GK 800RB newbie, is hiss common with these?

[mouthmw]

I definitely don't like running the Volume so high that it causes distortion before the Boost circuit. That is not how this amp should be run IMHO.

I currently have my Boost at 11:30, my Tweeter at 12:00 and my Woofer at 14:00. If I run the Masters much higher than this, the amp gets a little hissy, but not what I would call problematic for live work. It probably would not fly in a recording studio though. I don't think I would ever run the woofer Master past 15:00. The Woofer amp is noisier when the Woofer X-Over switch is engaged. Not a surprise...extra circuitry adds noise.

The Boost control is just an attenuator on this amp as well. So you can keep the level hitting the Boost circuit the same by increasing the Volume while decreasing the Boost control, or by increasing the Boost control while decreasing the Volume. But the best S/N ratio is with the Volume set fairly high.

I'd see tweeter hissing, but not the woofer to be honest. Unless you crank the treble I guess. I never use the tweeter, that control is always off (turned down all the way to be specific) for me. Tweeter doesn't work well with OD, fuzz and distortion pedals and I tend to use those sometimes. GK RB love "riding the rails" with a mix of boost growl and cranked up master (woofer). Kind of like a tube power section. It opens up headroom as well.

 

[Christian K]

Ive had this amp a while, actually havent dated it but its older...just now spending time with it and wow, so many great tones!

Thru a 4 ohm Acoustic 8x10 (braced modded inside) and bi amped thru an 8 ohm EV15L in TL-606 cabinet, like i said, a LOT of great tones but hiss is more present switching from my Eden Metro head (which is 400 watt into 4 ohms).

The Bi amp feature is really something else, especially with my 65 Epiphone Newport (neck mudbucker) an astounding array of tones available, even more when i kick in an EQ pedal...gets very close to a 'P bass sound'.

But its the hiss....i need to spend way more time and write down some settings as so much control with all of the EQ and volume-master volume and boost feature.

Is hiss common and/or something i need to do differently? Honestly i was amazed how loud the EV15L is with the 100 watt amp mixed in with the 8x10 on the 300 watt side.

Sorry, i know i need to spend more time and write down some settings...also using a Yamaha compressor with light compression but the hiss is the same whether i plug straight in or not...thanks in advance!

Mines a ‘97 and I’m not getting any hissing (knock on wood). If you do decide to take it apart, I’d be happy to send over the schematics I used to bring mine back to life after it wasn’t working for a few months in someone’s garage.

thanks!