GK 700RB and Ampeg 1510 cab mismatch?

[Mike Edmonds]

I've got an Ampeg B2R and 1510 (175w@8ohms) cab that I bought new in the 90s. Recently I've been wanting to try something different so I got into a 700RB off eBay. It was part of a combo that someone separated. My plan was to run it thru the same 1510 cabinet. The output rating on the 700RB (225W@8ohms) is about the same as the B2R (200W@8ohms) so I assumed I'd be good. I don't gig or get too loud so I'm not really driving this gear. I've got the GK plugged into the 1510 via 1/4" cable.

I run the woofer knob all the way up and the input volume around 9:00. At these levels it does OK for just casual plucking, but when I turn it up any more or get a little aggressive the protection light turns red and the mutes the amp.

I still have the B2R and running thru that at any level doesn't cause any problems

Does this sound like a problem with the amp or do I have the wrong cabinet under it?

Thanks for any help.

 

[Wasnex]

Something is wrong somewhere. Could be the amp, cab, speaker cable. IMHO, try the 700RB with a different cab.

 

[Old Garage-Bander]

I've got an Ampeg B2R and 1510 (175w@8ohms) cab that I bought new in the 90s. Recently I've been wanting to try something different so I got into a 700RB off eBay. It was part of a combo that someone separated. My plan was to run it thru the same 1510 cabinet. The output rating on the 700RB (225W@8ohms) is about the same as the B2R (200W@8ohms) so I assumed I'd be good. I don't gig or get too loud so I'm not really driving this gear. I've got the GK plugged into the 1510 via 1/4" cable.

I run the woofer knob all the way up and the input volume around 9:00. At these levels it does OK for just casual plucking, but when I turn it up any more or get a little aggressive the protection light turns red and the mutes the amp.

I still have the B2R and running thru that at any level doesn't cause any problems

Does this sound like a problem with the amp or do I have the wrong cabinet under it?

Thanks for any help.

Check the manual. This one says 320 watts @ 8 Ohms. But maybe your's is different? RB vs RB II??
Regardless, 200 watts into a 175 cab is pushing it. Turn the woofer knob all the way down and see what happens. Be sure the cab wiring is good. But definitely try another cab, as previously suggested. Doing so will help isolate the problem to either the cab or the the amp.
https://static1.squarespace.com/sta...b01142025c9b56/1419972739424/700rb_1001rb.pdf