I had the exact same rig 3 or 4 years ago...(RB2000 / Acme Low B4 - 8 ohms). At some point, the head started to "fart" and "spit" and go into protect mode and what not.
A call to GK's service department pointed out the fact that my early production model RB2000 had only one cooling fan over the internal heatsink fins... and the GK service rep on the phone said that since I had purchased mine, they had decided to go with two heatsink fans. He then proceded to point out to me the fact that connections for this second fan already existed on the chassis.
Therefore, a simple fix to alleviate what (in my case) was a simple thermal problem. Check your amp to see whether there are one or two cooling fans in there.
PS... Getting my amp back from GK Service DID take longer than I would've expected for an otherwise upstanding corporate entity... but, hey... that GK/Acme rig was worth the wait.
A call to GK's service department pointed out the fact that my early production model RB2000 had only one cooling fan over the internal heatsink fins... and the GK service rep on the phone said that since I had purchased mine, they had decided to go with two heatsink fans. He then proceded to point out to me the fact that connections for this second fan already existed on the chassis.
Therefore, a simple fix to alleviate what (in my case) was a simple thermal problem. Check your amp to see whether there are one or two cooling fans in there.
PS... Getting my amp back from GK Service DID take longer than I would've expected for an otherwise upstanding corporate entity... but, hey... that GK/Acme rig was worth the wait.


