Saturday, August 27, 2011

Sure TA2024

The Sure TA2024 is my current favorite T-amp. It's cheap and commonly available on ebay for around $50. It sounds fantastic. It's well built, attractive and it has a couple improvements over my previous favorite, the Trends TA-10.1. Unlike the Trends, it has a front mounted power switch, a small, but to me important, detail. I hated the Trends' obnoxious blue power led and the Sure has a softer glowing ring around the volume knob. That's not to say everything is as I'd like it. Sure added an odd feature. When the amp is off, the orange ring around the volume knob slowly pulses. The Sure manual calls this "breathing" and comments that it will help you find the amp in the dark. Whatever.

There are several variations of the Sure TA2024. I have the AA-AB32157 model which has the Tripath TA2024C chip and uses a digital volume knob. It is definitely different than the volume controls I'm use to. It takes a little over 3 turns, 1080 degrees, to go from completely off to full on. It is an indexed volume control with roughly 25 detents, or clicks in 360 degrees. Based on this, I'm guessing the volume control is Sure model AA-AB11117 which has 83 total positions. When the amp is off, spinning the volume knob has no effect, the amp always starts with the same volume level it was set at when it was turned off. I would probably prefer a normal analog volume control, but honestly the digital one is fine. It has a good feel and even though it's indexed, there are plenty of settings and I can always find the volume I want.

There are at least 5 different variations on this model. The earlier ones have the normal analog volume knobs, and there is one variant with a headphone jack. Here's my understanding of the different models:

AA-AB32151: Front headphone jack, Digital volume knob with 12v 3a Sure power supply
AA-AB32152: Analog volume knob and 12V 3A Sure power supply, no headphone jack
AA-AB32156: Analog volume knob and no power supply, no headphone jack
AA-AB340: Seems to be identical to AA-AB32156
AA-AB32157: Digital volume knob with 12V 3A Sure power supply, no headphone jack
AA-AB32159: Digital volume knob with no power supply, no headphone jack

I'd sold the Trends TA-10.1 long before I got my Sure, but the Sure sounds like what I remembered of the Trends with an exceptionally musical presentation. I'm not good with audiophile terminology so I don't know quite how to express it. It's obvious that at least some parts like the speaker binding posts are made with cheaper materials than the Trends, but somehow the Sure seems more finished and less of a DIY project than the Trends. Still, if I look closely at the Sure from the right angle, I can see that the case isn't perfectly straight. That's quibbling though. This is a world class amp and an easy thumbs up.

Wednesday, August 24, 2011

Aune dac & headphone amplifier

I bought the Aune to replace my previous dac, a Muse DAC with 4 parallel Phillips TDA1543 chips. I don't really understand the theory behind parallel non-oversampling DACs, but the Muse did sound very good. The Aune sounded better though with better bass response. It was also much more attractive and well built. The headphone amplifier was a nice bonus, but I rarely used it. The power supply ran hot, and eventually the plastic of the power supply cracked from the heat and fell apart. Still, I'd have no trouble recommending the Aune. I sold mine as I found the built in dac of the Pure i-20 sounded just as good.

Muse M30 T-amp & dac

The Muse M30 is a great sounding but ultimately disappointing T-amp/dac combo. The most interesting thing to me was this T-amp uses the relatively high powered TI TPA3121D2 chip. This chip was based on the earlier Tripath chip amplifier designs but was reputed to be an improvement over those designs. Listening in my house I was impressed. It's certainly more powerful than my TA2020 or TA2024 amps have been.

There were some significant disappointments though for me with this amp. The PCM2706 based dac has a convenient USB input, but it's nothing special sonically. The volume knob was indexed. It had detents and not the smooth turn that I prefer. It also had a noticeable channel imbalance at low volumes. The amp itself just didn't seem as well made as the Topping, Trends or Hlly T-amps I've owned. I'm impressed with the TPA3121D2 chip, but I'd like to see it implemented in a better amp.

Qinpu A-3 hybrid tube transitor amp & Pure i-20 iPod dock & dac

After about 3 years with my Trends TA-10.1, I got itchy to buy a new piece of hifi gear. The Trend's replacement was the Qinpu A-3, a hybrid transistor tube amp. The tubes in the Qinpu A-3 color the sound in the preamplifier stage. You can tell that the tubes are running at a low wattage, they glow only faintly. To brighten up the tubes visually, the Qinpu has a couple blue leds that initially blink as the amp is warming up. After about a minute they come on solid, and the amp kicks in. My guess is that the preamplifier is using a "starved plate" design. I've always loved the sound of my ART tube mic preamplifier which also uses the "starved plate" design, so I've got no issues with the design of the Qinpu.

The Qinpu has great visual appeal, and I loved showing it off to guests. The Qinpu is also very affordable, I notice that Audio Advisor sells the Qinpu for $199.

While the Qinpu's visual appeal may have been head and shoulders above the Trends homely "project box" look, I came to miss the musicality of the Trends. That's not to say the Qinpu wasn't a good amp, it just didn't sing to my ears like the Trends. Also my wife got impatient with the minute or so that it took to warm up, so I sold it off and got another T-amp.

Shortly after the Qinpu arrived, I got the Pure i-20 iPod dock with integrated dac. I had been using a Wadia 170i itransport to get a pure digital signal out of my iPod. The Wadia cost me nearly $400, so it was the single most expensive piece of hifi equipment I owned. It also needed an external digital to analog converter ("dac"). The Pure i-20 sounds just as great, only costs $100 and has a great sounding internal dac. It also has both coaxial and toslink outputs if you want to pair it with an external dac (the Wadia only has a coaxial output). The Pure i-20 also has a much smaller footprint than the Wadia, so it pairs up really nicely with a small T-amp. The Pure i-20 is an easy thumbs up.

Trends TA-10.1

Welcome to my T-amp blog and my first post. I bought a Trends TA-10.1 from Obad imports back in November 2007 and fell in love with T-amps. It's nearly four years later, and I'm surprised there isn't a dedicated forum (other than the excellent Italian language forum over at I just sort of stumbled on T amps. I was looking for a small sized amp to pair with my iPod for an ultra compact system. I read the glowing review at and I was hooked.

The Trends amp really is wonderful, though I've since sold it and bought several other T-amps. This was my first foray into the audiophile realm and it really opened up my ears. The Trends amp uses the Tripath TA-2024 amplifier chip (like many other T-amps) and has a wonderful musical quality. The TA-2024 chip though isn't known for it's linear response. Audioheuristics has a very good write up of a similar TA2024 amp and it's frequency response is uneven. Yet, the result is musical. Much has been made of the similarity between T-amps and tube amplifiers, and maybe the non-linearity of amp is part of this. I have a personal theory that the wonderfully coherent sound of the tripath amps has to do with keeping all the frequencies consistent in the time domain. It's been written that some amplifiers "blur" sound by presenting different parts of the frequency range slightly earlier or later than others.

The Trends, like other TA2024 amps, has a meager 10 watts per channel. If your speakers are efficient though, you won't be disappointed. It's a little hard to find these days, I don't know of a source other than the Trends website which is based in Hong Kong. They have a new TA-10.2 SE model with an upgraded volume knob and power supply which I'd find tempting if it wasn't $225 plus shipping. My only criticisms are the plain jane "project box" appearance, rear mounted power switch and ridiculously bright blue power led.