Should you use certain types of tubes with a Mark IV?

[JPIndustrie]

Hey,

I'm thinking about swapping some tubes and wonder, if I want to run 6L6's + EL34's in Simul-class, would it be safe to use any 6L6 or EL34?

Thanks!

 

[GD_NC]

No. You need tubes matched to MB specs since you can't adjust the bias.

The easy way is to buy Mesa tubes or Groove tubes in the "Medium/white" range. You can also order Mesa spec tubes from Eurotubes or tubestore.com. Just be sure to specify that on your order.

 

[dodger916]

No. You need tubes matched to MB specs since you can't adjust the bias.

The easy way is to buy Mesa tubes or Groove tubes in the "Medium/white" range. You can also order Mesa spec tubes from Eurotubes or tubestore.com. Just be sure to specify that on your order.

+1. Use Groove Tubes with a "Distortion Rating" of 4 to 6. If you buy from one of the knowledgeable dealers GD_NC mentions (see also Doug's Tubes), specify which Mesa amp you have.

Have you thought about experimenting with preamp tubes? Having recently replaced most of the Mesa preamp tubes with vintage ones in my Mark IV, this amp was elevated to a whole new level of tone machine. It's amazing what a few vintage Tung Sols can do!

 

[JPIndustrie]

Have you thought about experimenting with preamp tubes? Having recently replaced most of the Mesa preamp tubes with vintage ones in my Mark IV, this amp was elevated to a whole new level of tone machine. It's amazing what a few vintage Tung Sols can do!

Yes sir, your post is exactly why I want to experiment with tubes! I love the way my Mark IV sounds, but I can't help but wonder if its possible to improve it.

When you say vintage ones, do you mean NOS?

 

[dodger916]

It can make a substantial difference in the sound and feel. I enjoy the Mark IV, but felt is was a bit "modern" sounding, sort of boxey, especially compared to the Mark IIs. Vintage tubes really improved the sound and feel, to a less modern sound that I prefer. I tube swapped in my C+ with very favorable results, but I didn't expect the Mark IV to improve the way it did.

By vintage I'm referring to older tubes typically manufactured in the 70's 60's or 50's. NOS means "new old stock", which means old tubes that are unused. VOS means "vintage old stock", meaning old tubes that have some mileage. Either will do. I usually get VOS as they don't carry that crazy NOS premium that tube "snobs" are willing to pay. If you're patient and know what you want, you can get good tubes for under $30 delivered, and often less than that if you buy two or three at once. You only need one or two to make a big difference. The biggest problem I found is many old tubes may test well but have static or other noises. It's good to buy from people who accept returns, but be prepared to get an occasional lemon. There's a wealth of information on this board concerning tubes. I'm a relative noob Here's a sample of what I mean:

http://forum.grailtone.com/viewtopic.php?t=749&highlight=timbre+wolf