Using a Guitar Amp

[chris_s]

The common wisdom seems to be that you can't get decent sound for a keyboard through a guitar amp. Guitar amps mostly concentrate on the mids so you don't get much of the lows and the highs. I've been running my Motif ES7 through a Peavey Bandit (Red Stripe) solid state amp and I'm quite happy with the result. I use a Behringer Ultrafex Compressor-Expander ahead of the amp and it gives me a bass boost. The Bandit amp has a pretty wide frequency range. The (12") speaker has a pretty good range for a guitar amp speaker. I play 60's music in a group so I don't need a lot of heavy bass. The mids are fine and the lows and highs are adequate. I'm thinking about trying a back-facing tweeter out of phase with the 12" speaker to improve the highs. The Bandit is a very solid amp, it's small enough to fit in my fairly small trunk, it isn't too heavy and it has plenty of power (80w). It also didn't cost me a bundle. It's fine for a Club and for a larger venue, I would probably put it through the PA system (it has a preamp-out plug).

I tried a few keyboard amps and I wasn't impressed with them. The ones I tried were too bottom-heavy and they were generally bigger and heavier than the Bandit. I am also a part time guitar player in the group so it keeps it simple to have an amp that meets my needs for the keyboard and the guitar.

Thought that I'd post this because I haven't found anything positive written about doing this. Yes, Jon Lord put his B3 through a guitar amp but generally speaking everyone seems to think it's a bad idea. It works for me.

 

[delaware dave]

How do you think your guitar would sound through a keyboard amp?

" .. The mids are fine and the lows and highs are adequate..."

" .. I'm thinking about trying a back-facing tweeter out of phase with the 12" speaker to improve the highs...

" ..I use a Behringer Ultrafex Compressor-Expander ahead of the amp and it gives me a bass boost..."

So apparently the highs aren't adequate or you wouldn't be trying a backfacing tweeter. Apparently the bass is inadequate as well or you wouldn't be needing to run it through the ultraflex to get the extra bass. These are things that keyboard amps provide, the full range of sound generally with EQ'ing that provides the right level of lows, mids, and highs to give you the right balance. That being said what might work for you is a powered monitor like a QSC K8 rather than a keyboard amp. With its 8" speaker you would get adequate bass but wouldn't get heavy bass, you'd get plenty of power and all in a full range cabinet (which a keyboard should be run through to properly amplify its sound) in a lightweight package (27 pounds) and compact size (18 x11 x 11 inches), which is smaller and lighter than your bandit. You will notice a huge difference in how your keyboard sounds as opposed to how it sounds coming out of a guitar amp. It really comes down to how well you want the keys to sound; since you play guitar as well in the band perhaps how the keys sound is as important to you as how the guitar sounds.

I am not trying to be critical of your posting. I simply have a different perspective than you regarding amplification that I feel is warranted for a keyboard.

BTW, Jon Lord played his B3 through a guitar amp for two reasons:

1) the overdrive from the Marshall amp that he wanted to get
2) the shear volume.

Leslies back in the day were 40 watt tube amps being driven into a 16 ohm jensen 15" bass speaker, not alot of power, and that power being cut by having the 15" taking up the power trying to replicate the bass notes as well as being a 16 ohm speaker. Keyboard players (like myself) drug hammonds and leslies around and would stick the leslie about 2 feet behind me, with the louviers off the leslie just so that I could barely hear it and in many instances had them mic'd into a monitor (along with my rhodes, my wurli, my clav D6 and stage piano), all run through full range monitors powered by full range amplifiers). When the rig didn't sound good I found myself focused on the fact that the rig wasn't sounding good rather than making good music. When the rig sounds good then it put me in a mood to play better. Go figure .....

 

[chris_s]

Hi Dave,
Not trying to say that it's the perfect solution but for me, its a very workable compromise that sounds pretty decent. Without the Ultrafex, the sound quality might not be adequate but it makes enough of a difference that it's quite ok. I already had the Ultrafex on hand so it was just a matter of plugging it in. The highs aren't bad the way it is but I figured that it would be worth a shot to extend the range. The amp is good from 60hz - 20000hz and the speaker from 70hz - 6.5khz. From what I've seen, that's above average range for a guitar amp (many of the speakers cut off at 5khz).

Powered speakers would provide an improvement in sound quality (and get it back to stereo) and it will be a consideration going forward. I still need the Bandit for the guitar so the amount of stuff I can get in the trunk of my Hybrid becomes a limitation (short of buying/renting something bigger to get to practices and gigs).

I appreciate your feedback. My only point was that this can be an acceptable compromise, especially if you choose an amp/speaker with a good range and then do some boosting of the lower (and upper) frequencies. It's also a matter of expectations. If you compare it with the sound from a B3 - Leslie or the Keyboard into high quality powered speakers, it might sound inadequate. If it sounds good to me the way it is, then I'm happy and motivated to make good music. What could be finer?

Chris

 

[chris_s]

Watched a few Dyin Breed videos. Good stuff. Used to play some of the Lynyrd Skynyrd stuff a few years back.

 

[b3maniac]

My best sounding rig was when I used a three way PA cabinet. It would cover all the frequencies I needed for any style of keyboard (piano, B3 emulation, synth, synth bass, clav, rhodes, etc) and they all sounded good. Now I use a pair of cheap 2 way powered speakers as a compromise between cost/weight/sound. Don