TAD 6V6's in a Mark IV & Schematics

[Monsta-Tone]

Hey everybody, I'm new to the forum. This is my 1st post.

I have a Rectoverb II Combo with a Vintage 30 and EL34's in it. I also have a brand new Mark IV head that is totally stock.

I have experimented with the Mark IV and tubes. I really liked the JJ E34L Blues and the stock 6L6's in the middle. I also tried a quad of TAD (Tube Amp Doctor) 6V6's in it which sounded fantastic.

I will probably never have the opportunity to unleash the Mark IV with 6L6's, and want to be able to crank it at lower volumes.

I have tried a Hot Plate, but attenuators seem to subtract all of the sparkle from the amp.





Has anybody tried TAD 6V6's in their Mark IV?

Is anyone running 6V6's in their Mark IV's at all?

Does anybody have a schematic for the Power & Bias Supply for a Mark IV??? I would like to add a Bias Pot. I have many drawings of the Preamp & Power Amp that I got from this link: http://www.tubefreak.com/mesa.htm, , but none of the Power Supply.

Any help would be greatly appreciated.

 

[mtnb1kr]

What was it about the 6v6's you liked? I'm in need of tubes and have thought about this set up. I'm under the impression that you can get power tube breakup at lower volumes. The manual says to be careful to run in the tweed mode though. Why?

 

[Monsta-Tone]

The Tweed Mode lowers all of the voltages in the amp, including the "Plate" voltage & the "Bias" voltage. These are 2 of the main voltages that you have to be aware of when changing Power Tubes. This would result in lower overall Output from the amp.

The Plate Voltage & the Bias Voltage are inversely related. If you increase the Bias (Idle Voltage when tube is not in use), the Plate Voltage (Voltage in from the Output Transformer) will decrease.


The Plate Voltage is much too high on the "Full Power" setting for most 6V6's.

Bob at Eurotubes (talked to him on Saturday) told me that if you install a Bias pot for the middle Power Tubes, & adjust the Bias resistor for the outer Power Tubes, then you can get the Voltages within spec of the JJ 6V6's. Even on the Full Power Setting.




As for the 6V6's, they breakup much earlier than 6L6's, which remain clean until ear bleeding volumes have been reached. Bob at Eurotubes told me that he uses 6V6's when people want more Bass out of their amps. I have always found the 6L6's to have more Bass, but I haven't used JJ 6V6's yet. They should be here in a couple of days.

The 6V6's could sound more "Flubby" at higher volumes. I went with them because I want Power Tube Distortion at realistic Volumes. I'll let you know what I find next week.

 

[AMG1]

I've used 6v6's in my MkIV for awhile.

I really liked them. Smooth and creamy distortion and the break up came at much lower volumes.

If you use them you get to hear the amp working at reasonable volume levels.

Also the amp is still more than loud enough to play with others. The only thing is your cleans wont be nearly as clean as with 6L6's once you start bringing up the volume.

 

[t0aj15]

I've used 6v6's in my MkIV for awhile.
I really liked them. Smooth and creamy distortion and the break up came at much lower volumes.
Also the amp is still more than loud enough to play with others. The only thing is your cleans wont be nearly as clean as with 6L6's once you start bringing up the volume.

What guitar were you using, and at what master volume setting did the 6V6's start to breakup. I ask because I'm also interested in trying some 6V6's but I love the powerful clean headroom I'm getting with 6L6's.

 

[mtnb1kr]

I've used 6v6's in my MkIV for awhile.
I really liked them. Smooth and creamy distortion and the break up came at much lower volumes.
Also the amp is still more than loud enough to play with others. The only thing is your cleans wont be nearly as clean as with 6L6's once you start bringing up the volume.

What guitar were you using, and at what master volume setting did the 6V6's start to breakup. I ask because I'm also interested in trying some 6V6's but I love the powerful clean headroom I'm getting with 6L6's.

I really don't care about the cleans so much myself. I just want that power tube breakup at more reasonable volumes. Which 6v6's are you using? SRS on e-bay has a Quad of Matched EH's for about $33. Mesa wants $34 for a pair. SRS claims the EH's are a design to handle the higher plate voltages of the old Fenders. What bias range should be used with 6v6's.

 

[AMG1]

I got the tubes from Mesa. So needless to say they fit into a middle bias range. I've used other tubes from The Tube Store. E mailed them and told them what amp I had and everthing worked out. Thoses were Jan Military. Tell you the truth they sounded about the same as the Mesa's.

This was awhile ago so I dont remember the exact settings. I've since gone back to 6L6's. Not for any particular reason. Just a change. I almost always run my MkIV on 3 or 4 and than work the channel masters up and down. Anything above moderate bedroom levels created break up. So it did'nt take much. You have to play very low to get clean headroom. Forget about clean headroom if you play with any power at all. So its as if your clean channel no longer exist but in a good way.

Guitars , I have many. I used it with Les Pauls, PRS Cu. Strats and Tele's and Asats and various Carvins. I just adjust the gain and retweak as I go depending on which one.

 

[mtnb1kr]

I got the tubes from Mesa. So needless to say they fit into a middle bias range. I've used other tubes from The Tube Store. E mailed them and told them what amp I had and everthing worked out. Thoses were Jan Military. Tell you the truth they sounded about the same as the Mesa's.

This was awhile ago so I dont remember the exact settings. I've since gone back to 6L6's. Not for any particular reason. Just a change. I almost always run my MkIV on 3 or 4 and than work the channel masters up and down. Anything above moderate bedroom levels created break up. So it did'nt take much. You have to play very low to get clean headroom. Forget about clean headroom if you play with any power at all. So its as if your clean channel no longer exist but in a good way.

Guitars , I have many. I used it with Les Pauls, PRS Cu. Strats and Tele's and Asats and various Carvins. I just adjust the gain and retweak as I go depending on which one.

Do you still have the Mesa 6v6s. If so interested in selling them if they're any good yet? PM me and maybe we'll work something out.

 

[AMG1]

I'm hanging on to them for now. Never know when I'll get the urge to put them back in. Plus I'm thinking of putting them in my Lonestar.

 

[Monsta-Tone]

I got my JJ 6V6's & High-Gain 12AX7's in the mail today. I'll have to wait till Monday to try them though.

Can't wait.