NAC 282 w. Logitech Transporter

Posted by: bhaagensen on 21 June 2009

Dear all,

after some months of lurking online and investing offline, I am
no longer nobody and so the time has arrived for my first post
here. I'll do a more proper introduction later if that is appropriate.

From the lurking I've learned that some members are using the Logitech
Transporter in Naim-based systems, and so am I (more or less). The
Transporter runs into a NAC282 using RCA-terminated Chord cables (the
modelname escapes me atm).

My question relates to gain matching between the 282 and the
Transporter. As far as I know the Transporter, by default, outputs a
line signal at standard levels. However sometimes it is as if the
Transporter overdrives the 282 resulting in distortion. Could this be
the case? Are there known issues related to using the RCA-inputs and
non-Naim sources with the 282 or other Naim preamps?

Btw. the 282 replaced an old Audiolab 8000S and the difference is beyond
words. Hence I'm not yet sure whether the distortion I'm hearing might
be present in the actual source-material, or something else.

Regards, Bjørn
Posted on: 21 June 2009 by AS332
Hi Bjorn ,

Welcome to the forum !
I don't think it is a cable problem . I don't have a Transporter myself but having a quick look on the owners manual from the Logitech website it could be the output attenuation issue with unbalanced analogue outputs that is described on page 26 . I believe there are a pair of jumpers that can be changed to a different setting to solve the gain issue .
I hope this helps .

Ed
Posted on: 21 June 2009 by yeti.fro
Hi Björn,

welcome to the forum :-)

I home demoed a Transporter a couple of month ago and had no probs at all with my 282. Sound was clear a and crisp with no signs of distortion. However, I was not really satisfied with the music presentation and ended up with a Linn DS, but this is a different story.

Some questions which might help to verify the source of the problem:

- When do distortions occur? Only during loud/quiet music or always?
-> If only during (very) loud passages, try to recode the track with reduced volume and see if it gets better.

- Only with certain tracks and always at the same time?
-> How do the tracks sound on a different system? Maybe an error during ripping?

- No distortions heard with your Audiolab? Try another input of the 282.

- What data rate/file format you use? Poor MP3 or FLAC?
-> The 282 can show quite drastically how rubbish MP3 sounds, so try different file formats with a higher bit rate.

If you still suppose that the transporter is kind of overloading the 282, there are cheap adapters available, basically a cinch coupling with build in resistors, which reduce the volume by a couple of dbs.

Hope you can solve your problem...

thx n brgds...
Posted on: 21 June 2009 by QTT
How would you set the "Volume Control" for your Transporter? I use "Output level is fixed at 100%" and I do not hear any issue. However, I use the Transporter with the NAC 252.
Posted on: 21 June 2009 by DaveBk
I also use a Transporter with a 252. The internal gain jumpers are set to their default 0dB settings and the digital volume is 100%. I've never noticed any distortion - are your music files lossless rips?
Posted on: 21 June 2009 by JYOW
I am using transporter with 202, no gain problems.

However, I do recall way back many firmware versions ago that I had an issue with very distorted sound on some songs due to replay gain problem. If this happens on some songs but not others then it is probably the same problem related to the Replay Gain tag in your FLAC files.

If this is the problem, it can either be fixed with fixing your FLAC tags or, more easily, by turning replay Gain off globally in your slim server.
Posted on: 22 June 2009 by bhaagensen
Thanks for all of the answers and suggestions so far. My preliminary
conclusion is that there should be no inherent issues in this regard.

I think I'll proceed with some of yeti.fro's suggestions to get some
reference points.

I should have mentioned in my first post, but most of my
library-files, and in particular those I'm reffering to here, are flac
ripped from my cd-collection. I'm not using replay-gain, crossfading
or other signal-manipulating features, digi. volume is set at 100, and
the internal jumpers at 0... But I shall nonethelss double-check these
points.
Posted on: 22 June 2009 by DaveBk
Best of luck getting it right, the Transporter's a worthy source when singing on tune. Maybe the Naim DAC will better it - I'll find out soon. Winker
Posted on: 23 June 2009 by bhaagensen
Thanks Dave. And my system is indeed singing. In fact I'm hearing so
many things in a different way now that, the oddities might just be
artifacts of the source material that where previously hidden (to me).

Seriously, the 282 is so far (after about a week) nothing but
spectacular; and I say so with a fair bit of confidence as the 282 was
the only change I made this time around. I realise that a ~1996
Audiolab 8000S isn't exactly state of the art, but over the years I've
had several younger and well-respected pieces of electronics do
guest-performances. I've even tried running the Transporter directly
into the poweramp, albeit not a Naim. Most managed to put on a good
show, but I never became a fan of any of them.

The 282 however plays in an entierly different leauge. I'm still
trying to understand what I hear (mind you, not how its done). How can
it be so light and airy without being bright and harsh? How can it be
so fast and precise without being analytical? How can the imaging be
so exact without sounding cooped up, or even just plain old boring...?
How can it so clearly bring out the harmonics of the bass without
enhancing the bass?

Whatever, whichever, or however the 282 cuts corners, they all surely
seems carefully chosen as to lie thoroughly out of the umpires
sight... Or have they actually got it right?

Bjørn

PS! Please let us know how the Transporter holds its own against the Naim DAC.
Posted on: 23 June 2009 by JYOW
You are making me wanting to upgrade my 202.

Seriously though I am quite confident that the Naim preamp is not the culprit, especially if other sources are ok.
Posted on: 23 June 2009 by bhaagensen
quote:
Originally posted by JYOW:
You are making me wanting to upgrade my 202.


Sorry about that Smile I'm confident the 202 is also doing the magic quite satisfactory. Its just that I had a chance to get a used 282 that, as the saying goes, was too good to pass up.
Posted on: 23 June 2009 by DaveBk
quote:
PS! Please let us know how the Transporter holds its own against the Naim DAC.


Bjorn,

The time came earlier than I expected as I was close to the Cymbiosis Summer Sounds event and decided to drop in.

The DACs good, very good, especially when powered with an external XPS2. It was partnered with a 552 and 500, driving a pair of the new Ovators so an excellent overall system. My next upgrade is speakers and the Ovators are currently at the top of my shortlist, but at present I'll be sticking with a 252, SC2, 300 to drive them. I'll need to to listen to the DAC at home before I can really comment on it relative to the Transporter, but based on what I heard today, I think it will beat it.
Posted on: 23 June 2009 by JYOW
Dave, if the DAC bettered the Transporter squarely then it must be up there with the megabuck DACs.

Of course in a full Naim system I am sure a Naim DAC has its advantages. Just curious, do you know what interface it was using to connect to the source? Any master/slave type connection? Any clock sync?
Posted on: 24 June 2009 by DaveBk
I think most of this has already been said on the DAC thread, but...

It was a coax SPDIF connection terminated with BNC connectors. No external clock, but the DAC reclocks everything through a FIFO buffer to remove jitter. The DAC chips are Burr Brown standard devices rather than custom and the same as used in the 555 (From stereophile - Burr-Brown's 24-bit 1704 digital/analog converter chip, introduced in 1998; the Pacific Microsonics PMD-200 digital filter chip) so not the latest spec, but ones that are tried and tested. I couldn't find out whether the passive components, and circuit topology around the DACs are identical to the 555, but it's certainly a circuit based closely on that from the 555 so very good. The 555 uses internal screening and vibration isolation which I guess is not included with the standalond DAC which might explain the difference in performance, but it does leave room for a refrence DAC to beat the 555 in years to come. I'll get one on home dem sometime in September, as I fancy one for a Christmas present to myself.