Not so clean

I've had my Mark V for about a year now, and although I love Channels 2 and 3; but Channel 1 is a whole different matter. I cannot get a good clean "clean" Even if I dial the drive way back to 9 o'clock, there's still a muffled growl to it. (I've even tried dropping to 45 watts and switching to diode to get more head room.) Is there a problem with the amp, or is that just the nature of the beast. I had a Mark IV before this and I seemed to remember loving Channel 1...clean, sparkling, and no break up.

Thanks

watch the first half of this video.....he shows you how to get an extremely clean tone out of channel 1.


http://www.youtube.com/watch?v=5kOIx7HbhxQ

masque said:

watch the first half of this video.....he shows you how to get an extremely clean tone out of channel 1.


http://www.youtube.com/watch?v=5kOIx7HbhxQ

Click to expand...

Nice tips, but unfortunately that's not my problem. Even with those exacts settings, I am still not getting a solid clean

I suggest trying some preamp tube rolling starting with V1, and whatever tubes Channel 1 uses. I wasn't happy with the tone of my V until I changed a bunch of the stock Mesa/JJ's to other brands and NOS types. Changing the preamp tubes cleaned-up a lot of the mud on my amp and made the tone more chimey, which is what I was looking for.

I've played through 4 Mark V's, and all of them had the same clear, crystal cleans. I'd say there has to be an issue with your amp. I use fairly high output Bareknuckle pickups and have my gain on channel 1 set right at 12:00. No breakup even at gig volumes. Channel 1 was actually the first channel I actually clicked with. 2 and 3 took a while.

I'm not an expert so can't offer advice to get it fixed, but just wanted to let you know that the cleans were "in there" so to speak. Hope you get it worked out, man!

Do you have the head or combo?
Also what speakers are you using if you have the head.

At the moment, I have all stock Mesa 12ax7 tubes in my preamp except for V7. Alright, a bit of some honesty here, the stock Mesa tubes I have are not current production, they are left overs from my Mark III which are the Chinese square getter type from the early 90's. V1, V2, V3 are the old Mesa tubes, V4, V5, V6 are current production and V7 is Sovtek LPS.
Power tubes, New SED =c= 6L6GC. I have not used stock Mesa STR440 since the originals redplated prematurely. TAD6L6GC-STR are also great tubes to. Clean channel is near perfect and is not hard to dial in a dry acoustic tone with the neck pickup. If you are running EL34's, it will not be easy to get a clean CH1 tone. Although KT77 sound good but still have the EL34 overtones and harmonics bleeding through.

I have one traditional sized 412 with the original Celestion V30's that I removed from the Mesa Recto (larger)412 which now has EVM12L black labels. I run the smaller 412v30 with the RA100 head, the EV cab is used with my Mark V. Size of the cabinet makes a huge difference for the V30's. They sounded terrible in the Recto oversized cab but sound incredible in the smaller 412.

If you have the combo, the MC90 is a bit taxed when playing louder. I would recommend a 1x12 deep extension cab. A deep cab with V30 if sealed works really good to fill in the tone. Same type of deep cab will work great with Eminence Tonker lite (neo). Running in parallel with the MC90 reduces the breakup you would get with the single speaker. I retired my MC90 in my Mark IV since it no longer provided a clean tone (sounded more like it was blown) and replaced that with a Fane Studio 12L.

I would definitely start with replacement of the power tubes and rectifier tubes first. They do not last very long if you play on a regular basis.

One other thing to consider, are your pickups active or passive? If they are really hot pickups you will get some distortion on the clean channel if the pickup output exceeds 1volt. (just a suggestion nothing more).

Either that, V1 may need to be addressed. If it is a bit on the hot side (super high gain) you will get some distortion on the clean side.

Depending on how much you play through the amp, power tubes do not last forever, when they begin to reach end of life, distortion may result when running clean. I usually keep the gain low on the clean channel (say around 9 to 10 o'clock).

Another thought, is the amp still dirty on the clean channel with the reverb off?
Are you using the master volume control with the effects loop set to active? try hard bypass and see if that changes anything. Could be V6 running a bit dirty. Also if you are using the effects loop, double check to see if your effect has input and output level adjustments. If they are not matched you may get distortion or gain from the loop. (you could try adjusting the loop gain on the back of the amp to see if that corrects the dirt on the clean channel).

Hopefully you will get this fixed. My Mark V has the best sounding clean I have ever heard, I thought that my Mark IV was great, the Mark V is the best so far, even beats the RA100 for clean and dry tone and has a nice natural acoustic guitar sound to it without the use of any effects other than reverb.

Note: I am currently running all stock preamp tubes except for V7. Power tubes are SED =c= 6L6GC, Rectifier is EH 5U4G.

Look at the back of the amp. If the EFX section switch is set to "Loop Active", change it to "Hard Bypass". AMHIKT.

My Mark V lost its clean sound. For mine it was not a growl, it was more like a fuzzy halo or ghost sound on each note. It was not loud or overbearing and with any dirt you could barely notice, but any clean tones it was there. And it was there in all three power settings. I did all of the diagnostic suggestions Bandit mentions, and recommend them. In my situation the problem remained after all preamp tube tests, so i focused on the power tubes. Since V8 is used in all three power settings, to diagnose, I used the 45 watt setting (which uses only V8 and V9) and swapped, V11 for V8. The clean tone was back in 45 watt, and the fuzzy halo noise was there in 90 watt. To confirm my findings I cycled through all "pairing" options in the inner two 6L6 sockets (V8 and V9). All tubes except the original V8 performed with great cleans in 45 watt setting. I replaced the original V8, and V9 with a new matched set and all has been good since. Recommend that you mark all the tubes and place any good ones back into their original locations. btw, I did the "tap" test and though the problem tube did make a different sound, it was very slight and only identifiable after I knew that tube was the problem.

I know this does not need to be mentioned, but I just have to.... the Mark V is awesome. I have had it for years and am still finding new tones. I have been experimenting with low gain Mark I settings using 10 watts really cranked, with a little reverb - just phenomenal tone, incredibly rich and thick. love it.

I would definitely agree with what JEB3 mentioned.

I had a JJ6CA7 operate intermittently. It would warm up fine, amp would sound good for a short while then shift in volume and sound more compressed. Only one tube was operating. An imbalance in the tubes will give you distortion, same would apply to the V7 (phase inverter tube). If only one side is working and the other is not, may make it sound like one power tube is bad.