GK 800RB.. Should I?

[Astronaut]

I'm eyeing one of these unicorns for little above 500 bucks and am wondering whether or not, to pull the trigger.
The amp is inside a rack, some buttons miss the indicator cover and the front panel seem to have a global discolouration (as in yellow tinted).
No pictures of the back panel.
The main question is; does anyone knows if the 100W output is somehow High passed? Is it wise to connect anything other than a compression tweeter?

Thanks.

 

[TonyP-]

I love me some 800RB, but I too think that's a little pricey. For $500 you could get a lightly used Legacy 500 (Robert Gallien intended it as the modern Class D version of the 800RB). I love mine - plenty loud, sounds like you'd expect.

It’s interesting, I’m glad you like yours and the Legacy is my favorite amp, but I don’t find it like the sound of a 800rb…

We all might perceive something differently, bur it sounds to me like a MB and 400 or 700 RB had a offspring

 

[shoot-r]

And GK will service it should the need arise.

+1.....Service from the factory is available for the newest series of GK amps.

Roughfully, at the first part of this year, I contacted the GK California factory about service/repairs for a MB Fusion.

I was told, because of parts availability, they no longer make available service/repairs/parts for any GK amps except their latest Legacy and S series of amps.

For MB's, RB's and any of the older GK series of amps you'll now have to find a qualified service tech outside of GK.

(This is becoming a common thing from most manufacturers. Because of parts availability, they are no longer making available factory service/repairs for anything but their latest series of amps.)

 

[shirojiro]

+1.....Service from the factory is available for the newest series of GK amps.

Roughfully, at the first part of this year, I contacted the GK California factory about service/repairs for a MB Fusion.

I was told, because of parts availability, they no longer make available service/repairs/parts for any GK amps except their latest Legacy and S series of amps.

For MB's, RB's and any of the older GK series of amps you'll now have to find a qualified service tech outside of GK.

(This is becoming a common thing from most manufacturers. Because of parts availability, they are no longer making available factory service/repairs for anything but their latest series of amps.)

This is a real bummer. If GK doesn't have parts, I can't imagine that a 3rd party service center would have any more luck getting OEM stuff. Hopefully there's enough folks who can source replacement parts that are equivalent. This makes the 800RB transformer replacement thread even more relevant.


https://www.talkbass.com/threads/gk-800rb-power-transformer.1680275/

 

[shoot-r]

This is a real bummer. If GK doesn't have parts, I can't imagine that a 3rd party service center would have any more luck getting OEM stuff. Hopefully there's enough folks who can source replacement parts that are equivalent. This makes the 800RB transformer replacement thread even more relevant.


https://www.talkbass.com/threads/gk-800rb-power-transformer.1680275/

It's not just GK.

I tried to get factory repairs for one of my Mesa M6 Carbine heads and was told due to parts availability they no longer would be making available factory service/repairs for M6's and M9's.

I don't know if that includes no factory service/repairs for all older Mesa bass amp models or just the Carbine series.

 

[pbass2]

+1.....Service from the factory is available for the newest series of GK amps.

Roughfully, at the first part of this year, I contacted the GK California factory about service/repairs for a MB Fusion.

I was told, because of parts availability, they no longer make available service/repairs/parts for any GK amps except their latest Legacy and S series of amps.

For MB's, RB's and any of the older GK series of amps you'll now have to find a qualified service tech outside of GK.

(This is becoming a common thing from most manufacturers. Because of parts availability, they are no longer making available factory service/repairs for anything but their latest series of amps.)

I had an out-of-warranty MB112-II that was fritzing out, and the only authorized service center near me wanted $195 just to walk in the door. I had gotten my money's worth out of it over several years so I just sold it to a guy who wanted to tinker with it, and moved on to a new amp.

 

[pbass2]

It’s interesting, I’m glad you like yours and the Legacy is my favorite amp, but I don’t find it like the sound of a 800rb…

We all might perceive something differently, bur it sounds to me like a MB and 400 or 700 RB had a offspring

I can hear that. Robert G says the Legacy 500 is the "modern 800RB" but I think he was more referring to the power configuration than the specific tone. I will say I never use the Drive circuit live, but I was doing a recording recently where they wanted mic an amp(rare for me these days), and we got fairly close-ish to an 800 vibe by fiddling with a little Drive.

 

[agedhorse]

It's not just GK.

I tried to get factory repairs for one of my Mesa M6 Carbine heads and was told due to parts availability they no longer would be making available factory service/repairs for M6's and M9's.

I don't know if that includes no factory service/repairs for all older Mesa bass amp models or just the Carbine series.

I have mentioned many times that we have had real difficulties sourcing lateral MOSFETs in the acceptably matched Vgs ranges to be able to continue repairing these amps at the factory.

The specialized semiconductor process for lateral MOSFETs has been shut down for several years, it was always a low volume specialized process which is no longer in demand at the quantities that justify the expense of maintaining the fab process. They turned out to be problematic devices l, and even when they were being manufactured, they went through 4 different owners/vendors and part numbers.

They were great devices when they worked, but a nightmare when they didn’t work. This in part explains the trajectory of this particular semiconductor process.

 

[TonyP-]

I can hear that. Robert G says the Legacy 500 is the "modern 800RB" but I think he was more referring to the power configuration than the specific tone. I will say I never use the Drive circuit live, but I was doing a recording recently where they wanted mic an amp(rare for me these days), and we got fairly close-ish to an 800 vibe by fiddling with a little Drive.

Agreed...I don't think He was speaking about the tone either, but more achieving that 'rail sound' so to speak. I never use the drive circuit either....Like ever, but I have used a little bit of rail sound and like you almost never get miked anymore :-( . I think its easy to do on a 400RB with a more controllable top.

 

[RasJay]

As for the class D suggestions I think I’ll pass just because my experience with both a 500MB

+1 for the modern GK class D.

I played an MB500 for a couple of years and it was just OK to me. I still keep an MB200 in my office for noodling. My main amp is the Fusion S and it is killer! I also played the Legacy at a store and it was killer as well. I would not dismiss the Legacy based on your experience with the MB. They are different amps. On these newer amps, you can shape the gain stage how you like, and get from vintage to modern GK growl.

I also have the Master Effects Super 800 and I like it as well when I play out and cannot use my own amp. And I use it with my MB200 in my office to get a GK tone. I dime the Boost, set the Master around 30% and bring the volume up just until I get some grind.

If you happen to try the Fusion S or Legacy, be sure to set the trim knob properly.

 

[Astronaut]

+1.....Service from the factory is available for the newest series of GK amps.

Roughfully, at the first part of this year, I contacted the GK California factory about service/repairs for a MB Fusion.

I was told, because of parts availability, they no longer make available service/repairs/parts for any GK amps except their latest Legacy and S series of amps.

For MB's, RB's and any of the older GK series of amps you'll now have to find a qualified service tech outside of GK.

(This is becoming a common thing from most manufacturers. Because of parts availability, they are no longer making available factory service/repairs for anything but their latest series of amps.)

That's exactly why I steer away from class D for now. Enclosed pots and SMD, not many(if any) techs available to repair that. Basically a 10 year old amp is now defunct while many 30+ heads remain road proof.

 

[agedhorse]

That's exactly why I steer away from class D for now. Enclosed pots and SMD, not many(if any) techs available to repair that. Basically a 10 year old amp is now defunct while many 30+ heads remain road proof.

Sure they are repairable if you have the necessary education and skill set, our techs do it every day and I do it a few times a week.

A 10 year old class D amp Is NOT defunct, I still run a factory service program that covers Genz Benz class D amps from almost 20 years ago. It’s flat rate too. The cost to repair our old class D amps is LESS expensive than our legacy class an amps too.

Top notch, qualified techs repair class D amps all the time, though the cheap ones may not be worth the cost of the repair (no different than class AB amps).

Quit posting inaccurate information…

 

[Astronaut]

Sure they are repairable if you have the necessary education and skill set, our techs do it every day and I do it a few times a week.

A 10 year old class D amp Is NOT defunct, I still run a factory service program that covers Genz Benz class D amps from almost 20 years ago. It’s flat rate too. The cost to repair our old class D amps is LESS expensive than our legacy class an amps too.

Top notch, qualified techs repair class D amps all the time, though the cheap ones may not be worth the cost of the repair (no different than class AB amps).

Quit posting inaccurate information…

Uhh yes it’s defunct, until someone brings it back from the dead. As I said accurately there are no techs willing to take my MB500 apart to tinker with it, in MY part of the world.

 

[agedhorse]

Uhh yes it’s defunct, until someone brings it back from the dead. As I said accurately there are no techs willing to take my MB500 apart to tinker with it, in MY part of the world.

That’s too bad, especially the expectation that they tinker with it instead of diagnose and repair.

Also, that’s not what defunct means…

 

[Astronaut]

That’s too bad, especially the expectation that they tinker with it instead of diagnose and repair.

Also, that’s not what defunct means…

No? So what does it mean?

 

[agedhorse]

No? So what does it mean?

No longer exists… for example steam locomotives are a defunct technology. Dodo birds are a defunct species.

A non-working amp would be defective, especially when the technology is still current or being manufactured.

That’s what I was taught.

 

[6thplanet]

You're both right.
I'd agree with agedhorse, in the electronics biz, it'd mean not repairable due to parts are no longer available (NLA). I'd consider the amp dead until further diagnosis.

 

[Bassdirty]

+1 for the modern GK class D.

I played an MB500 for a couple of years and it was just OK to me. I still keep an MB200 in my office for noodling. My main amp is the Fusion S and it is killer! I also played the Legacy at a store and it was killer as well. I would not dismiss the Legacy based on your experience with the MB. They are different amps. On these newer amps, you can shape the gain stage how you like, and get from vintage to modern GK growl.

I also have the Master Effects Super 800 and I like it as well when I play out and cannot use my own amp. And I use it with my MB200 in my office to get a GK tone. I dime the Boost, set the Master around 30% and bring the volume up just until I get some grind.

If you happen to try the Fusion S or Legacy, be sure to set the trim knob properly.

I have ZERO to add to the convo, really, so, I'll just go with the majority. (Mr. 'hot take, I know').



BUT, had to say that I LOVE that BASS in your Avatar Photo!

Do you have a full-size Pic you can share?



T$

 

[Astronaut]

No longer exists… for example steam locomotives are a defunct technology. Dodo birds are a defunct species.

A non-working amp would be defective, especially when the technology is still current or being manufactured.

That’s what I was taught.

Defunct means dead. You can use it as a synonym.

 

[agedhorse]

Defunct means dead. You can use it as a synonym.

Well ok then, maybe there’s a more liberal definition than what I learned.

 

[bass player 53]

Uhh yes it’s defunct, until someone brings it back from the dead. As I said accurately there are no techs willing to take my MB500 apart to tinker with it, in MY part of the world.

To Mr. Astronaut,
I have had two MB500 amps for
several years now that I bought
used.
One works perfectly, while the other
had intermittent sound. At the time,
I called GK and they sent me a few
small connector wires that are used
to connect various boards of the amp,
for example the preamp board to the
ICE power amp. This fixed one issue.
The other issue was dirty gain
and master pots. This is still an
annoying issue that I live with,
as the pots are not easy to clean
properly and not easy for me to
replace.
You may be able to find a tech to
at least look at the issues I mentioned
above.