09 October, 2011

Review: SinoVT Raphaelite TP-215AI Part I

Review: SinoVT Raphaelite TP-215AI Part I

And now for yet some more cheaptubeaudio...Now, don't say I don't review Chinese products! :-)

Taken in dim light. Click to enlarge.

One Night in Taipei
Rewind to 2009. I was in Taipei, staying at my uncle's place in 復興崗, near 北投, an old and humble residential neighborhood. Imagine my surprise when I accidentally chanced upon a tube audio shop on the street. But it was never open during the day. Finally, one evening during a stroll I was able to get in the dimly lit place.

The boss apparently is a respected DIY and modifier kinda guy, some sort of guru with a following. The place was loaded with SinoVT-Raphaelite gears. That was my first encounter, and I found the retro hammer tone chassis highly attractive. I seemed to recall the brand as Chinese, and asked the owner about it. He said it is a Taiwan company based in China. I did not express my skepticism.

I forgot what speakers he used; I think horns with DIY cabinets. Regardless of origin, using the transformer output 5842 preamp driving a modified version of the 6L6 SE amp (see pics above), sound was not bad, in fact much better than at the HK dealer, whom I recently got to hear, unfortunately.

Back in HK I checked and of course the company is very much Chinese, based in Tainjin. The Taipei place is listed on the Chinese home page, but not as distributor. And price? If you buy from China, from taobao (list here), price is about half of what I was quoted in Taiwan. In HK, the dealer concentrates on the more expensive items, and does not make buying the cheaper kits easy. Mark up varies from model to model.

Why the name Raphaelite, I wonder? In case you don't know, Archangel Raphael is the angel of healing. Perhaps that attests to the power of music? Of course, there is the painter Raphael, but that seems even further removed.

click to enlarge

SinoVT TP-215AI
I have always wanted to try out their most popular SE kit (here), only about US$235 or HK$ 1831 from taobao, at today's exchange rate. But I never got to it.

Just a few weeks ago, by chance I saw this beautiful integrated amp second-hand, for a fair price. Since I have always liked 6V6, I bought it. When I opened the bottom I was impressed by the superb built and reasonable component quality (click pic to enlarge). As evidenced by the Bennic coupling caps, perhaps there is a Taiwan tie after all.

The model numbers of SinoVT are confusing. The TP215 apparently is a series. The AI I got is an older version (official manual). It operates the 6V6 in fixed bias push-pull. There is a meter up front that shows the current for each tube. But you have to open the bottom to adjust the bias. There is only one bias pot for each channel, so it is desirable to have tightly matched pairs.

A newer version, the TP215AB, seen on the website but not seen in taobao, looks virtually identical except for the improvement of adjustable bias for each of the 4 power tubes, and adjustable from the top, without having to open the bottom plate!

Yamaha NS-10M pentode vs triode This amp is rated at 7 wpc in pentode operation. Switching to triode operation halves the power. I first tested it with the 90db legendary Yamaha NS-10M. It proved a match made in heaven. Not surprisingly, a little tube warmth complements the neutrality of the Yamaha. Even in my 300 ft room I could listen to big orchestrals at reasonable volume. However, triode operation (3.5 wpc) proved not too ideal for the Yamaha.

Adding a preamp As with many budget (actually even many expensive ones) "integrated", the volume is passive. With the volume maxed and used as an amp only, the Leben RS-28CX preamp added a great deal of control, and that was how I used it from that point on.

Tube Rolling The stock Chinese 6P6P (6V6) were used throughout. Substituting metal base 6SJ7 and RCA 6SN7 immediately brought more refinement. Although I usually prefer direct-heated rectifiers, in this flea-powered amp, the (similar to the Chinese 5Z4P) indirectly heated 5AR4 (with its lower voltage drop), just edged out the 5U4 in solidity, but the difference was not huge.

Tannoy Canterbury Convinced of its worthiness, I hooked it up in the reference system, with the Tannoy. With the much higher efficiency, the SinoVT sounded more effortless. Indeed, the bandwidth seemed quite reasonable and sound balanced for such a cheap product. Compared to my SET amps, the midrange is more recessed and there was a loss in details, but that is hardly surprising. The performance was still beyond expectation.

In sum, a great little amp. In Part II, I shall try out old-stock 6V6 as well as compare the amp to the much beefier Audio Note Kit 4. I am sure it would not measure up, but it would be fun to see how close it would be.

Click Schematic to view in full.

1 comment:

Charles Bates said...

Hi there. Thank you for your impressions of this amp. I would love to see more in depth analysis of any of the SINOVT lineup. They are very under represented in the US.