Genuine honesty is an attribute that quite often gets lost in the audio manufacturing world. In the age of slick marketing campaigns, a simple description about circuit design can be spun into a mythological tale of heroic proportions. Writers of advertising copy would have the reader believe that the design team had to glean the secrets of ancient magi in order to find the incantations necessary to create their latest offering. It is a refreshing change when an audio manufacturer steps up and provides a straightforward description of how their product is designed. Dr. Lloyd Peppard who owns Mapletree Audio is willing to lay on the table all the design parameters of his products. The following quote is from the design goals statement regarding the Mapletree 2SE preamplifier.
“An electronic preamplifier is not a new product; the basic design has been around for close to 100 years. The design decisions must be viewed in this light. In other words, the issues are more concerned with economics (e.g. high performance/price ratio) and manufacturability (e.g. suitable for small scale production) than with technical innovation. Of course, there are some technical matters that must also be addressed (e.g. evaluating alternative circuits, operating parameters, and components). The following initial design decisions are mainly subjective, based on experience and preference.”
Mapletree Audio 2SE Preamplifier review
Quite simply, the 2SE pre-amplifier is designed to offer the highest level of sonic performance that can be obtained within a real world budget. This is the kind of product that draws my attention, since there are very only a handful of quality tube preamplifiers that are near the $750 selling price of the 2SE. The price tag on this pre-amp becomes more attractive when you consider the fact that it is produced in North America, and hand assembled by Dr Peppard. For those audio enthusiasts who are competent with a soldering iron and multimeter, it is possible to save a hundred dollars and purchase the pre-amp as a kit. In my mind, the Mapletree pre-amplifier has the potential of being one of those rare audio gems, so I contacted Dr Peppard and arranged for a review sample.
Most seasoned tube veterans have an appreciation for the sonic characteristics of octal tubes. As a general rule, octal tubes are a far more neutral presentation than their 9 pin brethren. This preamp is designed to use two closely related tube types, namely the 6SN7 and 12SN7. With the flick of a toggle switch that is mounted to the rear of the unit, the 2SE is capable of switching between both types of output tubes. My review sample came with a pair of Electro-Harmonix 6SN7 tubes, but Dr Peppard was also thoughtful enough to send along a couple of NOS Raysonic 12SN7 tubes. The power supply section of this pre-amplifier is a hybrid design, employing a pair of HEXFRED diodes, and a 6X5GT rectifier tube. These components are installed in a second chassis in order to isolate the audio circuit from possible noise issues. A two-box design is considered an elegant audio design, but is usually found on pre-amps that cost considerably more than the 2SE.
Dr Peppard has taken a pragmatic course to the design and implementation of this pre-amplifier. The chassis consists of two moderately sized aluminum boxes; one containing the power supply, while audio circuit resides in the other. The preamplifier that Mapletree sent for review has a white eggshell finish, and black stained oak end caps. Mapletree offers a wide variety of colors to select from, and there should be a finish combination that would satisfy the most finicky audio enthusiast. While the chassis is an exercise in frugality, Dr Peppard has put a significant amount of time and thought into the parts selection for this unit. Many of the internal components are of good quality, but are not pricey specialty parts. On the critical components Dr. Peppard has carefully selected parts that offer the highest combination of performance vs. cost. For instance the 2SE uses Alps volume pot, Auricap capacitors, and silverplated hookup wire with Teflon insulation. The 2SE also has a pair of master volume controls located on the face of the unit. These controls allow the user to set the overall output level of the preamplifier. This is an option not often seen among current production pre-amps, but one that is quite useful. The master volume controls allow the user to adjust the overall output of the 2SE so the volume pot operates in its optimum range. Now the user has the ability to adjust the 2SE to a wide array of amps with different input sensitivity. To the casual observer, the Mapletree pre-amplifier may have a non-descript appearance. Upon closer inspection of the unit, it becomes quite evident that the 2SE has been put together with great care,
and attention to detail.
My personal pre-amplifier is an Electra-Print PVA, which is a passive design that utilizes a pair of nickel core transformers. These transformers convert the voltage signal of a source unit into a current style of output signal, which is then passed on to an amplifier. It needs to be paired with an amp that has high input sensitivity. Preferably below two volts, which is the standard output level of most line level components. If used within these constraints, the PVA is a stellar pre-amplifier. During my evaluation period I alternated between a pair Electra-Print 300 DRD mono-blocks, and a pair of Monarchy SM 70 PRO amps. Both units match up nicely with the PVA, so the MapleTree pre-amp is going to have quite a challenge in equaling the performance of the Electra-Print piece. The digital components for this review are the Audio Magic Kukuma DAC, which is partnered with a JVC XL-Z1050TN CD player. The Audio Nirvana Super 12 speakers excel at presenting low-level detail, and easily reveal the finer nuances of upstream components. Speaker cable and interconnects are from the Audio Magic Illusions 4D line. Power cables are also Audio Magic, but from the less expensive Extreme series. Now that all the proper pieces are in place, it’s time to find out what the capabilities are of this little Canadian pre-amp.
I installed the Mapletree preamp into my system and allowed it to break in for approximately 200 hours. For the most part, I would listen casually to the music coming out of the system, but I will admit to giving it a serious listen from time to time. The pre-amplifier went through an audible break in period, although it maintained its composure through the entire process. Once the 200 hours were logged, I decided to begin the critical listening sessions with a disc from Mary Chapin Carpenter. “I am a Town” [Come On Come On; Columbia CK 48881] is one of my all time favorite pieces from this artist. The opening acoustic guitar notes were simply stunning, and I began to form the opinion that the 2SE might be superior to the run of the mill entry-level tube pre-amplifier. Carpenter’s vocal performance had a liquid sounding presentation; one could visualize the notes flowing into the listening room. The piano melody sounded slightly forward, but retained a purity of sound that was quite believable. There was a slight forwardness to the overall sound of this disc when played through the 2SE, however this is the slightest of flaws. Given the modest price of this pre-amplifier, it is a non-issue in my mind. I replayed the Mary Chapin Carpenter disc, but with different output tubes for this listening session. I removed the Electro-Harmonix 6SN7s, and installed the Raysonic 12SN7 tubes. I made sure to follow Dr. Peppards instructions, and threw the switch on the back of the pre-amp to the 12SN7 position. The superiority of the Raysonic tube became readily apparent from the opening notes. The piano and vocals took on a natural presentation, and the forwardness that I previously experienced was removed. The absence of any significant coloration to the sound was quite impressive. Matter of fact, the Mapletree sounded almost identical to the Electra-Print PVA pre-amplifier. The 2SE was slightly smoother, and a touch of detail may have been lost when compared to the PVA unit. At the end of this evening listening session, both units were so close in their overall presentation, and I would be hard pressed to pick one over the other. It is important for the reader to keep in mind that the Electra-Print is performing with amplifiers that it was designed to work well with. So in essence, the 2SE was capable of holding its own on the PVA’s home court.
I kept the Raysonic tubes in the 2SE for the remainder of my listening sessions. In order to get an idea of how versatile the MapleTree preamplifier is, I swapped out the Electra-Print units for the Monarchy Audio SM 70 PRO amp. The Monarchy is a single-ended transistor design, and is intended to be used in conjunction with an active pre-amp. I have achieved excellent results with the Monarchy/PVA combination, although the Mapletree should in theory be a better choice with this amp. I dropped in Donald Fagens “Trans-Island Skyway” [Kamakiriad; Reprise 9 45230-2] and eagerly waited to hear what this pairing was going to be capable of. The quality of the bass track on this piece was excellent. The bass line set the foundation for this piece, and the music took on a rhythmic drive. While the Electra-Print preamp did a respectable job with the Monarchy amp, the bass performance of the 2SE was clearly superior in this instance. Fagen’s vocals had that smooth sound reminiscent of a vintage Steely Dan song, yet still retained all kinds of subtle detail. The background vocals had some dissonance in them, yet were still easy on the ears. The advantages of an active pre-amplifier in a system were easily discernable with this cut. There is a broader dynamic range to the system when the 2SE is in place. The passive design of the PVA is a liability when used with an amplifier that prefers an active pre-amplifier. With the Monarchy amplifiers in the system, the Mapletree pre-amplifier is the clear winner in this round.
I sorted through my disc collection looking for the song that would really stand out in this system configuration. All of my favorite discs sounded great on the Mapletree/ Monarchy stack. I did find one disc that stood out from the others I listened during my time with the 2SE. “I Can See Clearly Now” by the Holly Cole Trio [Don’t Smoke In Bed; Manhattan CDP 0777 7 81198 2 1] highlighted all the positive attributes of the Mapletree and Monarchy duo. When played through this combination of components, this song has an eerie presence to it. The acoustic bass that opens the piece occupies a definite acoustic space in the soundstage, it sounded like the performer was only a few feet away from me. I could easily hear the wood and string textures that make up this instrument. Holly Cole’s voice is gritty and rough, with a distinctive texture that is easily identifiable. Yet her delivery is smooth and relaxed, which results in a captivating sound, and a unique rendition of this classic song. When the piano comes into the mix, only then does the illusion start to come apart. The recording spreads the instrument across the back of the soundstage, and reveals the limitations of what occurs in the recording studio. Until that moment comes along, the creation of a live performance is complete, and a good portion of the credit for this feat can be attributed to the Mapletree pre-amplifier.
So what is not to like about this little jewel of electronics? Well, some people may not appreciate the frugality that Dr. Peppard has exercised in the chassis materials of the 2SE. While the diminutive pre-amplifier is attractive in my eyes, it does not have the heavy gauge steel enclosure, or the thick brushed aluminum faceplate. Also absent are the milled aluminum knobs, or sophisticated displays that can be found on electronics that are offered by Asian manufacturers. There can also be a consistently forward presentation to the music if the 2SE is used with the Electro-Harmonix 6SN7 tubes. The Russian tubes result in a respectable level of performance, but ultimately holds this pre-amplifier back. Replacing them with a good pair of NOS tubes will significantly improve the capabilities of this unit. The only notable issue that I could identify with this piece is a shortening of front to back depth in the soundstage. This is a common issue among moderately priced components. On the flip side, it could easily be argued that the 2SE gets soundstage depth correct, and other components exaggerate it. Although in my listening sessions the Electra-Print PVA created a soundstage that was slightly deeper than the 2SE. Given the nature of it’s passive design, I would expect the PVA to give the an authentic recreation of the depth found within a recording. In the department of soundstage height and width, the two units were equal. In reality, the 2SE does very little wrong, and what shortcomings it may have are easily overlooked when the price of the pre-amp is factored into the equation.
I enjoy listening to the offerings created today’s smaller audio companies. The individuals who invest their time and financial resources into these endeavors have a true passion for music reproduction. It has been said that the audio world has entered the second “golden age” of tube audio. While there is a large selection of tube audio components available in the market place, there are a few components that stand apart from the crowd. The Mapletree 2SE with PS2 power supply is one of these special pieces of electronics. In the years past I have owned several fine tube pre-amplifiers. I spent a significant amount of time with an Audible Illusions 3a, an Audio Innovations LS2, and a Quicksilver Full Function preamplifier. All of these units are fine examples of well-designed tube preamplifiers. Yet the 2SE is every bit as good as it’s more expensive brethren; and I would not hesitate to offer it a full time position in my system. The 2SE is a fine example of what achieved at an affordable price point. I am not aware of many tube pre-amps that have the equivalent level of sonic prowess as the Mapletree, and can come close to it’s price point. Audio enthusiasts who want to take that first step into the “Brotherhood of the Thermonic Glow” would be well advised to hear this piece.
- Mapletree includes 1 pair of NOS 12SN7 tubes for the 2SE. Dr. Peppard sent an additional pair of Electro-Harmonix 6SN7 so that I could experience how the 2SE performs with current production tubes. I incorrectly reported that the preamp came stock with E-H tubes.
- Aluminum is actually a better electromagnetic shield than a ferrous metal such as steel. The same size steel chassis is actually cheaper to obtain.
Components Used For Review
- Audio Magic Kukama DAC
- JVC XL-Z1050TN CD Player
- Electra-Print PVA Pre-Amplifier
- Electra-Print 300 DRD Mono-blocks
- Monarchy SM 70 PRO Mono-blocks
- Audio Nirvana Super 12 in Love-Craft Designs cabinets
- Monarchy AC Regenerator
- Audio Magic Illusions 4D Interconnects
- Audio Magic Illusions 4D Speaker Cable
- Audio Magic Illusions 4D Digital Cable
- Audio Magic Extreme
- Power Cable
- Low distortion NOS octal tubes (2 x 12SN7GT (included) or 2 x 6SN7GT with selector switch).
- Low impedance cathode-follower outputs.
- Three line inputs with custom gains of from 0 dB to 20 dB.
- Parallel outputs for bi-amping or driving a headphone amplifier.
- Source selector switch, volume control, and individual channel level controls.
- All point-to-point wiring using silver-plated Teflon wire.
- Includes PS 2 power supply.
- High quality components are used throughout: precision metal film resistors, Auricap and Black Gate signal capacitors, and plastic element volume control.
- Frequency response (100 kΩ load, 1 kHz, 1 V out): 12 Hz–20 kHz –1 dB
- Maximum undistorted output (100 kΩ load, 1 kHz): 13 V (rms)
- Gain (100 kW load, 1 kHz): 10–20 dB user specified
- Output impedance (1 kHz): 450Ω
- Input impedance (1 kHz): 220 kΩ with 10 dB gain
- Hum and noise at output (max volume): less than 0.25 mV rms (94 dB below maximum output) Phase: Inverting
from aﬀordableaudio, By John Hoffman