Melody Valve HiFi PM845 Mono-Block Amplifier

Published On: October 16, 2013
Last Updated on: October 31, 2020
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Melody Valve HiFi PM845 Mono-Block Amplifier

Terry London takes a look at the Melody Valve HiFi PM845 mono block amplifier. London puts the amplifier through its paces to see if the piece is more than simply audiophile eye candy.

Melody Valve HiFi PM845 Mono-Block Amplifier

By Author: Terry London

Terry London has always had a great passion for music, especially jazz, and has amassed a collection of over 7,000 CDs covering the history of this uniquely American art form. Even in his teenage years, Terry developed a passion for auditioning different systems and components to see if they could come anywhere close to the sound of live music, and has for the last forty years had great fun and pleasure chasing this illusion in his two-channel home system.
Terry is a practitioner of Rational Emotive Behavior Therapy by day, and runs the Chicago Institute for REBT. He has also authored nine books on this of type psychotherapy and education.

Melody-Valve-HiFi-PM845-Mono-Block-Amplifier-review-small-V2.jpgThe most famous large-sized power tubes in the history of audio are the 300B, 211, and 845. After having such an amazing experience with the Melody AN300B integrated amplifier, I was quite motivated to review another sister in this category of legendary power tubes. This time, I wanted to listen to a pair of mono blocks driven by my reference-level Concert Fidelity CF-080 line stage. Also, I was seeking a pair of 845 tube-based mono blocks because the sonic presentation of the 845 tube is different than that of a 300B. I made arrangements with Hugh Nguyen, owner of Angel City Audio, to set up this review of the Melody Valve HiFi PM845 mono block, for which he is also the importer. These mono blocks retail for $8,499 per pair. Each one weighs 99.2 pounds and measures 8.5 inches high by 11.8 inches wide by 27.6 inches deep. The PM845 produces 70 Class A watts into either into four ohms or eight ohms.

Additional Resources
• Read more amplifier reviews by Home Theater Review's writers.
• Explore Bookshelf Speakers and Floorstanding Speakers to pair with the amp.

The company name, Melody, is engraved on the front of each mono block, where there's also a single amber LED signifying whether the amplifier is in the on or off position. Around back are an RCA and XLR input, the main power switch, an IEC power inlet, and reference-level WBT-style speaker posts for either four-ohm or eight-ohm speakers. Residing above the top plate are four massive input and power transformers. Located in front of these transformers are the two input tubes, A2A3 and 6SN7. Nestled in between the transformers and outside the edge of the mono block is a pair of large 845 tubes. The PM845 mono blocks are self-biasing. Each mono block, including the tube cages, is finished in the most exceptional and exquisite piano-black lacquer that I have ever seen on a piece of equipment. The build quality and physical appearance of the PM845 rank at the highest level of what is being built in the market today.

My first selection to test sonic performance of the Melody Valve HiFi PM845 mono blocks was Grant Green's album Grant Stand (Blue Note Records), featuring Green on electric guitar, Yusef Lateef on tenor sax, Jack McDuff on 3-B Hammond organ, and Al Haywood on drums. Immediately apparent when I played the blues-drenched cut "Blues in Maude's Flat" were the overall macro-dynamics and the extremely taut and accurate extended bass pedals of the 3-B Hammond organ. These mono blocks developed a large and precisely layered soundstage and can be compared to my solid-state Pass Labs XA-60.5 mono blocks for being quiet and transparent, rendering all of the important little details and nuances of the music.

To test how the mono blocks reproduced the timbres and tonality of natural acoustic classical music, I chose Johann Strauss' "Thunder and Lighting Polka" from the album Ein Straussfest (Telarc Digital), performed by the Cincinnati Pops Orchestra and conducted by Erich Kunzel. This piece was rendered in a grainless, silky tonality that let all the individual timbres of the string and brass instruments easily flow into my listening space. With ascending crescendos, my room was completely pressurized, and the Melody Valve HiFi PM845 amps never ran out of steam, no matter how high the volume was set.

My final listening test was to evaluate the amps' ability to produce realistic vocals using Nat "King" Cole's album After Midnight (Capital Jazz). Cole's voice and piano playing showed me the subtle sonic differences between the 300B and the 845 tubes. The 300B is richer and offers a fuller sound regarding tone and image density. The 845 is slightly less rich and warm, and has slightly less three-dimensional imaging. Imagine these comparisons: velvet for the 300B and silk for the 845, both of them beautiful, yet different. Which one is better? The answer is neither. It's merely based on your discerning taste and system synergy.

Read about the high points and low points of the Melody PM845 on Page 2.

Melody-Valve-HiFi-PM845-Mono-Block-Amplifier-review-small-V2.jpgHigh Points
• The Melody Valve HiFi PM845 mono blocks are built to a superlative level and are some of the most attractive amplifiers I have ever seen.
• These mono blocks have the current and watts to drive virtually any speaker on the market today.
• It has a silky, grainless presentation that allows the true timbres of instruments to be clearly heard.
• As far as macro-dynamics and overall bass extension, these mono blocks will control the bottom end of any speakers with total authority.
• The PM845 mono blocks produce an airy, large soundstage, with excellent space between different players.

Low Points
• Like all tube-based gear, the Melody Valve HiFi PM845 mono blocks will need retubing in the future. Therefore, the cost of the tubes must be taken into consideration.
• These are large and heavy mono blocks, so they will occupy a lot of space in your room.

Competition and Comparison
Given the PM845's retail price of $8,499 per pair, the tube-based amplifiers that would be its competitors are the Berning ZH-230 ZOTL, valued at $8,360, and the Luxman MQ-88, valued at $8,000. The Luxman MQ-88 falls far short of the Melody Valve HiFi PM845 in the areas of macro-dynamics, transparency, and extension on both the top and bottom frequencies. The Berning ZH-230 ZOTL is much closer to the sonic signature of the Melody mono blocks in these areas; however, when it comes to ultimate power and control, it is not the equal of the PM845.

I came to this review with this question in mind: "How different or similar would a 300B-based amplifier be when compared with an 845-based amplifier?" After much listening, I have come to the conclusion that both tubes offer a grainless liquid tonality with beautiful natural timbres. The 300B is somewhat warmer and fuller-sounding, while the 845 is slightly more silky than velvety, but is quicker and more dynamic-sounding. The Melody Valve HiFi PM845 mono blocks are not only true "eye candy," with a build quality to match their appearance, but they also perform at a true reference level. Concerning tonal purity, transparency, micro-details, and power, these are some of the best amplifiers I have had in my listening room. If my budget were to allow for it, I would purchase this pair of mono blocks to add them to my stable of amplifiers. I strongly recommend putting the PM845 on your audition list if you are considering mono blocks in this price range.

Additional Resources
• Read more amplifier reviews by Home Theater Review's writers.
• Explore Bookshelf Speakers and Floorstanding Speakers to pair with the amp.

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