I just picked up a Pinbot and my buddy "Exidy" snatched up a Scared Stiff. I am looking forward to getting this thing setup and doing some bulletproofing to it.

The 1st thing I am going to do is rebuild the Power Supply. Everything is working fine but whenever I get a new pin to my collection I always rebuild the power supply if it still has the original caps.

I will also add a fuse in between the Bridge Rectifiers. I always do this to my System 6 & 7 games but this is my first System 11.

I will be removing the battery holder and installing a NVRAM.

Any other advice on bulletproofing a System 11 game?

Pinbot (resized).jpg

This may have already been asked but I could not find accurate info on it so I am asking it (possibly) again.

I am replacing my old, crusty speakers in Pinbot. The original, main Backbox speaker is a 4" x 10" 8ohm speaker. I can only find the 4" x 10" in a 4ohm and spoke with numerous re-sellers including Parts Express and a couple of others and they all confirmed that they only sell it in a 4ohm version now days.

So, I am assuming that I would need to add a resistor to the 4ohm speaker to make it 8 ohms. My question is, has anyone done this before on their Pinbot with a modern 4" x 10" speaker and did you add a 4ohm resistor or did you simply drop in the new speaker as is and had no issues?

Thanks for your feedback.

Putting a 4ohm in place of an 8ohm speaker would work but I am concerned about it overheating the amp. The amp has to work harder pushing the 4ohm vs the 8ohm speaker. I may just drop the speaker in and see how hot the amp get's without adding a resistor for now and keep a close eye on it but it apparently is working ok for you.

I am replacing them both but I ordered the 8ohm for the cabinet speaker so it is correct to the original. I couldnt find the 8ohm for the back box so I ordered the 4ohm which is why I was thinking of going with a single resistor for it.

UPDATE - So I simply dropped in the 4" x 10" speaker as "grbgemen" did and the speaker did work ok but I did notice that the sound levels of the speaker and the woofer in the cabinet were not equal. It wasn't a huge difference but because of my OCD I did notice a difference.

I was going to take "Grumpy's" advice next but figured I would try one more thing before I messed with all of that wiring in parallel and series. I installed the 4ohm resistor since it is such a quick and easy install. Fortunately the resistor fixed the sound level issue so everything is good to go and all running at the original 8ohms.

As far as the sound quality, I can tell a difference with the new speakers but it is nothing dramatic which I didn't expect. I replaced the 4" x 10" speaker in the back box and the 6.5" woofer in the cabinet. The only speaker I did not replace was the small 3" one. The technology back in the 80's on these pin's never had anything incredible when it came to the amp's, sound's, hardware and etc. You can spend $200 on new speakers and the quality gain is going to be very minimal in my opinion. It isn't worth spending a lot of $$$ when it comes to the sound in these older pins but I do like replacing the old 35 - 40yr old speakers just because they do deteriorate and the paper breaks down over the years.. I do like the ease of installation with the Pinball Pro and other branded kits but the bang for your buck just isn't there unless you are installing those kit's into later pins that have better soundtracks and better sound hardware to begin with. (Just my opinion)

I was also upgrading the speakers in my Theatre of Magic at the same time as Pinbot and spent a little more $$$ on TOM due to it having DCS, better sound hardware and soundtrack but I still spent less than $160 total for both pins. The installation was easy. The only thing that I spent any significant time on was researching the original specs of both machines.

I do want to thank Grumpy and grbgemen for their advice

PinBot Speaker (resized).jpg

No I didn't opt to go with an external sub. I just wanted to replace the old, original factory speakers with some new, more modern speakers but stay within a budget and keep it mainly stock.

I found the correct 4" speaker that Pinbot uses. I replaced the 4" x 10" speaker and the 6.5" woofer as documented above. I wonder if it's worth swapping out the final speaker which is the small 4" on the right side of the back box.

I'm curious if you could really hear any difference with that tiny speaker which is mainly for the higher frequencies. I haven't purchased it yet but would love any feedback.

I saw this on ebay today.

ebay.com link: itm