Need help with GK Backline 600

rabidgoatboy · #1 10-27-2011, 02:52 PM

I am having a lot of trouble out of my GK Backline 600. First of all, the amp distorts at band level volumes on the clean channel. I've tried every possible combination of settings I can think of to remedy the issue, but nothing seems to work. I can't seem to get a smooth, clean tone out of the thing to save my life. Also, I seem to be having issues with the overall volume of the amp. I usually have the channel A volume set at about noon, and the master almost all the way up with the -10db pad off because this seems to be the only setting that is sufficiently loud for a gig. I would prefer to keep the -10db pad on because it seems to cut down the distortion slightly, but when I have it on, no matter how loud I turn the main volume up on channel A, I can never seem to get the amp loud enough for to play with my band and be heard. I have the head rigged to an Backline 410 BLX 2 cab and an Acoustic B115 NEO cab. I've read that most people who own the Backline 600 seem to be pretty happy with it, so is there something I'm possibly doing wrong or does the amp just need to be serviced?

Slowgypsy · #2 10-27-2011, 03:01 PM

What are your EQ settings? Have you tried using only the GK 410 cab?

**butchblack** · #3 10-27-2011, 03:15 PM

I'll assume that both of your cabs are 8Ω. First how loud is your band? 300W into 2 cabs should be loud enough unless you play with a stupid loud band, then all bets are off. Also, as someone else mentioned where are your EQ settings, You may have more bass dialed in then your cabs can handle. Also, just to be safe, play your bass through someone else's rig to make sure it's not your bass, some basses are just louder then others.

Bass_Thumper · #4 10-27-2011, 03:25 PM

if everything that these have asked already is kosher, you've got a defect and you need to get in touch with GK, they will take care of it for you. I had this same problem, the amp kept switching to the dirty channel and GK ended up replacing two of them before they got it right. I believe that there was a bad solder joint somewhere.

drewfunk · #5 10-27-2011, 03:28 PM

Is your input signal to hot and causing clipping? I know on my BL600 my straight P-bass signal will clip the pre-amp like crazy. Since i always play through an OD pedal, i just turn the output level on the pedal down until the clip light on the amp goes away.

BTW, my Backline is loud as hell.

rabidgoatboy · #6 10-27-2011, 03:33 PM

Both cabs are indeed 8ohms. I originally only had the 410 cab, but the rig was not loud enough with that one cab alone. I was pretty much maxing out the volume on the head just to be heard with the band. I bought the 2nd cab to remedy this issue, because on the back of the cab, the two output jacks are each labeled 150 watts (the amp is 300 watts at 4ohms). I assumed the head required 2 cabs to realize it's full potential, and once I had the 2nd cab in place, I was able to achieve the same volume level with the channel A volume at noon instead of being maxed out. I wouldn't say my band is louder than a normal metal band. My EQ settings vary (I'm still trying to find a good tone on the amp) but right now: contour is off, treble 12:00, low mid 1:00, high mid 1:00, bass 12:00, boost 12:00. I play a 4 string Warwick FNA with an active humbucker. I've used the bass with 3 other friends' rigs with no problems.

craig.p · #7 10-27-2011, 04:50 PM

Try EQ set to (in o'clock parlance) 10/2/1/10 left to right. That's flat. Start from there. (Thank you again, fdeck.) With bass at noon (12), you're introducing somewhere around 10 dB of bass boost compared to flat. That is a truckload of bass boost. If you're adding even more with the Warwick preamp, then excessive bass boost is where your trouble is. But you didn't say whether you're using bass boost at that preamp. Run it flat to start with. Also understand WHERE that Warwick bass boost operates. Go chase down the spec for it. I know of at least one name-brand on-board preamp whose range is so low as to be essentially useless for anything except generating power-robbing subharmonics and muddying things up.

You may be getting severe cancellations running two different cabs. I'd have added a second identical 410. Even if you got lucky and those two non-identical cabs don't fight each other too badly at moderate volumes, it could all go to hell in that regard once you really start pushing them.

You've done the battery test on both cabs to make sure they're wired for identical polarity, yes?

nickrs540 · #8 10-27-2011, 05:04 PM

I've used this head with multiple rigs so far in my band; GK 4x10, Trace 1518, Ampeg SVT-50, Kustom 2x15, Ampeg 8x10, GK Neo 4x12 (as you can tell I have cab ADD). I loved the tone of the head with all of em', but I could never get the volume I wanted with out it distorting a bit. I just think the head didn't have enough power for me. I'm playing with one guitarist with a marshall full stack and a very very loud drummer so it kinda makes sense for my situation though.
I think its just a lack of power 300w has never been enough for any rock band i've been in. Now im running a QSC 1450 through my GK Neo 4x12 and I couldn't be happier (cept if I had another 4x12 of course

)

Savage_Dreams · #9 10-27-2011, 07:50 PM

[quote=craig.p;11675611]Try EQ set to (in o'clock parlance) 10/2/1/10 left to right. That's flat. Start from there. (Thank you again, fdeck.) With bass at noon (12), you're introducing somewhere around 10 dB of bass boost compared to flat.

how was this determined to be flat? just wondering

Savage_Dreams · #10 10-27-2011, 07:51 PM

Quote:

Originally Posted by craig.p

Try EQ set to (in o'clock parlance) 10/2/1/10 left to right. That's flat. Start from there. (Thank you again, fdeck.) With bass at noon (12), you're introducing somewhere around 10 dB of bass boost compared to flat.

how was this determined to be flat? just wondering