[zachawry]

  That is my intention: to offer different upgrades at different price points that require different levels of skill.
 
I was also considering offering upgrade "kits" to Head-Fiers.
 
Where as the individual would have to order from a dozen different sources and pay retail + shipping, I could let's say order enough parts to make 10 mZ2 DIY upgrade kits, and save all of your shipping excessive shipping and hassles. I could even have stuff like the B-Quiet chassis dampening sheets pre-cut to fit the mZ2.
 
After reading these upgrades, let me know...if enough of you want DIY upgrade kits I'll be happy to put them together for you

I think you need four options: 
 
1. Skilled       Cheap 
2. Unskilled   Cheap
3. Skilled       Expensive 
4. Unskilled   Expensive
 
I'm willing to spend money on my upgrade, but I have no particular skills in this area and I don't want to endanger the piece of technology that provides me with the most joy I get in the world outside of my children. 

 

[claud W]

I agree. I got no skills in modding electronics and no tools

 

[MojoAudio]

Stripping down your mZ2, part 2:
 
Removing unused wire harnesses.
 
I've stripped down my mZ2 to get better access to the places I need to solder and un-solder.
 
Note how I put all the hardware and spacers back on each connector as I removed them so they won't get lost.
 
Note how I completely removed the binding posts: I have no use for a flea powered amp.
 
What I may do in the future is add more preamp outputs in the holes where the binding posts were removed.
 
These parallel preamp outs could be used for a sub-out or for a tri-amped system.
 
Another thing I'll likely do in the future is replace the 1/4" jack with a 4-pin XLR for balanced headphones.
 
No need to use an adapter + better performance.
 
That won't make the mZ2 balanced, but it would eliminate the need for an adapter with your mZ2 for those of you with balanced amps.
 
Mark was smart to use the specific 1/4" jack he used: the hole is IDENTICAL to standard XLR connectors: all you need to do is un-screw/un-solder then re-solder/re-screw.
 
Below is a photo of my mZ2 ready to have un-used solder joints un-soldered and less complex connections re-soldered.
 

 

[MojoAudio]

Stripping down your mZ2, part 3:
 
Re-manufacturing the in/out harnesses you're keeping.
 
Below are image of the wiring harnesses I made using the stock parts from a mZ2.
 
With little more time you could upgrade your RCA jacks, hook up wire, and attenuator, as you are making your minimized wire harnesses.
 
You could also add more preamp outputs, add more preamp inputs, and/or change the 1/4" jack to a 4-pin XLR.
 
So I'm not going to show you the "how to" with the upgraded parts I'm getting in next week. Likely I'll post a photo or three, but the process and technology I've outlined will work with any connectors, any wire, any attenuator, or for that matter, almost any component in your system.
 
You could even use the empty holes from where the binding posts were removed to reconfigure your mZ2 for up to three inputs and two outputs. Mike Percy has some very high quality silver contact toggle switches in a double throw triple pull that would allow you to do that.
 
Just follow the same rules for any ins and outs:
 
1. Less is more.
2. Isolate every in, out, and power wire.
3. Use twisted pairs of wires to cancel out common mode noise.
4. Keep as much space in between all wires and parts.
5. Make sure wires are away from parts that get hot (tubes).
 

 
 
Above is the inside of the 1/4" headphone jack with all the additional outputs removed. Note that both black/ground wires go to the same pin. If you were to replace this connector with a 4-pin XLR for balanced headphones each ground wire would have its own pin.
 
You'll note how the binding posts had a common ground but the wires coming form the main board have dedicated grounds for each channel. This is actually perfect if you wanted to replace the 1/4" jack with a 4-pin XLR.
 
 

 
Above is the stripped down input wiring harness along with the attenuator and no input selector switch. Note that I took one of the unused wires form the 2nd input for the 2nd channel's twisted pair. Note how I soldered that added ground wire to the ground tab on the RCA. Since both RCAs are grounded through the chassis, this one grounding tab should work just fine. The big advantage of adding the second ground wire was to lower noise floor with a classic common mode noise cancelling twisted pair (plus lower ground resistance).
 

 
This is a close up of the second ground wire at the RCA end. Note the second ground wire is red.
 

 
 
This is a close up of the stripped down attenuator on the end of the input wire harness. Note how on the R side it says "L in" and how that far right red wire is the 2nd ground I added.
 
Note those pins at the output of the attenuator. They connect to females on the main board. They are SO bad I can't believe it. I could barely put the pins on the output wires from the attenuator back into the females. They were VERY lose. My recommendation will be to remove those pins/females and hard wire solder the wires exiting the attenuator directly to the main board.
 
Of course this will make it a real PIA to reassemble and I wouldn't recommend doing it until one of the last steps in your mZ2 upgrade.
 

 
Above is a photo of the stripped down DC power input. Not only did I remove the on/off switch (the ZOTL LPS has a power switch), but I removed all that wire that ran parallel to the sensitive input signal wires.
 
Just like with the input from the attenuator, I recommend hard wiring the DC input as well. And also like the attenuator input, hard wiring inputs and outputs should be among the last things you do.
 
In my last re-assembly I'll be removing the DC input jack and replacing it with a strain relief that will allow the DC power cable to be hard wired to the main board plus eliminating two low quality DC power connectors.
 

 
Above is a photo of the L side with fully stripped down inputs and wiring. Note that the L and R twisted pair are kept separated. Note that I put the R connector on the R and the L connector on the L as opposed to the high/low stock configuration. Note how the twisted pairs are away from everything.
 

 
Above is a photo of the stripped down output wire harness reinstalled. Note how the twisted pairs are both positioned away from each other and away form the hot output tube. This is one more connector that I recommend hard wiring at the final assembly of your mZ2 upgrade.
 
 

 
And finally the photo above has all the connectors, wires, switches, and face plate that were stripped off this mZ2.

 

[jamato8]

I think you are voiding the warranty. Not sure though. 

 

[MojoAudio]

Stripping down your mZ2, Conclusion:
 
So that is the "no cost" upgrade.
 
I'll be dropping this mZ2 off at Dr. Blue's early next week for him to compare to his stock mZ2.
 
My guess is if you have a decent source and a ZOTL LPS you'll hear a notable improvement from stripping down your mZ2 and applying some of those simple rules to minimize cross-talk and noise.
 
After Dr. Blue is done comparing this modded mZ2 to his stock mZ2 I'll be upgrade some of the parts and have him compare how much of the performance came from the circuit and how much from the parts. I'll also do the anti-resonance upgrades at the same time.
 
Since these "strip down" upgrades deal with wire and connectors I consider them to only require a modest level of skills. If you screw up a wire harness all you have to replace would be a connector and/or the wire. Much upside and little downside.
 
Upgrades that involve removing/replacing parts from the main board I would not recommend for the novice. If you screw up you may be buying a whole new mZ2

 
An interesting phenomenon of lowering your noise floor that most people don't realize is that if you lower your noise floor by 3db you have in fact increased you dynamic range by that same 3db.
I'm looking forward to reading some of your feedback as to who heard what improvements with this simple no-cost upgrade

 
 
 

 

 

[MojoAudio]

  I think you are voiding the warranty. Not sure though. 

I know for a fact this would void your warranty from LTA.
 
As far as I know, any upgrades to any components voids the manufacturer's warrant.

 

[drbluenewmexico]

 
I know for a fact this would void your warranty from LTA.
 
As far as I know, any upgrades to any components voids the manufacturer's warrant.

as Yoda mumbles, "Don't Avoid the Void and Praise the Droid"
gotta get our Mojo on.......but I'm quite aware of the tendency for "placebo" upgrades to
be praised by biased observers (naive or experienced ones).
in the original psychophysics research of the 19th century there was a term:
VEXERVERSUKEN, in German, which was the "ghost stimulus" that subjects hallucinated
HALF THE TIME, in a ganzfield, or moving light field in a dark box. i.e.. our brains want to
to find meaning and stories in random changes in stimulation to make us feel the world is predictable
and makes sense. we have to guard against hearing what we want to hear.

 

[MojoAudio]

 
as Yoda mumbles, "Don't Avoid the Void and Praise the Droid"
gotta get our Mojo on.......but I'm quite aware of the tendency for "placebo" upgrades to
be praised by biased observers (naive or experienced ones).
in the original psychophysics research of the 19th century there was a term:
VEXERVERSUKEN, in German, which was the "ghost stimulus" that subjects hallucinated
HALF THE TIME, in a ganzfield, or moving light field in a dark box. i.e.. our brains want to
to find meaning and stories in random changes in stimulation to make us feel the world is predictable
and makes sense. we have to guard against hearing what we want to hear.

 
Spoken like a true lab rat

 
You do get the idea that everyone is counting on you to determine which of these upgrades are worth the $$$ and which are not, right?

 

[willsw]

I'll step in for a moment and mention that the Loctite applied to the screws holding the power switch and headphone jack can sometimes prove very difficult to conquer, though it is breakable Loctite. So, be careful. 

 

[jamato8]

 
I know for a fact this would void your warranty from LTA.
 
As far as I know, any upgrades to any components voids the manufacturer's warrant.

Yes, I was joking. 
 
I have pulled the wires apart, something I always do on the equipment I build but I have never touched the MZ2. There is an increase in transparency. 
 
Also for my own equipment, I rarely have switches etc. My preamp has one for 2 different input but the unit I use is one I took apart and redid in hyper pure dead soft silver for the internals. I even have the IC's soldered directly to output, no RCA's. I have never liked all that brass in the signal path to begin with. Also I use a Goldpoint in most everything and my own special wire. For resistors I like the old tantalum 2 watt but the Japanese made ones are hard to find and my stock of them is limited in values. 

 

[MojoAudio]

  I'll step in for a moment and mention that the Loctite applied to the screws holding the power switch and headphone jack can sometimes prove very difficult to conquer, though it is breakable Loctite. So, be careful. 

 
Hey Will.
 
Interesting on the Locktite.
 
Do you know if ACETONE (nail polish remover) is the best solvent for the type of Locktite you guys use?
 
Obviously by the screen printing on the inside face of the chassis that my personal mZ2 is one of the earlier ones (duplicates screen printing as on face plate). I've heard that you guys have gone through a few subtle changes with the mZ2 chassis, switches, packing, etc, since the earliest prototypes.
 
Apparently my mZ2 didn't have any Locktite on the power switch or headphone jack, so it was fairly easy to remove.
 
BTW, it is the power switch and headphone jack that hold the mZ2s face plate onto the main chassis. Even if some of you decide to remove the on/off switch as I did, but decide to keep the face plate, you may want to keep the power switch itself in it's hole if for no other reason, to hold the face plate on (no wires inside).
 
I did a theoretical test with my mZ2 and removed the face plate to lower the chassis mass. As many of you may have heard, there are contradictory opinions as to if less mass or more mass improves performance. IMO it depends on the component's resonance frequency and sensitivities, so I don't know if an mZ2 will sound better or worse with or without its face plate.
 
My plan is to do the anti-resonance stuff I described in an earlier post to my mZ2 chassis before I do the last of my upgrades and final reassembly. As one of my final tests I'll be comparing my mZ2's performance with and without it's face plate.
 
Point being, there are several theories and opinions on what is better for anti-resonance and I plan on testing some of these theories first hand as opposed to simply intellectually accepting their validity or assuming something I did in the past will automatically apply to the mZ2.
 
Now that I've redone my wire harnesses in my mZ2 for all inside mounting, adding/removing the face plate and listening as to if it improves or degrades the sound will take relatively little time.
 
Similar to how the optimal anti-resonance mods may be different from person to person, the same connectors won't sound best on everyone's mZ2.
 
I always recommend that people match the metallurgy and/or brand of the connectors on their cables and in their chassis. Personally I use Furutech's best rhodium plated silver over copper. My guess is that most of you have gold plating on your interconnects connectors. I would certainly recommend staying with a similar gold plated metallurgy, but ideally I recommend that you attempt to use the specific mating connector from the specific brand used on your interconnects.

 

[MojoAudio]

 
Yes, I was joking. 
 
I have pulled the wires apart, something I always do on the equipment I build but I have never touched the MZ2. There is an increase in transparency. 
 
Also for my own equipment, I rarely have switches etc. My preamp has one for 2 different input but the unit I use is one I took apart and redid in hyper pure dead soft silver for the internals. I even have the IC's soldered directly to output, no RCA's. I have never liked all that brass in the signal path to begin with. Also I use a Goldpoint in most everything and my own special wire. For resistors I like the old tantalum 2 watt but the Japanese made ones are hard to find and my stock of them is limited in values.

 
I'm a big fan of the better Caddock and Vishay resistors, but they are INSANELY expensive...$6-$13 each

 
I find the Caddock to have a subtle more organic sounding character and the Vishay to have a subtle more transparent sounding character.
 
I've had a few conversations over a beer with Mark at RMAF'15 about upgrading the resistors in LTA products - he confirmed that David used the better Caddock resistors in his $70K amps.
 
Mark also confirmed there were few resistors in the signal path, so even if you upgraded your mZ2 with insanely expensive resistors, it won't break your bank account

 

 

[jamato8]

   
I'm a big fan of the better Caddock and Vishay resistors, but they are INSANELY expensive...$6-$13 each

 
I find the Caddock to have a subtle more organic sounding character and the Vishay to have a subtle more transparent sounding character.
 
I've had a few conversations over a beer with Mark at RMAF'15 about upgrading the resistors in LTA products - he confirmed that David used the better Caddock resistors in his $70K amps.
 
Mark also confirmed there were few resistors in the signal path, so even if you upgraded your mZ2 with insanely expensive resistors, it won't break your bank account

 

That is true, when few in the signal path, it is worth it to go all out. Though the other resistors can add or decrease noise those in the signal path as you mention, are at the top of the heap in specs. I have always like the Dale for many board uses. Really inexpensive but for many applications, it does an excellent job. 

 

[MojoAudio]

 
That is true, when few in the signal path, it is worth it to go all out. Though the other resistors can add or decrease noise those in the signal path as you mention, are at the top of the heap in specs. I have always like the Dale for many board uses. Really inexpensive but for many applications, it does an excellent job. 

 
You can't go wrong with Dale resistors - one of the best values.
 
My question would be, if you could hear and how much you would hear a performance increase over what LTA is using?
 
The resistors LTA is using are already a good quality metal film resistor to begin with.
 
Possibly one of the mZ2 threaders that does some of these upgrades can answer that question for us?
 
I feel the same way about the connectors used on the stock mZ2 - they are of such high quality to begin with I would think you would need to spend quite a bit to get a performance upgrade.
 
On the other hand, the wire used in the mZ2 appears to be a high-temp tin plated copper. My guess this was selected for optimal durability as opposed to optimal performance. 
 
Some good sources for upgrade parts...
 
For a modest priced resistor I would consider the Holco "whole copper" (about $0.45 to $1.85 each depending on value).
 
I mentioned how Mike Percy and VH Audio sell the same plus specialty products?
 
Mike Percy is the guy for the exotic resistors.
 
http://percyaudio.com/
 
You could get both Dale and Caddock resistors from a mainstream electronics parts supplier like Mouser.
 
http://www.mouser.com/
 
But you can get Holco, Vishay, Yamato, and several other more exotic brand/type resistors from Mike Percy.
 
On the other hand, VH Audio is my #1 exotic wire source. You can buy much of what Chris sells from other vendors, but Chris specializes in some of the best PROPRIETARY high-end bulk wire for just about every end use.
 
http://www.vhaudio.com/
 
Once of the cool things I'm liking about upgrading my mZ2 and Stax T1 headphone amps is that I can hear EVERYTHING that I do.
 
A perfect way for the more advanced DIYer to compare this and that similar part to learn which they find to be best and which they find to be best value