, completely new to this and i have a crack+speedball running with hd800's and using a Raytheon 6080wb + Mullard 12AU7. Wondering what i should upgrade next on it? Would going from a 6080wb to a 5998 be a noticeable upgrade?

[howzz1854]

guys, so today i just received a whole bunch of tubes. Tunsol 6080wb graphite (looks like there is a slot inside the graphite too), a Phillips Miniwatt E80CC, Mullard ECC82, a Amperex ECC82.

thus far i am not too big of fan of the ECC82s, in particular the Mullard one, which sounded way too soft. the Amerex ECC82 was a bit better, but not as dynamic as the stock 5963.

but the Phillips E80CC was something different!. and a did a quick search on this tube on the forum and sure enough confirmed my observation. it's a LOT more dynamic, although almost pushes everything forwarded. the bass is better, but also made the mid and treble more forward as well. overall like someone turned up the volume.

1. i know you guys said that the E80CC can be used in place of the driver socket, but can this be used long term safely? people say it has a higher current than stock 12au7/5963. how much higher are we talking? the stock 12au7 is .3 amp, how much higher are we talking?

2. some of the posts suggested that for best result, you have to change resistors. what does best result mean? will it burn down my headphone in the long run without a changing of resistors? or are we just talking that it puts extra load on the power tube that it decreases power tube life? Doc?

keep in mind that i have a bone stock Crack no speedball

[Tom-s]

Your observation that the e80cc has more gain is correct.

1. The E80CC is a sort of drop-in as long as the speedball CCS boards are installed.

2. The resistor changes are meant for the resistors on the CCS.

[howzz1854]

thanks for the info.

do you think any damage could be done without the resistor mod? i did try out the E80CC last night for an hour or two. not sure.

[Tom-s]

I'd only use the e80cc/12bh7 with the speedball build into crack.

The resistor mod isn't necessary but a worthwhile upgrade.

[JP]

I've had my Crack & Speedball since 2011 with the original tubes.  I was getting some fluttering sounds over the last few months, so just replaced both tubes.  Based on the 1st post in this thread, I went with the Russian 6H13C (6AS7G) and a JJ Electric 12AU7 Gold from thetubestore.com.

I started by just replacing the 6080 with the 6H13C and while that resolved the fluttering, I've noticed that the 6H13C is significantly hotter than the original 6080 that came with the kit.  The chassis plate is hot to the touch - it's not burning hot, but it's definitely quite a bit hotter than it used to be.  The tube itself is significantly hotter - you can feel the heat coming off of it when you hold your hand about an inch away.  The caps on the bottom are warm to the touch.

Is it expected that the 6H13C will be significantly hotter than the 6080?  How do I know if it's too hot?  I'm also concerned about how the additional heat might impact the life of my Crack.

It sounds phenomenal, but just curious about the heat.

Thanks!

[Paul Joppa]

...

Is it expected that the 6H13C will be significantly hotter than the 6080?  How do I know if it's too hot? ...

Normally there would be no difference. The way to tell is to do the voltage checks.

It's possible the old tube was running at a cooler operating point as it neared the end of its working life.

[Doc B.]

It could also just be that the tube has a different structure that changes the radiation pattern around it. Unless you are seeing glowing red plates it's not something to worry too much about. The fourth law of thermodynamics is - tubes get hot.

[JP]

Awesome - thanks for the quick feedback.

Turning it back up to 11 and rockin' out.

[12AU7-6SN7]

If a 50s RCA black plate 12BH7 was extremely microphonic (even touching the headphone cable results in a tinging noise) in a Speedballed Crack amp, was that the fault of the tube or the amp? The output tube I was using was mildly microphonic with a quiet 12au7 up front. I could barely hear a tap on the chassis plate. I tried a quieter output tube, but it was still very sensitive on the input tube.

The seller is kind of brushing it of as it being due to higher gain in a circuit that normally uses 12au7 or being due to a component in the circuit. After initially offering a replacement. (edit: we worked it out) still curious about microphonics with the SB installed though.

I don't know enough about this to know if that warrants a refund or exchange, or not. Any advice?

[attmci]

That is a solid Graphite plate tube not the slotted ones I have come across a number of different Graphite shaped solid column tubes  cross, round, semi oval. They are normally found branded Tungsol, Chatham or Bendix irrespective of the branding to my knowledge they were all manufactured by Bendix.

They are nice sounding tubes, I have had a couple of NOS ones in the past that have had a tendancy to give loud pops through the headphones during their warming up phase this effect dissapered after a numer of hours use but was a bit scary.

I have a number of Bendix 6080WB tubes, most are slotted ones, and never have the "loud pop" problem. The non-slotted tubes may take like 20 min to warm up. These are very nice power tubes.

The domino plate 5998 is definitly the better tube and I expect you will be able to pick up one for a similare price you just need to be paitent they do turn up.  You would also be able to pick up a GEC or Mullard 6080 for less which are both very good options.


You might like to try the E80CC as a driver instead of a 12au7 a cheap Tungsram with the holes in the side will cost a lot less than a premium 12au7 I liked them immensly and prefered them to some highly rated and expensive 12au7 options. The E80cc are also long life tubes 10,000 plus the 12au7 life span is more often given seen around 2500hrs.  They are a straight swap for the 12au7 and work well there is even a really inexpensive (couple of dollars) resister switch mod detailed on the forum which allows fine tuning the Speedball voltages for running the E80cc in the sweet spot.

Link for details and impressions of the mod

http://bottlehead.com/smf/index.php?topic=5989.0