Was just looking at my GnR for sound... It's going to be interesting - will have have to get back to it later as I moved it on location.

But first glance - It's nice that they developed a completely stand alone amplifier board to run the speakers. In theory this should make it easy to replace it with a new amplifier if nescessary. Even the power will be easy as you can re-use the power going to the board. (providing the new amp will not draw more power than the line can provide)

The JJP amp board does use the Texas Instrument TPA3118 amp chips. This is a step up from amp chips Stern uses. The TPA3118 appears to be rated to a max 2x30watts.

Anyway, nothing I plan to tackle right now A Rush is coming soon that will get some attention and I still need to program that high power amp. The Sigma Studio software is presenting a big learing curve challenge - and not much time to do it.

A couple of pics of what's behind the JJP panel. The Amp board is in the center.

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Just a quick update.

Still haven't been able to put more time into the SigmaStudio programing.

I've been working on setting up a brewery with pins, leaderboards and digital signage. That's been taking a bunch of my available after hours time.

I did get my Rush Premium delivered and was pretty stoked thinking about the huge sound upgrades I could get started on....... UNTIL - I opened it up. Shipping must have knocked it over and the cabinet is heavily damaged, split, and wracked. I'm working through that now. Its going to be a slow process and most likely require swapping everything over to a new cabinet. On the plus side - I'll have a junk cabinet that I can practice cutting bigger holes into for subwoofers.

On a side note: not super impressed with the JJP sound system on GnR... No DSP, bass stinks, you'd think seperate components have the potential to sound better with the highs and mids... but something is not right. I mean there is some effort put into the better components and amp - but for some reason it just isn't showing up. This will be a future project, I'm not exactly sure how I'm going to approach it yet.

OK - side track.

I also picked up a Rush Pro for the brewery. But as I play it - the sound system stinks. The low quality is magnified because I know what Rush sounds like on my home stereo or with headphones etc.

Soooooooo - I have all this extra gear around and I just can't help myself.

The Rush pro is getting JBL 5.25's in the back box and JBL 8" Sub. It'll keep the stock Stern amp, as I know we can get the performance we need out of it.

This is a simple upgrade for any pin. Below are some pictures of the wiring process. If you can manage an ugly solder joint then this is real easy.

Desolder the pigtails off of the stock speakers. Then reattach them to the new speakers. Just be careful to connect positive to positive etc.

You can easily identify which wire is which just by looking at where they are soldered on the stock speakers. In this case you can see the backbox speakers use red for positive and black for negative. The cabinet uses yellow for positive and yellow/black for negative.

Your new speakers will also have positive and negative signs in the same location. Generally the large terminal will be positive and the small is negative. If your speaker has a capacitor on it(like the ome in the picture) be sure to attach your positive lead to the actual spade terminal. NOT to the piece next to the "+" symbol. This would be wrong because it will bypass the capacitor/filter.

Now the wiring is plug and play.

** no word yet on the premium cabinet replacement.

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Just for reference. JBL versus stock.

You can see the model #s in the pictures.

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Ok - Installing the JBL810 subwoofer.

This question comes up alot. And there are many ways to do it. From easy, to rocket science....

But let's not overthink this, and just do it the easy way.

Swing by the hardware store and pickup 4 x #8 wood screws that are 1" long, and 4 washers for them. That's it. Can you run 1.250"? yes, but the tips will stick out the bottom of you cabinet a smidge. Add 2-3 more washers per bolt if you need to run the 1.250" screws. Otherwise stick with the 1" and all will be well with the world.

1 - Remove the stock cabinet speaker.
2 - Tap out the studs from the inside with a hammer.
3 - Remove studs from underneath with pliers.
3a - Remove the stock plastic speaker mesh.
4 - Place new sub in place and screw down using the new wood screws with washers. Run them into the holes where the studs were.
5 - Pinch the ground strap between the washer and speaker and tighten.
6 - Connect wires..

Done.... No need to make it rocket science.

FAQ:

- Will I need a spacer? Not for the JBL810. The spacer attached to it, as well as the diameter of the stock cutout gives it plenty of room to move without contacting the cabinet. This applies to the stock Stern amp and the mini amps that have been used(Fosi, Dayton, etc.)

- Should I put the plastic speaker mesh back in? ABSOLUTLEY NOT. The plastic piece has a tendency to resonate at lower frequencies. This will drive you nuts. The speaker will also contact the plastic during excursion at high volumes. Just toss it in a box with the stock speaker and put it in a closet never to be seen again.

- Will this work with speakers other than the JBL810? Sure, but you are going to have to do some thinking. Does it have a spacer? Can it be flush mounted? How long do the screws need to be? You will need to answer these questions yourself for the specific needs of the subwoofer you choose to try.

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And the back box speakers.

These mounts are something I made a while back, if you want to know more go back to page 2 or 3ish.

Keeping this post simple.
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Just FYI.

I am only using the JBLs in the backbox of Rush because they are leftover for me.

The speakers I prefer and recommend are the Kicker and Alpine - go back in the thread as I conducted speaker fights comparing different brands of speakers.

As far as older games and non-Sterns, I do not have any recommendations as I have done no research or testing on older machine. Therefore can not give any credible recommendations for speakers or amps etc. This may/will change in the future if and when I take on an older upgrade project. However there is a ton of common information in this thread that can be applied to your own project regardless of what it may be.

I also recommend reading this entire thread - I understand it's long, and who has the time etc. It would be a real bennifit to spend the time doing so.

Back to my Rush Pro......

How does it now sound you ask?

BLAAAAAHHHHH..... Don't get me wrong, it's better... But it didn't have the same improvement as GZ.

To be fair - I am doing this in the middle of a room with 16' ceilings and it's literally in the middle of the room(not against a wall). This really messes with the soundstage.

To be fair #2 - My perspective of good sound is soooooo skewed now. Working with amps putting out 120 watts(measured) to the sub etc. and working with good gear and so-so gear has me a bit of a desensitized junkie now. It's either something spectacular or it may as well be stock.

I didn't see that coming...

What to do now? Since I'm hitting the limits of the Stern amp - I'll take the opportunity to install a mini amp not being used and hardwire it in for 1 button use. It should give the needed punch I'm after, and provide a great opportunity to write it up and show everyone the details of how it can be done easily.

Amp'n up Rush - PT1

Going to break this into 2 parts because of 4 Picture restriction per post.

None of these items are my primary choices for doing this. I am using extra parts I have laying around so they don't go to waste. I just want to improve the sound to the new standard of acceptability.

I'll be using the Fosi 2.1 mini amp, and wiring it for single button use. (Aka - turn the machine on and the amp turns on, turn the machine off and the amp turns off)

ADVISORY - DO AT YOUR OWN RISK.

STEPS
1 - Take the included power brick and cut the end off that plugs into the wall.
2 - Strip back the wires and attach "Piggyback Connectors" to each wire. Size 16-14 AWG.
Tip - the wire is small compared to the terminal. I recommend stripping back about 5/8 of the insulation then folding the copper back on itself to double it up, then slide in the connector and crimp.
3 - Remove the switched side leads from the machines power button, then install the new connectors and reconnect the machines switched side to the connectors. DONT MIX UP YOUR WIRES.
Note: for the fosi power supply, it does not matter which wire is attached to pos or negative. An easy check is to look at the plug, if the plug has 2 identical terminals and can plug into the wall and then be turned 180 and plug intot he wall again then it's fine. If your plug goes into the wall only 1 way, then you are going to need to pay more attention the the pos and neg.
4 - Loop and secure your wire up in a manner that does not put stress on the connectors.

That's it - power brick/supply is ready to go, and will be operated with 1 button machine turn on.

We did it the easy way and safe way. No need for an over engineered method of tapping into power from the main Stern Spike board.

Now that we have power, we need an audio signal. In this case I am using a pinovators adapter I have laying around. This isn't first choice, I'd rather come off of the CN2 connector on the board versus using a speaker line level tap. But - so is life... I have it and can get this done this weekend.

That's it for Part 1 - We now have switched power supply, and our audio signal ready.

Next up will be installing the amp, wiring the speakers, and dialing it in.
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Amp'n up Rush - PT2

I used one of my under cabinet mounts to secure the amp inside the cabinet. It's still reachable from the coin door. So this is kind of a set it and forget it approach.

I used some velcro tape from home depot to attach the power supply to the back corner of the cabinet. Pretty easy solution and I had a roll of it. I technically could have velcro the amp down too. But I had the mount already made for the fosi.

The speaker wiring is fairly simple - so no details to get into there. Just pay attention to your Left, Right, positive, neg etc.

I joined up all the wires(power, audio, back box speaker cables) and sent it down the hole on the right side of the backbox. I made a harness out of it all with zip ties to keep it clean. Making sure to leave a loop and slack at the back for when the head gets lowered.

Loop any extra wire and tie it up - look at just behind the amp.

That's it. Upgraded Audio system that puts out more power, sounds better, and has significantly better components than those $425 systems. Plus it has Bluetooth so it can be used as a jukebox in your game room.

Now to dial in the sound to my liking.

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I have a roll of 16g, and just use it for everything. Keeps it simple.

I'm not sure how you are getting 300 watts from this Fosi 2.1 amp. It's absolute, little engine that could, wishful thinking is 200 watts. Of which it doesn't even come close - maybe 75.

You can certainly get a bigger power supply for this amplifier, but you are not going to increase its performance by doing so. You will hit the internal protection long before you take advantage of the 300 watts you are making available to it

Clipping is generally driven by the voltage rails not being wide enough. So if the amp wants 24v but you hook it up to a 12v source then you will clip and distort at lower output wattage levels.

Step #1 - Always feed an amp the max voltage it wants.
Step #2 - Give it access to enough wattage(Volts x Amps = Watts) that it can use/output.

Let's keep it simple.

This amp comes with its own power supply/brick. The amp wants 24v and the powerr supply delivers 24v. Measured with a meter to confirm. Check that box.

The amps wishful thinking output is 200 watts.(50x2 , 100x1). The power supply can make 108 watts available. (24v x 4.5 amps). The amplifier trips its protection circuitry prior to max volume. Making 300 watts available for this amp will not change this limitation. The supplied brick checks the final box.
(Further verified by giving it a 6.5a supply to verify)

There are times when the supplied brick/supply will be under valued and can be improved upon. Nobsound comes to mind, with its included 19v supply.

Go back a few pages as I have a big writeup on choosing power supplies and calculating wattage etc. Also my review of this amplifier, and a few others.

Go back a few pages, I did a writeup/review on this amplifier as well. Lots of really good info that may help you with your installation.

Edit: Found it, post #778

yes to all.

Unfortunately, I can no longer edit the original post.

You bring up some good points, and tips. Hope this can clear things up.

ADVISORY/PUBLIC NOTICE - WIRING AMPS FOR 1 BUTTON OPERATION:

Doug has a few good points in his post and things to watch out for.

1 - There are instances where Stern may have their hot side and switched side terminals mixed side to side and opposite what I marked in the picture. You may want to verify this with a voltmeter before beginning.
a - With the machine switched off, and plugged in, you can check for voltage across the pos/neg terminals. Whichever has voltage is the hot side. Whichever side does not have voltage is the switched side.
b - If you have a continuity tester or OHM meter - you can also test this. with the machine switched OFF unplug it from the wall. Check for continuity from the end of the power cord to the terminal on the switch. The side that has continuity is the hot side, the side that does not is the switched side.

2 - Unplug your machine from the wall when you are making these connections. It'll keep you from sparking, getting electrocuted etc. Plug it back in after the proper connections are made.

3 - Double check that the amp is turning on and off with the machine power switch after all connections are made. If the amp turns on and off with the pinball machine switch then you are good to go. If it stays on regardless of the switch position, then you have the hot and switched sides mixed up. Unplug your machine and switch your connectors to the other side and try again.

NOTE: You can also tap into the 110v bill acceptor power that is behind the metal cover in the backbox. I did not do it this way, because this is a location game and I will need to utilize the 110v bill acceptor power source for the bill acceptor. If you want to use the 110V bill acceptor as your source that will work too. I will probably do this and write it up at some point in the future.

Hope this clears things up and adds some additional context to the procedure.