First time Chip Amp Builder Question

[frank04211969]

I hope this is not a stupid question but this is my first build and I got the mono amplifiers from chipamp.com. I was planning on purchasing the torid from apex jr. Looking at the pictures all seems clear using the 4 diodes rather than the 8 but what does not seem clear to me is when hooking up the power supply to the amp board do I only hook up the V+ and the V-. Meaning the connection from amp board to power supply of the PG+ and PG- do not get hooked up. I did do connections on power supply board PG+ to PG- and D6 to D7 and D2 to D3. What all this stuff does is kind of foreign to me. I do have soldering skills from building numerous loudspeakers over the last 15 years. So I do somewhat understand what capacitors and resistors do. I have put the boards all together I am getting ready to purchase the torid from apex jr. within the next week. From what I think I have learned is to get them hooked up and working before thinking about enclosure which I plan to do. I would like to get a little assurance before I get to point of plugging them into wall. I have multi meter and do plan on doing measurements recommended before they get plugged in. I am taking it a step at a time and trying to not get ahead of myself. Any help would be greatly appreciated.

[AndrewT]

first.
download the build guide.
second.
build a bulb tester and learn how to use it, interpret what it tells you and always use it every time you start up a new or modified mains powered project.
third.
Build and test in stages.
eg. wire up the transformer (nothing else). Plug it into the bulb tester and prove your transformer wiring. Then add the rectifier and re-test via the bulb to prove that section. etc.
fourth.
look at the back of the PSU and amp PCBs. You will see that some of the marked holes are on the same commoned trace.
The amp requires a 3-wire connection to the PSU. You leave some of the commoned holes empty.
fifth.
if you are unsure, ask !!!!! you are working with a mains powered project. Don't take risks and don't guess.

[godfrey]

Originally Posted by frank04211969

I hope this is not a stupid question but...

No, but it would help if you included the pictures or a schematic or link or something, so we can see what you're talking about.

In general, you normally need at least 3 wires from power supply to amp: V+, V- and ground. With 8 diodes, you might have 2 grounds to connect. (PG+ and PG- sounds like 2 power grounds)

[bcmbob]

Hi Frank,

Here's a link to my version of those amps. AS a matter of fact I'm listening to them as I write this. Fantastic for the price and simplicity!

Hopefully you can get a few ideas from the gallery.

BrianGT Build - My Photo Gallery

Regards

[CanAm Man]

Frank.....it sounds as though the Apex Jr transformer has a center-tapped secondary (three secondary wires), as opposed to having two distinct separate secondary windings (four wires). Is that the case? That will help our understanding of your implementation little, if that's the case.

[CanAm Man]

Frank, #2. Some pics of my BrianGT build, at Chip Amp Photo Gallery

I used a dual secondary transformer from Antek. Note that the secondary has two green and two blue leads going to the PSU board. You'll have a different configuration if you use a center-tapped transformer.

As a first timer, I fully agree you go with Andrew T's advice. Wire the primary and secondary, and test. Then wired the rectifiers, and test, then add the caps and check as you go. A bulb tester will help save you from smoke and unneeded excitement.

[bcmbob]

The transformers in my gallery are from ApexJr. I bought six and have had no problems what so ever.

This was my guide: