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Muh-soggy-knee -
Re: Roland HP-1 Electric Organ/Keyboard audio output noise
I think what happened is what would be expected to happen.
Pins
1 Sig L
2 Sig R
3 AGnd
4 Mute Send
5 Mute Ret
6 LED K
7 LED A
removing the 7 pin plug the piano switched on but the power led did not light up (Pin 6&7), no sound at all - Pin4&5 (no fault noise or key stroke tunes) either from built-in speakers or headphones obviously.
So I removed just pins 1 and 2 Sig L and R, piano powers up with led and still get the faulty noise through the speakers.Last edited by notallbad; 10-13-2013, 05:38 PM.Comment
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Re: Roland HP-1 Electric Organ/Keyboard audio output noise
Solder side of the Main board.Attached FilesComment
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Re: Roland HP-1 Electric Organ/Keyboard audio output noise
So, I'm going to connect an external speaker to the 'Output' jack, looking at the schematics this will bypass the Equaliser and Amplifier circuitry.
These I take it would need to be powered speakers?
If possible I shall then also try connecting an external input, which would presumably bypass the sound generator circuitry on the main board.Last edited by notallbad; 10-14-2013, 05:45 AM.Comment
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Re: Roland HP-1 Electric Organ/Keyboard audio output noise
Theres also a Local Control On and Off function which is for connecting MIDI devices, in the off state 'the keyboard and the internal sound generator are in an unlinked state. No sound will be produced by the keyboard when it is played.'
The faulty noise still persists with this on or off.Comment
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Re: Roland HP-1 Electric Organ/Keyboard audio output noise
Hacked a few wires and mashed up a connection between the piano input/output jacks to a Logik LOGLM101DU Micro Hi-Fi System.
Connected powered external speakers and get 'fault' noise through both left and right speakers with volume on piano turned up only.
Connect an Aux input and plays through the pianos internal speakers fine, the 'fault' noise only occurs when the volume on the piano is turned up.
Not sure exactly how conclusive this is?
Does this narrow it down any?Comment
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Re: Roland HP-1 Electric Organ/Keyboard audio output noise
No, doesn't seem to make a difference tapping or twiddling the volume knob.Comment
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Re: Roland HP-1 Electric Organ/Keyboard audio output noise
Would it be possible to disconnect on Power/Amp Board CN4 Pins 10 LeftCh Signal, 11 AGnd and 12 RightCh Signal (these are AOUTL+/- and AOUTR+/- on AK4324 96kHz Sampling 24Bit DAC) and connect directly to speakers, bypassing the Control PCB i.e master volume and bypassing Power/Amp board.Last edited by notallbad; 10-24-2013, 05:54 AM.Comment
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Re: Roland HP-1 Electric Organ/Keyboard audio output noise
Still no success fixing this but an update:
Scope connected to CN8, Agnd (Pin 11) and LeftCh-Signal (Pin 10) or RightCh-Signal (Pin 12) and get the 'noise' waveform. Also get the 'noise' waveform on pins 1 and 7 of the M5218AFP - Dual Low-Noise Op-Amp.
The next step is to check between the 96kHz Sampling 24-bit DAC (AK4324) and the Op-Amp (M5218AFP).
Not really sure how to check before the DAC and getting the feeling that if the fault is before the DAC the problem is going to lie with an I.C.Comment
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Hi all,
I am working on a sound processor, it tends to overheat so I fitted a fan inside. The fan is connected to the +15V of the PSU via a DC-DC converter based on the LM2596 to reduce the voltage to around 10.5V.
Unfortunately the analogue circuitry is picking up the noise from the fan in two ways:
1. The fan is close to the analogue section, the motor itself gets into the outputs so I'll have to move it somewhere else
2. Even with the fan running outside of the case, there is still some noise which is clearly going back to the processor via power line.... -
Surprisingly enough, this receiver doesn't have the DSP chip issue. The HDMI board does not get hot, and sound over HDMI works fine.
Regardless of the input, the right channel has noise that is clearly noticeable even on average volume level. The only cases when there's no noise is when VCR input is selected (some tracks on the board are damaged, maybe that's why), or if HDMI input is selected but nothing plugged into it. In all other cases, even when no input is connected I still have the noise.
There's some logic behind it. As soon as I select an input I get only left...04-23-2025, 10:09 PM -
Hello
I have since a long time a Philips HTS8010S/01 which has been old but was doing the job.
Since a few days, it starts by making a weird "static" nois when switches on for a few seconds to a minute and then works like a charm.
Noise loudly outputs from the 3 channels, even if no signal is sent by the controler.DVD to the subwoofer/amp unit.
I was thinking of a soldering that was starting to be damaged and that was only doing the job after a few seconds of heating, most probbaly on the power board
Removed each of tyhe boards
...02-08-2025, 08:22 AM -
Good day folks. Today, I came across something kinda special, which I haven't worked on before: a Roland RD100 electric piano. It was just sitting there in the shop covered in dust, no doubt having been ravaged and then abandoned by my oh-so-skilled co-worker. I actually remember seeing him struggling with this thing and I recall briefly witnessing the problem too: some of the notes play distorted. I'll try plugging it myself and maybe do some captures for you to hear for yourselves, but let's just say it sounds....bad.
I haven't actually dug into it myself yet, so this is mostly... -
Hello,
I know some might say... just buy another one. Sell it as parts..!
So had this AMP for quite some time. Recently I saw light smoke coming out of the AMP. Had my fire extinguisher close by. Just kidding. Turned immediately all devices off from mains.
Let things cool a bit, and opened up the amp device. I clearly saw on the main board which hosts the 5X amp (5.1), 3 10 ohms 1W resistors had their leads looking black, while the rest of the remaining 2 x 10 ohms were brownish as being installed from factory.
Spent some time downloading the Service...06-11-2024, 08:38 AM
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