# ELECTRONIC GADGETS



## drallen (Mar 30, 2011)

Does anyone out there have any of the latest gadgets such as iphone ipod etc. I am well into technology. I currently have 4 ipods, an ipad, computer, xbox, playstation. No wonder I can`t get any machining done. What is your latest toy?
Dave


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## mklotz (Mar 30, 2011)

I just bought the newest Sony 500mw encabulator with the 3 meter antenna. It's really great. I don't think I've ever had such perfect toast before.


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## Troutsqueezer (Mar 30, 2011)

drallen  said:
			
		

> Does anyone out there have any of the latest gadgets such as iphone ipod etc. I am well into technology. I currently have 4 ipods, an ipad, computer, xbox, playstation. No wonder I can`t get any machining done. What is your latest toy?
> Dave



You must have a pretty big belt to fit all those gadgets on.


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## milotrain (Mar 30, 2011)

I'm building a tube headphone amplifier, and got a capacitance meter to do some checking around the local junk yard.

should look sort like this when I'm done


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## Troutsqueezer (Mar 30, 2011)

Good God, load lines, transformer-coupled stages, that takes me back.


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## Maryak (Mar 30, 2011)

Latest gadget.

Ethernet over power for Galina's internet TV. Plus a Sig 340 internet set top box.

Best Regards
Bob


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## Tin Falcon (Mar 30, 2011)

A laptop
Tin


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## Anko (Mar 30, 2011)

A set of 2n3055 transistors for a very loud 100w pc subwoofer proyect :






Hey Milotrain I will love to see some pictures of your headphone amp!! :bow: Im also a tube lover and tube stuff amateur, And more that tubes I like almost all vintage styles: machines, amplifiers, old radios, hands tools etc..

I want to show you some of the tube equipment I have and still building, all ofcourse with a vintahe wood style:

This is my current guitar amp, unfinished and with a little dust on the top, has a N.O.S Tung-Sol 5881 in the power, I still have to make a new front panel, lacker the wood and made the letters of the logo to finish it totally:











the one in the top is a guitar preamp unit, and the other is a transistor audio amp






Saludos!


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## deere_x475guy (Mar 30, 2011)

Droid X
LG 23" IPS LED monitor
Logitech Orbit AF web cam
Logitech k750 wirless keyboard
Logitech M705 wirless mouse...
Logitech G930 Headset ...
Well you asked.


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## Foozer (Mar 30, 2011)

A Radio

And would you believe that they have phones now that need no wires? Went out and got me one of them new fangled things. In the 21st century now I is.

Robert


Robert


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## Deanofid (Mar 30, 2011)

I have a phone that has a wire going into the wall. And a computer, of course, four years old. Got some rechargeable AA batteries a few months back.
Yes, my lathe does run on electricity!


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## Hilmar (Mar 30, 2011)

I have three phones with wires and looking for a encabulator with Tape cassette player 19 ", not the boom box type. 
Hilmar


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## Troutsqueezer (Mar 30, 2011)

Amplifiers! I made a million of 'em when I was a young buck. Here's one of many - this is a single-ended Class A 15 watt per channel. THD is almost lower than the signal generator used for signal input. Back then it put Mark Levinson's overpriced junk to shame. ;D


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## bearcar1 (Mar 31, 2011)

I just purchased a new B & W TV if that counts for anything.  : :big:

BC1
Jim


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## BlakeMcKee (Mar 31, 2011)

You guy's amps put mine to shame! I've made 2 chumoys.... and I've never even bought enclosure's for them... but I was so happy when I made my first one, it was like seeing my new born son for the first time!  :big:


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## milotrain (Mar 31, 2011)

Anka, that's some really nice woodworking.

Trout, you don't happen to have a schematic lying around do you


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## milotrain (Apr 1, 2011)

Finished this last night. Still messing around with the first gain stage tube bias.





It will get a better box later. A fair bit of AC hum from the filaments in this setup but that's to be expected with how long I left the leads. I didn't want to cut them short until I knew where things were going. It's a 12AU7 gain stage with a 6DJ8 White Cathode Follower. Running off a 110V secondary winding that's putting around 178V out the B+ after that big honking blue cap. That's why my bias is screwed up. Swapped out the electrolytics on the output to some huge 47uF Solen MPKs.


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## Troutsqueezer (Apr 1, 2011)

Now this is going to show my age but looking at all those caps reminds me of the early days of using transistors for power amps (and other things). The engineers back then were using proven tube design theory as precedence to figure out where they should use caps to decouple, filter, stiffen, stabilize the various transistor stages. If you look at early schematics of solid state power amplifiers you can see there were capacitors all over the place, obviously artifacts from the tube era. As time marched on, we figured out we didn't need 80% of those. One or two strategically placed caps was all that was needed to prevent oscillation and provide the necessary high/low pass filtering.


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## milotrain (Apr 1, 2011)

In my defense I'm bypassing a lot of those caps with other caps.

The Greenies are 100uF 25V Nichicon Muse Bi Polars
The Yellows are a mix of .22uF and .174uF MPKs from various manufactures.

Big blue is a 1800 uF 450V power cap. Simplified my life to go with that rather than a pile of smaller values.

Figured out the new resistor values for the bias I want to try, but I'll likely put that off until I rebox it as the cathode bias resistors are buried in there.


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## Troutsqueezer (Apr 1, 2011)

Now here's a gadget from the early '70's that some folks might get a kick out of: Back then I was fresh out of college and was part of an engineering team that developed a new speaker system for an audio company called ESS. This particular sound system was called the AMT-1, and it propelled ESS into the international audio industry limelight for a couple of years. The tweeter in it was a brand new invention by Oskar Heil and it was the rage of the industry because of the way it worked, which was to squeeze air rather than push it, increasing the efficiency of the driver by a factor of 5. 

So here we are, showing off our new product at the Consumer Electronics Show and this guy comes around offering to have his picture taken with our products for a sum of around $500. We decided to go for it. 











A little younger back then, huh?

-trout


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## Maryak (Apr 1, 2011)

Trout,

I reckon the smug smile is because they had better on "Enterprise" 

Best Regards
Bob


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## Troutsqueezer (Apr 1, 2011)

Being star struck, we followed him around for a little while. I did notice that eventually he did have to go where many men have gone before. :big:


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## JorgensenSteam (Apr 2, 2011)

Beam me up Scotty!


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## Alchymist (Apr 2, 2011)

Nothing like the old 6146's in push-pull. So what's them there transistor things you speak of? ???


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## mocaquita (Apr 2, 2011)

5K pot for a dc motor control conversion on my mill!

Dave


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## JohnC (Apr 2, 2011)

Anko - awesome work there!
Really nice art deco look to some of that stuff.
 :bow:

J


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## imagineering (Apr 2, 2011)

My original Stepper Motor Control Board for my CNC Router (2005).





And the Complete Control System for my CNC SX3 Mill (2011).
Things have come a long way in a few years.





.


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## spuddevans (Apr 3, 2011)

With all these amplifiers showing here I thought I would share mine. For the last few weeks I have been working on building a HiFi amplifier, and I thought I'd share a few pics for your visual enjoyment.

This is the front panel view,





Some close up's of the knobs (what I made myself)














And the Inside view (I havent finished the lid yet)





And some close-ups of the insides with some identifier labels.





















A few details on this project. 

The valve pre-amp circuit is taken from the one in this link . I made one very slight change to the HT psu circuit. Because the 100uF smoothing caps I had were packaged as 100+100 caps, I added an extra RC stage.

The main amplifier modules are based on the LM4780 chipamp ic, they have their own bridge rectifier and smoothing caps so only need 28-0-28 VAC supply. Each module is a stereo amplifier, but by having 2 of these modules it means that I can Bi-Amp my speakers. (use one amplifier for each speaker cone, not just one amp for left and one for right) I dont know if this will make a big difference or not, but I thought it would be fun to see :headbang: :headbang:

I also got a remote control circuit that also has a bunch of relays on it to select the input.

I turned the volumn, power and input selector knobs out of some brass, and then engraved the designs on my mill.

When turned on, power is only applied to the valve heaters and the remote control circuit, then to switch on the rest of the power you just press the silver power button below the volumn knob, and then that turns on a latching relay that powers up the main transformer that feeds the amp modules and also feeds a step-up transformer that gives the HT supply for the valves.

I used my newly aquired bending brake to make some brass "U" channels to run the ac wiring, you might be able to see one running the width of the amp under the amp modules, and there is another one that runs along the bottom edge just behind the front panel.


I still have the lid to finish off, I have to drill some cooling vent holes above where the big heatsinks are. And I also have to modify the pre-amp circuit to increase the gain (the plans give the option for 7 or 11 times gain, I choose 7 but I think I need the extra gain)


I cant tell you how it sounds as I have only hooked up just a little speaker to check if it has hum or problems, and I am very happy to report that it is as quiet as a dead mouse, even turned up full. But when doing this test I noticed that the gain is not as much as I need, so I will modify it and then test it on my main speakers.

Tim


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## milotrain (Apr 3, 2011)

Biamping makes a huge difference if your crossover network is active (Before the amplifying stage) because you can get rid of the speaker crossovers. Active speaker systems (systems where each driver is amplified separately) have the potential to sound much better at much lower cost than passive systems.

Additionally costs of active crossover systems keeps dropping massively. At this point I wouldn't even bother buying a EQ or an active crossover but rather save up a little scratch for a Yamaha dme24n.


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## Troutsqueezer (Apr 3, 2011)

Biamping has many advantages. Here is a tri-amped system I had once. I used a phase-coherent active crossover. The tweeters were driven by the 15 watt/ch ClassA amplifier, the mid-range was was driven by a 45 watt/ch push-pull Class A amp and the woofers were driven by a 75 watt/ch. cascode-type amplifier. All homemade of course. 

The preamplifier is a Threshold NS10. The turntable is a JVC direct drive using an AudioCraft arm with a moving coil cartridge. 












My wife built this amp under my tutelage. The amp next to it is a headphone amp I made to drive electrostatic Stax headphones. 

-Trout


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