Markbass 121H - Combo Head 2 - Problems with pre/power Amp?

[Chris Bold]

Hey guys,

my 'used to be' intermittent problem with this Combo just turned permanent.
It has happened maybe 1-2 times in the past 2 years, for a couple of hours .. then went away.

The amp makes a strong background noise, sort of like a distorted ringing .. don't know. The sound of the bass does come through, and doesn't seem very distorted. (of course, ringing/noise is still there). This happens indifferent of whether a bass is plugged in or not. Gain / Master Knobs (or any other ones) don't influence the level of the 'noise'

I've uploaded a video (Tweeter is disconnected, as i first thought it was on it's way out. With tweeter on, noise is only louder) with the sounds its been making. Please have a look and let me know if the issue is familiar or something ..



Thanks for the help!

 

[Doufuss]

I had one of those. Loved it. It blew up. The authorized repair facility here couldn't fix it due to parts not being available.

The end.

Hope you have better luck than I did.

 

[Chris Bold]

Oh snap. Sorry to hear that & really hope i can find a decent fix for it.

Otherwise .. it shall be the first and last MB. (despite tone..)

 

[Doufuss]

Don't give up yet. Worse comes to worst you could pick up a new head (new to you/used) and it'll fit right in the opening. You'd have to takeoff the cover IIRC. Other guys have done it, see this thread. Markbass Combo head replacement

That's a great sounding cab. Really nice and smooth and very broad frequency response. I used mine with both a 112 markbass cab and the 210 cab and it sounded huge.

Really wish I had kept it, but I flogged it cause I was miffed about the head. Dumb.

 

[Chris Bold]

Thanks Doufuss! : ) Will definately try to get it fixed. It's been my go to for small sessions/jams/shows exactly due to the response & sound + the 'enourmous' weight.

I come from the 'guitar world' originally, and I'm used to less than stellar reliability from old tube amps, which crack up here & there every now and then, but that's fine, it's what they are and their analog tech is easier for me to fix. The MB i've bought new in order to not even think about things like repairs. Just a pick up & go.

Will keep you posted, atm i'm looking for a good tech in my area to have a look at it.

Cheers & stay safe

 

[PhatBasstard]

Any of the Little Mark series heads will retro fit into that cab.
They all use the same internal frame.

Remove the top 4 mounting screws of the cab.
Slide the (unplugged) old head out/forward.
Remove the top plate from the new/replacement head.
Once the plate is off, you may have to remove some of the foam strip,
on either side of the internal frame,
that's covering the holes for the combo's top 4 mounting screws
(You'll see where they are on the old head).
Slide in the new/replacement head until the first one of the mounting screws lines up.
The other 3 should now be a breeze.
Plug everything back in.

I've done this on several of their combos with several of their Little Mark
or Combo Head (a rebranded LM II) or Combo Head II (a rebranded LM III) amps.

 

[Chris Bold]

Thanks Doufuss & Phatbasstard for the helpful & useful replies.

Since I came from the 'guitar-world' i'm quite used to having troublesome tube-amps, and others.
So I've taken quite a few apart and put them back toghether.

Now .. the MB, and replacing the head inside would be a breeze, or not that difficult. My fingers are itching to open it up..
However, i'm uncertain in whether i'd invest in a new / second hand head ... if they prove to be so sensible anyways...

We'll see. At the moment, the Combo's been sent to be serviced, it is surprisingly still in warranty. (Glad i bought the extended one now .. ) and i'm looking forward to find out what went wrong with it.

Will keep you posted. Keep the low end rolling!
Cheers
Chris

 

[SJan3]

Love to hear what the problem/fix was. FWIW, I've had the best experience with my LittleMark head. 11 years and running and not so much as a hiccup. Some people here take pleasure in bashing Markbass products, but most are extremely happy with the product.

 

[PhatBasstard]

Between combos and heads, I've owned 8 or 9 Markbass amps.
All bought used. Never a problem out of any of them.
I think the problem is, on the rarest of occasions there is a problem,
their servicing procedures are more difficult than other brands.

 

[Chris Bold]

Well, here I am to let you guys know how it (didn't) work out.

The 121H Combo went into the service, for about 3-4 weeks. They first swapped out a bunch of internal components (didn't tell me what..), which brought no result, noise was still there. Eventually, after me complaining more than usual, they swapped out the head in the combo, with a replacement unit (Prod. Date April 2020) and sent it back to me.
Not sure what went wrong, but the noise was still present, but had a different "behaviour". It now sort of interacted with the Master Volume. Just weird, it sort of felt like a tube amp that got "gainy" and noisey, like radio static/hiss, when using the Master. Gain was only 1/4 up, a mild setting.

Oh well, since it took ages, and i didn't get a proper result .. i ended up returning it & am now looking for a new head, since I have a couple cabinets to use with anyway. Maybe a Genzler 800.

Thanks for the support & replies!