OK guys ive been lurking for a while but after making this discovery i had to register and share my findings....... right here is where i feel sorry for those who sold their Mark V's without experimenting with preamp tubes.
My main complaints with the mark V were:
1. Lack of clean headroom in channel 1.... couldnt go past 11 on gain and 12 on master in clean or fat mode and still retain a high headroom clean sound. Because of this i was struggling to balance channel 2 and 3 with channel one and couldnt experiment with higher (above 10 o clock) master volume settings on the gain channels.
2. I had a squeel whenever i turned channel 1 master volume up past 2 o clock.
3. The 80hz slider added a boxy boomy low end to channel 3 and always felt out of control when up too high or too thin when set lower. Channel 3 was never big and tight enough sounding.
I did change the stock power tubes to JJ 6L6's...but this was a couple of weeks ago. They sound nice and thick, i prefer them to the stock 6L6's, they sound less hollow, but they have a slightly more sterile sound i guess. My next step is trying some Sed 6L6's and some Ruby EL34BHT.
Now today, for the 1st time after owning the mark V and having a love hate relationship with it for months i decided to experiment with preamp tubes. I wanted to get to know the amp really well before trying to fix problems with new tubes.
Firstly I changed the phase inverter tube (stock JJ) to a Jan 5751. It made the amp slightly duller (ive always found the Mark V has plenty of presence to spare though so not a problem) but it greatly increased the amp's headroom and the boomy boxyness of channel 3 was GONE. Everything sounded more open and natural. I actually could back off the 80hz slider to half way between the middle and top line and have a much bigger, tighter sound than before. Even 2C+ mode sounded big!
Next step was a Tung-sol RI 12ax7 in V1. Brought all the sparkle back to the clean channel and I suddenly had a pleasing top end across all 3 channels. Clean channel stayed clean in fat mode up to 12 o clock gain and 3 o clock master! Oh and no more squeeling.
All the modes sounded good and the eq's in general responded better and did more of what one would expect a mark series amp to do. Even mark 1 mode sounded less choked with the gain up higher. I can actually see myself loving all of the modes (yes even 2c+, edge, and mark 1)
I tried some Shuguangs in v 3-5 but felt they sounded a bit more compressed and springy.... naturally i backed off the gain a tad to get a fair comparison to the stock JJ's but they still felt more "2d" so I left the stock JJ's in v3-5. These might be good for someone going for a more straight up metal sound.... they might do better in conjunction with more harmonically rich sounding power tubes also.
If any of you are having similar problems to what I described above (and from reading this forum it seems there are plenty) please do yourself a favor and try just these 2 tube swaps. V1 and the PI. I think the key to solving the mark V's low end problems is a phase inverter tube that has slightly less gain (please note that this did not have a negative effect on available gain, in conjunction with the Tung-sol in v1, quite the opposite actually)
YMMV but it sure worked for me!
I know im not the 1st one to discover this but i thought a more thorough explanation of what these tubes did would be more helpful to people. I do think that one of the stock tubes i swapped out might have been "bad" which would account for the insanely positive difference im hearing with my amp.... i just cant see why mesa would ship the amp with these stock tubes if they dont do the amp justice.... and come to think of it i completely understand why people comparing their "settled in" mark IV's to a stock mark V would be less than impressed with channel 3 on the V. Its the TUBES!
My main complaints with the mark V were:
1. Lack of clean headroom in channel 1.... couldnt go past 11 on gain and 12 on master in clean or fat mode and still retain a high headroom clean sound. Because of this i was struggling to balance channel 2 and 3 with channel one and couldnt experiment with higher (above 10 o clock) master volume settings on the gain channels.
2. I had a squeel whenever i turned channel 1 master volume up past 2 o clock.
3. The 80hz slider added a boxy boomy low end to channel 3 and always felt out of control when up too high or too thin when set lower. Channel 3 was never big and tight enough sounding.
I did change the stock power tubes to JJ 6L6's...but this was a couple of weeks ago. They sound nice and thick, i prefer them to the stock 6L6's, they sound less hollow, but they have a slightly more sterile sound i guess. My next step is trying some Sed 6L6's and some Ruby EL34BHT.
Now today, for the 1st time after owning the mark V and having a love hate relationship with it for months i decided to experiment with preamp tubes. I wanted to get to know the amp really well before trying to fix problems with new tubes.
Firstly I changed the phase inverter tube (stock JJ) to a Jan 5751. It made the amp slightly duller (ive always found the Mark V has plenty of presence to spare though so not a problem) but it greatly increased the amp's headroom and the boomy boxyness of channel 3 was GONE. Everything sounded more open and natural. I actually could back off the 80hz slider to half way between the middle and top line and have a much bigger, tighter sound than before. Even 2C+ mode sounded big!
Next step was a Tung-sol RI 12ax7 in V1. Brought all the sparkle back to the clean channel and I suddenly had a pleasing top end across all 3 channels. Clean channel stayed clean in fat mode up to 12 o clock gain and 3 o clock master! Oh and no more squeeling.
All the modes sounded good and the eq's in general responded better and did more of what one would expect a mark series amp to do. Even mark 1 mode sounded less choked with the gain up higher. I can actually see myself loving all of the modes (yes even 2c+, edge, and mark 1)
I tried some Shuguangs in v 3-5 but felt they sounded a bit more compressed and springy.... naturally i backed off the gain a tad to get a fair comparison to the stock JJ's but they still felt more "2d" so I left the stock JJ's in v3-5. These might be good for someone going for a more straight up metal sound.... they might do better in conjunction with more harmonically rich sounding power tubes also.
If any of you are having similar problems to what I described above (and from reading this forum it seems there are plenty) please do yourself a favor and try just these 2 tube swaps. V1 and the PI. I think the key to solving the mark V's low end problems is a phase inverter tube that has slightly less gain (please note that this did not have a negative effect on available gain, in conjunction with the Tung-sol in v1, quite the opposite actually)
YMMV but it sure worked for me!
I know im not the 1st one to discover this but i thought a more thorough explanation of what these tubes did would be more helpful to people. I do think that one of the stock tubes i swapped out might have been "bad" which would account for the insanely positive difference im hearing with my amp.... i just cant see why mesa would ship the amp with these stock tubes if they dont do the amp justice.... and come to think of it i completely understand why people comparing their "settled in" mark IV's to a stock mark V would be less than impressed with channel 3 on the V. Its the TUBES!
