Powering Vintage Speakers with a Micro Amp

When I purchased my beloved Clairtone G2, the components had been “upgraded” to a Marantz 2235 integrated amp and a Phillips 22GA427 turntable.

My G2 waiting to be picked up in Chicago.
My G2 waiting to be picked up in Chicago.

I traded the Marantz for a pair of Magneplanars, and though it’s not in the G2 cabinet anymore, I still use the Phillips turntable every day (running through a Carver C-2 preamp and m400t Cube amp and into those Magneplanars).

I’ve been searching for 15 years for an original Clairtone T10 or T14 (horizontal mount variant) to bring the G2 back to its original state. Yes they’re out there, but they’re usually in Canada (where Clairtones were made), overpriced, and hard to ship. As for the turntable, over the years I’ve actually won three Garrard Lab 80 mkII’s, but all were destroyed during shipping. Finally I found one locally in less-than-satisfactory mechanical shape, and I ended up tearing it completely down and restoring it. It now has a proper home in the G2 cab.

So I’ve got this gorgeous Mid-century stereo cabinet and globe speakers with a lonely British turntable that doesn’t make any noise. Not an ideal situation.

The original Clairtone T10 amp isn’t “normal” in that it is oriented horizontally (the controls are on top) so it can fit in the shallow cabinet of the G2 (vs. a traditional oriented stereo component with the controls on the front). So I can’t just use any old integrated amp as a replacement. The amp can only be around 5 inches long (which translates to “deep” in the G2 orientation) in order to be able to fit vertically in the cabinet (with room for knobs on the top/front and plugs on the back/bottom). Until recently, there wasn’t a whole lot available to make this possible without seriously customizing a component amp by tearing it apart, de-soldering everything, and putting it back together in a “flat” (horizontal) configuration with the face plate moved to the top. I started to do just that with a vintage Pioneer receiver that I wasn’t too worried about “destroying,” but after days of de-soldering things, I grew weary and changed my plan of attack.

The original Clairtone T10 amp drove the Wharfedale speakers in the G2 orbs at only 12 watts per side. That allowed me to search safely in the new-ish “micro amp” category of stereo amplifiers (cheap Chinese digital amps designed to be used with bookshelf speakers). Since this is likely a temporary set up and I wasn’t sure what I’d be getting myself into with these surprisingly small (some the size of a pack of cards!) and disturbingly affordable amps, I decided I would cap my search at around $100.

This meant I was looking at Topping, SMSL, and Lepai, as the main contenders.  After a bit of research, I decided that the Lepai was going to be “less than” for my needs; apparently they focus on the “cheap” aspect, while SMSL and Topping put a little more effort into making things sound good.  The Lepai also looks cheaper than the more solidly built SMSL’s and Toppings.

There are various things inside these tiny amps that can change the final flavor of the output, from the capacitors to the main chip to the power source.  There is also the D class vs. T class factor (most would say T is “better,” and it’s definitely more efficient).  Build quality is also another issue when talking about something that costs less than $100.  Some also have “features” like Bluetooth or WiFi and remote controls, but the reviews seemed to indicate that models with these kind of bells and whistles weren’t as good as the more simplified models.

I was all set to purchase the Topping TP22, based mainly on this guy’s Amazon review (which also contains a lot of good “general” information), when I started thinking a little more about how important power is to get good sound.  The TP22 has a TK2050 chip and is rated at 30 watts per side, but I started reading about distortion and what happens at the “high end” of these amps’ power ratings (usually a decent amount of distortion).  So even though the TP22 is rated at 30 watts per side into 4 ohm, the distortion at that level is .65% THD (total harmonic distortion).  Way too much.  Not only that, but the G2 speakers are 8 ohm, which is another drop in power from the amp, so realistically, the TP22 is rated at 15 watts per side into 8 ohms at .018% THD.  That’s probably enough to drive speakers originally driven at 12 WPC, but it seemed a little iffy to go with something right on the line, especially when there were more powerful options out there.

So I started looking at micro amps with more power, like the Sound Appeal SA-100t, SMSL SA-160, and the Dayton Audio  DTA-100a.  Just when I had decided to go with the SA-100t over the SA160 (the SA-100t being pretty much exactly the same at the DTA-100a, just price a little cheaper on Amazon), Dayton upped their game and came out with the DTA120, which is 60WPC instead of 50WPC, which means an actual 40WPC into 8 ohms at the top end.

So I went for it.  $78 on sale at Parts-Express.com.  Tripath (T Class) with 40WPC max at 8 ohm, and since my G2 speakers were originally driven at 12 watts, the 40WPC was going to be plenty of power (I wouldn’t need to take it to the top end where distortion lives).

And it is!  The amp actually sounds great in the G2.  I had to move things around a little inside the cabinet, as the amp is definitely susceptible to noise from electricity, but once things were situated it’s quiet and drives the G2 globe speakers quite well.  I run the turntable through a phono preamp and into the rear RCA inputs on the amp, and I can plug my phone/media player into the aux input on the face of the DTA120.  Eventually I will implement a stereo switcher since the  DTA120 only has one RCA input source on the back, and then I will be able to select between the turntable, WiFi streaming, and Bluetooth streaming.

Finally, music once again emanates from those beautiful G2 orbs.

Dayton Audio DTA120

G2 with DTA120

G2 guts

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