A Very Strange Week

Sometimes it seems nothing works... All within the last few days - the hot-water heater shut off (no idea what happened, had to reset the controller), the UnRAID server died after working trouble-free for more than a year straight, now it shuts down after 15-30 minutes after reboots. Urgh! At first, I could not access it via the network, which led me to think that the on-board ethernet port was busted, alas, it turned out that was not it at all.

Since one of the fans on the server was dying and made loud noises, I decided to get them replaced, first I ordered them on Taobao, from the model number Delta 1208, the search showed it was a type "8025" fan, so that was what I ordered. But of course, they turned out to be too small, the correct size is 9mm not 8mm, so lesson learned again, don't just trust the search, measure the damn thing to make sure.

Anyway, pissed off at the mistake, I then head off to the local computer mall hoping to "quickly" find the 9mm fans, since I remember a place specializes in case cooling and fans, I went there directly - but the damn place is gone. Walking around the mall did not turn up anything, so I went across the street to another mall, same thing - oh well, this place did have them but wanted RMB38 each for it, which I know is more than double the actual retail price online, so my whole morning was shot. I swear, I am never going to one of these frigging PC malls again, the service sucks, you get harassed, hustled and you may still not get the parts that you want, so fuck them!

Back to Taobao I went, they were delivered promptly the next morning, it just goes to show why go to the physical malls and put up with all that shit? So in went the new fans, they are nice and quiet, so one thing out of the way. But the server would boot up fine, worked for may be 30 minutes then shut off again, so the old fans might be noisy but they were not causing the problem after all, the chassis was still getting airflow, and there wasn't that much heat to dissipate anyway in the server.

After some more troubleshooting, I discovered that the power supply was definitely shot, this came as a surprise because the Corsair TX 750 was the most robust and costly one that I have! WTF... I submitted a RMA request with the company online, hopefully they will respond shortly, the unit is suppose to have a 5-Year warranty period. But even if they give me a new one, I would still be disappointed at the short-life span of the one that I bought...

I then swapped out the Corsair with a generic PS, which has only 3 SATA connectors, so I had to splice in two more for the server, hopefully it has enough juice to run the server in the interim while I get the Corsair repaired.

Here is the shot of the UnRAID array when it is fully operational, so it took me four frigging days just to get the server back online, what a pain.

In a way, the server went offline at a "good time" because Lao Hu took my OB speakers for some finishing work but after a whole damn week, I just found out that nothing has been done to them, why the hell did he take them in the first place then?!

In any case, I can't listen to any music in the study while I work, and the silence really stinks! Not only that, it has taken nearly a month since I ordered some speakers made by Lao Hu - one pair of OB with plywood (replacing the MDF prototype), and one 10" guitar cabinet based on AX84 design, yet I got nothing so far... Is it really that hard to put them together?! Sometimes I just want to get the damn table saws and tools so I can build them myself, but since I am really not that handy with power tools, I'd better stick with the electronic stuff... It is however very irritating to wait for something that never show up on time...

In any case, I just can't remember a week where so many things seem to go haywire all at the same time, let's hope next week will be an improvement...

Tube Breadboard Power Supply

It has taken me awhile, but I finally managed to put together the power supply section for the tube breadboard. The delay was primarily caused by all the hardware - the frigging screws, washers, connectors, etc. It was very irritating that small things like this could be such a PITA, wiring things up was a breeze compared to getting these parts, perhaps it was because I am starting from scratch, and I had no spare parts from other projects, anyway, I think I have actually spend more money and time on sourcing these buggers than the active components! WTF...

As shown in the shot, the power supply except for the tube rectifier and the power transformer is housed in a surplus power supply casing, with the silicon rectifiers, caps, and resistors mounted on a perf-board, the solder pads on these perf-board are totally shit, so basically the whole thing was wired point-to-point... All the connections to the board are available via connectors, so it will be easy to dis-assemble, or modify later as required. The case also puts high voltage out of reach... All the external connections are routed to the terminal strip on the back of the power supply module, and makes easy connection to the tube amp bread-board module.

Here is a shot of the power supply module, ready for the amp board...

Where My Damn Tools At?

While I managed to build the Fender kit and Fat Booster/Bastard without much difficulty, after going through the various DIY sites, it is pretty clear that I need more tools! The selection of tools available to the hobbyist is quite daunting, one can easily spend thousand Dollars not Yuan on these things. Of course, it is possible to do the job with your everyday handyman tools, which I already have, but to get decent results from them, one need to be very creative and/or very good with tools, which I am not, so the solution is to get "professional quality" tools to compensate for my own shortcomings.

Aside from the typical small tools like - table vice, metal/wood files, tweezers, center punch, metal shear, step drill bits, etc. I found that to fabricate PCBs and cutting holes in chassis, I really should have both a drill press and a high speed cutter/grinder a la Dremel tool, then there is whole business of drilling PCB holes, which I never knew required very high speed drill speed (60,000-over 100,000 rpm!)

Please bear in mind that people have done PCBs for years with nothing but Drumel tools, or even power/portable hand drills, so it can definitely be done. But these options just do not seem like the right way to me... I am definitely not going to attempt drilling holes in the PCBs free hand style... At the other end of the spectrum is a mini CNC machine, which has dropped in price over the years, and many are available for around 2,000-5000 yuan (~$350-800), which is well within the reach of the hobbyist, but there seems to be a pretty steep learning curve with all the CAD. CNC control software involved, so it may be worth a look in the future but not now. If I can find a shop that not only sells the CNC machines, but can also provide training and support, I will definitely get one, since not only I can eliminate the need for heat or UV image transfers to the PCBs, chemical etching (the worst part), manual hole drilling, it can also mill the elaborate designs for the stompboxes directly. The whole idea just really appeals to me.

Anyway, back to reality, I decided for now, just get the following:

1) a bench drill press (13mm),

2) high speed jewler drill/polish set and

3) drill press adapter for the high speed drill.

All three will cost me only about 500 yuan, so why not. I will also order some Tungsten Carbide drill bits to try them with the high speed drill, since the max rotation speed is only 30,000 rpm, these bits may or may not work (I have seen posts on both online), anyway they are cheap enough, so it is worth a try.

Here is the drill press that I plan to order (280 yuan or $43), it is darn cheap and has good

specs, hopefully it won't be a POS like many things Made In China.

Here is the high speed drill press adapter (70 yuan or $11), it looks pretty cheap, hope it doesn't tip over when I work... But it looks like the Drumel drill press stand that I saw online.

Here is the high speed drill kit (76 yuan or $12), the max rotation speed is 30,000 rpm. It can be used with metal blades to cut PCBs as well. Of course, grinding and polishing the stompboxes, I think this should come in very handy.

Building A Parts Inventory - The Zen of Taobao

As I gear up for my amp and pedal board builds, the first task was to build up a parts inventory, well it turned out not so easy - in China, there is no Digi-key, Antique Radio Supplies, Angela Instrument, Mojo Amps, etc. to meet the demand of the DIY market, I am so jealous of the people in the US, who can just go to a few solid sources and get all the parts, here I had to resort to order from multiple vendors via Taobao over several weeks of searching - thus the name of this post.

First, I must say that Taobao is quite impressive, you can source almost anything through it, its root with Alibaba is clearly apparent, it is The Place to hawk your wares in China, even office workers, students have open stores on Taobao. Where is your Taobao store?!

Overall, I think Taobao is even better than eBay, but then again I have not used eBay for quite sometime, so who knows... Unlike eBay, the site is not auction driven, so everything is available for "Buy It Now". But like most of the Chinese websites, the Taobao site is tacky and hard to look at, the site is too busy and chaotic to the eyes of a "western eye" like me, may be I lived in the States for too long but I really can not stand the look and feel of the typical Chinese websites, I think there is definitely a culture reason to explain why that is so... Any, back to the topic at hand.

Anyway, it took me two solid weeks of Taobao-ing to gather the parts, some came easily, but some were surprisingly hard to track down, in nay event, I manged to get 90% of the parts that I needed, so some modifications to the designs will have to be made later, it could get interesting, being the lazy person that I am, I really just wanted to get all the parts as specified, but that is not to be...

The Zen of Taobao - be patient and use the search engine wisely, while I tried my best in translating everything from English to Chinese for the parts, but not knowing the actual or proper names of them in Chinese was frustrating, since electric parts are not common everyday terms that people use, I can't just ask someone "how do you say xyz in Chinese", so the process to determine the proper names for the parts turned to to be rather time-consuming and tedious...

Typically when you do a search on Taobao, hundreds of matching parts will pop up, or the opposite happens, either way, lots of fine-tuning in the search terms were needed, you will also see some vendors purposely put multiple parts under the same category or worse, just fraudsters low-balling the price to get traffic to their stores, so the first thing to do is to weed out those "fillers" and drill down to some real vendors with actual items of interest.

Once you get to the store, it will still take sometime to get the exact item that you want, but because all the vendors are using the same Taobao storefront engine, one can usually navigate through the store with ease, but I must warn you that it is very easy to get side-tracked - many foolish items were ordered because of this, even though I tried my hardest not to be temped by the "shop window", I still ended up with a bunch of parts that I probably don't really need.

Anyway, before you get to the shopping cart, you need to double-check the inventory with the vendor, usually via Alibaobao or QQ. Make sure that they have the parts in stock before you hit the check out button - you can of course cancel or change the order later, but it takes a bit of extra work, so best to just ask and make sure... As it is often the case, you will need to get the vendor to adjust the shipping rate, as a majority of them do not bother to use the Taobao program properly to group the orders together and figure out the proper shipping rate, instead you get charged for every single item that you order so it is possible to get a shipping rate larger than your actual order, really!? Why can't shopkeepers spend sometime getting that basic thing right?!

For small orders, and there were many, I had to source some of the parts locally at Cai Ge Electronic Market, which is a topic for another day. The unit price there are usually 25-100% higher than those shown on Taobao, WTF, you say. For electronic parts, especially passive parts, it is quite common for the vendor to establish a minimum order like 100 or 1000 pieces, you can of course find vendors that are willing to sell a piece or two to you, but be prepare to pay top yuan for such orders. Every time I shop at Cai Ge, I felt like I was ripped off, because when the vendors know that you are just a hobbyist (your small order gives it away) - a small fry, they really have little incentive to treat you fairly, it is "get as much you can while you can" with them, bastards!

It turned out that sourcing components for the tube amps was relatively easy, first of all, the part count are much smaller than the pedal boxes and because there are many specialists that cater to the burgeoning tube DIY market in China, it makes ordering parts a pretty simple process. I will do a post on some of those stores later.

While it was relatively easy to source the parts for the tube amps, I still wasted a lot of time and wasted energy because I could not make up my mind to turret boards, epoxy boards with through holes, or just point-to-point? Each method requires its own special parts which take time to track down. In addition, like the cheap bastard that I am, I just wasn't about to fork out top yuan to get the audiophile-quality parts, which were all readily available, so I have no one to blame in this case. I saved money but at what cost?! Even with my cheap-ass way of parts selection, I think out of everything, a surprising 20% may be even more were spent on the stupid hardware, i.e., the parts that do not even make any damn sound at all! Let's not even get into whole issue with the chassis now, that is another can of worms, and will discussed in due course later.

But getting the parts for the pedals was another story altogether. Man! I really did not think it would be this difficult, for example, just for the transistors, I had to order them from half a dozen stores and I am still short of a couple of them... It was also difficult to track down a common part like the potentiometer, unless of course if you want to pay more than 8 yuan for one cheap carbon comp pot! May be I am just being too cheap as usual...

Even though a single pedal may just contain a few parts, given the large number of pedals that I want to try out (I set my sights high ;-), I still had to order a lot of parts, especially the transistors, resistors and capacitors, some of which turned out may be obsolete or very hard to get, especially with some of the older designs. Many a time, I thought for all the yuan I was spending, I could have bought all the pedals I ever need, why do I put up with all this bull shit?But then I think what is the fun in that? Did I not start this whole project with the intention to try out different pedal designs, and to learn/refresh my basic electronic knowledge which is unfortunately woefully lacking these days...

There are many takeaways from this saga so far, first, proper planning is a must, or as they say "measure twice, cut once". Since there are so many plans available for the amp and pedal build, I probably bit off a bit more than I can chew by try to build so many different ones all at once, this may be partly justified by the fact that it is very inefficient to order parts in small quantity, if I do that I might as well just buy the finished amp or pedal, as there is not much difference in price after you factor in all the time, energy that goes into an exercise like this... I guess we will see if my "efficiency theory" will work out or not.

I did a quick calculation, so far, I have "invested" close to 10,000 yuan in the parts, some were no doubt impulse purchases, I mean do I really need to have hundreds of knobs, am I really going to use them all? How many pedals can I build or use?! But in the heat of reading diystompboxes.com, AX84, SEWatt, etc. it was very easy to got carried away and start ordering parts like a mad man, oh well, there is always the Salvation Army to haul my junk away later.

With the last of the parts coming in the next few days, I am finally ready to bread-board some amps and pedals, I am also relieved not to be spending hours and hours going through Taobao, looking for those damn parts, my eyes really could use a break!

Another side note, my experiences with the orders have been just great so far, most of the orders were delivered within two days, even on weekends. I didn't have a single order screwed up because of the delivery company. Another finding was that, most of the orders were carefully packed, labeled, and stuffed into the boxes for shipping, good job I say!

This post is really getting too long, be back with more later...

Tube Amp Test Rig

Finally got around to put together a guitar amp test rig for trying out different designs, the idea came from several experienced builders online, my version is based on a cheap Chinese amp kit, since I don't have the time nor the skill to make the rig from scratch.

Here is a picture of the chassis before the conversion with a lighter for scale. The chassis is actually a bit crammed for a multi-stage guitar amp, but it will have to do for now. The chassis came with 5 pre-cut holes for 8-pin tubes, so I ordered some 8-to-9 pin adapter plates to mount the 9-pin triodes that are typically used in guitar amps onto the chassis.

Here is a shot with the terminal strips taped to the chassis with double side tape, not ideal, I may have to drill some holes so they stay put, they already moved around when was wiring up the power supply... Anyway, these strips form the "bread-board", so I have the ability to change the passive parts easily without having to solder, or if parts substitution can improve the sound, even modify the design to tweak it to suit my own taste.

Side note, I quickly found out why these friggin' Chinese kits are so cheap (I paid RMB458 for a stereo amp with all the parts) - because they are cheaply made, duh! The chassis is full of sharp corners, the un-finished edges are like shrapnel that can slice the fingers, knuckles if one is not careful, I already got a few cuts, ouch!

The first thing I did was to wire up the power section, transformer, rectifier, choke, filter caps, and the heater wires, since the PS is pretty much the same in all the amps. I don't plan to spend much time tweaking the PS. Although, I may add a switch later for selecting solid state or tube rectifier to see how that affect the sound.

Here is a shot of the heater wiring which unfortunately wasn't done the "proper way" i.e., twist, measure, cut to length then solder (should have read the online tutorial before I started wiring), I just wire them point to point then twisted the wires... For the actual build, I will definitely do it the proper way!

Tomorrow the whole rig should be wired and functional, I will then start bread-boarding a AX84 build, probably the High Octane SE, but with a different PT. Can't wait!

Workbench

Finally got around to setup the workbench, the desk is bit shallow but should be sufficient for most projects, here is the shot of what it looks like without anything on the bench, it won't stay like this long...