The Boogie Board

Discussion Forum for Mesa Boogie Products
It is currently Sun Nov 18, 2018 4:18 pm

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 12 posts ] 
Author Message
PostPosted: Thu Apr 05, 2018 9:34 pm 
Offline
Mark III

Joined: Sun Feb 18, 2007 7:55 pm
Posts: 197
Hey errbody, having a 6 month issue...

My Mark IV is sounding bad...very bad. Let me start by saying I am an experienced Mark IV and Mesa user, it is not setting related. 15+ years with Mesa, including Mark IIc+ through the Jp2c. I have kept the mark IV through all of it. I took the amp to an authorized Mesa repair shop. Had it fixed, the guy said basically nothing was wrong. Got it back, still sounded terrible, fizzy, lifeless, no bass, harsh, distorting way to fast on the clean channel. So...I send it to Mesa. I just got it back, they said it had no problems but they replaced a few caps that were on the verge of going bad. Got it back, sounds the same. They said my tubes were fine, so I take their word for it. Amp still sounds very fizzy and harsh, no smooth fat lead tones that I’ve always had. I cannot figure it out.
What would a bad speaker do to this combo? I’ve already spent over $500 repairing this amp and it is the same. Any ideas? I’m on the verge of buying a different mark IV because this has been 6 months of frustration. I’m at the point of begging, please help.


Top
 Profile  
 
PostPosted: Thu Apr 05, 2018 9:43 pm 
Offline
Mark I

Joined: Sun Aug 21, 2016 10:00 pm
Posts: 35
Interesting if the amp USED to sound good or great then to me it seems like tubes, I know that they said the tubes were fine but its such and easy thing to check and a set of tubes is way cheaper than a new amp.
also try plugging into and extension cab to remove the speaker from the equation

_________________
Mesa MKIIb ( my first in 82 )
Mesa MK V
PRS 2 Channel H
Tonal Insanity Guitar Effects
TC Electronics Nova System
PRS Guitars


Top
 Profile  
 
PostPosted: Thu Apr 05, 2018 10:37 pm 
Offline
Mark III

Joined: Sun Feb 18, 2007 7:55 pm
Posts: 197
I have an entire set up tubes coming, pre and power. I read the speaker (8ohm) with a meter and it’s reading fine, 9.2.


Top
 Profile  
 
PostPosted: Fri Apr 06, 2018 2:13 am 
Offline
Mark II

Joined: Tue Sep 08, 2015 3:35 am
Posts: 62
Sounds like it's heading towards a 11 or 12 ohm (?) you've got in there; not that that's necessarily a bad thing in a MkIV, just so long as the speaker's healthy

But a static reading on resistance should fall under the rated figure by a fair margin, and I'd expect an 8ohm speaker to read high 6s or low 7s if it was healthy. Checking with another speaker sounds like a good idea right now, given your concerns.

Incidentally, I use a Thiele under mine, and a lot of the time the combo speaker isn't used at all.

_________________
MkII eh?


Top
 Profile  
 
PostPosted: Fri Apr 06, 2018 9:40 am 
Offline
Mark III

Joined: Sun Feb 18, 2007 7:55 pm
Posts: 197
Does that reading indicate a potential speaker issue? Is there another way to test? I’ll try to find another speaker to try for the time being.


Top
 Profile  
 
PostPosted: Sat Apr 07, 2018 1:52 am 
Offline
Mark II

Joined: Tue Sep 08, 2015 3:35 am
Posts: 62
Go ahead and do it - what Rider1260 said above - get the speaker out of the equation, by subbing in another (preferably similar) speaker. First in another cab, then in the combo itself. What is the speaker - an EV? Did I miss this? What else do you use with the amp? More info about your signal chain might be helpful.

The speaker seems the likeliest candidate in this case, but who knows... you'll just have to go through the process of elimination, one thing at a time.

_________________
MkII eh?


Top
 Profile  
 
PostPosted: Sat Apr 07, 2018 12:32 pm 
Offline
Mark III

Joined: Sun Feb 18, 2007 7:55 pm
Posts: 197
Guitar straight to amp. Loop has Strymon Big Sky and Flashback delay. The problems persists with loop disengaged and unplugged as well. Guitar is fine on other amps.
I DID use the Jp2c with it, and it sounded terrible. I didn’t suspect the speaker until I got the IV back.


Top
 Profile  
 
PostPosted: Sun Apr 08, 2018 1:34 am 
Offline
Mark II

Joined: Tue Sep 08, 2015 3:35 am
Posts: 62
fatbagg wrote:

I DID use the Jp2c with it, and it sounded terrible. I didn’t suspect the speaker until I got the IV back.


Sorry, having a hard time following you here - when you say you used "the JP2C with it", which "it" are you referring to, and how was it "used" instead of the MkIV's own amp? Maybe I'm just missing the obvious, in which case I apologise.

_________________
MkII eh?


Top
 Profile  
 
PostPosted: Sun Apr 08, 2018 4:45 pm 
Offline
Mark III

Joined: Sun Feb 18, 2007 7:55 pm
Posts: 197
I used the Jp2c head into the speaker, my Mark IV head was already gone.


Top
 Profile  
 
PostPosted: Sun Apr 08, 2018 4:46 pm 
Offline
Mark III

Joined: Sun Feb 18, 2007 7:55 pm
Posts: 197
I’m unsure what it was supposed to sound like (Jp2c) but it surely didn’t sound anything like my iic+, it was very Vish.


Top
 Profile  
 
PostPosted: Mon Apr 09, 2018 6:52 pm 
Offline
Mark III

Joined: Sun Feb 18, 2007 7:55 pm
Posts: 197
I also noticed the lead channel sounds very different when I have the amp on lead channel with selector switch versus going into the foot switch lead.


Top
 Profile  
 
PostPosted: Thu Apr 12, 2018 12:53 am 
Offline
Mark II

Joined: Tue Sep 08, 2015 3:35 am
Posts: 62
Ah, I was confused when you wrote "What would a bad speaker do to this combo?", thinking it was a combo we were looking at fixing.

I think you have at least two, maybe three problems - a duff speaker, and a faulty relay on the lead channel switching. Maybe more...

I dug this old thread on Gearpage out: it's somewhat similar, and probably worth a read in any case:

https://www.thegearpage.net/board/index ... em.907384/

How's the speaker substitution going?

_________________
MkII eh?


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 12 posts ] 

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 4 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group