Tube Rolling w/Crack

[Doc B.]

I guess that guy didn't want to replace just the power tube. Might as well let that sucker burn, and take out the output transformer too, right?

[SxVa]

Hello. I'm new to tube rolling with the crack. For my first time to replace stock i went with a 7236 Tung-Sol for my power tube and i'm finding it pretty interesting, quite the change from the stock RCA that came with my unit, the instrumental parts are much more present to where i feel like i'm sitting right by the band but the vocals aren't as prominent and don't stand out as much as i typically enjoy and tends to be a focus on basic setups to emphasize vocals and so it was somewhat of a drastic change for me but it's interesting.... and now i want to get a new input tube, firstly i went with a NOS Tesla which hasn't shipped yet, and now i have my eyes on a Brimar yellow T.

I found a 6060 yellow T from the early 60s on tubeampdoctor which i could go with.

There's also cv4024 and a 6059 yellow T on valvetubes with little info provided and i could get both of them for the price of the 6060.

And i just found another one on bestsfad.top which has 4 of the 6060 at only 43.99.

How do i know what's a good buy and what isn't? There isn't really a lot of info or high quality pictures in a lot of these various listings.

Are any of these good options or should i keep looking elsewhere?

Also, another question. I'm more interested in medium range priced tubes than the best as i find i'm the most comfortable in this range in most things and was wondering if there was any up to date list of reputable vendors for this tube/valve range that exists? Is simply going by Ebay ratings a good enough indication of getting legit valves/tubes? It's very overwhelming coming into this whole thing with so many different things to look for and not knowing what's a sure thing. So far i like thetubeking on Ebay because they show dates and where the tubes come from and don't shy away from the fact the tubes might not be the best unlike a lot of the others on Ebay which hypes up every tube. That's where i got the Tesla but it's difficult to know what's legit or not.

[attmci]

Hello. I'm new to tube rolling with the crack. For my first time to replace stock i went with a 7236 Tung-Sol for my power tube and i'm finding it pretty interesting, quite the change from the stock RCA that came with my unit, the instrumental parts are much more present to where i feel like i'm sitting right by the band but the vocals aren't as prominent and don't stand out as much as i typically enjoy and tends to be a focus on basic setups to emphasize vocals and so it was somewhat of a drastic change for me but it's interesting.... and now i want to get a new input tube, firstly i went with a NOS Tesla which hasn't shipped yet, and now i have my eyes on a Brimar yellow T.

I found a 6060 yellow T from the early 60s on tubeampdoctor which i could go with.

There's also cv4024 and a 6059 yellow T on valvetubes with little info provided and i could get both of them for the price of the 6060.

And i just found another one on bestsfad.top which has 4 of the 6060 at only 43.99.

How do i know what's a good buy and what isn't? There isn't really a lot of info or high quality pictures in a lot of these various listings.

Are any of these good options or should i keep looking elsewhere?

Also, another question. I'm more interested in medium range priced tubes than the best as i find i'm the most comfortable in this range in most things and was wondering if there was any up to date list of reputable vendors for this tube/valve range that exists? Is simply going by Ebay ratings a good enough indication of getting legit valves/tubes? It's very overwhelming coming into this whole thing with so many different things to look for and not knowing what's a sure thing. So far i like thetubeking on Ebay because they show dates and where the tubes come from and don't shy away from the fact the tubes might not be the best unlike a lot of the others on Ebay which hypes up every tube. That's where i got the Tesla but it's difficult to know what's legit or not.

Sorry, I don't think you can use ecc81/6060 tubes on a Crack.  You need a 12au7/ecc82/7316/5814/cv4003/cv491/ecc802/b749.

[SxVa]

Sorry, I don't think you can use ecc81/6060 tubes on a Crack.  You need a 12au7/ecc82/7316/5814/cv4003/cv491/ecc802/b749.

Oh really? Well dang. I had my heart set on the yellow T.

Thanks for the response. At least i found that out before i bought it as i was close to buying it. I figured it was an "equivalent to" as there seems to be so many equivalents and i read a description of it under an 12AT7 tube guide. I guess i should just stick to those specific tubes listed then to be sure.

Okay, so... regarding the Brimar cv4003 there's an Ebay seller out of India called Totempole that has NOS listings of this. A single and double. Anyone have experience with this seller having legit NOS? Upscaleaudio seems to charge for one of the same tube at platinum grade that the Ebay seller lists for two of them.

Oh and one other thing. So ECC83 definitely doesn't work? Only ECC82? I've come across a lot of ecc83 and so it would be good to know for sure.

[Paul Birkeland]

Oh really? Well dang. I had my heart set on the yellow T.

Thanks for the response. At least i found that out before i bought it as i was close to buying it. I figured it was an "equivalent to" as there seems to be so many equivalents and i read a description of it under an 12AT7 tube guide. I guess i should just stick to those specific tubes listed then to be sure.

A 12AT7 and a 12AU7 are very different tubes.

Oh and one other thing. So ECC83 definitely doesn't work? Only ECC82? I've come across a lot of ecc83 and so it would be good to know for sure.

A 12AX7 (ECC83) and a 12AU7 are very different tubes.

The direct coupling in the Crack means that you need to stick to 12AU7 types or you will damage your amplifier.  Using a 12AT7 will bring the bias voltage for the 6080 up and you will burn up the 3K resistors in the process.  The 12AT7 also has a lot more gain, and that will make the amplifier more difficult to use.

The 12AX7 will do the same thing, but much worse.  It will draw so little current through the plate load resistor that the amount of signal that you can send through the Crack will be severely limited.  Whatever does go through will also be very distorted (Because the amp is designed for the 12AU7, not the 12AX7). 

[SxVa]

Alright thanks. Glad i asked then. I was under a different impression due to seeing these various equivalents thrown around and things being lumped together. I thought it was all under one umbrella.

Good to know. I will stay with the 12au7 and ecc82 and avoid the other stuff. Luckily my Tesla that i ordered is an ecc82 and so i'm still in a good place for now. I haven't moved forward with any other tubes yet before i had more info. Always good to ask questions/research before rushing in.

[Paul Birkeland]

Sometimes you will see these thrown around for guitar amps, where substituting one tube for another may impart "tone" into the amplifier, which is to say that the substituted tube is running poorly.

[SxVa]

So, i received my Tesla tube from the Tube King and replacing my previous input tube that came with my unit. I bought my speedball crack from someone else and now i discover it had a 12bh7a. The only extra markings that were still there was USA and "NC".

What's up with this tube? I see it's marked as "sort of" a drop in equivalent on the first page. The fact that i've been running the crack with this input tube does this mean i can safely tube roll this 12bh7a tube?

Using my new Tesla in combination with my Tung-Sol 7236 so far i'm liking what i'm hearing. It's familiar to what i usually enjoy than the previous setup with vocals being more prominent and feels more musical but i do kind of miss how close i felt to the instrumentals with the previous tube. There's more distance with this one but that distance also makes it a bit more pleasant to my ears where i can sit back and take it all in easier. So far how i would describe them is with this Tesla ecc82 i'd sit back and chill out getting lost in the vibe of the music as a whole sound and the vocals for awhile whereas with the 12bh7a i'd have more intense listening sessions/feeling closer to the sound and paying attention more and being in every moment of separated instrumentation.

[Paul Birkeland]

There are adjustments to be made for the 12BH7 to bias properly in the Crack.

[SxVa]

There are adjustments to be made for the 12BH7 to bias properly in the Crack.

That's the tube that came with my unit and i've been running it awhile not realizing which tube was in there. Does this basically mean i could order any 12BH7 off ebay and should be okay using it since i've been using one or are they different from tube to tube and i should avoid trying others? Basically what i mean is since one of them worked does that mean all of them will work. The person i ordered it from was some type of studio engineer and so i assume he knows his stuff and must've modified it but i have no way of knowing how much or what he did to it.

[Doc B.]

The person i ordered it from was some type of studio engineer and so i assume he knows his stuff

Thanks for the chuckle.

[SxVa]

Thanks for the chuckle.

 
Don't think he was an engineer or don't think they know their stuff? Well, he knows way more than i do that's for sure hehe.

[Paul Birkeland]

The only ways to know if it was modded are to measure voltages or measure the plate load/c4s R1 resistors on the 9 pin socket. 

[SxVa]

The only ways to know if it was modded are to measure voltages or measure the plate load/c4s R1 resistors on the 9 pin socket.

But i've been using that tube for like 2 years at least. I just started tube rolling but i've had my unit for like 2 years now. If using that tube requires modification and i'm using the tube without any problems doesn't that suggest it's been modified to use that tube already or how could i be using the tube? I guess it's better to be safe than sorry and i should just stick to the basic stuff and that one tube that i already know works since i don't have any real understanding of the technical stuff. That's why i chose to buy it and not build it.

[Paul Birkeland]

The modifications would align the plate voltage of the 12BH7 to properly bias the 6080.  In an unmodified amp, the output tube won't bias well.  The amp will still work, but won't perform as well as it should.