Zen Switching Box after upgrade with WBT RCA female jacks. I think that ZMA owner who also uses Zen switching box as in put selector should consider to do this upgrade. It is a must since Zen switching box is a weakest link in audio chain system. You will feel like get new sound level of ZMA when you did upgrade.

ZMA after upgrade with WBT Next Gen 0705 pure copper. I highly recommend to upgrade at first priority. It is one of most worth upgrade I did.

My upgrade plan of ZMA has 3 sections;

1) Upgrade signal path by changing factory's RCA female jacks, Speaker binding posts and signal wire for maximize efficient flow of signal and minimize distort of signal. If we use car racing system to compare. This section is like making high speed road for racing car. If the road is not good, car cannot run as their highest speed. If the signal path is not superb high resolution and superb transparency, your expensive components cannot shine in term of transparency, speed, sound stage, focus image, transient and dynamics. It really affects all key attributes of sound quality. It is first priority.
2) Upgrade power supply section by changing factory IEC inlet and adding super high quality transient load decoupling capacitor for maximize power. It affects to transient, authority, speed, PRAT, dynamic and bass impact. This section is like fuel for racing car.
3) Upgrade key components, for example capacitors and resistors in signal path. This section is like engine, gears and brakes in racing car.

If you prepare signal path well but your section of 2 and 3 are ordinary, not thing special will be happened. It will have ordinary sound. But if you have section 2 and 3 well, but section 1 is poor then all section 2 and 3 cannot be shined. Or the sound quality is poor because of section 1.  If you have section 1 well, all section 2 and 3 are well too. The section 2 and 3 will be shined as their full potential.

This time, I upgrade resistor in signal path of switching box to be 10K Vishay VAR series 'naked" Foil Resistors. (aka. Texas Components TX2575 or Charcroft Electronics CAR Series). The result is impressive and highly recommended because total cost is not high. It is only USD 51.04 (4 resistors @ cost of USD 12.76 each) I confirm same result as Dgarretson got as below;

08-11-08: Dgarretson
What is remarkable about TX2575 in signal path(replacing Caddock MK132 and Caddock TF020/USF340, which had previously replaced Roederstein and generic carbon comp), is how much more detail & nuance of pitch & timbre TX2575 reveals across the entire spectrum, without sounding in any way thin or sterile. That said, these resistors eliminated bass slurring that some might consider warmth. There is also a blackness behind an airy, resolving yet smooth HF, that I want to believe is an attribute of a quieter resistor.

http://forum.audiogon.com/cgi-bin/fr.pl?htech&1218474065&openfrom&1&...

http://www.diyaudio.com/forums/parts/119229-vishay-audio-resistors.html

http://www.higas.net/audio-hifi/audio-reviews/vishay-var-z-foil-review/

I've heard of those resistors before - I wish they were 1 watt so I could use them in some of my guitar amps that call for 1 watt resistors, that I want to get a little more detail out of.

Hi Stone of tone.

I agree with you. It is a revolution in sound quality, if the alloy metals in signal path of connectors (Male and Female RCA jack, Speaker binding posts of Amp and Spade of speaker wire and binding posts of speaker) are replaced with pure copper or pure silver metals.

If I have to buy new Zen Mystery Amp again, the first thing I do is that I will change female RCA jacks and speaker binding posts to be WBT Next Gen pure silver. The ZMA's sound quality is not just better but it moves to another level of sound quality. Now I am considering to replace my WBT male RCA (old design version which uses alloy metal in signal path) of my MIT Oracle interconnect cable to be WBT -0102 Ag RCA.

Even though I said: "If it ain't broke don't fix it". I am seriously considering this MOD vyokyong. Both the RCA Inputs on my ZMA an the 8ohm Speaker Binding Posts with the Silver Solder, replaced with WBT's best Ag's. I am going to price it out.

Thanks for posting this vyokyong. I will have my guy at Midwest Speaker (most excellent solder slinger) do the MOD. Sometime between now an the end of November I should be able to get it done. If, I decide to do it.

In for a penny ~ in for a pound. Nice tweaks.

By the way, are/were you in the process of doing both the 8ohm an 4ohm Speaker Taps at the time of the picture posted?

Hi Stone of tone,

I did only 4 ohm speaker binding posts because I have no plan to change my Avalon Avatar speakers which is 6 ohms. I feel connect with 4 ohm binding post, sound is better than 8 ohm binding post. And the cost of WBT binding post is expensive. I will change only the one I use now. I am in different situation than you because I do mod by myself. I can do it later if I want. But you have to send out for some one to do for you. And you have many speakers to use then you may need to do both.

I forgot that the holes of current binding posts are too close to each other that two sets of WBT binding posts cannot be installed together. You can see from my posted picture. I have to move location of binding post to both ends to solve the limited space. And I have to use small piece of plastic to insert between binding post of WBT and current one in order to make sure that they are not contacted each other to have short circuit in amp's operation. Then you have to decide to install only one set.

Hi Vyokyong,

I have been following every step of your mod intently as I believe the Tori 11 MK1V will benefit from this mod as well. Wouldn't it?  But if implemented would these modification void future warranty?

Happy listening

Hi Glineus,  

Your total cost of Torii MK IV plus mod cost may be equal to buy Zen Mystery Amp. Then it is a good question to debate that it is worth to mod Torii MK IV or just buy ZMA at the first time, not Torii MK IV.

Then the answer will depend on sound quality of moded Torii MK IV. If its sound quality is better than ZMA (un-mod).  Then it is better to buy Torii and do mod.

I don't hear Torii MK IV before. However I believe that Torii MK IV after mod will have sound quality better than ZMA. Just my believe after I progress mod with ZMA. Now I am listening to Mod ZMA of section 2, power supply unit mod. I will report soon.

Hi Stone of tone,

Here is the picture of before mod of speaker binding posts of ZMA. From left hand, it starts with 3 wires, one green and two black, connected with negative binding post of 4 ohm. (Black post). Next is red binding post (positive) of 4 ohm. It is connected with 2 bluish green wires. The rest are 8 ohm binding posts.

This time, I replace factory signal wire in Zen switching box with Duelund Hook Up wire 2.0, silver foil & silk/oil, Version 2, USD 50.10 per foot and get 50% discount, net USD 25.10 per foot. This is end of first section of signal path upgrade. Please be noted that I use Zen switching box as inputs selector for my ZMA. Because ZMA allow only 1 input. I need at least 3 inputs for my home theater, CD/DAC player and turntable. I still cannot replace internal signal wire in ZMA because the Duelund wire is not enough.

The result is phenomenal, it transforms my hifi system from very very good hifi sound to be like now the musicians are playing in my room! It provides more low level details and ambien sound to be heard. I believe that I feel like musicians are playing in my room when the system can provides these low level details and ambien sound to be heard.  Before these, I still think that my system provides very high resolution already. But that is misunderstood. The low level details and ambien sound is different from high resolution sound. The low level details and ambien sound means that you can hear all low level of loudness of sound, like whisper, clearly. I am surprise that I play CD record and now I can hear all low level details which I have never heard before. Is it same as DSD playing of PW Direct Stream to claim that you will hear what you don't hear before in CD, I don't know. This is the first time, I feel that musicians are playing in my listening room with me.

Remark : The picture is taken  before I finish all wire replacement with Duelund Hook Up wire 2 Version 2. The small white cable is factory wire (The factory provides 1 wire per channel. But in pictures, there is two wires per channel because I move the replaced factory wire to be used in channel of no Duelund hook up wire), the flat silver wire with silk black cover is Duelund Hook Up wire 2, version 2.

All of that looks like some great looking parts!

I'm looking forward to what else you might do.

Next phase is to mod the power supply unit of ZMA. I start with replacing factory IEC inlet with Furutech IEC inlet FI-03 (R) Rhodium plated. It is exactly same size as factory IEC with 5x20 mm fuse holding.

The effect to sound quality;
Plus side : 1) sound stage is more 3D, particularly the depth dimension. It is more expand to front and back stage with layers of instruments. It is not make singer vocal sound forward to your face. It is still same location. But you feel the music band is not flat 2D.
                2) speed, dynamic and bass control is better, not subtle, you feel different. But it is more lean. Some will prefer gold plated with more warm sound.

Minus side:  the magic of all details gone or disappear. The feel of band playing inside the room is gone. It is just like listen to very good hifi. It is very disappoint. Its sound is congest like new amp, not burn in yet.

I hope that it may be that Furutech IEC inlet is new and burn-in will help to smooth the sound congest out.

http://forum.audiogon.com/cgi-bin/fr.pl?ddgtl&1225183019
http://www.drhifi.net.au/Hi-Fi/Furutech%20Power%20Inlet/1.htm

Have you guys thought about getting rid of the IEC and just going straight into the amp. I know some like their special power cables, but it would seem you could take the end off your preferred cable and just run that into the amp. This way bypassing the IEC and saving some money. I am a fan of the least amount of connections. You could always create a plate with a grommet to cover the existing hole, running the cable in. I know IEC are used for easy removal if you are moving your components around but how often do you do that. The only time I do that is if I let someone borrow something.  ;)
I have thought about running wires straight in a few times, especially with RCA cables. I hate RCA connections and their prices. This would make it real hard to move stuff around and try different cables, but once you find which cable you like, bypass the weak link RCA or IEC. It would be harder to live with on RCA cables but easy with power cables.

Quote:


Oh yeah, I've done that for speakers before. From the amp, directly to the driver, no connectors. Most of my (vintage) guitar amps came with two prong cords going directly to the Power Transformer in the chassis. I've replaced them with decent, server grade computer power cables.

If I was building my own gear, I would absolutely be that nutty and just remove all connectors, even from component to component.

Also, IEC connectors came about as a result of UL certifications. Something in the UL guidelines states that a device needs to be able to support itself by the cable in case it falls off a shelf. You don't want the cable breaking and leaving hot wires flailing about. So the IEC connector was the work around to this. Just a little bit of history.  :)

"Also, IEC connectors came about as a result of UL certifications. Something in the UL guidelines states that a device needs to be able to support itself by the cable in case it falls off a shelf. You don't want the cable breaking and leaving hot wires flailing about. So the IEC connector was the work around to this. Just a little bit of history.  :)"

I did not know that. Thanks for the history lesson.

The bottom view of Furutech IEC inlet FI-03 (R) Rhodium plated. The Furutech IEC inlet is at right hand in picture.

Thanks Lon and Will. I have solved the sound congest problem. I remembered that I uninstall two fuses from fuse holder when I disassemble factory  IEC inlet. I though that I may install two fuses back in Furutech IEC inlet by switching locations of fuses. The fuse in reserved box may be installed in operate fuse location while fuse in operate fuse location was installed in reserved fuse box. Then I switched two fuses location in Furutech IEC inlet and played music again. Yes, the sound sonic improve. It is more smooth, fast, dynamic and no more sound congest. But the magic of sound details is still not here. This means that fuse is needed to be burn in. The problem is caused by new fuse was switched to use instead of old fuse which is already played for 6 months. Every new Hi-Fi players, the sound is congest of first 100 hour playing. It may be caused by new fuse, not burned in yet.

I tried again to reverse poles of fuse. Yes, the magic of sound details come back now. But it is a little less than before changing IEC inlet. This means that fuse after burn in has direction of poles. If you reverse fuse pole direction, sound will change.

At this stage, I am happy with Furitech IEC inlet FI-3 (R) Rhodium plated. Unit price at USD 27, very little investment. It improves sound stage more 3D, depth expand to back and front, can feel layers of instruments. Image is more focus. Sound is faster, more dynamic and much better bass control. It is more dark background. But the sound is thinner, more lean, less warm.

Next step after finish install of Furutech IEC inlet is to bypassed Electrolytic caps with film caps!

There are many debates about is it effective to bypassed Electrolytic caps with film caps?

http://www.diyaudio.com/forums/power-supplies/126697-bypassing-psu-capacitors-ef...

http://www.head-fi.org/t/216167/why-are-electrolytic-caps-bypassed-with-film-cap...

I would like to try by using 10 uF/630 Volt Obligatto, Premium Gold capacitor to be parallel connected with current 47uF/ 500 Volts F&T electrolytic caps to see the result effects to sound quality? The caps price is USD 27.  You have to order in matched pair. I pay USD 1 fee per one matched pair.

I believe that electrolytic caps has slow charge and recharge rate (high ESR value) which cannot cope with high frequency range. The film caps has very low ESR value or very fast charge and recharge rate. Then film caps is used to bypassed electrolytic caps helps eliminate high ESR value of electrolytic caps. Even though ZMA has huge 4,400 uF per channel, but it is electrolytic caps. The bigger it is, the slow recharge rate or high ESR value it is.

This is from Jensen catalog of their caps:
The importance of attenuation and high
frequency behaviour.
No matter how fast the amplifiers signal
processing circuits are, you cannot utilize
that speed if your power supply is too slow
to follow rapid signal changes.
The power supply's reservoir capacitor
constitutes a vital element in the amplifier
chain, effecting the signals on the main
signal paths as well, because most power
amplifiers reservoir is conceptually placed
in series with the loudspeaker line.

The main issue is not only that the capacitor can give you enough charge and quickly enough, but the attenuation of the power supply toward the amplifier. In spite of the fact that the audio band is nominally 20 Hz -20 kHz, the stability of the amplifier and the overall sound quality is strongly influenced by reservoir capacitor behaviour at very high frequencies.
The function of the reservoir capacitor is not only to store energy, but also filtering, providing decoupling between the power supply and the amplifiers signal processing circuits. For energy storage a conventionally constructed aluminium electrolytic capacitor with sufficient Capacitance (F) x Voltage (V)/ Volume (cm3) ratio and satisfactory low ESR and inductivity at higher frequencies would be suitable. However the capacitors filtering characteristic plays a very important role in decoupling and suppressing unwanted transients and  i.e. digital high frequency noises.
Extremely low inductance makes excellent high frequency capabilities.
The high inductance value of a capacitor is particularly harmful when they are used for filtering at higher frequencies, as the impedance of a high capacitance capacitor over the resonance frequency - which is typically a few tens of kHz - is strongly dominated of the inductance of the capacitor winding.

I'm continuing to follow too vyokyong. Thanks for your clarification in reply #19.

LR, in regards to your reply #29... . I can remember discussing years ago with some about why do premium cables matter when after all, they hit the binding posts of the Speakers an run up different wire to the Xover(s) an then to the Driver's. But, as we know, their is a difference to Speakers an Components....or I would not be putting at least 300 hours on my new Kimber Select 1030 IC RCA downstairs between my Rotel an XPA2. Then it comes back upstairs in the Listening Room for a Listen... . But, it would be cool to hear it all wired direct for fun!

Quite frankly, I do get (by comparison to my lesser cables), all the detail, transparency/musicality I'm accustomed to (when I went without a Pre for 12 years)...with the CSP3w/Jupiter Caps because of my Cabling.

Listening Room:
Room Treatments from Michael Green & Home brew
Sony as Transport
Illuminati D-60 (.5 meter)
Chord Chordette QuteHD DAC
Kimber Select KS1030 IC RCA (.75 meter)
Decware CSP3 w/Jupiter Caps
Kimber Select KS1030 IC RCA (.5 meter)
Decware Zen Mystery Amplifier
Kimber Select KS3035 Speaker Cable
Vintage Polk SDA1 Speakers (in Stereo)
XLO Pro Power Cords to CSP3 & ZMA
All four units plugged into Adcom AC-Enhancer 515

Hi Lonely Raven,

Here is picture of circuit of my ZMA. My ZMA's caps in signal path are V-Caps TFTF  (Fluoropolymer Film & Tin Foil) Series Capacitors. Because at that time, the 600V CRYO TREATED FLAT STACKED COPPER FOIL BEES WAX - SIGNAL CAPACITORS was out of stock. I requested Steve to use V-caps instead and I was willing to pay extra cost. He was very kind to installed V-caps TFTF series for me with no extra cost. My ZMA may be only one ZMA with V-caps TFTF in market!

The sound improvement from Obbligato caps by passing electrolytic caps in PSU (power supply unit) of ZMA is ;

1) Upper Mid to high frequency is noticeably much better! It is not subtle. The surprise is note decay. The long note decay is something, every one looking for.  

Attack and decay

Attack is the extent to which the note is hit. Rhythm is communicated through attack. Once hit, how long is the note allowed to sound? Decay is the time within the full duration of the note that the sound is made.

ZMA is already excellent in note attack. But for note decay, I still want more, particularly high frequency notes of cymbals. I feel that the Obbligato caps by passing caps makes note decay double longer than before mode. It is very enjoy, my face has a big smile!

2) It is about control, control, control! in all full frequency spectrum, not just bass. It is very excellent control in timing and rhythm. You feel rhythm is perfect timing, not too early and not too delay. Previously, I feel original ZMA play music like little hurry! It makes you exciting but feel little exhaust. After bypassing caps mod, it is perfect timing. The rhythm is very beautiful of both slow and fast songs. quiet moment and loud moment.    

3) Much more full body and weight.  After I change factory IEC inlet to be Furutech IEC inlet Rhodium plated, the magic details of sound come back. But the sound is thinner (-30%). After adding by passing caps, the sound is full and weighty or rich. It is more full and rich than before IEC inlet changing. It transforms your Hi Fi system to be like singer and music band are playing in your room. It is very natural, liquid smooth and involving. I like to use word "Having music band playing in your room". You feel like you listen to live concert, not Hi Fi system. Because it makes totally different experience from listening to very excellent and expensive Hi Fi system, It is very enjoy but you still know that you listen to Hi Fi system.  

I must say that Bypassing Electrolytic caps with Film caps is a must to do, not just highly recommend. And it is not expensive or high investment.

Next, I will change factory Fuse to be Synergistic Research Quantum Fuse. (Blue).

Please be noted that any mod must be done with your own risk. Please study well before doing mod or hire professional electrician to do for you.

One observation is that warm up time is longer. Before mod, warm up time is one hour. But after mod, warm up time is two hours. I think that new Obbligato caps may need more time for warm up. I hope that after more burn in, its warm up time will be shorter.

I have to say sorry to report that Synergistic Reseach Quantum fuse is not worth to spend. I make a wrong report.

The problem is that I test SR fuse when ZMA is not warmed well enough. As my observation is that mod ZMA has longer warm up time. But I use my usual warm up and test SR fuse. The sound congest comes from Amp did not warm up well.

This time, I warm up ZMA more than 2 hours to make sure that it warms up well. The SR fuse provides both extended sound in high and low frequency, particularly in high. It is very sparkling. Sound is more refined and more transparency that make more precise focus image. But it trades off of warm sound (little less warm, little more lean). However I love it.

Conclude : worth to buy SR fuse.

Hi,

My conclusion of modification of PSU section (changing IEC inlet, add film caps by passing electrolytic caps and Audiophile fuse, Synergistic Research Quantum fuse), the sound improvement is;

1) Improvement in 3D sound stage, better image depth, image focus, feel space surround music instruments.
2) Improvement in pace, speed and rhythm control. The timing is precise in all frequency. But the bass is more easy to be captured that bass is better controlled, no bloated boom bass.
3) Improvement in mid to high frequency. The high frequency is more sparkling. The notes decay is longer.
4) Improvement is scale. Sound is fuller, bigger and more dense.

The above improvement is compared to before mod as bench mark and after mod is better. Remark : My listening room does not have any room treatment.

I feel that it may be boring to always report again and again that "Oh, the sound is more transparency after changing this. And after changing those, the transparency is more again, etc" Is there any changing that it is disappointment. Until now I will say "No". I ask myself that what is the ceiling of transparency, 3D image, dynamic, etc. Because every time, new mod improves sound better. It should be at certain point that any mod cannot improve it further. But until now I don't reach its ceiling yet.

I did mod again by double Duelund hook up 2 wires (two wires in one signal path) in Zen switching box. Because I observe that all top signature IC cable of top line (Cost is no object) is just double the quantity of wires in second top line. Then I think that what happened to sound improvement, if the Duelund hook up 2 wire is used 2 cables instead of 1 cable per signal path.

EUREKA! EUREKA! EUREKA!

It is a huge step improvement. I would like to compare by using LCD TV definition as following.

Before mod, ZMA is very excellent Standard definition TV.
After mod of 1 cable Duelund hook up 2 wire, pure copper and pure gold signal path connectors, Fuurutech IEC inlet, Obbligato caps, SR fuse, mod ZMA transforms to High Definition TV. (HDTV).
But if you add more 1 cable Duelund hook up 2 wire (2 cables per signal path), the mod ZMA becomes 4K Ultra High Definition TV (4K UHDTV).

I think this is my best definition of what sound improvement you get when mod by double wires or cables in signal path. (4 cables are used per channel, 2 cables for positive signal per channel and 2 cables for negative signal per channel)

It is worth every penny to spend double cables of Duelung hook up 2 wire which is very expensive cable. But the result is huge improvement to next level of itself, not just better.

Remark : I just did double Duelund hook up 2 wires in Zen Switching Box, not inside ZMA yet because the wire length is not enough.

I already ordered more of 32 feet of Duelund hook up 2 wire .
Total cost is USD 803, The wire price is USD 50.20 per feet, 50%discount, net price after discount is USD 25.10 per feet.
I plan to connect Zen switching box with ZMA by hard wire, no connectors. (You can save USD 796 from USD 388 WBT Ag 0210 RCA female jack and USD USD 408 from WBT 0110 Ag RCA male plug, if there is no discount. But you trade off of convenient of IC cable changing and convenient transport of Amp and ZSB.) I need 8 cables of 4 feet Duelund hook up 2 wire. I am very curious to the result when ZMA's internal signal cables are changed to double cables of Duelund hook up 2 wires. I will report soon when I got the cables and do changing.