Okay, well, worked on the thing for a while. Not going too badly, considering that the jumpers were my first soldering project ever. The first two took a while, then started to get the hang of it. Only burned myself occaisionally.

So anyway, I think I need some clarification before I screw things up. All I've done so far is the power supply. Take a look at my progress. Okay, I know I'm not getting any style points, but will it work? (By the way, tangent, the link you provide to the "power supply schematic" is broken.)

Anyway, after reading though tangent and cmoy's articles a few times, I'm still confused about how to set up the LED. If anyone can post some pics, I'd appreciate it. (I haven't decided what kind of case I'm putting it in yet, but probably a mint tin.) Do I need an LED cover thing an some insulated wires here that I'm missing? And, tangent, do you have your amp hooked up to dual 9V batteries in the photos, or is there another wire I'm missing?

Also, I'm going to be using this amp with low-impedance cans, Grado SR-80 and Sony MDR-V6, primarily. Any extra resistors you suggest I throw in or anything?

Okay, I'll have more questions as I get to the components that are actually difficult to install, I'm sure. Having fun so far, thanks everyone for the help.

kerelybonto

The power supply schematic image link is fixed.

On the LED, you put the resistor inline with one of the leads, like I show in the pictures in the tutorial. Then, you connect the positive lead to the same place you connected the battery's + connection, and the negative LED lead to the - conneciton. On the LED, the long lead will be the positive one. If both leads are the same length, you'll have to find a datasheet or do some experiments to find out which led is which. If you hook it up backwards, it won't light -- it won't hurt the LED.

As for dual batteries, I think one of the amps uses dual batteries and the other doesn't, but that shouldn't affect what you're doing. The dual-battery amp will have them in series, so only two wires are going to the amp board. The other two wires are connected to each other, away from the board.

And on the "extra resistors" thing, I say leave R5 out until you determine whether you have a hiss problem or not. If there is no hiss, leave R5 out.

kerely,
tangent is the sensei, he recommends putting in all the jumpers.
It will help make the rest of the project..uh...understandable.
Sorry if you already did this, I cannot tell from the pics.
The leds, I just soldered them in..and drilled a hole in my serpac to accomodate the uh..head of the led. I used the wire tension to hold them in place...not the best of advice, but it's what I did. I also used some radshack shrink wrap to hide the resistor. I used shrink wrap on the 1/8 connects also.
hope that helps.
md

I went ahead and put the R5 in because, well, just because I had them sitting there. They looked lonely.

I have the power supply and amplification components all set up now. I installed a few things in the wrong holes various times and had lots of fun removing them. But hey, I'm learning.

I have no idea how to connect the power toggle switch, volume control, and audio inputs/outputs. I think I understand where they go based on the diagrams, but I've simply never put anything like this together before and don't know how to hook up the wires. For instance, the power supply has three contacts. I assume one's a positive, one a negative, and one a ground. But really, I don't know. Anyone feel like posting close-ups of those connections?

I really feel like my next amp will be pretty solid. I think I've finally figured out this soldering thing and playing around with all these tiny parts isn't so annoying any more. I'll go get some better tools and really be exacting next time around.

So anyway, just need to finish this one up and see if it blows up or not when I hook it up. Then I'll be off to the next project.

Thanks.

kerelybonto

hi kerelybonto, im also constructing my very first DIY amplifier. Well, I left it half finished, sitting on top of my desk, because I have no will no finish it. Dude, im a loser.

If you look good at the board, you see there is one positive + side and one neg - side. Hook up the battery at the front of the board before the round caps. I put the toggle between the positive lead.
The center section of the board is the "ground".
The line right line in is on the pos + after the cap next to the amp. Likewise the left is on the neg - side after the cap.
The left and right outs are on the same sides of the board only after the R5 resistor.
if you ordered the same 1/8 in jacks: the first pin where the jack is mounted is your ground. That should be connected to middle rail of the board.
the second pin is the left channel. The fourth pin is the right. I would solder all this up and check for sound before even thinking about the volume pot.
hope this helps
md
by the way, there is a pdf file with pictures on tangents tutorial page.

Haha, HD-5000, don't tell me that or I might cop out on mine too. By the way, I'm also in KC.

Thanks for the info, millerdog. I'll check everything in the morning and get back to work. ...

kerelybonto

I don't know if you figured this out on your own yet, but I remember from your pictures that the jumpers in the lower section of the board (i.e. not the power supply jumpers) weren't right. Make sure you made them as 'M' jumpers.

On the power switch, that just goes inline with one of the battery wires. It breaks the connection to the battery when the switch is off, and connects the battery to the circuit when the switch is on.

On the volume control, well, that's a little difficult. Best to just study the pinout and figure it out. The main rule is not to hook the pot up backwards. You know you've got it right when you get no volume with the control turned all the way one way, and full volume turned the other way. If you get weirdness at one end of the pot, you've hooked it up backwards. (You're shorting the input to ground in that case.)

On the audio I/O jacks, you first figure out the jack's pinout. I do this with a mini-to-mini cable. Plug it in, and then use your ohm meter to trace the connections from one contact on the plug to a pin on the jack. The tip of the mini plug is the left channel, the "ring" is the right channel, and the rest of the plug ("sleeve") is the ground.

Yeah, I figured out about the 'M' jumpers as soon as I started in on the amplification components. And then I put it back in the wrong place, moved it -- moved the wrong one ... took out a jumper, made a jumper on the solder-side ... we'll see if it works. I would have had to have taken everything apart anyway.

So, okay, I'll fiddle around with the outputs and everything. The pinout's a diagram for the opamp, right? My opamp, unfortunately, came with no such diagram. ...

kerelybonto