Mark IV clean tones, tube swaps, and settings

[SugarNap]

Hi all,

Long time Boogie owner, first time poster. In recent years I’ve grown a bit out of love with my Mark IV as I’ve drifted from the progressive metal and hard rock stuff to different sounds - predominantly dominated by fuzz faces, sparkly cleans, and big muffs. I could never feel right parting with such a special amp though, and certainly not while their value has only doubled on the market since I bought mine.

Some major sounds I’ve been going for is early 70’s Pink Floyd and Siamese Dream (Smashing Pumpkins) - so lots of British tubes, phasers, and Big Muffs.

It’s a tough amp to dial in well, no doubt, with so many tonal options and influences in the circuit. I’m running a single 1x12 open back Fane Crescendo A speaker right now and playing a strat with early 70’s pickups.
Still playing the Mesa brand tubes (4 6L6’s) that came with the amp. Recently discovered the option to swap EL34’s for the outside tubes. I love the tight bottom end of the 6L6’s but wonder if a tube swap would get me closer to what I’m wanting out of the amp. I LOVE the power section and would love to dial in the preamp section to give a flatter Hiwatt-esque platform to hit my pedals with and then do final shaping with the 5 band EQ.

Does anyone have any recommendations for settings and info about the tube swap? Any modes I can’t use if I swap to EL34’s? And general tube swap recommendations for a non-metal voicing? Whats the best channel to set up that sort of British clean sound on?

Finally, I can’t afford to buy another amp. I have a little Orange OR15 that’s great for traveling that I could sell and get something of the same value, but I’ve heard the Hiwatt T20/10 and 40/20 are a pretty big departure from the original Hiwatt Custom 100/50 sounds. I don’t need to be totally spot on - again I love the power section and the pre of the Mark IV, just want to see what sort of guidance I can get to steer it in another direction, it being as versatile as it is. Thanks!

 

[bandit2013]

Which Mark IV do you have, the A or the B? I had a wide body Mark IVB which is a bit different than the smaller Mark IVA model but probably about the same sound. I have run the EL34 tubes in the class A sockets and thought it was a good change. It will change the overall tone but will not cut out the amount of gain the amp has. It may actually add more to the mix. It has been a long time since I owned a Mark IV so my memory may not be all that accurate on what I felt made much of a difference. I was more after the higher gain character most of the time. I do not believe the Mark IV has a bias switch on it. Been a while for me since I had one. All channels and mode will work fine with the EL34/6L6 arrangement.

There may be a way to relax the amp just a small amount for front end pedal use. JAN/GE 5751. I have used that tube on several occasions. There is also a JAN/Sylvania 5751 as well, just $20 more in cost. It will reduce the gain factor and it does sound really good in the V1 position. You can leave the rest as is. This change will also affect the tone stack too as it is sandwiched between V1A and V1B triodes. Not sure this is the answer to what you seek. If you wanted more of a hi-fi sound, the JAN/Phillips 12AX7WA tubes will provide more clarity but the gain will be much higher than the Mesa (JJ ECC83s) characteristic. Probably should not have mentioned them. They sort of fall in a medium plate category so the characteristics will be different than the short plate design of the JJ tube. You only need just the one JAN 5751. They are quite musical even though they are supposed to have a drop in gain.

Sure, I appreciate the Gilmore tone and have chased it too. Just never really got there. The guitar player in the small group can do Gilmore quite well and with my Badlander no doubt. I play the drums when I have others over for jam sessions. The Badlander is much like a Mark amp and has plenty of gain on tap. I suspect it is all in the hands and I lack that ability to replicate it. I do play a few Pink Floyd songs, mostly from The Wall album even though I lack the ability or skill level to pull it off. Mostly while I am using the RA100 but have done the same with other amps too.

Sorry if this is no help. I get what you are after, I saw your other posts. I hope you find the tone you seek.

 

[swbo101]

I own Mark IV A. long head paired with a 4 x 12. I use 6L6, EL34 combo. However at times, I have switched out to all 6V6 tubes. That'll give you some of those late 60's Fender Bassman sounds (really close) if you are looking for that for early 70’s Pink Floyd.