Lights Out said:
Hi
I have finally rack mounted my MKIV
with a Replifex in the FX loop .
It sounds a little unclear & muddy at times
I have replaced my Valves with a JJ Tesla "High gain" set.
6L6's & all 12ax7's
Being a MKIV A should I be using a 12at7 in the position marked "12at7"
Im assuming its the phase inverter ?
Does the type of valve used in this position make a big difference to the FX Loop & general tone ?
Ok here is some things I found out about my Mark IV series A amp and tubes.
Obviously V1 is the most important tube and affect all the channels. And I got a hi-gain Tung-Sol marked 110/110 and it maid big difference to what I had before JJ EC83 marked 111/114.
V2 tubes A/B controls the effect loop in and out, I had old tube and I always had to max out G-Majors out level and still had weired problems so I changed it to JJ EC83 and now G-Major is at unity gain and loop in or out doesn't make any level changes.
V3 tube is the lead stage and I have that JJ EC83 marked 111/114 on this.
V4 is the reverb tube and I have Mesa 12AT7.
V5 is the phase inverter tube and I got Shuguang 12AX7 balanced tube 105/105 in this place, previously I had some unknown gain GT 12AX7.
And I have changed all power tubes to Winged =C= SED 6L6GC and I feel now my amp is really responsive and I can emulate some of the sounds in the manual.
After power tube change I can here very specific differences between tweed/full, classA/simul and Penta/Triode modes, presence controls became very responsive too.
I have played with V1 position using a Chines Ruby tube/GT Rusian/Mesa SPAX7-A/JJ EC83 and last Tung-Sol and I wold say the Tung-Sol made a big difference in my clean sound of my JS1000 neck/single coil mode.
I don't know how to explain those sounds, and don't like to use very subjective terms like three dimensional and such. Basically I wanted some non uniform but bright with subtle variations in harmonics clean sound that shines when added little delay and/or reverb some times Vai's old songs have this kind of tone and then again Eric Johnson has it always.
As per everyones recommendations of the net forums I bought the tubes from Dougstube.com and he was very helpful and very fast service too.