Roland JC-120H Head

[sean106alcon]

I'm looking forward for it... Just got VH4 and concidering a new cab. Any suggestions?

Yeah man I have two Diezel FRONT loaded not the rear loaded IMO 4x12 with V30's. Amazing cabs. Pricey but worth it. Very tight bass response and articulate. I used to have 2 VH4's and back in the day recto cabs and it was way too boomy as the Vh4 is boomy in general and IMO so are the recto cabs so the combination was way too much bass. The Diezel ones are real focused and tight. But HEAVY as ****.

 

[Sanctuary]

Well a good start is using the low input.

 

[thebigbowy]

Hey man. I just got one of these, and I had some similar questions so I called roland. If you notice on the outputs, it says "8ohm/min" per channel. The guy at roland told me the running 16ohm speakers would damage the amp because it wasn't drawing enough power. He said 8ohms per channel is recommended, and 4ohm is ok too. Just thought I'd tell you what he said. I'd hate to damage this bad boy.


What cab are you using with it now? You said you don't like the mesa rectifiers?

Take care.

 

[sean106alcon]

Hey man. I just got one of these, and I had some similar questions so I called roland. If you notice on the outputs, it says "8ohm/min" per channel. The guy at roland told me the running 16ohm speakers would damage the amp because it wasn't drawing enough power. He said 8ohms per channel is recommended, and 4ohm is ok too. Just thought I'd tell you what he said. I'd hate to damage this bad boy.


What cab are you using with it now? You said you don't like the mesa rectifiers?

Take care.

Hey thanks for the feedback.

Well right now I have two Diezel front loaded 4x12's. One at home and one at my vocalists house as he brings it to gigs and my SUV is packed enough and I can't be lugging a Diezel cab down 3 flights as it is two heavy. So that is why I converted to the Roadster cab to stereo with two 8 ohm inputs. But right now it is out of service as my Mark V with a Boss Super chorus and PS-5 in De-tune mode sounds amazing. I am holding on to it for down the road and use it down the road if I move as it is tooooo loud my neighbors would kill me.

Yeah I am not in to recto cabs. I found them too boomy. The Diezels although a pretty penny are sick. So tight and focused. JMO Thanks.

 

[thebigbowy]

Sweet. Ya, I had a Mark V i bought direct from boogie. Had to sell it for cash to pay off debt later. I miss it so. Do you happen to have a sound clip for your said clean tone? I would like to here it. Take care.

 

[94Tremoverb]

Hey man. I just got one of these, and I had some similar questions so I called roland. If you notice on the outputs, it says "8ohm/min" per channel. The guy at roland told me the running 16ohm speakers would damage the amp because it wasn't drawing enough power. He said 8ohms per channel is recommended, and 4ohm is ok too. Just thought I'd tell you what he said. I'd hate to damage this bad boy.

This is absolutely wrong, false and dangerous to the amp. I can't believe anyone at Roland actually told you that!

It says 8 ohms *minimum*. This means exactly what it says: you can use 8 ohms, or you can use 16 ohms (because it's higher than 8 ohms), *but you must NOT use 4 ohms*. 4 ohms is below 8 ohms, therefore it is below the amp's minimum load. Using a 4-ohm load will draw too much current through the power transistors and probably blow them. (This is true of any solid-state amp - respect the *minimum* impedance rating at all times.) A 16-ohm load will simply draw less power - that won't harm anything. Anyone who tells you otherwise does not know much about solid-state amps.

By the way, if you should happen to blow the transistors in an old JC-120, they can be quite difficult to replace; there have been many different versions and some use types that are less than common nowadays.

 

[thebigbowy]

This is absolutely wrong, false and dangerous to the amp. I can't believe anyone at Roland actually told you that!

It says 8 ohms *minimum*. This means exactly what it says: you can use 8 ohms, or you can use 16 ohms (because it's higher than 8 ohms), *but you must NOT use 4 ohms*. 4 ohms is below 8 ohms, therefore it is below the amp's minimum load. Using a 4-ohm load will draw too much current through the power transistors and probably blow them. (This is true of any solid-state amp - respect the *minimum* impedance rating at all times.) A 16-ohm load will simply draw less power - that won't harm anything. Anyone who tells you otherwise does not know much about solid-state amps.

By the way, if you should happen to blow the transistors in an old JC-120, they can be quite difficult to replace; there have been many different versions and some use types that are less than common nowadays.

Well in the 120H operation manual, it says 8ohm or 4ohm on the output connections. Check it out.... page 4.

http://media.rolandus.com/manuals/JC-120H_OM.pdf

Thanks for the advice though. Take care.

 

[94Tremoverb]

Ah, got it - it's 4-ohm Minimum amp. The jacks say 8-ohm minimum EACH, which means that you can plug two 8-ohm speakers into each channel, or *one* 4-ohm. I've never seen a JC120H in person, only the combos, and the extension speakers sockets on those (of which there is only one per channel, not two) are *definitely* minimum 8 ohms, because they don't disconnect the (8 ohm) internal speakers. That all makes sense now - sorry for the confusion.

But still, using 16-ohm speakers will not do any harm. Solid-state amps (with a tiny number of exceptions, of which this is not one) will happily drive any impedance above the minimum rated, all the way up to no load. (Unlike tube amps.)

 

[thebigbowy]

Interesting. Thanks for letting me know.