stewblack

I think this should put the whole debate to bed "So... where does this bring us? As you have probably seen in amplifier spec sheets, manufacturers rate the output of their amplifiers in watts RMS. For example, let's consider the vintage amplifier Kenwood Model KA-9100. This amplifier is rated to put out 90 watts RMS per channel into an 8 ohm load. Technically speaking, the term "RMS" is not defined when referring to power (watts)! RMS is a valid term when referred to voltage or current, but not power! Watts are watts, period! Despite the term "watts RMS" being an incorrect term, it stuck with the community and has become the accepted way to rate an amplifier's output. The reason that audio amplifiers are rated in "watts RMS" is because they are rated to deliver that amount of power using a sine wave signal. Because amplifiers are rated this way, their peak power output will be twice the RMS rating. So, for the Kenwood KA-9100 (which is rated to deliver 90 watts RMS into 8 ohms), the peak power is 180 watts. Most amplifiers cannot sustain output at their peak capability for too long (and the characteristic of most music signals is such that this is not necessary anyway). So, despite "watts RMS" being a technically invalid term, it is used with audio amplifiers because of the sine wave signals that are used to determine their power output specifications. Question: What are (at minimum) the rail voltages necessary for an amplifier to deliver 90 watts into an 8 ohm load? It is not too hard to figure this out. We simply look at the equations for power: P=VI = I2R=V2/R In this case, there are two known items: power (90 watts) and resistance (of the speaker, 8 ohms). Plugging these numbers into the equation (P=V2/R) yields a value for V of 26.83 volts. Is this the answer to the rail voltage question? No... REMEMBER, if we applied 26.83 volts of DC (note: DC) across an 8 ohm speaker the power to the speaker would in fact be 90 watts. However, amplifiers are rated using sine wave input signals, and (as described above) we need to apply more voltage to a load (for a sine wave) in order to get the same amount of power that would be delivered by a DC voltage. For sine waves, the multiplication factor is 1.414. So, if we take the voltage of 26.83 and multiply it by 1.414 (the square root of 2), we get a value of 37.94 volts. This value is the absolute minimum rail voltage needed for an amplifier to deliver 90 watts (with a sine wave signal) to a load! Had we mistakenly determined that 26.83 was the correct rail voltage, the amplifier would begin to clip as the output tried to exceed 45 watts of output. Note that 45 watts is exactly one half of the 90 watt value. This shows that by increasing the rail voltage by a factor of 1.414 results in the amplifier having twice as much output capability! This can also be deduced by looking at the equations for power." Full article here http://www.rocketroberts.com/techart/powerart_a.htm

That's an awesome looking rig.

Excellent review thank you.

btw the BF one 10 is £350 new so I'm guessing a second hand one (if anyone was ever mad enough to part with it) wouldn't be too crazy. Time to explain to the family why Christmas is cancelled this year.

Was lovely to meet you Paddy, always nice to help out a fellow Basschatter!

Following with interest...

You all stepped on my feet on your way back and forward to your seats!

General public don't notice nuance. They often are unaware of what it is makes them enjoy one band and not another. All the stuff we obsess over is a matter of extreme indifference to your average punter. I ran a live music venue for years and the bands which didn't quite work were invariably those with a substandard drummer. The crowd knew they didn't like what they heard but couldn't tell you why. The bands where drummer and bassist were super tight went down a storm. Don't expect Joe P to give a hoot about your rig (unless it's enormous and has flashing lights) but get into the groove with the monkey behind the kit and he or she will like your band.

A lot of Arsenal fans in last night got the whole crowd doing the Theo chant. Mr Katzman seemed genuinely touched.

Just made it home. What a collection of musicians. Unreal.

Queue is right around the building. Anyone not here yet just chill and enjoy wherever you are!

I'd given up. Late forties, couldn't get an audition never mind a gig. Too old. 54 years old and another band I'd not even heard back from contacted me, desperate. New Years Eve, they'd chosen someone else but he couldn't do NYE. Bit of a cheek but would I consider it? I still tease them now about the bloody cheek of asking after not even giving me the audition but I did it and now I'm their regular dep, playing bass in three other bands and hosting regular jam nights. Playing bass every day, taking lessons, learning to read music and having the best extra curricular activity I've ever had. Give up? I tried to. No point. Bass isn't a hobby, a job, an obsession, it's in my blood.

I'll be there Thursday. Very excited.

+1 for the charity shop suitcase route. It's my go to for gig bags. I turn up looking like I robbed the baggage carousel in 1987 but my gear is nicely stowed. The addition of some bubble wrap completes the job.

Even though my gear is well maintained I've still had stuff break on me. Markbass amp being the most recent. A wedding, I was depping. Approving looks from the band when I switched to my spare.

Amazon have a couple returns sub 200 quid...

Imagine killing it like this to a room full of feckin tables. I'd be on the damn table!

Don't know about your wardrobe but I'd like to raid your record collection. God you have great taste in music.

No worries, happy to help.

If you're knowledge enough not to get caught out by such number crunching and mischievous marketing then they won't influence your purchasing decisions. If like me you find all the numbers and their subsequent dissection by wiser heads a little difficult to follow then you'll probably ignore them and they won't influence your purchasing decisions. So really the numbers make no difference to any of us and consequently everybody is happy. I choose my amps based on such considerations as colour, size, name, weight, lights and handle design. If they turn out to sound nice and they're loud enough I keep them. The TC combo I bought here sounds nice. When I link my BF cab to the extension speaker socket it sounds even better and is plenty loud. I can't comment on its pre baked thrusting hefts I'm afraid as I'm not entirely sure I understand their use or effect on my sound.

Whereabouts on the Mendips are you Paddy? If you want to try before you buy another BF and you're round my way I can lend you either a 1 10 or a 1 15 for a gig. You could see how much difference it makes.

Pics?

Where did you find it? I can find anywhere has them in stock...