Mark V: Mark IV mode squealing, need help

[jressell]

Ok, anyone else have squealing when the master volume on CH 3 is put to 3:00? Lowering the Master Volume will remove the squeal but I don't think it should ever be present. Am I wrong?

Settings:

Gain 3:00
Treble 3:00
Mid 9:00
Bass: 7:30
Presence: 1:00
Master: 3:00
Toggled to Bright
GEQ: V
Triode selected

 

[Nermel]

microphonic preamp tube/s...the manual states at higher settings of gain (probably around 3 o'clock) the tubes will start to get microphonic...how close are you to you amp when you play

Try tube swapping

 

[jressell]

I swapped the tubes about an hour ago.... All of the preamp tubes, that is. I'm about 10' away.... distance doesn't change the squeal pitch or volume. I can unplug my guitar and the sound is still there.

 

[EtherealWidow]

You know I had a weird problem at the music store with squealing. I would play and hold out a note until it fed back, but then the high pitched feedback wouldn't go away. I turned the amp volume down, guitar volume down, and unplugged the guitar. I had to turn the **** thing to standby.

 

[jressell]

I pulled the power tubes one by one and ran it without them one at a time..... same issue.

 

[jressell]

Anyone else with a Mark V able to dial in those settings to see if they experience the same squealing? That would be a great help to know that it's just me and not in the design of the amp.

 

[4406cuda]

The squealing will only happen with the Mark IV mode when the master on channel 3 is set too high. No way around it.

 

[scott7d]

Master at 3:00? Is this with the FX loop actice, with the output low? In bypass mode, I would think 3:00 would destroy anything in site if the speakers didn't blow out :shock:

 

[4406cuda]

I was running my channel master almost maxed out on channel 3 with the IIC+ voicing and the master output set accordingly. It sounded very nice and also worked well with the Extreme voicing. However, for what ever reason, setting the channel master above 12 O'clock or 1 O'clock while in the Mark IV voicing will cause squealing.

 

[Mark III Madness]

I just got my Mark V (a late 500 serial number) the other day. I have an identical gripe. I was getting ready to change the tubes and I saw this post. I have the EXACT same issue with the Mark IV setting on Channel 3 and not on the IIC+ or Extreme settings. Hmmm... I wish I knew how to rectify this concern too...

 

[jressell]

Mark III Madness:

I simply stepped back off the master volume and brought up the output volume. This completely removes the squealing. If you like high master volume you need to stay in C+ or Extreme. Hope this helps.

 

[Mark III Madness]

Yes... I've found the same... Thank you for the tip. I guess I like the sound of Channel 3 with it's volume up some, so I don't suppose I'll end up using the Mark IV mode that much if at all. I just was disappointed that it had to act like that. Yet, it's oddly comforting to know I'm not alone!

 

[jressell]

Yeah, definitely. Have you tried using Ch3 with Master at 8:30 - 9:00 and output at 12:00+? You can get a really killer tone out of that.

 

[Mark III Madness]

Well... I've only had it for less than a week, but I like to twiddle knobs on Mesas! :lol: I've not tried those settings exactly yet, but I'll definitely try it! I must admit I've played and owned the gamut from IIC++, Mark III and Mark IV. I've got an idea how to get what I like to hear out of those models, but I know I'm not done exploring with this Mark V, yet! Personally, I've played on all of the Marks... and I really think this one is pretty swell for doin' it's own thing! I really like it for the most part!

I've read that others don't necessarily agree, but I just think you've got to play around with the amp's settings for a minute before you find EXACTLY the tone you're after. I'm sure this amp's no different. Once I've found those "secret settings" that I dig hearing on other Mark amps, I've not really changed the settings (except presence and volume) that much subsequently. But that's just me!

I'm sure it's the amp - not the guitar or guitar cable. I promise I know a little somthin'! :wink: I actually used to work at a guitar store that sold Mesas once upon a year!

My favorite Channel 3 settings so far has been:

Mk II C+
"V" EQ with just the right 750 hz setting :wink:
90W
Gain around 9ish
Master and Presence near noon
Mids and Bass near 9ish too

That sounds pretty swell to me!

Now if I could just flip the switch and try those settings on the Mark IV channel without nasty feedback!!!!

I'm not done... I'll work with this... more to come!

 

[jressell]

The C+ setting is really phenomenal. The voices you can pull are varied and smooth. It crunches nicely too. The IV mode is really the unsung champion of this amp though. A ballsy setting for that push without being too overpowering. The longer I have the amp the easier it is for me to dial in the sound in my head without too much effort. I feel bad for the guys that purchased the amp and then kicked it to the side after a couple of weeks. The differences between the V, IV and IIc+ are minimal. The learning curve is what is offsetting to some.

To the guys that are still out there tweaking and turning knobs: Let's do our best to keep this community solid and pleasant. It's good to be able to know that others share the same love for tone that I do.

Mark III Madness: Gain at 9:00, huh? I'll have to play around with that.

 

[vae]

I totally agree -- still loving the amp and finding new sounds daily.

In one of the other threads someone mentioned something about the V's being rushed -- if this is an example of a "rushed" product from Mesa, I'm impressed.

 

[Shang Chi 66]

Thank you vae, and I agree 100%.

It seems as though some folks just are,nt happy unless their trying their best to tear down, talk down, or belittle something that others are satisfied with & happy about...I for one don,t quite understand it. Just the human nature of some folks I suppose.

[To the guys that are still out there tweaking and turning knobs: Let's do our best to keep this community solid and pleasant. It's good to be able to know that others share the same love for tone that I do.

I,m all for just that my man!...and that,s all this board should be about. We don,t all have to agree on everything...however, civility, decency, and respect should always be at the front of a public forum...

especially one about something that,s supposed to be about the enjoyment of musical equipment.

We,re not talking about abortion rights, politics, or personal relationships here...topic,s to get extremely over the top passionate/serious about...just amps, guitars, musicians, etc.

Of course it would be unrealistic to think that it will always be that way, but hopefully it will be more often than not.

All in all, at least at this point in it,s history, I really believe that this board is one of the better ones to be a member of.

 

[4406cuda]

Don't use the MESA/JJ's tubes... Try a a set of Sovtek LPS,Tung-Sol, or a Chinese 12AX7. ALWAYS keep a couple of NOS Jan Phillips 5751's on hand also. You may even find that you prefer the 5751 in the V1, and (or) PI socket. Most players use a 5751 in their MK II's. Plug-in a different guitar also. un-potted pups are notorious for causing squeal! If it squeals w/o the guitar plugged-in, then you know it's the amp. If your using a head - remove it from the cabinet. Vibration is not going to be good for these amps at all. The connections are more brittle than the older MESA's - so keep it off the cabinet. You can place a piece of foam between the head and cab. That's what I do with my Cornford MKII.

None of these is the issue with the Mark IV mode. Dude, you don't even own a Mark V any longer.

The problem can be resolved with the squealing in the Mark IV mode by keeping the Channel Volume below 12 O'Clock. I currently am loving the Mark IV mode in channel 3. I have mine set at 11 O'Clock on the channel as well as the Master Output.

 

[littleguitar]

do you have an effect in the loop ?

 

[Mark III Madness]

Nope, I don't have anything in the effects loop... I'm beginning to wonder if I do actually have a microphonic preamp tube. This week as time permits, I'm going to try different preamp tubes in the sockets that apply to Channel 3 and see if that helps the usability of the Mark IV mode.