Asteroids coin-op audio hum

[sideburn]

Hello,

I'm getting a hum on my Asteroids cocktail that I'm curious about. It used to get loud intermittently and I may have fixed that now but I still have a constant humming.

I have determined that the noise is coming from the main logic board and it's related to the vector display output because it changes depending on what is being drawn. For example, one buzz comes and goes as the "Press Start" text flashes on and off the screen.

 

Disconnecting the logic board by unplugging the edge connector DOES eliminate the noise (I have to put my ear against the speaker and turn volume up all the way to hear any noise when logic board is disconnected).

 

- The noise is a lot like the hum/noise you get from a Vectrex.

- Noise increases as you turn volume up.

- The game sounds are louder, but the hum is always there.
- Disconnecting the vector monitor makes no difference.
- I've replaced all of the caps on the AR-1 board.
- I've replace both of the TDA2002 amplifier ics.
- I've replaced big blue on the power supply.

Is this normal or could it be the pre amps or something on the logic board? If I turn the volume down to about half way, you can barely hear the hum at all and the game sounds are not too quiet but could be a little louder for my taste. If you turn the volume all the way up, the game sounds are very loud and the hum is very noticeable.

Thanks for reading/helping,

-Tavis

Edited March 26, 2018 by sideburn

[davyK]

My Deluxe cabinet has a hum. There is also "chatter" off the screen that is connected to the number of shapes on the screen but that it pretty quiet and I rarely notice it. The hum seems to come from the monitor and doesn't seem to be connected with volume control - hard to isolate. When the volume is turned up on mine I don't notice the background hum over the game sounds though.

 

I've watched videos on youtube and you can hear a hum in those too - I suspect it goes with the technology.

Edited March 29, 2018 by davyK

[sideburn]

My Deluxe cabinet has a hum. There is also "chatter" off the screen that is connected to the number of shapes on the screen but that it pretty quiet and I rarely notice it. The hum seems to come from the monitor and doesn't seem to be connected with volume control - hard to isolate. When the volume is turned up on mine I don't notice the background hum over the game sounds though.

 

I've watched videos on youtube and you can hear a hum in those too - I suspect it goes with the technology.

 

 

I have no hum form the monitor. the only noise I get gets louder as you turn the volume up. Volume all the way down and its silent. unless I put my ear against the speaker. I've isolated it down to the noise solely coming from the cpu board. its chatter off the vector display driver.

[davyK]

To be honest I'm not sure where the noise is coming from!! I haven't tried to figure that out. I think it's louder when I'm looking in the back with the door off. I'm also pretty sure I hear it with the sound all the way down so I doubt it has anything to do with the audio - though it could be the amp humming I suppose. Also pretty sure I hear it when the game board is disconnected so it isn't coming from that.

 

I have the back door off all the time too as I'm worried about heat even though I've been told it will be OK. So that makes it louder I guess. It isn't all that loud really. There could be noise off one or both of the fluorescent tubes too perhaps?

 

Whatever it is with mine, it's at a level where you don't notice it after a few minutes unless the house is very quiet and the game is silent between lives. It isn't getting any worse either so it isn't an issue for me really.

Edited March 30, 2018 by davyK

[sideburn]

Yeah sounds minor. But if you are curious anyway. . . if the hum doesn't get louder when you adjust the volume then that means that the cause is AFTER the audio input. So that rules out the main logic board. You could unplug the connector to the monitor to rule that out. I bet the problem is a filter capacitor on the audio/regulator board. If not that, the Big Blue cap on the power supply. If not that, possibly the tda2002 amplifier Ic's on the audio/regulator board.

 

Sounds like filter caps to me though. I just replaced all of my caps and its pretty easy to do. There's 8 of them. You can get a cap kit for the ar-1 here-> https://www.arcadepartsandrepair.com/store/rebuild-kits/atari-audio-regulator-1-a034485-01-105c-axial-cap-kit/

 

And a big blue cap here-> https://www.arcadepartsandrepair.com/store/components/atari-big-blue-capacitor-27000uf-25v/

 

I've got some extra audio amp ic's that I could drop in the mail for you if you want to try those as well but I'd try those as a last resort.

 

Maybe inspect the caps first. See if any are bulging. If they've never been replaced its not a bad idea to just replace them anyway.

Edited March 30, 2018 by sideburn

[discgolfer72]

can be lots of things

first it may be feedback from he 120 volt fans in the cabinet

next would be dirty /bad volume pots

then bad filter caps in the audio section on the board or 12v section of the power supply

without a probe I would diag the hum in that order

 

if the sound changes pitch along with changes on the screen it may be a fault in the monitor or the dac

[sideburn]

For my issue I have ruled out everything but the dac.

It does change pitch with the changes on the screen.

[davyK]

I got mine from TNT in january. They rebuild the power supply, monitor and they recap everything. They also clean & reseat all the ICs on the game board and check for dry solder - so unless something got damaged in transit it's probably just one of those things. It really is pretty minor and only noticeable if the rest of the house is quiet.

 

The power supply malfunctioned and they sent me another one but the hum was with the first one too. The power supply also does the amplification.

 

If the pitch changes with screen activity then it's what's known as vector chatter which seems to go with the tech. Have seen a video of a room with 4 or 5 vector games on the go and the sound was noticeable. But it's hard to convey sounds when recording them as it doesn't always recreate the reality.

 

Let's face it - I've yet to see a video that really conveys the majesty of a vector arcade game - you really have to experience it.

 

Edited March 30, 2018 by davyK

[davyK]

Just played a bit there - there IS a hum from the speaker. But it isn't all that loud really. Had to put my ear up to it to notice it was coming from there.

 

I've had a mini saga with this cabinet - there's a thread about it here. The replacement power supply is giving me some minor distortion on explosion sounds. TNT are repairing and returning me the original board. The two boards are visibly different. TNT tested the replacement in a Centipede which supposedly has the same system as they didn't have Dx cabinet to test it with.

 

But I've been told by a guy who services them that the Dx power supply isn't 100% compatible with the other Atari boards and sound distortion can happen if using a non Dx board in a Dx.

 

So while the game is playing great apart from the explosion sound distortion - have been enjoying it for about 6 weeks now with daily play - I'm going to see what happens when the original board is returned to me. TNT are going to test it in a Deluxe they are working on now before they return it.

 

Maybe when that is fitted the hum with disappear. Maybe it hummed with the original board because it was faulty (it failed after a week).Will wait and see. Maybe it just hums! It really isn't very loud at all. The volume control is a bit twitchy but I don't think that's what is causing it as the game sounds were perfect with the original board.

 

I haven't checked the 10.3 volts on the replacement board (I tested the 5v when I got the replacement before connecting up the game board because the failed board was only pushing out 3.9 on the 5v) so I'll test that with my meter.

Edited March 30, 2018 by davyK

[Keatah]

I've watched videos on youtube and you can hear a hum in those too - I suspect it goes with the technology.

 

It does. I clearly remember hum, hiss, white-noise, and other background sounds, from Asteroids and many other arcade machines back in the day. And an early emulator even simulated it!

[sideburn]

Ok I think the noise Im getting is normal then. Its vector chatter. I also have a Vectrex and its basically the same noise I get from that.

[Keatah]

Mm-hmm.. it should be quiet, perhaps 2% - 5% volume compared to the other sounds. From 10 meters away you shouldn't hear it.

[sideburn]

I think thats about right. At half volume or so, the noise practically unnoticeable. Noticeable at full volume from a distance but the game sounds are much louder.

[Keatah]

Yeh, it's probably alright.

[sideburn]

Yeah this video has the same vector chatter / humming that mine has but actually this one sounds like it might even be louder than mine.

 

Edited March 31, 2018 by sideburn

[Keatah]

Sounds ok. I'm sure you could eliminate it entirely with squadron of scopes and meters, armed with capacitors and filter kits. Map out your plan of attack with the schematics. Or just have fun playing the game!

[sideburn]

Na I just want it to be how it's supposed to be when it rolled out of the factory warehouse. If it needed repair to get it back to that condition then I'd want to fix it.

 

This started when it was periodically making very loud a/c hum type noises. Then I recapped everything and replaced the amp chips so I think I have solved that problem. I just wanted to confirm that the existing noises I still have are normal.

[davyK]

Enjoy the game!

 

I'm adoring mine! Asteroids is the definitive classic arcade Atari game. I don't think they ever did anything better. It's timeless and the HD graphics means it has aged gracefully and I don't see it ever being topped as a redux or remaster. It needs nothing added - Deluxe plugged the lurking, decreased the luck by swapping hyperspace for shield, and added bit of variety with the killer satellites. Any more additions would sully its purity. We are privileged to own one as far as I'm concerned.

 

 

 

Edited March 31, 2018 by davyK

[sideburn]

Oh yeah. I love mine. Got it a few years ago on Craigslist for $300.00. It needed some minor restoration. New buttons, some paint touch up and had to bondo a broken piece of wood where the control panel is. Got it like new except for the glass was scratched. But then one day a brand new old stock glass in the box showed up on eBay. I payed $200.00 for it and ended up getting $200.00 for my scratched up one!

 

So it's almost like new now inside and out. I recently put a Braze multigame kit in it so it plays asteroids, asteroids deluxe, and lunar lander. Only thing I kind of dont like is the multigame kit has the newer asteroids rom in it that makes it harder to do the lurking so now I can't reach my original high score anymore.

 

Did Todd put up a video of yours?

Edited March 31, 2018 by sideburn

[davyK]

yeah..

 

at 21'25''

 

[sideburn]

Nice! Very clean and a TNT original! I saw that video already when he posted it. The plus tax and freight! to Ireland must have been pricey. . . I would much rather have an upright but ended up with a cocktail.

Edited March 31, 2018 by sideburn

[davyK]

Nice! Very clean and a TNT original! I saw that video already when he posted it. The plus tax and freight! to Ireland must have been pricey. . . I would much rather have an upright but ended up with a cocktail.

Pricey is right!!! I had to pay 20% import tax which includes the cost of the game AND the shipping charge. Ouch.

 

It's a one-off for me. I had a big birthday nearly 2 years ago and my wife agreed I could get a cabinet. I financed it my selling a couple of hundred games from my multi-console collection. I cleared my collection of games I just wasn't going to play for various reasons. At the time the money was used to tile and refit our downstairs bathroom with the agreement when the time was right I would get a cabinet.

 

I also chose the supplier carefully. We just don't have a supplier like TNT in the UK. I actually think TNT are pretty unique. To be honest I bought into Todd Tuckey and his amazing team who seem to be extremely capable and the work they put into a machine means I consider they take most of the risk out of buying a classic cabinet.

 

So I took my time and chose a game I knew would last me years, cannot really be done justice via emulation, is an Atari classic, and would look good in a home setting. Pictures are here:

 

http://www.davykelly.com/asteroidsdeluxe. Its final position is in my hall under the stairs. Those are the 2 pics called hall1 and hall2.

 

For all the work they have done - I think I have been a bit unlucky. I had a couple of problems with it - all really related to a failed power supply. Unfortunately shipping is always a risky thing - at the end of the day my cabinet was sitting in a container for a month - winter months at that. So that may have caused the problem. TNT sent me another power supply under their warranty scheme but it's a different revision and the sound isn't 100% They are repairing the original and testing it in an Asteroids Deluxe before returning it to me. It's been emotional But TNT are supporting me extremely well considering the distance between us!

Edited April 3, 2018 by davyK

[davyK]

 

Also meant to say. Uprights are great but cocktails are far more practical........ I have space for an upright but these things are BIG and HEAVY!

[sideburn]

Looks nice. Yeah Ive been watching TNTs videos for years. Todds cool. Hes answered several questions Ive had over the years through emails.

 

The first arcade game I bought was an upright marble madness about 15 years ago. I drove 3 hours to get it and haggled with him for it for $700.00. I drove home thinking it was one of the stupidest things Id ever done and I had a new mortgage payment to come up with on top of it. Finally got home and dragged it into the house then ended up playing it til the sun came up. A good investment after all I think. I still have it. It was one of my favorites back in the 80s.

 

So I have the Asteroids cocktail the the MM upright. If I had a basement Id probably have an arcade.

[davyK]

I had buyer's remorse for several weeks after mine arrived - it wasn't anything to do with the problems either. I just kept asking myself what had I done? The size of it was a factor, as was the import price. Even when you have the dimensions you don't really get it until it arrives.

 

Still....more than happy with it now. Hope the last niggle re the sound is resolved when I get the original board back. TNT are starting to work on a Dx next week so will test my board in that.

Edited April 7, 2018 by davyK