Hey y'all I usually just creep around with the search button but I believe I have a problem that I don't think I've seen posted about yet with these bitter sweet 121p'. My amp is a few years old (5 or so) it gets a lot of PT. My first problem with it was the whole power supply issue where it just cuts off randomly. Got that fixed and a year or so later it started doing this thing where it cuts out the low end while I'm playing. Started out as once or twice during a gig and now it's a few times a song. My setting are essentially 12 o'clock all across the board, no vle or the other knob (I forgot what it's called), and master at about half way with the gain comfortably behind it (no drive or distortion). No pedals or effects. I believe the tweeter was blown, though that was about a year before the power supply issue happened. Only reason I mentioned it, is because the only other thing I read close to my problem had to do with the tweeter. Before I ourchase a new one. Anybody have an idea what this may be or some trouble shooting tips?
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Patience.
TB hosts readers from around the world. Give them a day or two to read and respond.
We are noted for our helpful answers, not our breakneck response time.
TB hosts readers from around the world. Give them a day or two to read and respond.
We are noted for our helpful answers, not our breakneck response time.
I have owned several Markbass heads, cabs and combos and the only one that ever failed was the Combo head 2 in my CMD121P combo. I wonder whether the head orientation (facing upwards) at the rear of the combo subjects it to more thermal and vibration stresses? Mine failed twice, once for a broken solder joint on the speakon connector and a preamp PCB fault. It might be more cost effective to have your combo looked at by a competent amp technician before replacing it. Another option is to buy a newer LM3 and swap the faulty one out.
Just to add . . The Combo Head II in my CMD121H is failing and I'm gonna return it under warranty, just over a year old. Giving off a burning smell after it's turned on for a while even when idle.
I note the internals on this later version of the Combo Head II is quite different to the one in my CMD102P which has never failed and is about 5 or 6 years old. Perhaps this latest 'version' is not as reliable?
Let's hope MB aren't cutting corners and producing an inferior product.
I note the internals on this later version of the Combo Head II is quite different to the one in my CMD102P which has never failed and is about 5 or 6 years old. Perhaps this latest 'version' is not as reliable?
Let's hope MB aren't cutting corners and producing an inferior product.
Your older combo could well have the class AB power amp which some people, me included, think sounds better than the newer class D version. It's easy to tell which is which as the class AB has two aluminum heatsinks inside whilst the class D only has (needs) one smaller heatsink for the output transistors. The older unit does get considerably warmer on a gig however due to the less efficient AB topology.
Yup, absolutely right. I can only think the newer class D version is less expensive to manufacture. It looks like my newer version is cooking the output low pass filter for some reason, perhaps it's switching a too low a frequency, who knows?