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Trichord Clock mod to DPA T1 Transport

U

UKSwede

pfm Member
I am thinking of the Trichord mod to my aging 1992 DPA T1 Transport. Has anyone tried this on this transport or others. Is it worth it for the clock 4 over the clock 2 and how about the external supply

Inside the player I find a PCB alone containing the the xtal 11.2896MHz. I think with a DPA DAC this transport would be synchronised by the DAC by the Deltran Sync Lock. But I dont have a DPA DAC.

So a better xtal in the DPA Transport should improve things

Comments welcome...
 
I was also told that if you wanted to move the mod to another CD player with a different frequency they would swap the xtal for £20. I guess you must take care of the old components, or sell the transport as Trichord clocked. Maybe when I have done the mod I wont want to sell. Just hope the rest of it lasts

BTW Did you know the DPA T1 is a modified Marantz CD52

Pat
 
I am considering reclocking my Rotel 965 Descrete.
Does anybody have any opinions as to whether I should buy a Clock 2 for £49.00 or is it worth paying £149.00 for a Clock 4, bearing in mind the age/quality of my CD player.

Also, Trichord are selling a power supply for £175.00. Are there any cheap items from the likes of Maplin that will do the job.
 
I dont know how old your CD player is or the quality. I assume from what you are saying it is an old budget model. In such a case I would have a good think. What is the cost of an off board DAC. Maybe I would re- clock the CD player for £50 then later buy another DAC for it, assuming it has a digital output. I think £150 on an old CD player is too much, as maybe a newer (or even second hand) integrated CD players for not much more money would be better. I made by choice as I have a good seperate DAC and wanted to have a go with the transport only.....
 
I'm having a old CD6000 and always wanted to change the existing flimpsy crystal for a better one, but just don;t know what spec to get.....................

King
 
Also, Trichord are selling a power supply for £175.00. Are there any cheap items from the likes of Maplin that will do the job.
Click to expand...

Having experienced the improvements that decent power supplies can make, I don't think a cheapy from Maplins will really offer much of an improvement. I know John & Jake has recently installed some of Andy W's superregs in his CD player to excellent effect, so perhaps the DIY power supply route is the way to go. I've not dared venture into my Marantz CD17 (yet), so can't really offer any CD tweaking tips other than a comment re the importance of a decent power supply.
 
Richard
I thought a cheap power supply might be suitable. If you look on the Trichord website, in the reviews section, there is an article that indicates that powering the Clock2 from a battery gives improved results.
However, I think you are probably correct, if a job is worth doing, do it right. I have been onto Andy W’s website and to be honest the superregs looks far too complicated for me to build. (I have never built a circuit in my life). The great Homer Simpson once said “If a jobs difficult, it’s not worth doing “I do recall somebody giving details of a simple prereg/reg circuit on the Hi Fi Corner suitable for a CD3.5. I will try to find it again.

I may be totally wrong, but the clock3 and 4 looks like the clock 2 with voltage regulation added. If this is correct, it follows that, if you pay £149.00 for a clock4 you don’t really need to spend £175.00 on a dedicated power supply. But if you buy clock2, the power supply is more important.
 
My Clock 4 has arrived but the module does not look the same as the web page. It looks like they have made it shorter eg There are no leaded components, just surface mount. The PCB is labelled Clock 4b.

If anyone would like a digital picture, just send me an email. I have not fitted it yet

Pat
 
Finally, I got the clock 4 into the DPA T1 transport. First you had to remove the old crystal with 1 resistor and 2 caps. Then the Clock 4 PCB was fitted and a suitable supply found for the clock 4

I must say I was bit nervous that the player may not work at all after such surgery. However, I connected the transport back up the DAC and started to listen. Well, I have to stay this improvement was not slight, it was HUGE!! There seemed to be more detail, better dynamic range, and any harshness was now much reduced. I could go on to describe, but the sound was just fundamentally better. Now I am thinking what about the DAC, can there be improvements to be had there?

It is clear to me that these re-clocking mods to work, but why the hell do manufacturers still continue to fit crapy xtals in there CDPs

Pat
 
You should have measured both the input and output clock jitter with the Xtal installed, then measured again with your Clock 4 in place. Xtals are usually a very accurate clock source. Don't
just assume the original design was "crapy".
 
Well, I did measure before and after, with my ears which is most important. Re-clocking is not a new thing to the audio market, why not look at www.lcaudio.com or www.trichord.com. Even look in the naim forum, I have seen no negative comments from other users

Sadly I dont have a phase noise system at home, or any CRO that is capable of measuring the jitter. But I am sure if the measurements were done on suitable equipment better results would be found
 
Originally posted by markf
You should have measured both the input and output clock jitter with the Xtal installed, then measured again with your Clock 4 in place. Xtals are usually a very accurate clock source. Don't
just assume the original design was "crapy".
Click to expand...

I am sure that an Xtal is accurate, indeed look at any commercial clock upgrade on the market and you will see a xtal of some sort on them. The problem is that a xtal combined with a couple of caps and resisters does not produce a very good square wave signal.

It is my understanding that this is where a decent clock will help.
 
The crystal is rarely the relevant thing here.

Most CDP's use simple Pierce oscillators that are jittery and have high phase noise. The worst ones are often those inside another chip where it's PSU modulations worsen results still further.

Marks comments are fair enough, but realistically few of us have the necessary kit to measure jitter or phase noise. Even my £30k analyser at work has insufficent resolution for this job!

The standard oscillators can be improved by careful check of operation and attention to PSU-induced jitter effects, but I doubt a cheap inverter based Pierce oscillator wil ever beat a good discrete circuit here.

Look at www.wenzel.com in the library section bit - loads of good ideas there.

Andy.
 
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