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Markbass shutdown
- Thread starter telejojo5
- Start date
Maybe the total load of the cabs is 2 ohm, and the amp's minimum impedence is 4 ohm?
Checked the Hartke cabs with a multimeter for ohm readings? Something could have knocked loose or blown, causing a malfunction
Like @Plucky The Bassist mentioned, I'd be testing those cabs with an ohm meter. If you got two 8 ohm cabs shutting down your 4 ohm capable amp, and then two 8 ohm cabs that work fine with it, good chance it's a cab issue. It's definitely the 1st place I'd start trouble shooting at.
It could be the "Hartke detector circuit" shutting the amp down, prompting you to go buy another MarkBass cab.
My guess is it's a thermal shutdown.
You say the "volume was at about half".
OK, let's discuss what that means. I'm assuming your volume control was at about noon, and you're thinking that means half power. Does it?
Well, .....no. A volume control at noon does mean there was more gain available, but it does not tell you much at all about how much power you were putting out. The position of a volume control is not indicative of the power being pushed out of an amplifier - halfway on the volume control does not mean half power. There are plenty of amplifiers that (depending on what else is goin on in the rig) can be driven to full power with the volume control at noon. If you plug a bass with less sensitive pickups into an amplifier, you will need more gain to drive the rig to full power - there, you may need to go above noon on the volume control to get full power. If you have any pedals in front of your amp that add gain to the signal, you may need to turn down the gain even more to avoid clipping the amplifier.
Unless you have a meter somewhere telling you how much power is being delivered to your speakers, you can not say with any certainly anything about how much power was being delivered - you just can't. The likelihood is that you were driving things hard for a while, the amplifier sensed it was overheating, and it thermally shut down. A bit later, the thermal protection turned off, you plugged it into different cabinets, and it started working again - because some time had elapsed, and it had cooled off a bit.
You say the "volume was at about half".
OK, let's discuss what that means. I'm assuming your volume control was at about noon, and you're thinking that means half power. Does it?
Well, .....no. A volume control at noon does mean there was more gain available, but it does not tell you much at all about how much power you were putting out. The position of a volume control is not indicative of the power being pushed out of an amplifier - halfway on the volume control does not mean half power. There are plenty of amplifiers that (depending on what else is goin on in the rig) can be driven to full power with the volume control at noon. If you plug a bass with less sensitive pickups into an amplifier, you will need more gain to drive the rig to full power - there, you may need to go above noon on the volume control to get full power. If you have any pedals in front of your amp that add gain to the signal, you may need to turn down the gain even more to avoid clipping the amplifier.
Unless you have a meter somewhere telling you how much power is being delivered to your speakers, you can not say with any certainly anything about how much power was being delivered - you just can't. The likelihood is that you were driving things hard for a while, the amplifier sensed it was overheating, and it thermally shut down. A bit later, the thermal protection turned off, you plugged it into different cabinets, and it started working again - because some time had elapsed, and it had cooled off a bit.
Last edited:
- Feb 12, 2006
- 61,092
- 5
- 221,221
- Disclosures
- Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
True - that'd be a specialized meter.Which multimeter can measure AC impedance?
But most meters can detect shorts and measure DC resistance, and checking either of those would give good insight.
Also could be a speaker cable issue.
A frayed strand of wire bridging the hot and neutral connectors will show as a short and (hopefully) trigger the amp's protect mode.
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Sounds like the Markbass is going into a protection mode, unhappy with the load it's seeing.
Try each Hartke individually.
Check owner's manual for minimum ohm rating of outboard cabs.
More food for thought- you're not the first to inquire about such issues here:
Try each Hartke individually.
Check owner's manual for minimum ohm rating of outboard cabs.
More food for thought- you're not the first to inquire about such issues here:
Not sure if its relevant, but my tube800 would do this when the tweeter was cranked and you played too aggressive. turn the tweeter off? no issue.
- Feb 12, 2006
- 61,092
- 5
- 221,221
- Disclosures
- Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
