I've read that some folks hear a hiss on the 310, but I don't with PortaPros or Sennheiser IE 7s. I even hooked it up to a 'scope to see if maybe I could see the noise and didn't. There's also no DC at 0 volume.
Perhaps there is a bit of a difference from batch to batch or even radio to radio.

I've never jacked a portable radio into my stereo set-up (now that I think about it I don't have a tuner on my main stereo at all) so I can't really comment on full-on through a good stereo sound, but with headphones I can.
My phones seem to like the PL- 310 FM sounds nice and fairly full and even the AM is decent at @ 6KC filter (sounds much wider than that). I find it has better sound than the G6 though the G% has it beat on FM I find the 310 better on AM. The Tecsun R012 has a bit of bass boost it seems and there's no way to switch it off. It's on the low end instead of the mid bass boost so many of them have which is a welcome change, but it's still not true fault hi-fi...and the AM is distorted. Not that great for DX anyway so not sure why I brought it up. The Kaito/Degen DE1123 is not so great on any band. Sony couldn't build a decent FM tuner to save their lives and never have that I'm aware of. The Eton E100 is..sorry to the fans of this one, but...meh.
The Tecsun PL-230 (YB-550) has decent sound, but is a bit large.
The Rat Shack 12-587 is about as average as average can get and only tunes in 10KC steps. The Sangean DT-200V and DT-200vX are decent and have quite a bit of output power. The Grundig Mini 300 and 100...meh.

All in all I'd take the PL-310.. though I have yet to try any of their other DSP rigs including the G8.

Oh..and for AM sound alone the Sony SRF-AX51V has a wide switch and AM stereo and great sound. I think it's still in production. Unfortunately it has an off-the-wall 3/32" stereo headphone jack, but there are adapters available. The Sony SRF-42 is worth keeping an eye out for too as it's actually AMax certified. Sadly it's out of production.

--- In ultralightdx@..., "dhsatyadhana" <dhsatyadhana@> wrote:

Thanks Rick for your usual sharp insights! I agree - quality control may be the issue here, even though Tecsun seems to be pretty consistent from batch to batch.

Those who have multiple Tecsuns, any conclusions on audio quality from radio to radio??

Kevin


--- In ultralightdx@..., Rick Robinson <w4dst@> wrote:

On 1/10/2011 11:19 PM, dhsatyadhana wrote:

...and this just in! I just tried out all of my ULRs with my Grado SR-60 "near-audiophile" and fairly power-hungry headphones, with the volume attenuator. I did A/B tests on various stations here in the Seattle area, and the clear winner from an audio perspective is...

What could cause significant differences in audio when all these small
portables, Eton, CCrane, Tecsun, that I've dissected use the same CD1622
audio output chip and the same value caps, resistors, etc. in the audio
circuits? The circuits are all identical in the 7 different radios
I've examined and are straight out of the CD1622 datasheet posted in the
files section. Using quality headphones is obviously the way to test
them, but it still leaves me wondering what the determining factors
could be. Kiwa and Big Sky Audio have kits to improve the audio in
communications receivers which involve replacing polarized electrolytic
caps in the audio stages with non-polarized electroylitics and ceramic
caps with mylar. I could understand if Tecsun was using a better
quality cap, or design, than say Eton, but from what I've seen, that
isn't the case. Maybe it's just a case of variables in the particular
batch of CD1622s, caps, etc. In that case, my PL-380, or CCrane SWP may
be my audio winner. Using good headphones is definitely the way to
enjoy FM and also pull out the weak ones while DXing MW.

The CD1622 is made for low coast small footprint portables not for
audiophile quality sound. Anyone looking for sound comparable to high
end tuners is not going to find it in a $50 portable radio. These are
truly "pedestrian" radios meant to sell at a price that the average
Chinese worker can afford and not aimed at the US/European audiophile.

I would think Silicon Labs has a high standard of quality control and
the audio response out of one Si4734 would be very close to that of
another.

Anyone else have any ideas regarding what Kevin and others are noting?

Rick W4DST