Although not a difficult job, this rebuild can be rather fiddly and there are a number of things to watch out for, especially for noobies and these tips are mostly for them. If it seems daunting, please get some more skilled help, as I cannot be held responsible for Zero's going phut! This is your own choice to take this task on board.
While a number of Head-Fi readers have already modded their Zeros to varying degrees, I am going to focus specifically on the FrankenZero, though these tips can apply to any circuit board mods or creations from scratch. There will be a few photos along the way to add to my meaning, something I've always appreciated when building kits.
Firstly, some essential tools:
A nice fine tipped soldering iron, no more than 25W is needed here. I also used a very fine tipped battery powered iron, which came in very handy at times.
Solder wick - preferably the fine stuff, 1.5mm is plenty, you'll use a bit of it and it's particularly useful reaching under raised parts on the top of the board.
Solder sucker, de-soldering pump, whatever name is appropriate for your country of origin.
An old toothbrush and some Isopropyl alcohol to clean the newly soldered areas underneath the board when you're done.
An old white towel. Once you've taken your main board (and amp) from the case, lay it on the towel, it stops things moving around and it's a heck of a lot easier to see any parts that you are about to put onto the board and any that you may drop.
Other tools you'll need are some tweezers (I've used a terrific pair of medical ones for many years) or fine long nosed pliers, small wire cutters for trimming legs after soldering.
I also found a small 1mm drill bit was necessary in a couple of places to clear holes that were rather tight. You may be able to get away without this, but I found it invaluable, particularly for parts with thicker legs like the diodes and the larger power caps.
I used a battery powered hobby drill for this job, like a Dremel or similar.
A brief warning here: be very careful that you don't over do it and wreck a soldering pad that is part of a copper track!!
The copper tracks in the Zero are rather thin! While I have a warning here, please don't use too much heat on the solder pads to remove a part, you might end up lifting the copper and worse, cracking or tearing a pad away from the track! It happens, I did it with a pad that fortunately wasn't attached to a track and there are a few like that.
You ought to be ok with it, just be aware though.
Righto, let's get into it.
The board itself is pretty easy to remove, don't get too boisterous prising out the two sets of power connectors though, I noticed one of mine by the 5V regs was already cracked on assembly.
A tip here, especially for taller folks like me, find a platform to raise the work area to near chest height, it saves greatly of the back and shoulders! The lay your old towel over the platform. Take your HDAM or op-amps out of the socket and put it away somewhere, then I tend to start with the tall components and get them off the board first, it lays flatter after that. Remove the 4 power supply caps; put the tip of your iron on the solder pad and apply heat enough to melt the solder, then using the solder sucker (I'm used to that expression) place it right over the tip of the iron and suck up the solder. Eject the solder from the pump and push the plunger down again ready for the next pad.
You'll get the hang of it after several goes. Once you've done, say, one capacitor (two pads) use the solder wick to suck up the remaining solder; lay the end of the wick on the pad around the part's leg and apply the side of the iron's tip on top of the wick, you'll literally see the solder disappearing from the pad once it's done correctly. Please don't hold the iron there too long! If the solder is not sucking into the wick, just change the position of the iron's tip to give it a bit more heat, it's easier to do than describe. Once you've got it, you've got it.
You will need to use the wick on the pad at the top of the board under the component as well, in many cases. Please be patient here, this is the most time consuming and trickiest part of the whole job, I reckon.
Once the caps are done, then do all of the diodes, as specified in PP's instructions. Do all at once is easiest. Do this for all the remaining parts. Use the solder wick to clean up all of the solder pads, carefully. I specify 1-1.5mm wick because it uses a lot less heat to desolder than wider wick. If you have a hole with solder in the middle of it, sometimes it can be sucked out with the wick, or, if you can stand the board on it's edge, heat the pad on one side of the board and use the vacuum of the solder sucker/pump on the other side to remove the solder. If that fails, that's where the tiny drill bit can come in handy as a last resort. I needed to a couple of times.
Ok, then you are ready for the next stage, once all components that need to be are removed.
It's good practice to always start with the lowest/smallest parts on the board and this applies to starting from a new board as well. Start with the diodes then, pre-bending them and lay them out on the towel. You can use one the old diodes that you've removed as a pattern if you like. Bend them gently with the long nosed plier or tweezers. See pic below. I wanted the pics with the associated paragraph, but it may not turn out that way.
Start in one area with a small group of diodes, say, the ones around the digital power supply (PS) on the corner of the board near the transformer. Be very watchful that you replace the diodes exactly as is marked on the board, the cathode end of the diode is marked with a white bar, as is also marked on the board,
see pic below. If you don't, you will be sending smoke signals that you got it wrong on firing up again! The silk screening on the Zero's board is correct, follow it and you will be fine.
Same goes for the capacitors, the barred side of the silk screened circle under the caps is the NEGATIVE side of the polarised capacitor, which is also clearly marked on the cap body itself - the white stripe with the - - on it is NEGATIVE.
Something to watch for: some of the capacitors are raised above the circuit board, there's an extremely good reason for this, you have to solder those legs on the top of the board as well! It becomes obvious when you look closely at the board, but if you miss one you may have a problem later. There are a few of the caps that are soldered to tracks on the top of the board and underneath to a pad only that is not connected to a track. IF you lift one of these pads that are connected to no copper track, just don't worry about it at all, just solder the top pad and you're done.
A soldering tip. When soldering, you apply the iron FIRST to the pad and component leg TOGETHER. If you heat the pad and not the leg, the solder won't stick to the component leg very well and a dry joint could well be a problem later. This is especially essential when using silver solder if you choose to use it. Once the leg and pad are heated (gently) apply the solder so that it flows around the leg and pad, then remove the iron. I always let the legs cool before snipping the extra length off, usually soldering several components first then cut all the legs later, this lets the join solidify. I've had joins fracture when cutting them too soon. There's a picture here of a group of diodes I've soldered, note also that the solder is shiny and bright, unlike many of the joins that came with my unit.
A dull join is a bad join, more often than not!
Now we're getting somewhere, if all that has gone well, then comes the addition of the Russian Beauties! This can get tricky from the point of view of placing the green caps around the board so that they all fit in without shorting other components. I find the neatest way is the best way (pics below). Straighten the legs first and heat shrink the protective tubing onto them, then bend the legs into the required shapes, the pics below and those that PP has given you with the kit instructions are a good guide. Once you've done a few, it's pretty straight (um ... bent ..) forward. You'll need to shape them so that the capacitor body lies very close to the board to fit between the board and the case when reassembling. Do your best to get this right first up, as relying on squishing the caps flatter when you put the board back can easily strain a solder join!
On firing my board up for the first time, I had no power to the front panel or the digital stages, yet had power to the analogue stages and amp. The problem turned out to be a cracked copper track where I had soldered a Russian Beauty to one of the power supply caps in the digital stage. This is very thin copper and it's not hard to crack a track when bending a PIO cap a little flatter! All became well when I made a new little bit of track with a leg cut-off and Frankie fired up to my great delight!
I will reiterate that neatness assembling the line-up of PIOs makes things easier! Be careful with the four around the DAC, I have included a pic here, though I believe PP has more with the instructions in the kit.
The amp mods are pretty straight forward after the main board!
Lastly, there is the big 1uF PIO for the HDAM, if you have one (For God's sake, why NOT?
) Pic below. I found it fit quite well as shown in the photograph, I don't like adding extra leg, so to speak, if I can help it. Well, not in this context, anyway.
My HDAM sits quite nicely in there with the cap just resting on one of the relays.
CHECK ALL SOLDER JOINTS for clean and shiny solder and that there are no tiny cracks in the copper tracks around them! Better now than later. Use a magnifier if you have to. Many techs do.
Once the boards have all the parts soldered in, use the toothbrush dipped in a little Isopropyl alcohol to scrub up your joins - not too forcefully - and remove excess flux, either on your own joins, and/or the original soldering on the board if it needs it.
Well, that's about it for the moment, if there's anything I've forgotten, I will add it in later or someone will remind me about something. I welcome any other questions you might have and I will answer as best I can, or PP too.
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Now for the very best part! If all has gone well and Frankie has fired up ok and you have music streaming from the DAC, you have many many hours of delights that await you.
My God, do you ever! The effort is worth it, persevere if you have an issue here or there, there are a number of us who can help out.
In fact, the joys of Frankie are so great that I feel a little emotional even starting to talk about it now. Forget how the old Zero used to sound, it's gone now. Even from cold and new, things are quite different, if a little cool and edgy for the first couple of hours. You ought to notice that everything is bigger and this will increase as time goes by. I'm not going to go too may details here, Penchum has a no doubt magnificent write up and review coming that will describe in his inimitable way pretty much what I and PP have experienced. It will stun you, knock your socks off, take you into a realm where the meaning of budget audio is completely blasted into whole new dimensions of musical expression. You may find yourself not even considering price any more, as it has become rather meaningless in light of how Frankie transforms over time into something vastly beyond such considerations. It takes time. The PIO caps take a long time to form, some 250 hours plus. My Frankie is only at the 100 hour mark and has gone through several stages of quite gobsmacking shifts in all areas of musical expression. So have I, for that matter!
Ah me, sometimes I have been completely lost for words, (though when I could find them, PP's had a few!). True musical expression comes from and moves to the heart and this is where Frankie excels magnificently, stunningly, gently, stupendously, exquisitely. Beautifully. I am utterly spellbound, even at this very moment, by an effortless flow of musical art flowing into my being that transcends the very electronics themselves, a gestalt of beauty.
Albums I could barely listen too previously have become gems, old favourites are shifted into new realms of musical communication and expression, all instruments and human voices gain a level of reality and solidity that I have rarely heard from megabuck gear, let alone anything remotely considered quality budget kit. We're talking quantum leaps here in ways that are very difficult to describe, though I'm pretty sure Pench will take you much closer to that understanding. Best of all, experience it for yourself!
Here's something I didn't expect, Frankie's amp has turned into quite something else!
True, it is still no KHA (speaking personally, of course), but this amp is an absolute hoot of a ride with my Denon D1000's!! Man, did I have a ball with the B52s this evening!
I had originally found the amp somewhat lacking in pizzazz, chutzpah and general interest, likable enough at times, but not really my cuppa Joe. Well, that's out the window now, she's come to life and kicks butt, even if the highs are still not that extended or the lowest bass for that matter (the Meier 2Move cleans it up for neutrality and extension both ends of the spectrum, as I found out this evening with Frankie's DAC connected). It's a blast and good news for Denon owners who choose Frankie as a new life.
PS Gear used by myself for these musings are, FrankenZero (Frankie) with OPA Earth HDAM in the DAC; KHA (my kit amp) as Mk I.5 with with OPA Moon onboard, amp is upgraded with Nichicon Muse FG and FA caps and Elna Silmic II caps in power supply and on the main board and Russian PIO caps in the output stages. Headphones are Senn HD 650 and Denon D1000's.
Adding the higher SQ cps to KHA has taken it to new heights of musical expression as well and is still burning in, with the same number of hours as Frankie. Stunning upgrade!
S-Man
