Modding my 800RB

smemm · #1 01-06-2011, 09:18 PM

So I'm thinking of having the bass control on my gk800rb modded to 40hz instead of 60. Just looking for a little more b**ls out of the amp. Stupid, crazy, unneccesary, or impossible. Let me know what you think.

johnk_10 · #2 01-06-2011, 10:00 PM

IMO, moving the eq 20Hz lower isn't going to be all that noticeable and not worth the trouble, but then again i don't associate 40Hz with 'more b**ls'.

personally, i think 60Hz is a more 'useable' frequency.

Standalone · #3 01-06-2011, 10:08 PM

I think it's a bad idea. The 800RB's apparent power and well loved tone has a great deal to do with a bass roll off that is designed into the amp from the get-go. I run mine though a NEOX 212, which has a lot of deep bass. What cabs are you running?

Also, the 800 is considered a classic amp. Do what you want, but folks will cringe to see unencessary mods on classic amps and instruments....

smemm · #4 01-06-2011, 10:19 PM

I used SVT's for a number of years and liked where the bass control was at in these amps (40 hz I believe) which is roughly the frequency of the open E is on a 4 string. I'm not looking to go super deep but I just like the push on the bottom a bit more at 40 than 60. I wasn't trying to imply the amp isn't ballsy, I just wishing it could go a bit deeper. I love every other aspect of what this amp does.

ampegfuzz · #5 01-06-2011, 10:25 PM

FX loop! Add an simple eq, i did when i had one or maybe even a sonic maximizer.

smemm · #6 01-06-2011, 10:27 PM

I'm running it into an ampeg 8-10, bass is a ric 4003 w/barts. I guess the notion of modding one of these amps didn't seem overly risky given that they are cheap, plentiful and still being made. I have as much respect for the lineage and track record of these amps as anyone, that's part of why I bought one. I would never mod any piece of gear without being able to return it to it's original condition.

johnk_10 · #7 01-06-2011, 10:39 PM

IMO, you're still not going to notice a 20Hz difference.
it would be easier (and better) to cut a little mids or use the contour to make it sound a bit more subby. 810 cabs aren't really known for subs though (at least neither of my ampeg 810's are).

i've scratch built quite a few amps, played around with eq freqs, and it's almost completely undetectable having a 40hz center freq as oppossed to a 60hz. all it really does is eat up more headroom and make the speakers fart out earlier.

BassmanPaul · #8 01-06-2011, 10:45 PM

So you want to take a CLASSIC amp and improve it??? Perhaps you should apply for a job with GK's design team. John is right, as he always is, leave well enough alone!!!

rpsands · #9 01-07-2011, 12:29 AM

IIRC the 800 RB does not have much output under 50hz -- it's got a steep rolloff down there from what I recall reading.

I'd move the bass control up to 80-100hz before I'd move it down to 40hz. 40hz is really hard to hear out of most bass cabinets..borderline impossible.

All in all better solution would be to buy a GEB-7 Boss pedal.

BassIan · #10 01-07-2011, 01:05 AM

If it's a shelving control, this will actually make it less effective. Often, EQ sections will leave the top and bottom adjustments as shelving controls. In this case, shelving means everything from 60Hz and down is boosted, rather than the boost being *centered* at 60Hz. I'm not sure this is the case with the 800, but it's very common.

Most bass cabinets don't have significant output at 40Hz.

Boosting bass excessively is a great way to sap power with minimal noticeable volume gain.

powellmacaque · #11 01-07-2011, 01:05 AM

Quote:

Originally Posted by smemm

I'm running it into an ampeg 8-10, bass is a ric 4003 w/barts. I guess the notion of modding one of these amps didn't seem overly risky given that they are cheap, plentiful and still being made. I have as much respect for the lineage and track record of these amps as anyone, that's part of why I bought one. I would never mod any piece of gear without being able to return it to it's original condition.

Doesn't sound like much of a low-end oriented bass. Maybe that's the problem.

Sartori · #12 01-07-2011, 06:17 AM

Quote:

Originally Posted by smemm

I used SVT's for a number of years and liked where the bass control was at in these amps (40 hz I believe) which is roughly the frequency of the open E is on a 4 string. I'm not looking to go super deep but I just like the push on the bottom a bit more at 40 than 60. I wasn't trying to imply the amp isn't ballsy, I just wishing it could go a bit deeper. I love every other aspect of what this amp does.

Are you sure that's where the bass control was centered? That sounds fishy to me, considering that the 810 barely gets down to 40 hz.

If you liked SVT's bass control, why not just get one?

Sartori · #13 01-07-2011, 06:17 AM

Quote:

Originally Posted by powellmacaque

Doesn't sound like much of a low-end oriented bass. Maybe that's the problem.

Depends which pickup he's using. The neck pickup on those is very deep sounding.

JoshuaTSP · #14 01-07-2011, 06:23 AM

Another idea is to look at the 700RBII.

With the 4/5 string switch....it might be exactly what you're looking for.

kringle77 · #15 01-07-2011, 06:38 AM

The best idea is to add an eq in fx loop. If you want to mod, the best thing to do would be to lower the frequency where the roll-off occurs. It's probably as simple as changing a cap.

Standalone · #16 01-07-2011, 08:03 AM

I do think that an EQ in the loop makes sense. But remember, the 800RB only has 300 Watts available. The reason that the amp seems so loud for its rating is, from what I've read, due to this bass roll off. Bass takes more energy to produce, so dropping the 30-50 HZ information out of the signal effectively increases the power.

Point taken that these amps are still being produced and maybe it's not so bad to mod them. I'm still skeptical, but starting to be curious about how it turns out.

Ewo · #17 01-07-2011, 08:11 AM

Quote:

Originally Posted by JoshuaTSP

Another idea is to look at the 700RBII.

With the 4/5 string switch....it might be exactly what you're looking for.

+1

I've got a GK combo with the 1001RBII. Yep--that 4/5 string switch definitely does something!

Go to a music store and try either the 700 or 1001 out. See if that's what you're looking for, tone-wise.

christw · #18 01-07-2011, 08:36 AM

Don't tell me a Ric won't go deep. The two 4001's I've owned have been anything but anemic. The 4003's weren't as good but still will kill small animals with the right amplification. My '81 sounds super phat on the neck or with both pickups on, although certainly more scooped in the latter position.

How do the Barts sit tonally? The 810E is a good low mid cab, not a low low cab. Boosting lows won't help much. It'll probably mud you up in the mix or end up with you feeling like you're losing headroom. Try some other RB's and look at getting a good ported cab or cabs.

nanookofnj · #19 01-07-2011, 09:38 AM

I recently changed out one of the 12" speakers in my 2x12 that had froze up, and just got my 800RB back from GK fixing some cold solder problems.

Now, when using it, my tone seems a lot 'rounder' and more mellow then before. The EQ is still set flat (bass at 1 o'clock) and no boosts or cuts. Master 300W is set at 10 o'clock, boost is around 10 as well, and volume is set at about 1 oclock. In messing with the bi-amp button, I find the amp runs a lot more quiet when it's pushed in as opposed to full setting. I have the frequency set to about 10 o'clock as well.

Just wondering what are other 800RB users are setting their amps at? Thanks.

JoshuaTSP · #20 01-07-2011, 12:59 PM

I'm playing loud heavy rock. We tuned to C standard, and sometimes drop the C down to A#.

I use a 800RB into a 2x15 with kappalites.

My settings are:
Master - 1pm
Boost - 3pm
bass - 3pm
lo mid - 1:30pm
hi mid - 1pm
high - noon

None of the buttons engaged.

the highest I usually go on the pre level is 9pm (overall volume)