Author Topic: F1X and 2 channel amp question (Read 143 times)

toddharris · « **on:** June 20, 2010, 05:39:22 PM »

Hi,
I've always used a combo head but am considering using my F1X with a 2 channel power amp. Have a Crown XLS 402 that I use for my stage monitors but am looking at the QSC PLX 1804 given I'll never use more than 4 cabinets (4 ohms per side) Here is my question - If I take the high frequency output of the crossover in the F1X and run an instrument cable to channel 2 of the QSC, can I use that to drive a separate, treble only speaker like a 4-10 cabinet? - I've always shied away from bi-amping for not wanting to carry two amps (amp combos) with me. For that matter, using a stereo split from my any of my Series 1s and DS5R, can I use the QSC as two separate amps, inserting two F1X's as pre-amps? Trying to get a split sound (want to chorus just my high end content) without carrying two separate heads. Thanks for sharing, Todd

sonicus · « **Reply #1 on:** June 20, 2010, 06:17:22 PM »

Hi,
I currently have set up a mid size rig using an F-1X & a Crest VS900 power amp with a 4 /10 and a 2/10 Bi-amped and it works swell. If you just want to use a chorus on just the high end then and if you have a chorus that can accept the pre-amp level from the f-1X then feed the high frequency out from the F-1X to the input of the chorus and then run the chorus output to one of the input channels of the power amp and the low frequency signal to the other channel of the power amp . If you have a 19 rack type effects unit you should have no issues doing it this way rather then the effects loop signal path. Results will vary depending on the specs and compatibility of the chosen effects unit .

(Message edited by sonicus on June 20, 2010)

toddharris · « **Reply #2 on:** June 20, 2010, 06:28:00 PM »

That's great - I like the idea of driving two separate cabs with a crossover for separation and having just one head. Love the F1X sound. Used it last night straight into my GK700RB with no issue, but wondered if I might harm the pre-amp section of the GK by going straight in - any thoughts on harm that could be done by going pre-amp to pre-amp? It sounded fine. Thanks, Todd

mike1762 · « **Reply #3 on:** June 20, 2010, 06:32:44 PM »

(Message edited by mike1762 on June 20, 2010)

sonicus · « **Reply #4 on:** June 20, 2010, 06:44:31 PM »

I too like to use GK gear from time to time and have done so with both my F-1X & F-2B . The thing to do to avoid an input over load is push the input pad -14/-10 /or -? and there should be no worries regarding damage. Another approach is to use the Alembic preamp through the effects loop as an effect Results will vary with usual disclaimers . There are many ways to do it .

toddharris · « **Reply #5 on:** June 20, 2010, 07:09:41 PM »

That's great - I had been using both pads(the Alembic and the GK) and had thought about going from the GK effect send into the F1X and back out through the full range. Mike above had written asking why I want to bi-amp, but the post is gone - I don't go through the pa - clubs of no more than 400 people so far - I like the idea of splitting my bottoms and fattening the sound dedicating my 115RBH GK bottom to the low end and leaving it free of any effect. I use a Carl Martin Bass Chorus (floor pedal) that I love. Also am using a superfilter - a wealth of stand out sounds.

sonicus · « **Reply #6 on:** June 20, 2010, 07:15:21 PM »

Yes, I like too experiment as well. Experiment should be my middle name .

bsee · « **Reply #7 on:** June 20, 2010, 07:35:47 PM »

It has been reported that the full range output on an F-1X is in reverse phase to the bi-amp outputs. Be aware and wire accordingly.

Various power amps have different specs. Some will run both channels individually off a single input (dual mono). Some will run bridged in mono mode, but that universally means a higher minimum impedance, so probably not your best bet for adding more cabs.

As far as going pre-amp to pre-amp, that will depend on specs of the individual pre-amps. You may need to use a pad or play with the respective gains in order to avoid distortion, but it should be doable. I wouldn't expect any harm to come to your amp if you're not generating a distorted signal. I'm not an expert on this, but I would expect that an overload large enough to cause harm would result in audible distortion. I checked specs on a few preamps and the max input voltage was above line level, but I didn't check any GK gear.

gtrguy · « **Reply #8 on:** June 23, 2010, 10:20:54 PM »

I have an ADA B500B rack mt. bass amp that is two amps in one and can do what you are thinking of. I have used it with my F1X and it works great. You can still find one if you look for one on EBay. I also have a spare I might be interrested in selling! They work great for Series stereo instruments and real Bi-amp stuff.

Dave

charles_holmes · « **Reply #9 on:** July 29, 2010, 05:04:30 PM »

charles_holmes · « **Reply #10 on:** July 29, 2010, 05:19:28 PM »

My Rig consists of two QSC 2450 (One dedicated to treble and one for bass)two F-X1 One dedicated to treble and one for bass. I use 2 Y cables. one Y for channel one and two QSC treble and one Y for channel one and two QSC bass. Originally I used the set up that you are talking about, but I found that (for me) when I tried to get more bottom end the QSC tended to get really warm, so that's when I purchased another 2450 to dedicate for bass. For me, that was the answer I was looking for! To me it seems that it just takes more power to get the thunderous room engulfing lows and not as much power for window sonic boom highs.