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Doug, it is a lot of tuner went over your hand. I wonder what drove you to do so.  Was any specific quality of sound that you were looking and the tuner that you own did not serve you?

doug s. wrote:

romy, there is a tuna freak in los angeles who insists that the only way to get the best sound from the l-02t is to use kenwood's proprietary cabling.  i dunno, i have never tried one.  i have tried two earlier analog kenwoods; my experience is they need serious mods to sound good.  then, they really do sound quite good.

I am sorry to say it but this “freak in los angeles” is  a moron if he converts the sonic and performing characteristics of  L-02T only into the “Kenwood's proprietary cabling”. It is the same as the fools who power these amps with AC that has 20% of sinusoid distortion and claim that it might be “improved” if used a “better” power cord. I wionder why O so love all that crowd. Anyhow, I did have the Kenwood's proprietary cables with my L-02T

doug s. wrote:

i am interested in what you think mr chow does that is not a good idea...

Looking juts at what he said at his site:

**** Replace all audio stage coupling capacitors with coupling grade Blackgate capacitors, which by enhancing the audio transfer efficiency enhance all aspects of the audio performance, especially more body to the lows and more airy highs.

It not necessary true.

*** Replace the power supply capacitors with larger, higher voltage, upgraded capacitors to insure better dynamic range and tighter, more controlled bass response.

And how higher voltage capacitors would “better dynamic range and tighter, more controlled bass response”?

*** Upgrade the existing grungy chrome RCA fixed outputs and skimpy wire with new gold plated Teflon RCA outputs and new high Q Teflon wire run from the new RCA’s to the PC Board).

Yes, the change of the RCAs is good thing but the right new RCA must be used. Good RCA are not sexy and they never used by the update people. The update people put in play the expense RCA with large mass of negative terminal and they are bad. A right RCA terminal shell not change the thickness of the wire that goes before and after. Most of the “expensive” audiophiles RCA jacks do. Changing the wire better might be a good thing but he did not mention other things hat need to be done with those output wires - this might me nerves.

*** Replace the audio stage Op Amp IC’s with Burr-Brown or equivalent, using a plug in socket so when improved Op Amp IC’s become available, the old ones can be removed and the new ones easily inserted. Improved Op Amp IC’s improves all aspects of the sonic performance.

Possibly. Still it shell be used very accurately.  Many of old time use vintage “slow-running” op-amps and nowadays the op-amps much faster. There are some designers who do prefer older slow amps and there is some merits in it. However,  to have the op-amps swappable is a good feature.

*** Check narrow and wide band IF filters. Replace if necessary. Often the filters in these units are of higher quality than many currently available filters, so they should not be replaced unless they are bad.

Does he converts ceramic filters into LC filter too?

*** Replace DC power supply rectifier diodes with High Speed Soft Recovery (FRED) Diodes because their fast response time, high current capability, soft recovery and lack of ringing and overshoot place them a big step beyond other high speed diodes in dramatically lowering noise, increasing dynamics, reducing grain and glare.

Not necessarily.  I had in many devises used ultra high speed and under 40mS recovery used and it is not always lead to sonic differences. In fact in SS tuners that uselessly run at low vantages there is no need to use FRED but Schottky, as are much more preferable as they have no “soft recovery” but no recovery at all. Intellectually the FREDs, Schottky or whatever make scene but in practical result it not necessarily affective. With one of my Rohde & Schwarz EU-6201 I did change the PS’s diode from 30-year old “crap” to the  contemporary soft-switching and then to Schottky. I recognize absolutely no sonic effect.

*** Raise up and isolate the transformer from the chassis if there is room in the chassis to do so. This will further reduce the noise level.  Check the lights.  Align the tuner. This is indispensable if the tuner is to perform up to its potential. Clean the exterior and interior of the tuner. Provide an itemized list of parts replaced, including a bag with the replaced wire and replaced parts.

That is all good. I would personally would like them to list the specific points they check during alignment as it would give more indication how serious they are.

*** Replace the 18 awg power cord with an IEC input, which permits us because of the ground, to isolate AC noise. If there is no room to install an IEC socket, a 16 awg upgraded grounded AC cord will be hard wired to the component.

That might be good but it has absolutely nothing to do with “isolation of AC noise”

*** Install a high grade AC line filter in line between the IEC input and the power supply to further reduce line noise.

I would call it controversial and use it very sparingly. Probably the ferrite “generic” filters is better then “high grade AC line filter”. Do they select the filter with respect to the given tuner load? I doubt.

*** Replace and upgrade the wire from the IEC to the Power supply PC Board with low noise, high Q wire. This will result in lower losses and better signal transfer across the entire bandwidth.

OK

*** Replace critical audio path wire with high Q wire and if necessary reroute.

The fact of rerouting is very important, I am glad he mentions it eventually.

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