Post pics of your builds.... - Page 295

Fitz,

What power switch is it that you are using? It looks like a Bulgin but I haven't been able to find anything about black ones on their website.

It’s surprising me time after time how you guys (Fitz, Seaside,TzeYang...) can make beautiful amps on perfboard like this.
Congrat Fitz, very sexy in black.
This is an example of… totally out of my ability.

Maybe these Those are momentary so maybe there is a latch hiding somewhere in the build? Great perfboard, wiring & casework for sure!
Got that site from someone here... They have nice feet too.

Very, very nice, Fitz! We know those boards look just as great underneath, too!

Do you guys use software to plan your stipboards, or do you just wing it?

I can assure you Mojo there was no winging going on in Fitz's house that weekend!!! lol

That build was meticulously planned and tested then planned some more. Notice the fact that every component is black!!! No mean feat in it's self.

Ask fitz to show you a picture of the under side.. A work of art is all I can describe it as!

[QUOTE=isao2k8;5450891]

Hi Isao2k8 ! Where have You bought this nice golden input stereo jack?

Marek

Yep. I got it from Performance PCs. The PSU is always on when the switch on the power inlet is on, burning only a minimal amount of power. The switch triggers the a toggle circuit based off Winfield Hill's schematic (basically the same as amb's e24), which in turn triggers a relay feeding power to the amps and begins the power-up muting delay. I can also turn it back off by touching the right spot on the board holding the toggle circuit.



Coming from you thats quite a compliment. I promise not to try competing with you on casework if you don't take up doing perfboard designs.



You better be sure to show up at the next local meet and listen to it again, it sounds much better without all that power supply noise the temporary setup had.



Graph paper, pencil, and a lot of eraser. I start out by placing any big parts or components with a lot of connections (ICs, relays, etc), and draw partials of the circuit separate from my main drawing to figure how much space roughly each section is going to need. My layouts are a little more difficult than necessary since I refuse to use any wire jumpers on the underside of the board (for no particular reason, just a stylistic choice). After I have a general idea how it's going to flow... opamp stage here... rail splitter and isolation here... buffer here... feedback loop comes back around here... etc, I just start drawing the components that connect directly to the big ones serving as anchors, and work along the circuit from there. Sometimes I'll paint myself in a corner so to speak, and just have to erase and redo that section. After it's all drawn up, I go back over each connection one by one to make sure it's right and double-check all my pinouts for ICs and transistors, then solder it up.

I should actually take a picture of one of my sheets I use for drawing the layout, they can look quite the mess by the time I'm done.



Heh, you might be surprised. The amp itself got proper planning and testing, but the power supply and board with the power switch circuit + input/output relays was done right at the last minute and only casually tested before I started assembling it 2 days before the meet. Had to fix a couple dumb mistakes with my layout (well it was quickly drawn up in the middle of the night after all), as well as figure out that a supposedly non-polarized Omron relay actually was polarized (those dirty liars), and it just so happened the correct polarity it would trigger with was opposite of how I had it connected. You're right about the black components, that had me banging my head on the wall at a few points; I had to scavenge the depths of NOS parts on the innerwebz to find some of them. I was planning to have this eventually serve as a preamp to a pair of monoblocks, I can't decide if I want to do the same all black theme or not for that too.

What are the black resistors? link please

The blue Vishay's are nice, but I really like your black ones. That really is a beautiful build.

IRC RC55LF 0.1% metal film from Mouser... just search for "rc55lf". Cost about a buck each.

a dollar each R. wow. and I thought *I* was taken to the cleaners at 29cents per R with the blue/purple vishays.

I enjoy nice parts, but a dollar per R? wow.

Yeah no kiddin'. The good old Irish CGW resistors I have thousands of are more of a dark blue/purple than black, otherwise I would've just used them. I think I've ended up with a couple dozen or so extra of the black resistors too, from various changes during development of the amps. =/

I originally posted pics of this amp way back in May last year, but I've finally got around to finalising a few changes yesterday, and couldn't resist taking new photos with my new camera......









σ11 is at 27V with a 30VA toroid. Filtered, double-fused, DPDT switched IEC inlet. Amphenol umbilical connectors. Neutrik RCA and headphone jacks. MMM has AD8610 all round, biased to 4.5mA. Output stage biased to 100-105mA. All electrolytics are Nichicon UHE/UPW. Pot on the left is configured as variable gain (2-12), but is currently shunted out of the circuit as I never use higher than 2 with my phones. Teflon SPC input wire, bog-standard copper hookup elsewhere.

And it is finally exactly how I want it

good job, beefy.

a hint, maybe: place something 'pure white' nearby (even if outside the normal frame, once you crop). then you can use that white area as a whitebalance calibration area (use the 'levels control' in pshop) and that will ensure your colors don't have a cast to them.

that PSU is quite dense. such a huge trafo, too! any hum induced at all? did you rmaa test it?

also, what is the red on the browndog-style chip carriers. are those your own carriers?

At this early stage, I'm just happy when I get the DOF v diffraction right. Playing with the whitebalance always seems like too much effort......
And aside from the top-down shot, which was hand-held with a lamp very close and thus a bit over-baked, I kind of like the warm look for amp photos

My ears are the only test equipment that I have. There is some hum with the volume control at max, particularly at maximum gain, but I don't notice any hum at levels well above normal listening volumes with my sensitive AD900. I have actually used this amp with my Super.Fi 5Pro and it has a much lower noise floor than any of my other amps ever did including an Arietta, 2Move and various Millett Maxes.

When I am finally in Canada, I am going to investigate getting a custom potted and fully shielded torroid from SumR. I will probably do the same for my Buffalo DAC.

Aries socket adapters from Digikey.