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icehockeyboy

Theta dac and TLC (re clocking anti jitter device) question

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I have two options regarding connecting my Squeezebox to my Theta dac.

Straight into the dac via toslink lead, and then select coax/opti input, or,

Into the TLC device, again with toslink, which then feeds the dac itself with a coax lead, and this time I select the coax/opti input on the TLC itself.

So, the question, does it make any difference the fact that im going in with an optical lead, and out with a coax one?

The answer I bet is no, but im not 100% sure, as it is I cant detect any difference......

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There is an interesting review here of four of these devices, including the TLC.

The TLC was found to be pretty effective through it's optical input, but hopeless through its coax. :shock:

There was no comment on audibility, results were measurements of jitter before and after.

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Thanks MIB, incidentally the code for the Monarchy distributor is wrong, it should read 0115, and then stick a 9 in before the 284

It looks like someone just re did the old code (0602)

Thats assuming they are still in Wollaton, I didnt realize they were so close to me (3 miles)

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I have mentioned this before, the TLC requires some modding to it's co-ax phono sockets as they share common ground, easy to fix by fitting two separate phono sockets such as WBT next Gen, and very beneficial to jitter reduction. With this mod it's performance is far better than the review states and it outperforms the toslink measurements.

As you can see from the above link this common ground is mentioned, and as stock it has good jitter suppression via Toslink due to this breaking of common ground.

I am sure in a couple of past reviews that the TLC worked very well as a toslink to SPDIF converter giving an increased performance over the toslink only connection? My own did such duties with my optic only Technics SL-PA10 transport.

It was stated that daisy chaining TLC's was even more beneficial, and that the TLC benefits were suitable even for some of the more exotic systems of those days. Even so, my own findings were that the benefits were subtle, and the better the transport and DAC the less apparent this became, of course amp and speaker ancillaries had to be capable of showing the slight performance increase.

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i'll relate my experiences with reclocking devices...

one of the notorious problems with the original squeezebox 1 was it's very jittery output of wav files - mp3's were fine but due to the internal architecture there was no natural 44.1 time signal so one had to be (badly) synthesized. my dac at the time had 2 methods of locking onto an incoming signal - one for low jitter and one for crap ones - status of this was shown on the front panel via a light. so i effectively had a way of objectively measuring the performance of any reclocking device.

i initially tried a monarchy audio dip and found it to make no difference - either to the lock status or to my ears.

i then tried a bheringer - again no difference to either the status light or my ears.

tests using dedicated transports showed that the lock status and my ears could both tell the difference.

i was on the lookout for a genesis digital lens which is the mother of all reclockers involving a ram buffer and all kinds of voodoo. when the squeezebox 2 was released whcih had a totally different architecture and jitter performance which 3 seconds after i fired it up produced the little glowing light indicating a 'quality' lock. the difference was also immediadely noticable to my ears too - although if you said it was psycosomatic thanks to the little light i'd not argue - but it sure sounded better to me.

to my mind they are foo and not worth the hassle.

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Read the review - if you go in through optical it DOES reduce jitter, if you go in through coax it does FECK ALL.

So if you believe that reducing jitter will improve the sound - and there is little evidence for this - then go for it.

OTOH, if you believe that introducing an optical conversion will degrade the sound - and there's not muchevidence for this either - then don't bother.

We're firmly in the realms of foo here; your results may well depend which fairy tale you take more seriously. :D

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it should make no difference as the conversion will be done mostly in the digital domain - it may be that the optical signal needs to be put through an extra buffer and then reclocked again which is improving the jitter performance.

at the end of the day - if you want to use optical, use a quality glass, not plastic, cable and if you can;t hear the difference use whatever's most convienient. trust your ears.

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meninblack wrote:

Read the review - if you go in through optical it DOES reduce jitter, if you go in through coax it does FECK ALL.

So if you believe that reducing jitter will improve the sound - and there is little evidence for this - then go for it.

OTOH, if you believe that introducing an optical conversion will degrade the sound - and there's not muchevidence for this either - then don't bother.

We're firmly in the realms of foo here; your results may well depend which fairy tale you take more seriously. :D

On the first point, the Theta TLC did receive favourable reviews, and it's jitter suppression after breaking common ground was measured as better than via Toslink and reviewed as better sounding.

Most magazines found that in most cases reducing broadband jitter produced beneficial results with music, reduction of narrowband jitter (Monarchy DIP, TLC and such) was also reported as making a difference in most tests. It is the bandwidth of addressed jitter which is usually not addressed hence variable reports on success, two of the most successful jitter reduction products are the Meridian 518 and Genesis Digital Lense, both companies proved there was more to jitter, and better ways of tackling it I feel.

To this day it is still addressed by many companies during digital component manufacture, and probably less of an issue due to companies like the above bringing better understanding of inherent problems forward.

I am sure there is evidence of further conversions and poorly implemented optic conversion affecting digital data (hence the introduction of domed polished optic ends as poorly implemented optic ends were found to be detrimental) , one of the reasons why early players sounded better via Co-ax was due to the extra convertion into optics and back into an electrical signal apparently degrading data. Cheap poorly implemented circuits can cause various problems which there have been papers written on such. It is why design parameters are usually adhered to by the better manufacturers.

Not anything to do with Foo, but measured differences. Results are nothing to do with fairy tales but ancillaries, hearing acuity and such if deemed important. Otherwise all anyone would need if they believed the 0's and 1's doctrine is any old player at any old price as they would all sound the same.

;-)

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Sastusbulbas wrote:

On the first point, the Theta TLC did receive favourable reviews

Oh well, say no more. How could we doubt its brilliance.

Most magazines found that in most cases reducing broadband jitter produced beneficial results with music, reduction of narrowband jitter (Monarchy DIP, TLC and such) was also reported as making a difference in most tests.

Case proven then. No better authority than "most magazines."

They would never mislead or exaggerate. :nup:

IIRC some very highly rated CD players were found to have huge amounts of jitter, but the mags spunked over them anyway.

Have you heard evidence of audible improvements from jitter reduction, or just read it in magazines? :?

Your points about fibre ends and polishing are relevant to multi-mode fibres carry huge amounts of high bandwidth data, eg undersea telephone cables. The big chunky monomode things used in audio don't have the same issues.

If your DAC sounds different with optical - it's shit! :D

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