Category: Ampro Journal

Last night about 20mins into watching Austin Powers, there was a pop followed by that bad electronic smell that I usually associate with a capacitor giving it up.  The picture stopped being watchable, and the best description I can give is that it looked as if vertical hold had gone somewhat random – as it wasn’t a “rolling” picture, but one that had an unpredictable vertical position from frame to frame.

Listening to the projector, the ‘hum’ sound I attribute to the HOT board was gone as well.  So there was certainly something wrong.  Even after turning it off for an hour or so and returning to it, it seemed clear that there was something seriously wrong with the projector.

So tonight I figured I’d take a look and find the blown capacitor or whatever, get in touch with Curt and have him send a replacement board.  I was pretty confident that the HVPS and the LVPS were both working – so I figured it was worth trying to fix.  After poking around inside for half an hour, I hadn’t found anything suspicious looking – and that burnt smell was a lot fainter than it was last night.  I powered up and took a look at the help screen to see if it was input related, or if the whole system was toasted.  Help worked fine, exiting to normal picture mode showed me that it was fine too?!

I know that something happened, but today I can’t find any evidence of it.  My current guess is that the projector needs to heat up (over heat?) in order for something to happen.  I guess I’ll find out next time I watch a movie.

Recently with my amp shuffle my audio power on sequence got a lot smoother, in fact – I was actually being pretty lazy sometimes and just not even bothering to power on the sub amp if the movie wasn’t an action film (terrible I know). What I needed was a 12v triggered powerbar.

Of course, I decided that the best way would be to build one myself. I could have tried to fiddle around with X10 (I have an IR->X10 box) but in the past I’ve found that X10 can be a bit random, and I’ve decided that X10 isn’t really a good solution for my needs. [when I finally get around to lighting and fix the bare bulbs I’ve got in my room I’ll be using a lutron graphic eye] The commercial solutions from Monster seem costly, and I like to make stuff anyways..

My local electronics stores carry NTE parts, so that’s what I used – if you want to build one yourself, equivalent parts should be relatively easy to get. The heart of the project is the RS3-1D10-51 a solid state relay (SSR). Now my SSR is only rated for 10amps, so I need to add a fuse or breaker to protect it as I’m plugging it into the wall current which has a 15amp breaker on it. The R59-10A seemed like a good choice. So then I needed a 3.5mm mini mono jack to allow me to connect this to my 12v trigger line, and some parts from HomeDepot (power cord, box, electrical outlet).

First step was to wire it up and check that the SSR was doing what I needed it to do. I plugged a lamp into the outlet and used a battery as the 12v trigger power source. The SSR works great, like magic, applying a low voltage across the terminals resulted in the light coming on – no click, no fuss – just the light. Very cool.

After that it was just a matter of making it all pretty inside the box – which involved some careful planning to get all the parts in and wiring it up. Now my transcoder and sub amp will both come on via the same 12v trigger that drives my power amps. So when I watch stuff, the sub will always come on along with the other power amps.  Total cost was somewhere around $60 (half of that was the SSR) and it took a few hours to put together.

Well, a long overdue rack reorganization finally happened last night. Karl was kind enough to drop in and help me move my equipment around. This all started back last summer when I realized that my gear was too tightly spaced in the rack, causing the amps to run a bit hot. This was due to the overly short interconnect cables (18″ cables are not long enough).

Step 1 – Build some cables. I referenced the Jon Risch website on cables. So based on this I picked up some Belden 89259 from Take Five Audio and some locking RCA connectors from Parts Connexion (WBT style knock-offs).

Step 2 – Procrastinate for about 5 months, then finally solder together some 1m cables.

Step 3 – Shuffle the components in the rack.

Getting past the second step was the hardest part. Both online stores were great to deal with, and I’ll buy from them again. The cheap locking RCAs I might pass on next time – some of the threads on the screw down barrels were not very accurate, making some connectors difficult to tighten. Locking RCAs are a great idea – even a strong tug won’t make them slip off.

While I was at it, I also put together some 3.5mm mono plug cables to chain my pre-amp/processor to my amps so that I could use the 12v trigger. This is pretty slick as I can now effectively remote on/off my power amps (well, not the sub amp but it doesn’t have a trigger input).

After we were done, we watched Hero.  Along with the noise in the image, I’ve been noticing that my convergence has a wobble to it.  During a movie, the convergence will go slightly out of alignment, then back to perfectly fine.  Mostly this isn’t noticible, but you see it on credits or sub-titles more easily.  I asked on the AVSForum and it seems that it may be my HVPS getting hot (or worse).  So after the movie, I pulled the case open and felt the HVPS case – it was pretty hot, so maybe some improved cooling will help resolve this.

Last night I tried out lower resolutions from the quadscan – and they still appear to have the noise in the image. The satellite signal doesn’t seem to have the same issue, and its running as a VGA pass-through via the quadscan – so it shouldn’t be a cable problem. However, the satellite signal has enough MPEG artifacting that the effect might be there and being hidden. I’ll have to try a PC plugged in to see if I have similar problems.

At simply line doubled, I have very clear scan lines. I’m not sure if I’m going to change the resolution I’m running DVDs at yet (currently line-tripled), more tinkering is required. I still need to tackle reducing my use of electronic convergence as well. I did discover than the Ampro supports left and right blanking — I had somehow convinced myself that it didn’t. I can use this to mitigate the problems with the cheapy transcoder I have that introduces a line on the left side of the image on some HDTV feeds.