Dynavox TPR-2

Published: 15/12/2024

Manufacturing date: 2007

Author: Karsten Hein

Category: Gear & Review

Tag(s): Pre-Amplifiers

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The German Sintron Distribution GmbH can look back on a thirty-year track record of sourcing and co-developing affordable yet sophisticated Hi-Fi gear “Made in China”. Sintron was among the first importers in Germany to leverage direct imports from China in an effort to introduce price sensitive customers to audiophile pleasures. Among their products are infamous tube amplifier classics, such as the well-regarded VR70E-II. In fact, one specimen of the VR70E-II has been performing admirably at eiaudio since January 2022 and has thus contributed to multiple tests and reviews. Given this tube amplifier’s solid performance, I could not help but wonder about the merits of Sintron’s line of tube preamplifiers. Would Dynavox preamps be able to offer the same bang for buck experience?

While lots of preamplifiers—solid-state, tube, and hybrid—deliver a decent sound when playing music from a line source, such as a network player, streamer, or CD player, many of them fail to deliver the same level of performance when playing music from a phono source. In other words: Good phono preamps are hard to find, because phono signals are far more delicate, ranging from 0.0003V to 0.006V (depending on the cartridge). This is about 100 times less than the output of a CD player, rated at 2 volts (or even 2.2 volts, as the Marantz CD-17). If you add to this the +/-20 dB RIAA correction that is necessary to balance phono signals across the frequency range, it is easy to understand how phono amplification can go wrong.

Dynavox offers four lines of tube preamplifiers: The TPR-1, which is based on the same cabinet design as the VR70E-II power amp and does not feature a phono section at all; the TPR-2, which is the subject of this review and consists of a solid-state phono preamplifier and one separate line input stage that are then teamed up with a single 12AU7 (ECC82) tube for sound conditioning. It is the only Dynavox preamp model to feature an external power supply for reduced circuit noise.

Then there is the TPR-3 that offers one phono and four line inputs, has a symmetrical circuit board design and uses one 6N3 tube per channel for sound conditioning. In contrast to the TPR-2, the TPR-3 has an onboard power supply that is counterbalanced by a better shielded phono section. Finally, there is the TPR-43, which has a more conventional and rack-friendly housing, offers the most inputs (one phono and five line inputs), and uses a single 12AU7 tube for sound conditioning in combination with an internal power supply. Depending on your application, listening experience, personal taste and expectations, each of these preamps might be an attractive choice. The price difference between them is not that great.

Rather than calling it a “phono preamplifier”, as I have chosen to do by placing the TPR-2 in this category of my blog, Sintron markets their device as a “sound conditioner” that is commonly used by audiophiles to give their HiFi system a richer and more analog sound through the use of tubes. And, indeed the TPR-2 is a strange cross-bread between a dedicated phono-pre, which requires an additional preamplifier before the power amp, and a full-fledged preamplifier, which connects two sources (line and phono) directly to the power amplifier. From reading the descriptions online, I was unsure of what to make of it and decided that I would make up my own mind of its best application through trial and error.

I ordered my TPR-2 used from its previous owner in Hamburg, who had started selling off his HiFi components due to his advancing age. When the parcel arrived, I was happy to find that he had taken great care in packaging the preamplifier and its power supply in two separate boxes to keep them from crashing into each other during transport. The TPR-2 was without scratches and any other signs of physical wear, and I was positively surprised by the very solid build quality of both components. Not only was the face plate made of a 5 mm sheet of aluminum, but its sturdy body consisted of folded steel that was 1.5 mm strong. This made for an excellent first impression.

Having given the newly arrived TPR-2 some time to warm up to room temperature, I connected it to our Dual CS 505-3 turntable using a well-shielded phono cable. When connecting the Dynavox to the line section of our Robert Grodinsky Research (RGR) Model 4 preamplifier, I noticed that this sounded best when I used a low capacitance cable to maintain the full range of the treble. Higher capacitance at this end created a low-pass effect which may or may not be desirable in your system. Our RGR was then connected to the Dynavox VR70E-II tube power amp driving Epicure EPI 500 loudspeakers. While I generally enjoyed listening to the RGR / VR70E-II / EPI 500 system from CD sources, I had previously missed some of the life-like sparkle in the music when listening to vinyl via the Dual CS 505-3 turntable. I was hoping that the Dynavox TPR-2 would improve this situation for me.

I love listening to vinyl best, when I forget that I am playing a record and just listen to the music. In my own HiFi setups, there is only one system that does this for me every time: This is the Dual CS 721 direct drive with Shure V15 III cartridge, paired with Dynaco PAS-4 tube preamp and Hafler XL280 power amp driving Epicure 3.0 loudspeakers. This combination of components sounds so carefully balanced that music is the only thing that comes to mind when I listen to vinyl on it. To my ears and understanding, there is no single characteristic that sticks out and would be worth mentioning, accept for the tonality, the rhythm, and the flow of the music itself. Epicure speakers do this for me, whenever the source stays faithful to the truth.

I knew that this benchmark was a tall order for the much simpler built CS 505-3 turntable and RGR preamp. However, it only took me a few seconds to realise that the TPR-2 contributed to a more life-like and engaging musical experience. Where the RGR phono section had sounded thin and constrained, the TPR-2 used as phono pre to the RGR gave the music colour and drive. Vocals became more palpable, as on Diana Krall’s 2012 album “Glad Rag Doll”. This album can easily sound a bit dark and muffled when played on a less than perfect system. With the TPR-2, “I’m a little mixed up” became an instant dance song that had me cheerfully tapping and bopping along with the music. Creedence Clearwater Revival’s greatest hits album “Chronicle” was great fun to rediscover with the small Dynavox as preamplifier. It sounded richer and more potent than before.

Eager to learn more about the TPR-2’s musical potential, I bypassed the RGR by connecting the Dynavox as a preamp straight to the VR70E-II power amplifier and adding my Pioneer PD-S604 to its line input. The first thing I noticed was that the knobs for input selection and volume control were overly firm and too tiny to allow for easy adjustments. In the dim light, it was difficult for me to see the current setting, so that I often attempted to turn the smallish input selector in the wrong direction first. The volume difference between the Pioneer CD player and the Dual turntable was considerable, and I found myself having to adjust the volume each time I changed between the sources. Unfortunately, this meant having to turn both knobs each time.

Wit the TPR-2 wired to the amp directly, the speakers at once sounded larger and more naturally engaging when playing music from CD. When I was walking around the room, I noticed that the precise location of the loudspeakers seemed to matter less to me and that the music had a new realism. Sitting back in my listening chair, however, I noticed that this loose impression came at a price: The sense of order and dimension that I normally enjoyed in this position had been reduced. I found that vocals were more difficult to understand and that some of the musical nuance was gone. When I turned up the volume to increase clarity, I found my ears ringing from exertion. This effect remained the same when I turned to vinyl as source, although I must say that it was slightly less pronounced.

I installed the RGR preamplifier in my system once again and thereby reinstated the sense of order and control I had previously lost in the direct setup. Again, I no longer felt the need to increase the volume for clarity, and—although walking across our large listening room I could more easily sense the position of our HiFi system once again—I preferred this sound to the more unruly Dynavox to Dynavox match. By setting the small switches underneath the main unit to higher amplification, the TPR-2 is also capable of matching its output to fit moving coil (MC) cartridges. However, given the audible distortion in my MM setup, I would not naturally recommend matching the TPR-2 with an MC pickup, unless you have a high output cartridge.

Used as a phono preamplifier and in conjunction with an MM or high output MC cartridge, and paired with a proper preamplifier, I do feel the TPR-2 can be considered an audiophile accessory. If you have a very dry and edgy sounding amplifier, it might also help to lessen some of these traits in line applications. In conjunction with our Dynavox tube amplifier, however, this proved to be too much of a good thing and resulted in overall imprecision. Of course, the TPR-2 is no match to a High End phono stage, such as that of our upgraded Dynaco PAS-4 or the Symphonic Line RG9 and RG10 phono stages. All of them add much lower levels of distortion and offer superior precision to the music, thus resulting in a purer and more accurate sound.

I will hold on to the TPR-2 for a while, because I enjoy its warm and smooth sound, specifically in combination with our Dual CS 505-3 turntable. It brings this turntable’s performance much closer to that which I have come to enjoy from far more expensive setups. Considering its bang for buck performance, I believe the TPR-2 is a worthwhile investment to enter the world of audiophile pleasures, even when keeping the mid-Fi gear you already own. For those looking for a preamp replacement with phono stage, the more versatile TPR-3 is definitely the better choice. It also has much better controls for frequent use. Where the ability to connect a turntable is not a must, the TPR-1 might also be an interesting option to play with. And if you enjoy upgrading electronics, there are plenty of ideas and upgrades for both of these preamps out there. But I guess you will have figured this out by now.