Butler Audio Model 5150 5-channel Power Amplifier - Review

Audio Heaven

Butler Audio Model 5150 5-channel Vacuum Tube Hybrid Power Amp
Butler Audio Model 5150 5-channel Vacuum Tube Hybrid Power Amp. Photo © Robert Silva - Licensed to About.com

Butler Audio has merged the best of the vacuum tube with solid-state audio engineering in a power amplifier that will please both home theater enthusiasts and the most demanding audiophiles.

Merging the Old with the New

The Butler 5150 is a 5-channel power amplifier with separate power modules that feature line input and speaker output for each channel. Its unique internal design features one 6SL7GC dual triode vacuum tube for each channel within the output stage to provide true analog sound. This feature eliminates the need for traditional output transformers.

Connections are easy; a single gold-plated RCA audio line input and heavy duty gold-plated speaker terminals are provided for each channel. Remote power switching is available with included 8-13VDC trigger.

A single on/off switch is on the front panel, but there are no gain or volume controls for the amplifier(s), the gain is preset internally to an input sensitivity of 1.5v. All volume level control must be done using an external preamp or AV preamp processor.

Amplifier Specifications

5 x 150 Watts RMS per channel at 8 ohms or 5 x 225 Watts RMS per channel @ 4 ohms (All Channels Driven)

Frequency Response: 20Hz to 20kHz (+/- 0.5dB)

Power Bandwidth: -3dB, 50kHz

THD: <0.10% @ 8 Ohms, <0.15% @ 4 Ohms

S/N (Signal-to-Noise) Ratio: Better than 110dB (A-Weighted)

Slew Rate: 15v/µsec

Input Sensitivity: 1.5V for 150 Watts into 8 Ohms

Input Impedance: 47k Ohms

Idling Power Consumption (when no input signal is present): Approx. 120 Watts (Approx. 1A @ 120VAC or 0.5A at 230VAC)

AC Power Draw/Consumption when in use:

1200 Watts when running 8-ohm speakers - 10 Amps (120VAC), 5 Amps (230VAC)

1800 Watts when running 4-ohm speakers - 15 Amps (120VAC), 8 Amps (230VAC)

Dimensions: 17-inches Wide x 16-inches Deep x 8.5-inches Height w/feet (7-inches High w/o feet)

Weight: 48 Lbs. (19.2Kgs.)

The 5150's simple front panel design consists simply of the main On/Off Switch and grill work that allows Butler Audio's trademark blue glowing tubes to be visible during operation.

It's the Sound that Counts

In actual operation, the Butler Audio 5150 releases the full potential of any audio source with powerful, pure, smooth, non-fatiguing full surround sound that can only be classified as "Nirvana". The sound was clean and undistorted, regardless of volume levels.

The audio portion of the setup included an Outlaw Model 950 AV Preamp Processor set to 5-channel operation, Technics DVD-A10 DVD Video/Audio player, Left, Center, and Main speakers were custom made with Electro-Voice drivers, two wall-mounted Klipsch S-2 Dipole Surrounds, and two 12-inch KLH powered subwoofers.

Monster Cable interconnects were used throughout, from the DVD player to the preamp to the 5150 line inputs. AC power was connected using a heavy-duty Belkin Surgemaster. No additional powered subwoofer was used; everything was sent to the 5150 via the preamp so that only the effect of the 5150 could be heard. In all sound modes, including the most demanding DTS soundtracks (Including DTS Sampler Disc #7) and DVD audio discs (Including Queen's Night At The Opera) as well as standard music CD playback, the 5150 showed no sign of distortion across all frequencies.

Summarizing the Positives Of The 5150

1. Stellar sound is obtained as a result of placing the vacuum tubes directly in the output stage of the amplifier. After listening for several hours at a stretch, my ears did not experience any sign of fatigue, even at loud listening levels. Also, the 5150 matched well with Klipsch dipole surrounds and the KLH powered subwoofers as all level balancing and equalized was performed using a sound meter in conjunction with setting options available on Outlaw 950.

2. Hookup is very easy. All connections on the back panel are well spaced to avoid cable clutter.

3. The unit itself is as solid as a rock, and just as heavy due to its massive heatsinks to maintain cool operation.

The Bottom Line - Quality has a Price

However, even with all the positives, there are factors that the consumer needs to take into consideration in purchasing this amplifier.

The Butler 5150 is a 5-Channel Power Amplifier. To make it fully functional you need to purchase (or add) a multi-channel Preamplifier or Preamp/AV Processor. You connect all your sources to the AV/Preamp Processor, which in turn provides all of the source switching and any audio or surround sound decoding/processing.

The preamp/processor, in turn, has line outputs that send the processed audio signals to the power amp, such as Butler 5150 discussed in this review.

The power amp then sends amplifies the audio signals, as they are received from the preamp to the connected loudspeakers.

In the case of the Butler Audio 5150, I would recommendation to purchase the best quality preamp that will fit your budget and provide you with the most flexibility that you may need (such as providing a separate subwoofer output and 12 volt DC trigger to control the on/off function of the 5150).

Also, this amp consumes a lot of power (note the wattage and amperage specs above), so, if you are concerned about your electric bill, keep this in mind. The 5150 can draw up to 15 Amps of current when outputting at full power. Only use a surge suppressor that can handle at least that much continuous current.

In addition, due to the massive heat sinks, this unit is a very hefty 50lbs, which is not a bad thing, just be careful when upacking, installing, or moving the unit for your own safety.

Lastly, the price: with a street price of approximately $3,000, this is not something you will find at Best Buy, or other discount mass retailer. This is an investment in pure vacuum tube sound quality and heavy-duty construction, not features or gimmicks. The 5150 is well worth your consideration.

Disclosure: Review samples were provided by the manufacturer. For more information, please see our Ethics Policy.