I am almost ready to trade my Mark IV for a Recto, but...

[Lopp]

I swear my Mark IV sounds "boxy" when compared to my TriAxis, even when running it through the same 4x12 cabinet. In fact, I'm almost to the point of trading it for a Rectifier. However, I noticed in another thread:

...as an experienced player I observe that: EL34s sound boxy, 6L6 sound round and fendery, EL84 sounds bright and chimy.

My Mark IV has two EL34's outside of two 6L6's. Could this be the problem? Will it be easy to just swap them for 6L6's fix it or will I need to rebias it?

I do like the Mark IV, but it is just not as thick as my TriAxis or my former Recto.

 

[trem]

No rebias necessary. Its not possible anyway without mod. Just get the tube in the correct bias range. Doug for example, would know. Different brand of tubes can also contribute to the sound difference. Just experiment.

~trem

 

[Schmoog]

different brands will make a huge difference. what tubes are you using in the preamp? EH 12ax7's are particularly boxy sounding, which is good for certain applications (loved them in my old peavy classic 50 2x12) but in a mark series they'll kill your tone. don't be afraid to cut mids and lows in your eq either, mark series amps are VERY mid heavy and this can tend to make them sound boxy also.

 

[Lopp]

Trem,
Ok. I'll just swap out the EL34's for 6L6's.

Schmoog,
All of the tubes are Mesa. I have experimented with the most extreme "V" eq setting and still get boxiness.

Rabies,
I have tried various settings and right now it is set at:
Triode, Simul, Harmonics, Full Power

Lead Channel settings are:
Gain: 8 pulled
Treble: 8
Bass: 2
Mid: 4.5
Drive: 5 pulled
Presence: 1.5

When I compare the two, I am using a Lee Jackson SP-1000 with the TriAxis and the Mark IV power amp with the Mark IV pre. Both run into the same Mesa 4x12 (not at the same time).

Thanks for all of your input.

Lopp

 

[MusicManJP6]

this is probly the first guy i've heard on this board that wants to go from a iv to a recto.

Not true! I traded my '93 Mark IV short head for my current '07 Roadster head. I haven't looked back since...

I found the Mark IV to be a little boxy, but for my playing style, the problem was that it was just TOO tight. I felt that the rhythm was what I wanted, but my leads felt stiff and restricted due to the amp being so tight and articulate. This works for some, but not for all - I am much happier with my Roadster... YMMV!

 

[HamerFan]

Boxy is kinda subjective, but I've never experienced either from my MK IV or Triaxis. You might notice something with a tube swap, but I don't think it's going to make a huge difference, especially the way you have the amp set. Perhaps it's your listening position. Try moving around a bit and see if that makes a difference.

 

[MusicManJP6]

It's easier to loosen up a mark iv than tighten up a recto.

Sounds about right... the Mark IV is inherently tight though. The Roadster is not terribly loose to start with and an EQ in the loop has tightened up any anomaly I found - which were few and far between.

If you use a g major with a mark iv you're set for leads and rhythm, guaranteed.

Never tried that... I guess I'm more of a pedal guy...

 

[Random Hero]

It's easier to loosen up a mark iv than tighten up a recto.

Sounds about right... the Mark IV is inherently tight though. The Roadster is not terribly loose to start with and an EQ in the loop has tightened up any anomaly I found - which were few and far between.

If you use a g major with a mark iv you're set for leads and rhythm, guaranteed.

Never tried that... I guess I'm more of a pedal guy...

What type of music do you play?

 

[MusicManJP6]

Anything from blues to hard rock...

 

[visualrocker69]

Does a G Major have an EQ function? I can't figure it out...