(Topic ID: 24704)

Data East speaker noise - ideas for a cure


By roc-noc

7 years ago



Topic Stats

  • 561 posts
  • 146 Pinsiders participating
  • Latest reply 60 days ago by NYP
  • Topic is favorited by 132 Pinsiders

You

Linked Games

Topic Gallery

There have been 58 images uploaded to this topic. (View topic image gallery).

C6CF0614-EB50-4AA1-B175-C86AF62B9C0C (resized).png
Screen Shot 2020-02-16 at 3.46.42 PM (resized).png
20130806_312509 (resized).jpeg
IMG_20200215_213616573 (resized).jpg
14BEA662-93E0-4F27-A196-FFC501344C0D (resized).jpeg
72830EAE-6AC1-4C18-9233-E105D0DB486A (resized).jpeg
014337EE-420C-4448-8B33-959749FB3C80 (resized).jpeg
20190921_110322 (resized).jpg
20190921_110226 (resized).jpg
20190921_110738 (resized).jpg
20DF2860-BF50-4FB9-968E-6EC7C6CA306F (resized).jpeg
IMG_6984 (resized).jpg
5 (resized).jpg
4 (resized).jpg
3 (resized).jpg
2 (resized).jpg

There are 561 posts in this topic. You are on page 11 of 12.
#501 10 months ago
Quoted from jorro:

Once i cut the right speaker wires of the hum was gone.

The right speaker is like a piezo speaker and is designed to put out the higher frequencies. I noticed the same thing when covering or unplugging the right.

Some have posted that when they replace the speakers, the hum is improved. I assume that is because the replacements don't have the same high frequency capability.

#502 10 months ago

Well the $150 PSU I had worked...so I guess the cheap one I tried was too shitty. Luckily I had an extra ATX extension cable I cut up so I don't need to damage the actual connector on the PSU.

I ended up just using wire nuts to splice into the switch and screwed the ground into the cabinet ground braid. After doing this I of course noticed there was an unused connector coming out of the switch that went to the back of the cabinet...oh well. Either way the hum is totally gone. I have a cheaper power supply on the way, once I get that I'll use some L brackets to screw it to the cabinet.

20190921_110226 (resized).jpg20190921_110322 (resized).jpg20190921_110738 (resized).jpg
#503 10 months ago

ATX PSUs may have minimum current draw requirements.

1 week later
#504 10 months ago

Chiming back in here...

I replaced all 25 capacitors on the sound board (Data East Back to the Future) and it did not solve the buzz/hum.

It didn’t make it any worse or better, exactly the same. I had also replaced all the caps on the power board also a few weeks ago.

At this point I probably gotta go with the extra power supply solution, unless there has a major breakthrough since my last post?

Jim

#505 10 months ago

Based on my research from this thread...this power supply should do the job yes?

ebay.com link

Thanks!
Jim

1 week later
#506 10 months ago

I got a power supply that was suggested earlier in this thread, wired it all in and it works, now more buzz!

Now, there still is the “attract mode” buzz that happens when the lights flicker on and off...I wasn’t expecting this to fix that and I don’t think we have a solution yet, but the lower frequency buzz is gone.

I still have a slight buzz form the transformer itself...it’s just no longer filtering through the speakers.

Anyone know what to do about a buzzing transformer?!

014337EE-420C-4448-8B33-959749FB3C80 (resized).jpeg14BEA662-93E0-4F27-A196-FFC501344C0D (resized).jpeg72830EAE-6AC1-4C18-9233-E105D0DB486A (resized).jpeg
#507 10 months ago
Quoted from Pinballhorse:

I would like to thank all who posted on this topic of Data East noise solutions. As a new member i find this forum a great asset! I just purchased a Data East Time Machine. The background hum was taking the fun right out of playing this awesome game. After reading all 441 posts on this thread I decided the most sensible fix for me was just adding a small extra power supply dedicated to the sound board. I mounted it right next to the bottom speaker as it was easy to wire to the switched 120 v from the machine (as shown in the photo). From there a nice wire up to the soundboard with my +5 +12 and -12 then into an oem connector and problem solved. 20 dollars worth of parts and 1 hour install start to finish. The parts were obtained on Ebay and the description and part numbers are as follows.
Mean Well RT-50B PWR SPLY,SW ENCL,50W,+5/4A,+12/2A,-12/.5A, UL/CUL/TUV/CE 14.95
CT156F22-6-CA PANDUIT PANCON MAS-CON THROUGH CONNECTOR 300V AC/DC 22AWG 4.95
Thanks again for everyones help
[quoted image]

Hello! I ended super getting this power supply. I had one question for you...did you hook your ground wire to the COM port of the power supply, which then goes to the ground pin on the sound board? Just wondering why you didn’t put it on the actual ground port that is labeled with the ground symbol...kinda new to this field so forgive me if this is a stupid question.

1 week later
#508 9 months ago

Okayy, well a little feedback on my experience to get rid of the hum. Installed a new rottendog power supply, new speakers, new ribbon cables, checked all the grounds, groundstraps etc, tightened transformer, had ALL caps changed on sound board, isolated ground on sound board with plastic washers, MUCH improved but still a mild hum. Installed an auxiliary power supply and no hum! So like many things in life I took the long way around the block, I don't usually give up easy and I inherently do not like to hack machines (at least I consider it a hack-however neatly installed and reversible). And so now I know what I need to do in the future with Data East hum problems......

#509 9 months ago

I still get a slight buzz from the transformer, but it’s no longer amplifying through the speakers. Unless there is. Fix for the transformer buzz, I can live with it.

Same with the attract mode buzz...still have that.

#510 9 months ago
Quoted from NYP:

Okayy, well a little feedback on my experience to get rid of the hum. Installed a new rottendog power supply, new speakers, new ribbon cables, checked all the grounds, groundstraps etc, tightened transformer, had ALL caps changed on sound board, isolated ground on sound board with plastic washers, MUCH improved but still a mild hum. Installed an auxiliary power supply and no hum! So like many things in life I took the long way around the block, I don't usually give up easy and I inherently do not like to hack machines (at least I consider it a hack-however neatly installed and reversible). And so now I know what I need to do in the future with Data East hum problems......

It's good to see consistency... meaning you went those all those steps discussed in ~500 posts already and got the nominal result

To be clear, I tried pretty much everyone you did about 2 years ago and ended up with an external power supply that can easily be removed. I understand the spirit to explore and try. This wasn't a dig.

This thread could really use a Key Index or whatever that feature is that was added a year or two ago.

#511 9 months ago
Quoted from jimgravina:

Same with the attract mode buzz...still have that.

Your not talking about the buzz noise DMD makes when lit are you?

#512 9 months ago
Quoted from Neal_W:

Your not talking about the buzz noise DMD makes when lit are you?

Nope. This is a sound that follows the light show in attract mode. I dont have a DMD and I know my alpha numeric Isn’t the culprit.

#513 9 months ago
Quoted from jimgravina:

Nope. This is a sound that follows the light show in attract mode. I dont have a DMD and I know my alpha numeric Isn’t the culprit.

I've definitely experience a buzz in attract but I'd more formally describe it as a buzz that follow all the lights turning on and off (which happens in attract).

#514 9 months ago
Quoted from altan:

I've definitely experience a buzz in attract but I'd more formally describe it as a buzz that follow all the lights turning on and off (which happens in attract).

Exactly...I have a thread I started where I have pinpointed it to the "LAMP B+ FILTER on the MPU board where that attract mode buzz is originating from. With the sound board completely out of the system, I would still hear a faint buzz....I opened the back box and put a microphone around the MPU and sure enough, that's where the buzz is coming from...

Just dont know how to solve it!

#515 9 months ago
Quoted from altan:

I've definitely experience a buzz in attract but I'd more formally describe it as a buzz that follow all the lights turning on and off (which happens in attract).

Here’s the sound of that recorded using a pickup coil.

https://soundcloud.com/titan91-1/pinball-machine-lamps

#516 9 months ago
Quoted from Crash:

Here’s the sound of that recorded using a pickup coil.
https://soundcloud.com/titan91-1/pinball-machine-lamps

Yup, thats basically what I have.

#517 9 months ago
Quoted from jimgravina:

Exactly...I have a thread I started where I have pinpointed it to the "LAMP B+ FILTER on the MPU board where that attract mode buzz is originating from. With the sound board completely out of the system, I would still hear a faint buzz....I opened the back box and put a microphone around the MPU and sure enough, that's where the buzz is coming from...
Just dont know how to solve it!

It has come up before that the issue could originate from the MPU board. I have a MPU board out of a Star Wars that is really loud. I have another spare MPU that is almost silent. I haven't had a chance to compare the two boards but I had asked about what brand TIP transistors are used and other parts.

3 weeks later
#518 9 months ago

.

#519 9 months ago
Quoted from altan:

It's good to see consistency... meaning you went those all those steps discussed in ~500 posts already and got the nominal result
To be clear, I tried pretty much everyone you did about 2 years ago and ended up with an external power supply that can easily be removed. I understand the spirit to explore and try. This wasn't a dig.
This thread could really use a Key Index or whatever that feature is that was added a year or two ago.

I believe admins and the creator of this thread can mark key posts

3 months later
#520 5 months ago

In reading through this thread, it's obvious there are several different causes of hum and noise. Noise especially. However, as has been noted, there appears to be a fundamental problem with Data East machines and hum in the audio. This is 120Hz hum and will show up in the audio output when the audio board is completely disconnected from anything but power. My Secret Service suffered from this hum.

My machine has an XPin wms8345 power board in place of the original Data East power board. This will actually exacerbate the hum (makes it louder), though I would fully expect it to be there at a lower level with the original Data East power board.

My problem, and a fundamental issue with the Data East power supply board, exacerbated by the design of the XPin replacement is ripple on the +12V line.

The +12V supply comes directly from the bridge rectifier, and the only conditioning is a single bulk filter cap. The Data East schematics specify this as 0.18F (yes, Farad). All the pictures on original power boards I have seen have 18,000uF (0.018F), or 1/10th the specified capacitance. The XPin board has 1000uf (0.001F), or about 1/200th of the specified capacitance.

The +12V supply goes two places. It feeds the +5V regulator, which powers all the logic. It also goes to the audio board, where it goes through an inductor to filter high frequency noise, though a couple of small bulk filter caps, and directly into the audio output amplifiers. Because of the large load of the derived +5V supply, there is very significant ripple on the +12V supply. On my machine, with an XPin supply, the ripple is about 400mV.

Note that the -12V supply also has significant ripple, something around 200mv. However, it feeds the -5V regulator on the audio board and itself used directly anywhere. The -5V regulator does its job and there is no ripple on its output.

So, my solution? I bought an adjustable buck/boost DC/DC converted and wired it into the +12V feed to the audio board. I adjusted it for 12V output before powering it it. The result is night and day.

The yellow trace is the ripple on the +12V from the power supply board. The red is the output of the DC/DC converter. In both cases, the scope inputs were capacitively coupled, so all you are seeing is the ripple/noise. The hum is completely gone from the audio output.

Note this only fixes hum. It doesn't fix the "hiss" from the amplifier design. It achieves the same thing that putting in a separate power supply for the audio board, in a slightly more targeted fashion, addressing just the problem power feed.

IMG_20200215_213616573 (resized).jpg20130806_312509 (resized).jpeg
#521 5 months ago

Pretty sure the 18farad is a typo.
18f didn't really exist back then. Even today, 18f is only available as a supervisor used only as battery backup application.

#522 5 months ago
Quoted from wpmcnamara:

In reading through this thread, it's obvious there are several different causes of hum and noise. Noise especially. However, as has been noted, there appears to be a fundamental problem with Data East machines and hum in the audio. This is 120Hz hum and will show up in the audio output when the audio board is completely disconnected from anything but power. My Secret Service suffered from this hum.
My machine has an XPin wms8345 power board in place of the original Data East power board. This will actually exacerbate the hum (makes it louder), though I would fully expect it to be there at a lower level with the original Data East power board.
My problem, and a fundamental issue with the Data East power supply board, exacerbated by the design of the XPin replacement is ripple on the +12V line.
The +12V supply comes directly from the bridge rectifier, and the only conditioning is a single bulk filter cap. The Data East schematics specify this as 0.18F (yes, Farad). All the pictures on original power boards I have seen have 18,000uF (0.018F), or 1/10th the specified capacitance. The XPin board has 1000uf (0.001F), or about 1/200th of the specified capacitance.
The +12V supply goes two places. It feeds the +5V regulator, which powers all the logic. It also goes to the audio board, where it goes through an inductor to filter high frequency noise, though a couple of small bulk filter caps, and directly into the audio output amplifiers. Because of the large load of the derived +5V supply, there is very significant ripple on the +12V supply. On my machine, with an XPin supply, the ripple is about 400mV.
Note that the -12V supply also has significant ripple, something around 200mv. However, it feeds the -5V regulator on the audio board and itself used directly anywhere. The -5V regulator does its job and there is no ripple on its output.
So, my solution? I bought an adjustable buck/boost DC/DC converted and wired it into the +12V feed to the audio board. I adjusted it for 12V output before powering it it. The result is night and day.
The yellow trace is the ripple on the +12V from the power supply board. The red is the output of the DC/DC converter. In both cases, the scope inputs were capacitively coupled, so all you are seeing is the ripple/noise. The hum is completely gone from the audio output.
Note this only fixes hum. It doesn't fix the "hiss" from the amplifier design. It achieves the same thing that putting in a separate power supply for the audio board, in a slightly more targeted fashion, addressing just the problem power feed.[quoted image][quoted image]

I'd love to see more on how much this fix cost and how to hook it up. I'm not able to understand the fix from your picture, sorry.

#523 5 months ago

Actually, minor correction - Data East calls out 0.018F caps, not 0.18F caps. When you see 0.18F such as on the Secret Service schematics - that's a typo. Remember that they pretty much plagiarized Williams for awhile including power supplies. Bulk capacitance of that value in the 1980s would have been horribly expensive and impractical.

The noise you are seeing on the input is directly related to the switching supply.
Looks like the replacement board has included the capacitance for the switch mode power supply. But is there really no bulk capacitance? That seems very strange.

The input wave (yellow) appears to be a considerably higher frequency than the standard 60Hz/120Hz(FWB) hum and is actually the switching frequency of the regulator. You would have needed to change your time base on the scope to a much longer period to see the 120Hz hum. Your trace looks exactly like the "Input ripple voltage plot" posted in the Texas Instruments "Input and Output Capacitor Selection Application Report" for no (or insufficient) external capacitance. Their plot had a saw tooth like yours but had a 200mV p-p which they considered high.

What a few of the board makers use in their design is the application notes for their specific voltage regulators. The app notes specify that the regulator requires x amount of low-impedance input capacitance so that is what the board makers use. What the board maker totally disregards is that the regulator manufacturer is basing the design on a DC power source that has *already been sufficiently filtered* at the input - i.e. has sufficient bulk capacitance. A single, 1000uF cap for both bulk filtering and voltage regulator ramp up is insufficient. All that gobletygoop you see on that yellow scope trace would have been seen at the sound board as well (minus the minor inductance filtering of the cabinet wiring).

When I was selling pinball boards - I used 4x input capacitors. Two paralleled large caps for bulk capacitance and two paralleled smaller, low-ESR caps for the voltage regulator high frequency ramp up. I would have expected to see the same sort of arrangement on the replacement board as well.

What you did is unclear by how its written. You took the 12V unregulated power, inserted a regulator to give you...12V regulated output? Or did you take the 5V output and use the boost function to take it up to 12V?

I was going to suggest using a pi filter at the input of the DE board. But DE already has them on their board and pi filters are typically for higher frequencies. Is there really only one pin assigned for the power ground connection? Also looks like DE has only one 1000uF filter on the input, that could have been better for lower freq filtering.
If they're relying on the now nonexistant 18000uF bulk cap for filtering - that one is now gone from the replacement board. Plus the fact that the cap was remotely located on the other board only exaggerated the problem. Better isolation between logic 12V and analog 12V is what DE needed. Would not be an easy task to fix. If I were designing a replacement power board - I would include two 12V bridge rectifier circuits on the board - one for logic power and one for analog power. And include real bulk capacitors and a heavy duty, shielded power connection between boards and all kinds of bells and whistles. Gee, aren't "If I could build these, I would do it better" always great!

#524 5 months ago

My plan to fix the hum is sell the machine eventually.

I plan on just playing it for a while as it's fun and novices are cool with it. Eventually it will morph into a STPrem.

My hum seems to come and go a little though. Interesting, no? Not certain if that is indicative of anything.

#525 5 months ago
Quoted from Zitt:

Pretty sure the 18farad is a typo.
18f didn't really exist back then. Even today, 18f is only available as a supervisor used only as battery backup application.

18f is a car battery.

#526 5 months ago

For those commenting on 18Farads being rediculous, note that my post and the schematic specifies 0.18Farad, or 180,000uF. 18Farads would have, indeed, been crazy.

Quoted from G-P-E:

Actually, minor correction - Data East calls out 0.018F caps, not 0.18F caps. When you see 0.18F such as on the Secret Service schematics - that's a typo. Remember that they pretty much plagiarized Williams for awhile including power supplies. Bulk capacitance of that value in the 1980s would have been horribly expensive and impractical.

I thought 0.18F was awfully big, but then every schematic I came across (admittedly I was just looking at Secret Service manuals) showed 0.18F, including my original paper copy. For reference, the first image is from the Secret Service manual. Not that I don't doubt it could be a typo. More I'm including it for reference.

Quoted from G-P-E:

The noise you are seeing on the input is directly related to the switching supply.
Looks like the replacement board has included the capacitance for the switch mode power supply. But is there really no bulk capacitance? That seems very strange.
The input wave (yellow) appears to be a considerably higher frequency than the standard 60Hz/120Hz(FWB) hum and is actually the switching frequency of the regulator. You would have needed to change your time base on the scope to a much longer period to see the 120Hz hum. Your trace looks exactly like the "Input ripple voltage plot" posted in the Texas Instruments "Input and Output Capacitor Selection Application Report" for no (or insufficient) external capacitance. Their plot had a saw tooth like yours but had a 200mV p-p which they considered high.

Note that the scope timebase is set to 5ms/div. 120Hz is 8.33ms, or 1.667 divisions, which lines up with the scope capture and also agrees with the measured frequency of channel #2. See the measurements in the low left of the scope capture.

Quoted from G-P-E:

What a few of the board makers use in their design is the application notes for their specific voltage regulators. The app notes specify that the regulator requires x amount of low-impedance input capacitance so that is what the board makers use. What the board maker totally disregards is that the regulator manufacturer is basing the design on a DC power source that has *already been sufficiently filtered* at the input - i.e. has sufficient bulk capacitance. A single, 1000uF cap for both bulk filtering and voltage regulator ramp up is insufficient. All that gobletygoop you see on that yellow scope trace would have been seen at the sound board as well (minus the minor inductance filtering of the cabinet wiring).
When I was selling pinball boards - I used 4x input capacitors. Two paralleled large caps for bulk capacitance and two paralleled smaller, low-ESR caps for the voltage regulator high frequency ramp up. I would have expected to see the same sort of arrangement on the replacement board as well.

Yeah, and I made a mistake too. As noted in my original post the bulk capacitance on the +12V, on the XPin board, is only 220uF. The -12V rail has 1000uF, which does match the original schematic. So the +12V rail is about two orders of magnitude low in capacitance.

Quoted from G-P-E:

What you did is unclear by how its written. You took the 12V unregulated power, inserted a regulator to give you...12V regulated output? Or did you take the 5V output and use the boost function to take it up to 12V?

Yeah, not the clearest from my picture or post. I make a male to female connector to put inline with the power connection to the audio board. The +5V,-12V, and GND lines pass straight through. The +12V line has a buck/boost converter inserted into it.

amazon.com link »

Above is the one I used. It will switch between boost and buck mode automatically to keep the output at the set voltage. Honesty I didn't expect it to work as well as it did. It's a pretty simple and cheap board and I expected a glitch when the input crossed the output set point. However it behaves fine, both on the bench and installed. I'm sure you could make it misbehave under certain circumstances, but in an hour of play last night, I didn't have any problems. Suppose I need to dig up the datasheet on the controller and see what it says about the conditions I'm using it in.

Quoted from G-P-E:

I was going to suggest using a pi filter at the input of the DE board. But DE already has them on their board and pi filters are typically for higher frequencies. Is there really only one pin assigned for the power ground connection? Also looks like DE has only one 1000uF filter on the input, that could have been better for lower freq filtering.
If they're relying on the now nonexistant 18000uF bulk cap for filtering - that one is now gone from the replacement board. Plus the fact that the cap was remotely located on the other board only exaggerated the problem. Better isolation between logic 12V and analog 12V is what DE needed. Would not be an easy task to fix. If I were designing a replacement power board - I would include two 12V bridge rectifier circuits on the board - one for logic power and one for analog power. And include real bulk capacitors and a heavy duty, shielded power connection between boards and all kinds of bells and whistles. Gee, aren't "If I could build these, I would do it better" always great!

There are at least three grounds to the audio board. The main power connector, the data cable to the CPU, and the mounting studs. This is why some people are dealing with ground loop hum. If there really was only a single ground, things would be fine in that regard. As far as what I would do in a replacement design, well that depends. If I was trying to be as absolutely generic as possible, I probably would have put boost converters on the +12V and -12V rails, followed by buck converters to bring them back to exactly +/-12V, and a separate buck converter for the +5V line. You's lose a little efficiency with the double conversion, but it would still be way better than the original linear supply.

For others, I had also posted regarding this on the KLOV forums and G-P-E responded there as well. I thought I'd include part of my response over there, regarding the bulk capacitance, or lack thereof on the power board. Again, more information for those looking in the future.

Since the switching regulator on the XPin board is outputting 5V, the headroom is sufficient that the ripple due to missing bulk capacitance doesn't impact the 5V regulator. It outputs good, clean 5V. Unfortunately the unregulated 12V also directly feeds something that is sensitive to that ripple. The XPin board only requires about 20mA of load on the unregulated 12V to cause about 400mV of ripple. The original Data East board, with 18,000uF of bulk capacitance would have needed about 1.2A of load on the +12V line to get the same 400mV of ripple. Now, given that the Xpin is an efficient buck regulator, it could certainly get away with less bulk capacitance, but not 100 times less. A pair of 2200uf caps would have dropped that ripple down to the 20mV range. For reference, the 0.18F specified on the schematic would have put the original power supply at around 30mV ripple under 1.2A load. I don't have an original Data East power and CPU board, but I can certainly believe 1.2A load as realistic, meaning it would behave just like the XPin board -- or that the XPin board behaves just like the original.

Screen Shot 2020-02-16 at 3.46.42 PM (resized).png
#527 5 months ago

I did exactly the same you described and have installed a buck converter in my MSF for 2 years now and it works fine there. Reduced the hum a lot. Ripple is way lower than before.
In my case I set the voltage to about 9VDC (only had a basic buck converter) which is still fine for the amplifiers on the soundboard

1 week later
#528 5 months ago

So I am back to this thread 3 years later haha.
Started using Laser War again and it was "normal quiet" at first but then developed a super loud hum.
Long and short of my fault finding so far is -
The L+R audio pre volume control is good.
Left channel audio is good all the way to the speaker.
Right channel audio has hum and some audio, the MB3730 is amplifying what is presented to it.
Center channel is all hum and nothing else, super loud.

So all the hum is generated after the 2 channel audio goes through the volume control but before it hits the audio amps, and is in the right and center channels only. Let's look at the schematic......it does not match. I appear to have the super early DE 0288-1 with the factory ground rework mods. I cannot find a schematic for it anywhere.
I think the later schematic's are functionally correct for my board but the component designations are totally wrong.

#529 5 months ago

Well the right side MB3730 is dead and the center channel opamp appears to be causing the massive hum.
So as I have good audio pre volume control I just added a TDA7297 amplifier module I had kicking around and all is well again.
No center speaker but the sound is quite good from the stereo pair.

1 week later
#530 5 months ago

It has to do with current draw and the caps on one of the boards. I don't think it should be a problem. Honestly I would leave it alone.

1 month later
#531 4 months ago
Quoted from wpmcnamara:

I
My machine has an XPin wms8345 power board in place of the original Data East power board. This will actually exacerbate the hum (makes it louder), though I would fully expect it to be there at a lower level with the original Data East power board.

I recently tried an XPin power supply board in 2 different Data East DMD machines, in both cases the hum was made more noticeable

#532 4 months ago

My JP was humming, but mostly from the right speaker.
Floated the board, dmd switched, pin2dmd placed,rewired, recaped, even one day completely cut of the right speaker.
Now with pinsound with the movie files i'm back in love with my JP !
Pinsound peeps!
Epic!

#533 4 months ago

Pinsound bypasses the factory sound board, removing ALL hum?

#534 3 months ago

I have never noticed any extra hum i call it more of a high pitched whine. But then i have recapped all of my sound boards not long after i got each game and gutted power supply. The wine seems to correspond to the dmd activity it may also be if game is on i'm playing it or game next to it so its not really quiet.

#535 3 months ago
Quoted from cp1610:

I have never noticed any extra hum i call it more of a high pitched whine. But then i have recapped all of my sound boards not long after i got each game and gutted power supply. The wine seems to correspond to the dmd activity it may also be if game is on i'm playing it or game next to it so its not really quiet.

There seem to be at least 3 sources of noise on the Data East machines. Noise with DMD activity, noise from the controlled lamps, and general noise some from the power. Some games are worse then others. In attract mode when the machine is supposed to be quiet you can often hear when the controlled lights are moving.

I need to do some testing to see how much is generated on the MPU board. I have one MPU when in a game things are relatively quiet. Have another MPU when installed there is excess noise.

If any caps are bad then for sure re capping will help and in some cases may fix it. I just think there are other factors involved that hasn’t been isolated yet.

#536 3 months ago
Quoted from Robotworkshop:

There seem to be at least 3 sources of noise on the Data East machines. Noise with DMD activity, noise from the controlled lamps, and general noise some from the power. Some games are worse then others. In attract mode when the machine is supposed to be quiet you can often hear when the controlled lights are moving.
I need to do some testing to see how much is generated on the MPU board. I have one MPU when in a game things are relatively quiet. Have another MPU when installed there is excess noise.
If any caps are bad then for sure re capping will help and in some cases may fix it. I just think there are other factors involved that hasn’t been isolated yet.

I think the one that annoys most is the loud constant hum , which often seems louder from the right speaker.

#537 3 months ago

If ever there was a thread that needed some key posts... this is it.

#538 3 months ago
Quoted from Ive:

I think the one that annoys most is the loud constant hum , which often seems louder from the right speaker.

I have a Rocky and Bullwinkle. The noise isn’t too bad but most noticeable on the controlled lighting in attract mode. I guess I’m lucky that it isn’t too bad. I’ve also read that the loud constant hum is bad on some machines.

1 month later
#539 83 days ago

Not to sound like a broken record because this was said before (but lost in the abyss of 500+ previous posts) but the easiest solution seems to be a standalone power supply for the soundboard. Inexpensive and pretty easy to install and cuts out the hum entirely. It did for me anyways.

#540 83 days ago
Quoted from MoSeS_1592:

Not to sound like a broken record because this was said before (but lost in the abyss of 500+ previous posts) but the easiest solution seems to be a standalone power supply for the soundboard. Inexpensive and pretty easy to install and cuts out the hum entirely. It did for me anyways.

Tried that and made no difference on mine.
Dang this is such an annoying issue

#541 82 days ago
Quoted from Ive:

Tried that and made no difference on mine.
Dang this is such an annoying issue

I would disconnect the DMD it is probably the source if you still getting the hum after adding the new power supply.

#542 82 days ago

Is there a suggestion or a link for the power supply? What else is needed? My tftc is quite noisey. Thanks in advance

#543 82 days ago

I just got a TFTC with a horrible humming sound from the speakers. I floated the sound board, and that got rid of about 55-60 percent of the noise. I then hooked up an external power ATX power supply from an old computer I had lying around, and that got rid of another 30-35 percent. I would say I have about 10 percent left, but I think that is actually from the amplifiers, and then a really faint hiss that follows the GI. But these last 10 percent is really only noticeable with your ears against the speakers.

Så All in All, i would definitely recommend going the external power supply route. An old ATX PSU works just fine, and has 12V, 5V and -12V as needed by the sound board.

#544 82 days ago

Forgot to mention that when I had my DE Star Wars, floating the sound board didn't make any difference at all. But I never tried the external PSU option on that machine.

#545 81 days ago
Quoted from crassmage:

Is there a suggestion or a link for the power supply? What else is needed? My tftc is quite noisey. Thanks in advance

There were a few links posted miles ago in this thread to power supplies (available on ebay/amazon) that supposedly worked. I used an ATX power supply from an old desktop computer that I had lying around and it worked perfectly. My hum was originally bad, but tolerable as long as there was some other miscellaneous ambient noise in the room. After switching to a Rottendog power supply the freaking hum could be heard from across the street. I used the ATX power supply for the sound and now its silent. I rewired my service outlet so it no longer bypasses the ON/OFF switch under the cab and plugged my ATX into it.

This is probably unrelated but I had horrible hum on a Space Shuttle I picked up last year. Everything worked for the most part except for a faulty wire harness to the display logic. I attributed the hum to worn out caps. I had to remove the MPU/Driver board to replace a bad header pin connector. This required removing every wire harness from the MPU/Driver board. I cleaned all the male header pins with electronics cleaner before plugging the wire harnesses back in. After this the speaker hum vanished. So whatever was causing the hum was apparently from poor wire connectivity, probably from the PF lamps, since the humming would strobe and oscillate in lockstep with the playfield lighting sequence. Lesson here is you may want to check quality of the header pins and wire harnesses elsewhere on the MPU board, displays, etc, in places that would be seemingly unrelated to sound/speakers.

#547 81 days ago
Quoted from NYP:

I used this: ebay.com link » Mean Well Rt 50b

Has it held up?
How long have you had it installed .
What are the specs ?
When I go to Description it says unsecure site.

#548 81 days ago

Ok found this data sheet

C6CF0614-EB50-4AA1-B175-C86AF62B9C0C (resized).png
#549 80 days ago
Quoted from MoSeS_1592:

This is probably unrelated but I had horrible hum on a Space Shuttle I picked up last year. Everything worked for the most part except for a faulty wire harness to the display logic. I attributed the hum to worn out caps. I had to remove the MPU/Driver board to replace a bad header pin connector. This required removing every wire harness from the MPU/Driver board. I cleaned all the male header pins with electronics cleaner before plugging the wire harnesses back in. After this the speaker hum vanished. So whatever was causing the hum was apparently from poor wire connectivity, probably from the PF lamps, since the humming would strobe and oscillate in lockstep with the playfield lighting sequence. Lesson here is you may want to check quality of the header pins and wire harnesses elsewhere on the MPU board, displays, etc, in places that would be seemingly unrelated to sound/speakers.

Oddly enough I had a Space Shuttle last year with horrendous hum/speaker noises. *Really* tightening down the boards in the backbox removed 95% of the noise !

#550 80 days ago
Quoted from freddy:

Has it held up?
How long have you had it installed .
What are the specs ?
When I go to Description it says unsecure site.

Been about a year, got rid of the hum, holding up fine. Small enough to hide in the backbox, no complaints.

Promoted items from the Pinside Marketplace
$ 128.00
Playfield - Toys/Add-ons
ModFather Pinball Mods
From: $ 9.99
There are 561 posts in this topic. You are on page 11 of 12.

Hey there! Got a moment?

Great to see you're enjoying Pinside! Did you know Pinside is able to run thanks to donations from our visitors? Please donate to Pinside, support the site and get anext to your username to show for it! Donate to Pinside