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The pulse codes must be the same for the two boxes. I know the SCs are different than the 3W1s so those two boxes wouldn’t work together. I think the SCs were the first models that had different codes but not sure about that.
As Scudie says, it looks like the title strips print out in a different order for the two boxes but the letter/number selections look to be the same for the first 100 songs. Assuming the codes for any given selection are the same (I know the SC boxes are different than the 3W1s) it should work, but you’ll probably want to sort the playlists differently if you want the title strips to looks the same for the 100 songs in common.
Try it out and let us know.
Klaatu – Because I think the buzzing noise is in the signals at Pins 7 & 8 and it works fine as is.
Scudie – Keep in mind if you want to use the existing speaker lug terminals you’ll need to cut the PC board traces that go to it.
I use a program called AVS4U that I purchased years ago. It gives a visual display of the volume level for the entire song. What I notice a when using the normalizing function is that a single or a few instantaneous loud spots will limit the normalized volume at a fairly low level for 99.9% of the song. When that happens I manually increase the volume to match the level of other songs.
I notice CDs volume level tends to vary from one to another and I also download a lot of songs from YouTube and those volume levels are all over the place.
I’m sure there are better amps available if you have room to fit them in.
The PAM8403 amps actually sound pretty good to me with better speakers. I hooked one up to directly to my hifi stereo speakers and was impressed with the volume. The sound quality was similar to what it sounds like when I use a Bluetooth transmitter connected to the headphone output.
Something else I notice. The volume control on the emulator cuts the high frequencies when the loudness is reduced below about 80%. The volume control on the external amplifier doesn’t do that. On my SC boxes I’ve been keeping the volume at about 60% and using the built in buttons to control the volumes. With the external amp I can keep the emulator volume at 100% and adjust the external amp volume to 60% and I don’t get the cut in high frequencies. In that respect it actually sounds a little better to me.
Klaatu – I know a line out should be feeding the PAM8403 on the unmodified emulators but I think the headphone out is what’s actually feeding it. The max volume is the same on my modified emulator as it is on my other emulators that weren’t defective. I wouldn’t expect that if a much lower line out signal was feeding one of them. Also, I haven’t studied the PC board closely enough to figure out what the circuit looks like but the volume pot output appears to go directly to the headphone output. Bottom line is that the modified amp sounds identical to the others but without the buzzing.
UPDATE: Scudie couldn’t upload his video to the forum so he emailed it to me which I’ve uploaded to YouTube: https://www.youtube.com/watch?v=tu3gCtW8Dck
I also listened to my wallboxes again and it appears I have the same buzzing that you are experiencing. Here’s a video of mine with the volume set to zero. There’s buzzing in both channels but it’s clearly louder in the left. The buzzing volume remains constant no matter where the volume control on the emulator is set so it’s barely noticeable with the volume around 20% and not at all at 50% or more. In my Seeburg SC machines I use the built in buttons to control volume and leave the volume on the emulator at about 75% so it’s not a problem for me. I can see where it would be a problem in other installations where using the volume on the emulator is required. Bummer. https://www.youtube.com/watch?v=elwDCJXj4dA
On the brighter side… the emulator I modified to replace the audio amp has no buzzing.
Hey Scudie – Can you post a video of the hum in your left channel? I’m curious how bad it is and why Fabien/Gaelle haven’t sent replacements.
Sounds like you have a defective unit. Have you tried to contact Fabien or Gaelle?
FWIW, I notice a change of tone with volume on mine. When the volume is reduced from maximum the high frequencies are reduced. Sound like yours does the opposite. The balance control thing is strange too. Very odd that so many different issues seem to be occurring.
I saw on another post where Michiel mentions he has buzzing in his left channel speaker but not through the headphones. If that the case then it sounds like the left channel buzzing problem is in the power amplifier stage? If so you might be able to cure that by making this mod to your units too.
It take a long time directly from China but the amplifier is cheap!
Groet, Michiel –
Interesting thought about the jack mode switch. I was assuming it was to switch between the volume control mounted on the PC board vs. the remote volume control. Had never thought of it possibly being to switch between the speaker output vs. headphone output. I’ll have to do some testing on that.
More importantly, if the sound through the headphones doesn’t have the buzzing in the left channel, that means that the pre-amp output is okay and the problem is with the power amp section. All of the 5 units I have received have NOT had a buzzing problem with the left channel but I did receive 3 that had a defective power amplifier and had no sound at the speakers. It could very well be that they just had a bad run of the amplifier chips. Wouldn’t surprise me. I even received a power supply that was putting out double the voltage it was supposed to. Go to love Chinese quality control!
Strange about the sound dropouts. I noticed similar behaviour a couple of times when I had some built up static electricity and touched the wallbox. I also had one unit that would stop completely after playing for a few seconds. I think that one may have been damaged by the power supply that was putting out double the voltage.
The background hum in all of mine isn’t too bad. Hardly noticeable unless the volume is very low. I haven’t really compared to see if it’s any different with the new amplifier.
What I notice on all units is that the tone changes significantly with volume level. As volumes is reduced from max the high frequencies are noticeably reduced around 80% and below. It’s also kind of odd that the line out varies with the volume control. Make me think the circuit was adapted from a design intended as a headphone out.
I saw on the facebook group someone had done one in a Coke theme. It looked pretty nice so I’m thinking about that if I can find one with poor chrome for a good price that I wouldn’t feel bad about painting.
Klaatu – Yes a big problem with BT is having to pair it. Would be nice if a remote button could be included similar to the reject button. The other problem is of course that most small ones are battery powered.
As for the cover it looks great but I’ve removed mine in every application so far.
I like to keep my boxes as original as possible so no need for and LCD or remote. I would like to see a built-in Bluetooth transmitter though. Mine sounds great through my home stereo though BT. I have a small battery operated unit but would be nice to have something powered by the emulator’s power supply.
So you used Perspex between the records as spacers? That should be interesting. Still not convinced you need to polish the outside edge. It might diffuse the light better if you don’t. Might be worth a try since that would be easier too.
Look forward to seeing what you come up with.
Was your 1 amp fuse in front of the transformer? I was talking with someone else and they were using a 1 amp fuse in front with no problem.
