Pix

[Shannon Parks]

Posted a ton of pix at:
http://www.diytube.com/thumbnails.html

Shannon

[EWBrown]

These pix will definitely help me out. Mechanical design isn't my strong point. I have marked and center punched the 2 chassis, haven't yet dealt up the courage to start drilling and punching. Been pretty busy dealing with cleaning up after lots of winter damage in the yard. Enough dead wood on teh ground to build a small log cabin...

/ed B in NH

[EWBrown]

After seeing the Audio Ray unit, I have decided to go with larger chassis than the 12" X 8" X 3" and use steel rather than aluminum. Even though it can all fit onto the smaller chassis, I like to have more room, especially if/when I ever get the HWT trannies, as they are larger than Hammonds.
The original small chassis will have a future as small SE monoblox.

Speaking of HWT, I finally did get a response from them, they claim computer problems, and should get back on track soon.

/ed B in NH

[EWBrown]

AES has Hammond Steel chassis and bottom panels in gray and black painted .040 thickness steel, around $25 +/-. A few bux more than the aluminum, but also stronger and pre-painted to boot. I figure having more room for the board and keeping the trannies a little further from the tubes might help in reducing any unwanted magnetic coupling or other noise hazards. Besides, I just didn't feel that the smaller 12 X 8 X 3 aluminum chassis was quite hefty enough foor those hefty transformers - this was brought on by seeing how a home made amp I got on E-bay got crunched and grunged by bad packing and FedEx ground's gorillas. On that I was able to salvage the major components, it will re-incarnate into a SE monoblock, and be a test bed for some designs i have in mind.

/ed B in NH

[Shannon Parks]

Howdy Ed,
Steel enclosures are definately the way to go if you have the tools to do it, and there is no reason to not take advantage of a bigger chassis. Maybe I'll get a steel one next time and see how successful I can drill it without using a drill press.
Ed, are you thinking of using the 17X10X3?

Shannon

[EWBrown]

The lab at work has a decent drill press and better tools for making clean and neat holes in metal, plus there is a young mechanical enginner who is willing to help me out, so it doesn't look like Homer Simpson built it.

I have some greenlee punches my Dad gave me a few years back, for 7, 8, and 9 pin tube sockets and 1/2", 3/4" and a couple other sizes. So it should (hopefully) turn out decently.

I actually prefer the larger and heavier construction, I want these puppies to last a LONG time. I'll stick with aluminum for prototypes and experiments, which are going to get modified in process, and will be easier to mangle, er, work and re-work as needed.

/ed B in NH

[EWBrown]

I've decided to go with the 10 X 17 X 3, in steel. Next order I make, I'll get two of these and the bottom plates. Also some more rubber grommets for the xfmr lead holes (I had some on hand, but need 6 more).
I like to get the output trannies spaced out further from the power iron, even though the cores will be oriented 90 degrees apart, they were just too close on the smaller 12 X 8 chassis. Also, the board will be completely clear of the trannies, no overlapping.

Just a couple weeks ago, I got one of the small K502 amp kits, and mounted it on a nice red-painted chassis that was formerly the home for
an FM tuner with built in SCA decoder, that I found at a swapmeet years ago for a buck. The board is mounted on top, the trannise further back
and more widely spaced, and had room to put a 4 position terminal block for the speaker connections. This is for use with a CD player, or kicking up the sound card to a decent level. The original FM tuner and SCA decoder worked poorly at best, the previous owner had hacked the circuitry and made a mess of it.

No, the K502 isn't as good as the '35, but for the relatively low price and simplocity, it does an OK job. I built it up during lunch breaks at work, got some ribbing from the other engineers for dabbling in "Fred Flintstone" technology.

If I ever get the HWTs, it will make an interesting look, Pewter "hammertone" trannies on a black chassis. Maybe I'll have to do some custom pinstriping, too

/ed B in NH

[DG]

Veddy interesting mentioning that little kit amp. I built one too. Definitely not the overall quality of sound as the 35 but different anyway.
I'm using mine through a pair of Fostex 207's in a double bass reflex enclosure (95 db) and it is plenty loud. The plastic sockets were melting as those 11bm8 tubes get hoooottttt. I managed to retro-fit with ceramic sockets. Also, found the high end a bit hot and edgy .... with the fostex speakers only. Since I decided to dedicate the amp to the fostex speakers I went ahead and swapped out the mylar caps in the kit amp with Wima polyprops ..... alot of folks hate the Wimas. They have a "dark" sound. It was a great choice with the fostex speakers which tend to get a wee bit rough at their upper extreme. The low end also got a little bit stronger with the cap change. Now, the little kit amp has what I describe as a vintage sound and combined with the fostex speakers makes a great little amp after the cap change. Most folks find that amp well worth the $140 ...... I agree ..... it's hard to argue with the price :)