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Audio Amp Circuit - Revised

$30-250 USD

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Publicado há aproximadamente 7 anos

$30-250 USD

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I am reworking an old Sound Card project and would like to revise the audio amplification circuit. Attached are the old schematic files. I have replaced the AY Sound Generators with an FPGA using PWM output on 2 pins (Left and Right audio) and the new circuit needs to take this in to account. The current design has a Left, Right, and Center channel - same as on the schematic. I'm not sure much is needed to be done with the Center channel circuit, however I am open to changes and you can find details about the circuit online searching "Apple IIe Speaker" or I can supply links to schematics. Currently there seems to be a lot of noise and I want to make the circuit as quiet as possible (within reason). Peak-to-Peak from the FPGA is a bit more than from the AY's and could be part of the issue. The LM1877 is also not the best OpAmp and I would prefer something of better quality. My environment could also be an issue so I plan to use a 4 Layer PCB and cover the audio circuits with an RFI Shield, although you can advise is either are really is needed or not. A Negative Referenced Mixer design is preferred and I think will solve some of the issues as well with mixing. I think part of the noise could be related to the gain needed due to all the resistors to mix the audio. The old design was created by computer guys, not audio guys. Hopefully you can do better than they did. Any questions just ask. Thanks!
ID do Projeto: 13387731

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4 propostas
Projeto remoto
Ativo há 7 anos

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4 freelancers are bidding on average $220 USD for this job
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Hi Sir, We are expert in pcb designs and we know your pcb design has serious issues of EMI. we can cater it . dont worry if you can pay our fee we will make you worry free. We offer our services at very feasible rates. Please discuss with us in details. Let me give you a brief introduction about Turktronics. At Turktronics, We are team of developers and engineers professional in designing embedded system solutions, electronic circuit solutions, pcb designs, database programming such as MySQL etc, software designs and GUI/UI development, android applications, integrating software and hardware and providing complete solutions. In this bid, we offer you our solution at very low and affordable rates based on your desired requirements. we normally follow several checks to ensure the quality of service and products. In this bid prototyping is not included, if at certain point you would like to have prototypes manufactured, we can provide you at minimal cost including courier charges (DHL/FedX etc). We, very humbly deal with our clients and provide full technical support during all phases of project execution. We are very much looking forward to hear from you in coming days. Cheers, Ahmad Lead Technical Engineer Turktronics Inc. An Internet of Things Company
$400 USD em 9 dias
4,3 (17 avaliações)
4,8
4,8
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Hi Reactive, I am competitive to this kind of task, can take good care of this project. In fact, I already done related to this job before. Let me know the best of your time so we can discuss further based on your requirements and we can move forward to the next step. Thanks, Joseph C Ocero
$155 USD em 3 dias
0,0 (0 avaliações)
0,0
0,0
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*Rich experience in the Design and Development of projects with microcontrollers on Arduino, PIC, etc *I have worked with different communication protocols and many types of interfacing sensor modules. -*Schematics and PCB Design using Cadence-Allegro,Mentor-PADS, Altium,Eagle tools *Also supports to manufacture Proto type PCbs and Production type PCBs
$160 USD em 10 dias
0,0 (0 avaliações)
0,0
0,0

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Bandeira do(a) UNITED STATES
Cherry Hill, United States
4,9
9
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Membro desde out. 12, 2005

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