Author Topic: Just got an F-1X, I don't want to blow it. (Read 378 times)

edwin · « **Reply #15 on:** March 14, 2010, 01:53:39 AM »

There is a huge market of beastly power amps. Dave is right, and those are some the good ones. I used a PLX 2402 for a long time.

These days I've gone back to my McIntosh MC2105. 3 times the weight, 1/2 the power and 100 times the tone. Something about this amp just makes the sound bigger in all the ways you would hope. If only it was 300 wpc instead of 135. Of course, at that rate, it would be a 2300 and weigh 130 lbs.

Good luck and have fun! Finding a new great power amp is a great feeling!

keith_h · « **Reply #16 on:** March 14, 2010, 05:58:08 AM »

Dave pretty much covered the major power amp manufacturers.

I use a QSC PLX 3002 this is about 900W per channel at 4 ohms. It has been replaced by the PLX2 3102 at 1000W per channel. QSC also has the PLX2 1804 at 900W but it does not support 2 ohm or bridged operation. For Crown the XTI 2000 is 800W/channel and XTI 4000 1200W/channel at 4 ohms. These would cover your mentioned 1000W per channel at 4 ohms.

You should be able to locate any of the QSC or Crown amps either used or new online. If you don't like e-bay (I sure don't) try some of the local sound reinforcement companies. They will quite frequently have used stuff for sale. A number of them will also sell new and typically have better prices than Musicians Friend, Guitar Centers, etc.

Keith

cozmik_cowboy · « **Reply #17 on:** March 14, 2010, 07:39:17 AM »

Dave pretty much covered the major power amp manufacturers.

Except for the most transparent-sounding & reliable one. If you're thinking power amp, do yourself a favor & look into Yamaha.

Peter

keith_h · « **Reply #18 on:** March 14, 2010, 08:29:23 AM »

I forgot about Yamaha. I also forgot about Crest. As I have no experience with Stewart my expectation is some of the folks that use them will provide an opinion.

I don't think one can say Yamaha is the most reliable amp line. My feeling is they all have about the same reliability. I know that my 5 QSC's have never had a problem and are quite road worthy. I was also using QSC back in the 1980's and had no issues. Some of the newer amps with built in DSP have had issues with software but it is easy enough to stay away from those.

Any well designed power amp will be transparent to the signal path. All of the brands mentioned are well designed in my opinion. There are some folks that do not like the newer switching power supply amps for subs and prefer the old iron. The general opinion is the old larger transformers handle the low transients better. It also doubles the weight. For both my rig and PA I use switching amps and have never noticed any problems. Of course I don't drive my PA or rig at the limit so I'm not in a position to voice an opinion in this area.

Keith

sonicus · « **Reply #19 on:** March 14, 2010, 09:36:56 AM »

I bring these factors up EVERY time when helping to select power amps for folks; 1) CONVECTION or FAN cooling?
2) DAMPING FACTOR ? (higher = better definition in lower frequencies)
3) TRUE POWER RATING @ 8OHMS in RMS WATTS?
4) What is the procedure to operate in bridged mode?
5)WEIGHT?

When selecting an older used power amp you have the of ability of choosing one with a good track record reliability wise !

cozmik_cowboy · « **Reply #20 on:** March 14, 2010, 12:04:54 PM »

Keith, I base my statement on this: when I was a professional soundman (8 years fulltime), I used Crown, Crest, QSC, BGW, Trayner, Peavy, and probably some I'm forgetting. Every one quit on me mid-gig at some point - except Yamaha. All the others also changed the sound, from a mild coloring on the QSCs to outright mud on the Peavys. For bass (as opposed to reinforcement), some may prefer the various colors, but I think all would prefer the always-works bit. I will admit, however, that the afore-mentioned experiences were 1977-84, and it is possible that some of the others have improved. I have used Yamahas recently, and they remain the only power amp I'd buy (though I'm unfamiliar with Stewart - they may be just as good for all I know).

Peter

sonicus · « **Reply #21 on:** March 14, 2010, 12:30:19 PM »

I own 3 YAMAHA P2200 units that are from the late 1970's that are still GOING STRONG! (that is what I refer to as a good track record)

edwin · « **Reply #22 on:** March 14, 2010, 12:31:56 PM »

I'll side with Peter on this one too. I've used Crown, Crest, QSC, BGW, CM Labs (actually a great amp, but the design failed in the way they attached the monstrous power transformer to the chassis, resulting in a catastrophic mess when it would shake loose and bash the innards to pieces. Get some good lockwashers in there and it was a killer amp that was very reliable) and others. In a pro audio scenariao, they sounded OK, but when put up against an amp designed for audio quality, they come up pretty short. This is true not only while pushing the amp to its limits but in the low power performance of the amp. Pro audio amps are by no means transparent to the signal path. Straight wire with gain is the ideal, but the pro audio world has goals that have compromised that idea.

My Mac 2105 was my studio monitor amp after being retired from the road and it sounded wonderful powering monitors by Tannoy and Dynaudio. One afternoon I got a wild hair to replace it with my QSC PLX2402, figuring that the intervening years of 1970 to 1995 or whenever the QSC was designed would have come up with all kinds of improvement to the sound. In short, the QSC was unlistenable. The soundstage flattened right out, the high end turned to cardboard, the low end moved the speaker cones, but was somehow just not that present. I lost the ability to judge reverb amounts, the tails disappeared before I could judge their length, it was a mess. I think there was a huge tradeoff made in fidelity to achieve low weight, sheer power and a good degree of reliability (the amp finally had a problem a couple of weeks ago. The guy I sold it to has been dragging it around the country for the last 3 years in a trailer with no suspension, so things loosened up and I did the same since I got it in 1998. However, my Mac has had similar treatment and has never had a problem, despite being bashed, bent, beat up into weird loads, fed all kinds of abusive signals, etc.

What's my point? Who the hell knows? I guess it's just to be aware of the fact that pretty much every amplifier has made a decision about the tradeoffs that are inherent in design. You can have loud, light, or high fidelity, but not all three cheaply. Adjusting for inflation, there are great deals in amps out there today, but look carefully at what you are really getting. I've decided that good sound trumps light and loud. A 2300 would be nice, but I'm not that desperate to get that loud at the cost of that much weight.

bigredbass · « **Reply #23 on:** March 14, 2010, 07:39:40 PM »

I'm with Sonicus: The 80's Yamaha P-Series power amps were reqmarkably clean, spacious, and airy, and every bit as rugged as my yardstick in those days, the Peavey CS800, the Ford pickup of power amps if there ever was one.

J o e y

sonicus · « **Reply #24 on:** March 15, 2010, 09:35:00 AM »

HI J o e y !
What is nice about the P2200 is that it is convection cooled and is great for use even as a studio monitor amplifier for passive monitors. Some engineers have regarded them as the poor mans Bryston 4B SST Pro because of the clean high power uncolored performance.

keith_h · « **Reply #25 on:** March 15, 2010, 10:11:12 AM »

Joey,
I agree with you on the trade offs. As I said I know of folks that won't use switching amps for subs. They prefer the old iron transformers and are willing to put up with the extra weight. Of course a lot of these folks (pro audio) have help schlepping the amp racks around. The RMX line is fairly popular in the midsized to large systems of the pro audio world for it's standard transformers.

I will disagree on the PLX Series amps. I have couple of audiophile friends that use them in very high end audio systems with great results.

There is a reason why we have so many companies to choose from. If we all liked and wanted the same thing we would all own Behringer. :-)

Keith

electronicstud · « **Reply #26 on:** March 16, 2010, 06:57:30 PM »

wow..This forum is very rich in inteligence and experience, you guys should get together and write a book. Oh yea... my generation doesn't read books. This forum makes harmony central and BassTalk.com look like ...well.. what they are. I will buy a power amp most likely on craigslist. I have been looking the past couple days and havn't found enough power yet. I am not worried about weight at all, hell.. I pay money to lift weights. I dont travel at all and I am 32, So... I now know what to look for.. awsome thanks. On another note if anyone is still listening..I wanted to mess around with the tube in my F-1X, I wanted a spare and to hear a different tube; didn't work..at all. I took the tube out as to give a size reference, I bought what they had... a Groove tube Silver series ST-12AX7-C,(12 bucks) and a Groove tube-12AX7-R (20 bucks). Well..the GT-R wouldn't fit even though I had the poor teenager rip apart several boxes to find the slimest one which apeared to be the same size as the tube I pulled out. hmmmmmmm. The St-12ax7-c fit well but buzzed like crazy, I tried to let it warm up for a few min but gave up and pulled it out. Do I have to put the same exact tube back in? (Biasing?) The tube I pulled out only has 12AX7 in red ink written on it and barely fits in the sleave. J J? Thanks for the Tips guys, I am definantly moving forward.

elwoodblue · « **Reply #27 on:** March 16, 2010, 07:21:31 PM »

Here's a couple threads discussing tube swapping in the F-1x:

http://www.alembic.com/club/messages/394/21239.html

http://club.alembic.com/Images/393/22979.html

electronicstud · « **Reply #28 on:** March 16, 2010, 08:31:52 PM »

thx Mr. Blue. I guess something was wrong with the silver series groove tube. maybe I will try it again, or call that one guy off of the link and get a jj tube that fits. Or maybe the one than came with my preamp will last 20 years. cheers.

sonicus · « **Reply #29 on:** March 16, 2010, 10:12:35 PM »

Envelope vacuum and plate design play an interesting factor on the timbral aspects of 12aX7/ECC83 type design , I prefer a hard envelope vacuum over a soft envelope vacuum for the reproduction of the lower frequencies as experienced in the dynamics of a Bass Guitar. A hard envelope vacuum will yield more definition and cleaner response of transients, My picks for NOS tubes are Telefunken ECC83 with smooth plates & RCA 12AX7(red box). New tubes; Russian Electro-Harmonix 12ax7. I am still looking for a matched pair of NOS CBS Hytron or Raytheon 7729 tubes for testing which quite possibly would become my new choice of preference for my ALEMBIC F-2B.