Variac a Super Lead instead of attenuating

[jnew]

You have an O scope. You cheater.

[dirtycooter]

He will know he is there when the sine wave looks like this -VHVHVHVHVH

[vh junkie]

My amp is loud as shit even at 250V's on the plates.

Yeah mine is certainly loud enough.

I am running mine on 8 ohms into a 160hm cab... that might take the volume down a bit on mine... what are you guys running?

[dirtycooter]

8 into 16 for my clip. Much more tight/snappier this way but also looses big bold body compared to 16-16 but also sounds sluggish though at 16-16. Also I should try my lo input jack next as well. I am getting a bit too much gain for vh if you believe that. Also really grainy probably due to the bias being well into crossover distortion.
I wanna see if pullin 2 tubes at 8-16 brings back some body (as this is matched up more correctly with 2 tubes) but keeps the tightness as I was runnin 4 tubes in both trials. Of course I can't try 16-16 pullin out 2 but more body with keeping tightness would be cool. Not sure how that is gonna work out yet. I am still fiddle dickin with it. Its those little things....you never know.
Best to have a mic set up recording to sort out the naunces quicker in greater contrast during play back. The reference is priceless later when you can't make up your own mind.

Anyone know what happens with a single ended amp like a Valve Jr and a variac???
I am interested in this-its a different class of amp and functions differently than A/B.
Also the bias rules are different as well. Makes my little brain just swim here!
Just thinkin out loud. There was that one rumor Ed used one tube..... but how the fat fuck would that work in a plexi??? Could it??? Just throwin meat on the table here for the idea entree
If you blow an output tube in a 50 watter it doesn't quite immediatly go down with the other still honkin.

[rgalpin]

Forgive my stupidity but are you saying that pulling 2 tubes on a SL with imp selector set at 16 ohms is actually like having it set to 8 ohms at the amp?

Please be kind - I probably asked the same question last month and will probably ask it again next month.

[rgalpin]

... There was that one rumor Ed used one tube..... but how the fat fuck would that work in a plexi??? Could it???

i did some one tube stuff a while back - here are the results:

http://soundclick.com/share.cfm?id=11694472

http://soundclick.com/share.cfm?id=11688465

Was cool because once again - losing the attenuator was key to what I liked about the results. There is a thread about these clips but I can't find it - it includes a number of rants about tennis rackets and such... hahhaaa - madness.

[rgalpin]

Here's a song I recorded using the variac at 60V and a +9db bump with the MXR 6 band peaking at 800.

http://soundclick.com/share.cfm?id=13041941

Comfortable room volume.

The clean guitar on the right is through a Fender Pro Reverb. FYI.

[jnew]

Here's a song I recorded using the variac at 60V and a +9db bump with the MXR 6 band peaking at 800.

http://soundclick.com/share.cfm?id=13041941

Comfortable room volume.

The clean guitar on the right is through a Fender Pro Reverb. FYI.

Finally got a chance to give this a listen. BRAVO dude. I loved when the rhythm comes in panned over to the left some. A great example of less is more and letting the song and riff breathe while sticking it right in the pocket. Love it.

And the tone is wicked bro. I'm not a huge fan of too much mid boost sort of wah effect but this was done to taste and just worked killer. Wasn't too much of it. Really well done.

[dirtycooter]

Forgive my stupidity but are you saying that pulling 2 tubes on a SL with imp selector set at 16 ohms is actually like having it set to 8 ohms at the amp?

Please be kind - I probably asked the same question last month and will probably ask it again next month.

Heck no ! Lmao! Thats magic smoke land there. I have ran 4 tubes 16-16 + 8-16. When I pull 2 tubes though at 8-16 I wonder if it sounds like it has the body of the 4 tubes set up 16-16. Because two tubes pulled at 8-16 should be like 4 tubes at 16-16 ..... theoretically, due to halving the impedence anyway. That was what I was trying to convey.

Rob you actually ran 1 tube in a marshall plexi?? I see one labeled as bias jacked.
Because running so low voltage loses bias, adding it back defeats volume drop benefitsand its a viscious cycle. I am wondering about crossover distortion and cold bias issues in this regard ti the whole variac biz.

I guess when dude gets done running the Oscope he will be able to see whats goin on with crossover distortion more in this regard. I can hear I have it in my clip. Not a nice artifact while everything else is better though. So bias ans crossover distortion are my focus of ponderance

[dirtycooter]

Here's a song I recorded using the variac at 60V and a +9db bump with the MXR 6 band peaking at 800.

http://soundclick.com/share.cfm?id=13041941

Comfortable room volume.

The clean guitar on the right is through a Fender Pro Reverb. FYI.

Great tune! Love the tones. Kinda makes me think of guitar tones somewhere between Jackyl and GnR then the solo seems to spill some Vh onto it all while having a Great White kinda vibe about the song.
Awesome!

[rgalpin]

...Because two tubes pulled at 8-16 should be like 4 tubes at 16-16 ..... theoretically, due to halving the impedence anyway. That was what I was trying to convey.

pull 2 tubes, set amp to 8 ohms, plug into 16 ohm spkr = everything happy

TRUE?

Then does that mean:

pull 2 tubes, set amp to 4 ohms, plug into 8 ohm spkr = everything still happy

TRUE?

...Rob you actually ran 1 tube in a marshall plexi?? I see one labeled as bias jacked.

did you like the sound of the one tube clips? i thought they were cool because that little one speaker was getting a full dose from the amp - i think it's cup runneth over and produced some stuff that doesn't usually happen with 4 tubes and 4 speakers unless you kill yourself with volume.

did one of my clips say that the bias was jacked? i don't remember that. note that the ONE TUBE clips i posted were done with normal voltage. i don't think i even had a variac hooked up. i think.

[jnew]

...Because two tubes pulled at 8-16 should be like 4 tubes at 16-16 ..... theoretically, due to halving the impedence anyway. That was what I was trying to convey.

pull 2 tubes, set amp to 8 ohms, plug into 16 ohm spkr = everything happy

TRUE?

Then does that mean:

pull 2 tubes, set amp to 4 ohms, plug into 8 ohm spkr = everything still happy

TRUE?

...Rob you actually ran 1 tube in a marshall plexi?? I see one labeled as bias jacked.

did you like the sound of the one tube clips? i thought they were cool because that little one speaker was getting a full dose from the amp - i think it's cup runneth over and produced some stuff that doesn't usually happen with 4 tubes and 4 speakers unless you kill yourself with volume.

did one of my clips say that the bias was jacked? i don't remember that. note that the ONE TUBE clips i posted were done with normal voltage. i don't think i even had a variac hooked up. i think.

Pulling two tubes only means you double the speaker impedance. So if you have 4 tubes, amp on 16 ohm and a 16 ohm cab you're matched per stock spec. Pulling two tubes means you have to put the amp on 8 ohms into the same 16 ohm cab. That's still the match per stock spec. Same as 4 tubes, 16 ohm tap, 16 ohm cab, minus the total wattage output. If you pull two tubes and put the amp on 4 ohms into the same 16 ohm cab, now you you have a one step mismatch (the ideal one IMO) An 8 ohm cab would be a proper match, just like back to 4 tubes, 16 ohm amp, 16 ohm cab (again minus the total wattage output.

[dirtycooter]

A way to always remember is numbers can be the same or a littler number can be first-thats always safe UNTIL you pull tubes. Then you always wanna work at a 1=2 ratio of double load.
4 tubes at 16-16 should be like 2 tubes at 8-16. Only one exception though and thats= If you ran 2 tubes 8-8 you run into trouble I believe, at least I wouldn't do it myself. You need 2x's the load to reach a minimum 1=1 load ratio when you pull tubes. Thus...... 8-16 is 1=1 load with 2 tubes pulled . Safe to also try 4-16 and that equates to the same thing as 4 tubes 8-16 would be or a one step shift mismatch making a 1=2 ratio load.

Thanks for watching MetroAmp's after school special "Impedence 101" Lmao!!

The one tube was interesting.... but not sure what it was about the sound. Its like it became 1 dimensional. Something to do with probably along the lines of a steven hawking matter vs anti-matter thing lol! Other than that it sounded pretty good considering.

[Lindz]

Ed was interviewed at the Smithsonian and goes into a whole range of topics - a few good tidbits. about their upbringing etc. But of interest to those in this thread at about the 20 minute mark he goes into the Variac thing in detail. Take it for what its worth but its from his lips... Apparently as low as 60 was in his playbook too

http://www.guitarplayer.com/artists/101 ... ideo/50870

[Lindz]

edit: the guitar player link went down but I found this https://www.youtube.com/watch?v=Sl59RPs7PiI#t=20