TrendsAudio PA-10 SE: A Hybrid Amp Design
A while back TrendsAudio posted their Trends Audio PA-10 headphone amp on our wall. Curious as I was I asked for a sample in return which we got very shortly after.
Personally I had never heard of TrendsAudio but after this first contact I found out that TrendsAudio has actually been penetrating the market more and more and there are dozens of reviews to be found online already. For those interested in the company, I suggest you go read up on their website.
Each PA-10 has jumpers inside so you can choose between two tube types: 6DJ8/6922 and the 12AU7 type tubes. It’s fairly easy to switch between tube type and to adjust the bias but just to be sure TrendsAudio gives detailed instructions in their manual and on their website. I received The PA-10 SE version with the 6H23n Russian tube that had been biased by the factory before shipping. This hybrid amp is small, only measuring 114mm x 76mm x 46mm (DxHxW) with the tube sticking out just a tiny bit on top. So the tube isn’t really visible which is a shame for the tube lovers out there. On top of that there is a blue LED beneath the tube… Well, you like that or you don’t, I’m not sure if it is part of the circuit as often is the case but personally I’m not a fan of LEDS under tubes. Component wise we don’t know a lot of this PA-10 SE besides from the 2 Mosfets on the output stage and the Evox white cap.
On the back of this standard +24V adapter powered device you have 2 sets of switchable inputs. Besides the normal CD/DAC input with standard gain (x3) there also is a PC/iPod input with high gain (x6). The PA-10 SE not only is a hybrid headphone amp but you can also use it as a pre-amp. That’s a lot for such a tiny box!
Sound wise, Trends keeps on focusing on a few things in their communication: a pure Class-A circuit, 2 MOSFETs as output driver and an innovative circuit design providing an audiophile quality sound. But how does it really sound?
First of all this tiny amp plays loud! There’s a lot of gain even when using the normal (x3) input, with all the headphones I tried it with I never had to go past 10 o’clock with the volume control (LCD-2). Talking about the volume control, it is a bit noisy but very smooth to turn. Apparently the noisy pot is something “everyone” on the web is already aware of so I’m sure trends is too and I’m hoping they will upgrade it with a next revision. Sorry for digressing. Trends themselves claim this little hybrid produces 3.0Watts per channel @ 33Ohm. Come again? 3 Watts?! I don’t have any tools to measure this but in their defense it does drive the LCD-2s and HE-500 fairly well. In fact, the 300Ohm Sennheiser HD650 were way too loud and a “no go” with this amp, I really didn’t like how it sounded.
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