SS Power Amp Build: Icepower 700AS2

[Alex Kenivel]

Planning out my wiring scheme as parts are trickling in and I keep wondering about these duplicate wires for the speaker outputs.

I'm only going to be using one set of them per output, as I'm not planning on wiring a connection for bridging the channels, what I assume the redundant wires are for.

Would it be a bad idea to cut the redundant wires back?

 

[Boudoir Guitar]

Planning out my wiring scheme as parts are trickling in and I keep wondering about these duplicate wires for the speaker outputs.

I'm only going to be using one set of them per output, as I'm not planning on wiring a connection for bridging the channels, what I assume the redundant wires are for.

Would it be a bad idea to cut the redundant wires back?
View attachment 58700

Without looking anything up, my recollection is that you are supposed to connect white-white and black-black so you've got two wires running each polarity as a pseudo thicker speaker wire.

 

[Alex Kenivel]

Without looking anything up, my recollection is that you are supposed to connect white-white and black-black so you've got two wires running each polarity as a pseudo thicker speaker wire.

This is what I see people doing on their builds.

I've seen somewhere where these wires can be used to set up a bridged connection also, but don't feel like digging it up after an evening of tinkering. What I really want are less wires in the box that I have to deal with because space is pretty tight. I'm a little nervous about the bleed that may happen from the cramped quarters.

I still have a little more time to worry about that. I have some aluminum to drill!

I made a template for the fit and hole marking. I punched spots with a mallet and old phillips head screwdriver.

Drilled pilot holes and tapped holes for my first time ever. I know threading these holes isn't really necessary because the standoffs are threaded but I couldn't miss the opportunity to try it out. Of course I forgot to back out my first one and stripped it! The other ones went smooth after that.

With the standoffs attached, everything fits with just enough room for the components and wiring. I hope there's enough space for everything to play nice!

 

[Alex Kenivel]

Tracing out the components onto cardboard and painters tape for templates.

Im now waiting on a new soldering iron and another IEC socket because I destroyed the one I salvaged when attempting to desolder components from it with my backup iron. Not too happy about that, but I made some good progress nonetheless and will have a busy week ahead of me with family and band.

 

[Alex Kenivel]

Easy like a Sunday morning...

I'm about to cut the holes for the front and doing a test fit of some parts. The speaker outputs are pretty close to this EMI choke. I wonder if this is going to be an issue..

I have a little more room toward the front so I could just redrill new holes in the bottom and scooch it up a bit if it becomes an issue. Could use some ventilation anyway..

 

[Alex Kenivel]

More drilling

Had some feet kicking around that seem like they will work perfectly.

 

[Alex Kenivel]

Started wiring today

 

[Alex Kenivel]

I'm a little stuck, not even sure if this module is even powering on. Definitely no audio. Not sure if it's the power that isn't wired correctly or the audio not being wired correctly tripping some kind of failsafe so it doesn't come on?

The IEC female connector to rocker switch wiring seems to be okay, but I might just remove the switch from the signal and try to power it on without it to see if I get anything.

Wiring balanced connections to a potentiometer with 3 posts could be my issue. I have the Tip and Sleeve from my audio input going to the input and ground lugs respectively, then the middle lug is the output going to Signal+ on the module. Ground lug is also connected to the ground of the amp input. The Signal- input for the module remains unconnected.

 

[Alex Kenivel]

I took the rocker switch out of the equation but still had no signs of life, until I shorted Pins 10 and 12 on connector P103 as per something I read, not sure if in the manual or not (i cant seem to find it now!). When shorted I can hear switching happening, so I jumped the two pins together and now the amp works. I'm not sure if I've bypassed any safeguards by doing so.

Its alive!!!

 

[Boudoir Guitar]

I took the rocker switch out of the equation but still had no signs of life, until I shorted Pins 10 and 12 as per something I read, not sure if in the manual or not (i cant seem to find it now!). When shorted I can hear switching happening, so I jumped the two pins together and now the amp works. I'm not sure if I've bypassed any safeguards by doing so.

View attachment 59066

Its alive!!!

View attachment 59067

Pfew. I was about to have a sleepless night worrying if I'd sold you a borked board.

 

[Alex Kenivel]

Pfew. I was about to have a sleepless night worrying if I'd sold you a borked board.

Aww, I was pretty determined to get this done today as I've been pretty obsessed with it and need to move on to other projects. My participation in the Do Something challenge has been minimal, and I need to pay a little more attention to my band, lol.

I swear my kids at home and my students at work know a lot more about electronics now than they did a month ago and I may have even learned something, too!

I really appreciate you for being in my corner through this project, and if I ever find an old broken Atari or NES or some equally cool shell, I'll build another one


I also want to thank @Chocol8 again for his brain and his willingness to let me pick it!

 

[Alex Kenivel]

I've done a bunch of playing through both of the channels with my Axe FX III, HX Stomp and my son's Valeton GP-100 (we had a blast today trying out some of my NAM profiles. He doesn't play through a cab so it's always a nice eye-opener for him when he does).

It gets pretty warm, not super hot, but warm enough for me to want to make some holes for ventilation which I started to do today by tracing some holes on different devices before landing on something I liked. I don't know if it will help a heap but it also gives me a chance to put some loctite on the bottom screws holding the standoffs in place and tidy up some of the wires.

On my last couple of rows my drill bit snapped and caught me in the face, giving me a Cindy Crawford. A little blood but just a little kiss.

Loctite on the bottom screws and retwisted the power wires

Now off to reassemble!

 

[Alex Kenivel]

Small parts and wiring put back in with little sticky 3M pads to tie down cables. Audio cables will run along the bottom right, speaker cables along the top right, power top left.

Board back in, wires in place, solder and heatshrink the power cables back onto the switch and button it all up.

I'll have to wait until next week to get my label maker back or bite the bullet and draw some labeling.

 

[Alex Kenivel]

Resurrecting this thread because after some initial road testing I realized that this thing gets pretty hot after a while so I went about installing some blower fans to get some air flow past those output inductors where it starts to get good and warm.

I'm going to need auxiliary power from the 14-pin P103 header. Pins one and two are +12v and Ground respectively and I already have pins 10 and 12 connected with a bar of solder to bypass standby on startup so I'll bust out the JST connector that came with the cable kit and modify it a bit to fit over my hot wiring.

I scored the connector area I wanted to cut out with a razor, pulled it apart and removed wires I wasn't using until I was left with just wires 1 and 2.

I wasn't really paying attention to the specific blowers I was getting (never trust pictures in instruction manuals!) and ended up with a 2-pack of 5v blowers, which actually works out because I can wire them in series and send them both 6v, which is within their 20% rating and should be fine. One for each inductor!

Wired up, heatshrinked, and held in place with some blue tack for a temporary fitting, blowing test.

First test went well. Blowing action was very present but I had to rethink my final mounting scheme since these were meant to be placed on a 3D printer or something, the eyelets are on the opposite side of where I need them to go so off to the hardware store to find some M2 screws that are a little bit longer so I can flip them around and mount them upside-down, or is it downside-upside-down because they're upside down and going on the top of a case that will get flipped over?

 

[Alex Kenivel]

Back at home with some hardware and its time to pound and drill some intake holes for the blowers. Traced the spots with a pencil, hand drew in some dots for holes, 13 +2 mounting holes per blower, punched out with a screwdriver and mallet, drilled with a hand drill, filed, sanded, and some hammering back to near flat.

Repopulated with fan harness

A close up shot so you can see the upside-down mounting and the longer screws that were needed. I picked up a few extra hex nuts to act as standoffs as to be able to angle the blower and kept the blue tack ib for some extra stability.

I closed it up mostly to give it a test run with the mounting hardware in and there was too much contact between the fan and the case so I needed to figure out a way to keep space between the two.

I started by using electrical tape around the frame of the intake opening to build up the air gap which helped but the fans seemed a little choked out and the amp was pretty noisy from the fan noise. None of it came through the audio signal, which was a win in my book and at band levels the fans won't be heard at all but holy shit they're annoying at home practice levels.

I decided to go back in and make the intake holes a little bigger and rethink my airgap. After widening the intake holes I remounted the electrical tape and used heatshrink tubing around the mounting screws to be able to adjust the air gap and angle at the same time, similar to that of pickup height adjustment screw/spring. Good shot of the header modifications, too.

I don't really know if it helped the fan noise but this thing is staying nice and cool. I might just add a switch for the fan for playing quieter.

 

[James Freeman]

Is the chassis grounded with a short wire direcrly from the IEC socket?

Great work btw, I am a fan of DIY too.

 

[Alex Kenivel]

Is the chassis grounded with a short wire direcrly from the IEC socket?

Great work btw, I am a fan of DIY too.

It is, between the standoff and chasis mount screw right next to the mains power header which I positioned near the IEC socket. You can almost see it in the first picture on post #73

Thank you, it's a lot easier than building a pedal, that's for sure. I know you've built a load box and some cabs, right?

 

[James Freeman]

I know you've built a load box and some cabs, right?

Yes, and modified my fare share of things, well, almost everything. It's impossible to sell this gear later but at least I know it is exactly how I like it.

 

[Alex Kenivel]

I decided that I do want to have the fans switchable so I found this odd switch that had one terminal and one hole. I could see some metal move in the hole and it read continuity so I I tried wiring it up but couldn't figure out how to get the wire to stay in the hole without blocking the switch in one position.

I tried blindly soldering inside the switch, stuffing it with wire, and finally gluing the wire into the hole. I came back to check on the glue and it actually stuck really well..So well I couldn't flip the switch anymore!

My son was with me and we had just finished watching some toggle switch restoration videos so I had it in me to open this thing up, clean it out and attempt to solder a wire directly to the inside.

Of course I forgot to take pictures of that process but there was a flimsy metal tab that rocked back and forth with the switches motion that made the connection with another piece of metal lining the inner surface beyond the hole where I soldered a piece of wire, put the switch back together, wired it up, and..

The switch was dead. I didn't check continuity after I put the switch back together and I must have either out it back together wonky or broke something.

I guess another switch is in order..

 

[Alex Kenivel]

After a good break I decided to pull the switch and open it up again, messing around with the little tab and it's position. I left my probes on the connections and carefully put the switch back together and got it to work 80-90% of the time. Not bad

Now I have switchable active cooling!