Kennedyaudio.com Multi Function HI-FIDELITY Power Amp.
     Buying Or Dealing Direct Cuts Your Costs In HALF.
     Did Retail Electronics Mass Marketing Ever Work For Americans?

So why not compare a quality reliable Kennedyaudio.com
amp with fickle bass killer underpowered tube amplifiers?

Question :What kind of person should buy Kennedy Audio power amplifiers?

Here are some of the pros and cons of valve amplifiers:

• There are more American made instrumental brands. 99.9% stereo brands are imports. These include Marantz, Philips, Sony, Toshiba, Kenwood, Sansui, Technics, Yamaha, Fisher (Sold to Sanyo 1975), Pioneer, Dual, JVC, SSI, Rotel, Denon-Onkyo (i.e. Dolby), McIntosh and Boston Acoustic after 2002.
• Prefered by blues musicians and lead guitar parts for organ like sounds.
• Tubes are known for their 'fuzz' type sounds by sawtooth patterns in the peaks of half waveforms rather than square wave (flanging).
• Able to 'color' or distort and clip a signal already clipped or distorted.
• Smooth measured transition into clipping (RMS power is usually quoted at a given % Total Harmonic Distortion THD).
• High dynamic range (because the onset of clipping and volume vs. gain controls actually change the multiple of amplification factor not supply voltages).
• Overdriven sounds are "musical" (ie smooth and not harsh overdrive sounds) and only require compression or limiting, not sustain.
• No speaker crossover needed or possible as speaker resonant freq. used to make sustained mystic tones, fewer cabinet & porting issues.
• Sustain & resonance above eliminate the far away and non-musical character hard to avoid in Solid State amp's.
• Various models produce consistent standard high recognition value sounds. (dubbed 'modeling' - simulated and reproduced in digital processors)

• Circuit burnup. Especially true of larger power tube amps, usually 4 or 6 tubes. Worst are parallel push pull designs.
  Such a configuration cannot be turned on, even without
  any signal being input or volume control turned high unless speakers are connected. This takes only a millisecond. Organs are known for this. Some guitar heads have built-in protection circuits, but they don't always work in time.
• Not so much prefered by garage, grunge and metal rhythm guitar parts when they want a punck thrash sound, high volume, multiple sensitivity speaker sets and many available low cost effects.
• Limited bandwidth. (amplifier and speaker in combination typically cover 80-6000 Hz); only 30% of the audio frequency spectrum.
• Associated with the bandwidth, CD disk sensors are replacing pickup coils and these feature a greatly expanded frequency response intonation spectra, and some experts predict (accurately we think) the tube amp will not keep up with CD transfer of futuristic motion vibration technology. At the present time, aftermarket add-on conversion pickups hide these by embedding them in the plastic molding holding the collecing posts.
• Amplifiers are heavy, due to the requirement for a speaker transformer and larger power transformers. While our amp is heavy, it's extra rubustness is for the input power transformer.
• Valves typically need to be replaced up to once a year to maintain peak performance and can react to surface dust or oils or storage.
• Valves are noisier (there is almost nothing but noise at 6oooHz-20,oooHz). If a guitar driven typically they must use noise cancelling less sensitive forward and reverse pair coil pickups (humbucker). Activating two pickups has more noise and an unresponsive attack.
• Valve amplifiers run hot, take time to warm up, can't be bumped and some don't include cooling fans or rain protection or replacement alternatives. Speaker re-coning when originals blown reduces value.
• Expensive, poorly tech supported (or none at all) and housed in poorly made plywood metal and fabric boxes and dangerous to allow hands even near metal parts as shock jumps across gaps (hi voltage).
As preamps or distortion stomp boxes and pedals:
• Guitar pickup output is less than 2 volts, these convert to much higher voltages. This in turn makes using other effect pedals impossible or they cannot duplicate their original function as the tubes are interfering with the clean waveform they need as input.
• Size prevents good outer 'skins' and easy carry in guitar cases.
• Safe input to amp's is 1 to 10 volts, these tend to far exceed this.
• As distortion, they almost always use underpowering distortion or wear out very fast from being run near or over specification voltage. Less true overdriven sound.
• Active tone controls don't work inside tube powered amps due to their high internal direct coupled circuit impedance.
• Using an 'equalization pedal' to control and shape tone does not provide enough voltage ouput to help overdrive tubes or solid state amps, even popular small wattage practice tube amps used to get distortion effects. There is less overall control in the signal path unless a good pre-amp with active tone controls and higher output is purchased.
• Likewise impedance precludes feedback loop channel to integrate effects or equalization. Another fancy way of saying the same thing without offending too many customers.
• Splitting the less than 2 volt high impedance pickup output into more than one pedal before reaching a pre-amp makes even a strong high impedance (non-active pickups) guitar signal way too weak and noisy.
• Gain is not fixed and then attenuated by volume controls (op amps), sometimes desired but can make loudness control interaction difficult unless the tube amp is the last one in the line which in turn means controling a tube pre-amp from a central sound board is rarely practical. Tubes must be running at high gain to distort.
• Active tone sweeping greatly improves signal/noise ratios so that tube power circuits tend to use short cables to active tone pedals, pre-amps, noise filters & studio equipment to make best use of tube amplifiers on stage and in studios. Mixing clean with distorted signal is also only very rarely possible and not easily reconfigured onstage.
• Consolidation with solid state new bi-amplification channel splitting and digital power amplification is destructive rather than an improvement.

I would like to deconfuse and clear up the 'Power Rating' of amplifiers here.

This is technically more complex than this because the voltage

and the peak current wave that is driven by it are out of phase with each other.

There are two terms RMS power and PEAK power applied to power ratings.

Peak power is a 20 millisecond measurement of voltage times current.

Usually either voltage or current is fixed. Tube amps have fixed output current.

RMS power, originally averaged square root, (standard deviation), of sine waves.

However it became used as the integral or total sum of the curve area.

An improved formulation of the facts uses a 'standardized' normal distribution:

The currentXvoltage wave's peak then equals .3989 of the area under the curve.

Average Power equals 1.4825 times the RMS if RMS is root mean square method.

The Average power represents 1/2 (.5) of the RMS power if RMS is integral sum.

Usually for vintage amps, which were peak power rated, divide it by 2.5069 to get modern watts eqivalence or maximum speaker power requirements and tolerance.

One common rule says divide speaker watts by 2 to get vintage peak amp power.

It's based on the average of 1) average power factor and 2) peak to area factors.

Thus 1.48 plus 2.507 divided by 2 is 1.9935, but it's only a crude guideline.

Speaker wattages should be for 8 ohm loads. Derate 4 ohm loads by a factor of 2.

A vintage amp's 150 watts into 4 ohm is a 30 watt amplifier by today's standard.

Ask yourself if there is enough power in a tube amp to play in large arenas with people absorbing the sound. The off axis distortion, even for full stacks with horn projectors is very noticeable in midranges of the sound spectrum.

A 30 watt tube amp may sound good- at full volume. But what about your hearing loss being right in front of it and the sound reinforcement system costs designing a stage to re-project more subtle mixed sounds? Results -

No Control. Unbalanced brazen music. Your group swoons; so do your fans.

A more powerful amp with auto-impedance matching allows a small speaker behind the musician and others front stage where they look best and belong.

Almost always, a sound reinforcement system is needed, especially outdoors.

You can buy a Kennedy amp at the same price for a good condition vintage amp with plenty of power for several cabinets, facing left right and center.