My Mark IV lost the distortion! Please help me find it.

[jackieTHEjokeman]

I was playing my Mark IV in the lead channel and everything was fine. I powered it down for about ten minutes. Then I re-powered it and let it warm up, but when I took it out of standby I had NO DISTORTION on lead. I switched to clean and that was fine, I switched to Rhythm and that lost the distortion too! What happened to my distortion!!?? I don't even know where to look. I swapped guitars, that's not it. My cables are fine and all the tubes were lit up. Anybody know where I can start looking? Thanks!

 

[Boogiebabies]

Preamp tubes in the V3 and V4.

 

[jackieTHEjokeman]

Thank you. I will swap them and let everyone know how it turned out.

 

[Boogiebabies]

IMO, the gain in MK II's, III's and IV's is very hard on preamp tubes.
Not as bad as my DR though.

I would try a fresh tube instead of swapping them. Worst case, if you have to swap, use the V5/PI.

 

[jackieTHEjokeman]

I'd be bummed if it wiped out the tubes. They are only 6 months old from Eurotubes. Not a heck of a lot of hours either.

 

[Russ]

I noticed in my MarkIV that it likes to eat one side of V2 and V3 more than the other. I was just curious about my tubes so I slapped them in the tester and my jaw hit the floor. They were new on one side and near dead on the other. The other positions wore more evenly. I almost forgot, I have an older version that has the reverb on V4 as a 12at7 also. If you have access to a tester check your tubes.

 

[Russ]

Hey what part of SD? I am in O'side...

 

[Boogiebabies]

He's in Torrey Pines.

 

[jackieTHEjokeman]

^^ I'm too poor to live in Torrey Pines. I live in Chula-juana....Otay Ranch.

 

[jackieTHEjokeman]

This is the response I got from Eurotubes:

It's either a tube or a tube not seated well in V2, V3 or V4. It's easy to

find by reseating or changing them out one at a time. Only a VERY slim

chance that it's other than this.

I've got to work on it tonight...

 

[jackieTHEjokeman]

It was the tube in V3. I'm a little disappointed that the JJ's burned out that fast. This is the second problem I've had with them in less than 6 months. My stock Mesa tubes lasted for 3 years with no problems. I don't think I'll get JJ's again. Oh well. Thanks for the help boogieb.

 

[Boogiebabies]

U got it bro !!!

See you on the fairway.

 

[Russ]

Otay Ranch.... Man, that place has really come up in the last 10 years. I relocated back down here in 2000 from LA and I can't believe how crowded San Diego is getting. I am beginning to think that LA wasn't so crowded afterall.... just bigger.

Boogiebabies where are you at?

 

[Russ]

I am kind of bummed to hear that you have had problems with the JJs. I was hoping to try some on my next retube. Do you think that after such rave reviews that they have let the QA slip or what? Maybe Bob is just not screening as well...? How did you like them before they went bad?

 

[Boogiebabies]

Otay Ranch.... Man, that place has really come up in the last 10 years. I relocated back down here in 2000 from LA and I can't believe how crowded San Diego is getting. I am beginning to think that LA wasn't so crowded afterall.... just bigger.

Boogiebabies where are you at?

NC. A good freind of mine was from TP back in the day. His claim to fame was he went to TP high school with Tony Hawk and he lived in TP. He was a snob, who I later found out he lived in TP because his dad worked at the golf course.

 

[jackieTHEjokeman]

^^ Hah, that's funny.

To answer the guy's question about the JJ's: I really liked the way they sounded before-hand. I bought two sets of thier hi-gain kits. One for my Stiletto and one for my Mark IV. I get an enormous amount of hiss on my Stiletto after I have the JJ's in them. I'm positive no tubes are loose. Luckily, I play at pretty low volume levels so it's not a big deal. Now, with my Mark IV having a pre-amp tube go bad has really turned me off. Like I said before, I had the stock mesa tubes in my Mark IV for 3 years with no problems. I ended up taking all the JJ's out of my preamp section last night. For some strange reason, it sounded really odd to have the JJ's in 4 slots and one Mesa stock tube in the other slot. Not sure why. Anyway, I'm not dogging on JJ's. I just know I will try something else the next time.

 

[Boogiebabies]

What do you want from third world production on 50 year old machinery?

6 months, HA !!!! It's funny that I just took in for repair an old Yorkville Bass Master with 1985 Tesla E34L's. They were within 1 ma when I biased them and they had superb output. They have been in the amp since 1996. Made at the same factory and the same equipment as the JJ's. I love the JJ power tubes, both the 6L6 and the E34L, but the pre's have never been my cup of Boogie.

 

[Russ]

That is funny about the golf course. I am assuming you are talking about TP. I used to surf Blacks but the gays ruined it. It used to be great to sit in the lineup and check out all the nice nuggs and rugs....

I was in VA Beach for a while in the Navy. We went to NC a lot to pickup the gi-renes.

When I left the service I hauled butt back home. I made it from the Atlantic to the Pacific in 52 hours including a shower stop in OK City. I had gotten a room because I was soo tired of driving but after the shower I was refreshed and finished the drive non-stop. I think I only ate 2x in the whole trip outside of a bag of chips or an ice cream from the gas stations. I ended up sleeping for 2 days after I was home. I think it was from just finally being comfortable at home again.

Why is it that the tube companies won't spend the money to retool the old machines? The music industry by itself would support the expenditure. There are enough people playing tube amps and wanting tone to have created a new market of old tubes. It would be nice to be able to get real Mullards that are new for much less than the NOS. I am sure that whoever retooled those old machines would profit incredibly.