1st post.. Gk 800rb w/ 6x10?

Lots of love for the 800rb. Did you have a particular question about your rig that I am missing? Or just a concern that it is running hot through your cab?

 

Is the amp racked? Mine gets hot racked so I un-racked it.

 

I would check the wiring/speakers on your 610. Could it have something that is presenting low impedance to your amp?

 

What is the impedance of the 6x10?

 

This^^

Don't play it until you've verified all 6 speakers are working and the internal cab wiring is in order. If there is a series connection in there, 1 bad speaker can also take its mate out of the circuit.

Something is presenting a low impedance to the amp. The only time my 800rb got that hot was when I goofed, grabbed the wrong speakers and ran it at 2 ohms. They can push 4ohms all day long in the blazing sun and not miss a beat.

If you put a meter across the tip and sleeve of your speaker cable, it ahould read something between 3 and 4 ohms.

 

Mine gets pretty warm too, 800rb through a 810E.

 

IMHO, the one design flaw of the G.K. 800 was there was no cooling fan.
I bought my 800 new in 1984 and "always" parked a small 4" Radio Shack fan behind it blowing on the cooling fins.
I ran that G.K.800 through a Ampeg 810 for almost 26 years.
NEVER had any problems from that head.
The 800 and it's fan is still in use!
I give that cheap fan the credit for the heads longevity.



(Wish I had the flat back 810 back!)

 

I really don't think it needs a fan. The whole back of the thing is a huge heat sink. And the aluminum box is an excellent thermal radiator. I don't get it. Mine hardly gets warm.

 

Maybe.......maybe not.

But ask yourself why almost all modern S.S. amps are now equipped with cooling fans?

IMHO, heat is the enemy of electronics.

 

That big exposed heat sink is expensive and doesn't meet world requirements for exposed heat. Small heatsinks and fan are MUCH cheaper and not being exposed can meet world certification requirements.

Even if you received a second degree burn by touching it, you are not even close the the junction break down temperature of the output devices. A fan on it may make you feel better and if it does it's worth the trouble. But if you can hold the heatsink for at a minimum of 3 seconds, the amp is fine and safe.

 

Because......

Dolla bill, yo. Safety from burns? Ok, but mine has never gotten hot, ever. And no fan means the inside stays perfectly clean. Mine's 20 years old and the inside looks brand new.
OTOH my old fan-equipped SM900 used to get so hot you didn't want to touch the rack handles, and the inside has needed cleaning several times. I prefer the GK solution.

 

I don't think it was safety from "burns", I just know it didn't meet European cert for export because of the exposed warm heatsink. That is why G-K stopped using "universal" power transformers.

 

Euro-silliness. My company exports industrial machinery to Europe, and some of the CE stuff is just nuts.

 

I ran the exact same setup 800RB, Sansamp, Ampeg 6x10 for about 5 years. It worked great!! I used the head racked and unracked. It did get "warm", but nothing that i would fret over. As the head got older, i did have problems with power transistors blowing about once a year so i moved on to Genz Benz. Great rig you've got though!

 

I dont think any am in the world gets as hot as the old SWR SM's
My 800RB is racked with an open space above it. Our rehearsal room in an attic and gets hot. It will get pretty warm but not so much that your afraid of getting burned. My old SM500 you could fry an egg on.

 

The heatsink on my 400RB has gotten hot enough to the point where I can't comfortably touch it. Still going strong! Like the almighty B-string said, your skin would probably have to sizzle before you could say its too hot.

 

Modern? The 800RB was designed in 1981 and remained as unchanged as US certification would allow. If it had been majorly redesigned people would be screaming about how they ruined the 800RB. Damned if you do, damned if you don't I guess?