I will be setting up a computer in my kitchen as a jukebox (using Musicmatch or something). The trouble is that my amp (and junction for the various house speaker wires) is about 70 feet away (the cable will have to run down to the crawlspace and back up). Is there such a thing as a sound card that will power an amp this far away? Is there such a thing as a remote sound card, which can be driven via 70 feet of CAT5 cable? Any ideas? Thanks!
Any Soundcard Will Do........
You need to run balanced cables from your PC to your amplifier for this distance.
This requires an unbalanced to balanced convertor at the PC end, and a balanced to unbalanced convertor at the amplifier.
Running a balanced connection will allow good signal quality at the amplifier end, and will eliminate ground loop humm/buzz noise problems.
This is standard practice in FM broadcast systems when a PC is required in the system.
Eric.
You need to run balanced cables from your PC to your amplifier for this distance.
This requires an unbalanced to balanced convertor at the PC end, and a balanced to unbalanced convertor at the amplifier.
Running a balanced connection will allow good signal quality at the amplifier end, and will eliminate ground loop humm/buzz noise problems.
This is standard practice in FM broadcast systems when a PC is required in the system.
Eric.
tictoc,
I do exactly what you are asking for - computer with Delta 410 10 channel soundcard driving amplifiers all over the house, some up to 50 metres of cable.
As Mr. Feedback has explained, balanced line is the only way to go. Use shielded twisted pair (STP) to further reduce any noise, and the balanced cable & balanced tx/rx will do the job nicely. I'd recommend the use of DRV134 as the balanced transmitter and INA2137 as the balanced line receiver. Both the driver & receiver are laser trimmed for maximum noise rejection and this combination is well known for use in pro audio gear.
I also use a PIC controller connected to the PC via the serial port to matrix the 5 channels out of the 410 into 16 zones around the house.
Let me know if you need more info.
Regards,
Dean
I do exactly what you are asking for - computer with Delta 410 10 channel soundcard driving amplifiers all over the house, some up to 50 metres of cable.
As Mr. Feedback has explained, balanced line is the only way to go. Use shielded twisted pair (STP) to further reduce any noise, and the balanced cable & balanced tx/rx will do the job nicely. I'd recommend the use of DRV134 as the balanced transmitter and INA2137 as the balanced line receiver. Both the driver & receiver are laser trimmed for maximum noise rejection and this combination is well known for use in pro audio gear.
I also use a PIC controller connected to the PC via the serial port to matrix the 5 channels out of the 410 into 16 zones around the house.
Let me know if you need more info.
Regards,
Dean
Go to to the TI (Texas Instruments) website and look up the DRV134 and INA134. For the power supply use the Linear Technology LT137 and LT337 regulators for the +/- 15V. supply. Use a toroid power transformer (Digikey catalog). Heat up your soldering iron, use quality components. I suggest not messing around with anyting else. Use quality mike cable for the link (2 conductor with shield). You might be able to get free samples for the silicon or purchase from Digikey or Mouser Electronics. This can be a pretty inexpensive project--a heck of a lot cheaper than using UTC or Lindahl transformers, and with higher performance. if you play your cards right. I use this method as my preamplifier is situated about 30 feet away from my power amplifers and electronic crossovers. Good luck and have fun. Hope this is not too much beyond your DIY capability. --Larry
Ps. hope you are a subscriber to AudioXPress
Ps. hope you are a subscriber to AudioXPress
I would not use the P.C. power supply to power the balanced line drivers I recommended. Use a totally separate isolated power supply. See my previous message.
BTW, two good books on DYI audio are "Audio Electronics" by John Linslely Hood and "Self on Audio" by Douglas Self. You might want to purchase the CD-ROM back issues of ElectronicsXPress. Good website: http://www.linkwitzlab.com/ SMT soldering techniques are also starting to be necessary, but I'm getting by with a 10X eyeloop and micropoint iron. Good Luck and keep the analog audio hobby alive! --Larry
BTW, two good books on DYI audio are "Audio Electronics" by John Linslely Hood and "Self on Audio" by Douglas Self. You might want to purchase the CD-ROM back issues of ElectronicsXPress. Good website: http://www.linkwitzlab.com/ SMT soldering techniques are also starting to be necessary, but I'm getting by with a 10X eyeloop and micropoint iron. Good Luck and keep the analog audio hobby alive! --Larry
I have two 150' runs of Canare L4E6S cable from my living room out to the garage so that the same music can play on the stereo in the living room, and on the stereo for the garage/pool. Seeings how I dont exactly critically listen to the music in the garage, it works great. That is awesome cable, and is shielded quite well. I honestly dont think you will have any problem with sending the music 70 ft with this cable. It is also comparitively cheap, at about $.35/ft.
This thread has been discussing various approaches to running
a balanced line a significant distance (e.g. 70 feet). I don't believe
USB has been discussed yet. USB can be run reasonably long
distances using USB extender cables which effectively rebroadcast
the signal in both directions. You can daisy-chain USB extender cables for distances exceeding 100 feet.
a balanced line a significant distance (e.g. 70 feet). I don't believe
USB has been discussed yet. USB can be run reasonably long
distances using USB extender cables which effectively rebroadcast
the signal in both directions. You can daisy-chain USB extender cables for distances exceeding 100 feet.
amo: I'm currently in the process of building a toroid based PSU for my htpc so you can see how I'm planning to do it on my htpc psu page.
Anders
P.s sorry if I'm a little bit OT
Anders
P.s sorry if I'm a little bit OT
AndersZ, Nice design power supply, but I suggest substituting Linear Technology LT137 and LT337 adjustable regulators for the +/- 12V. supply--presumably for analog audio electronics, as they are significantly lower in noise than fixed regulators and lower in noise than the more common LM117T and LM337T adjustable regulators. the devices spec' sheets will show you how to wire them. ( www.linear.com) Be sure to use the recommended 10 uf (tantalum is best) bypass cap. off the adj. pin.
I've updated my psu schematic a bit as well as the webpage.
The LT137A/337 are not really applicable since they only have a current-rating of 1.5A. I have 4A coming out of my toroid which is barely enough.
The full schematic is here: http://www.t.kth.se/andzak54/files/htpc_psu.pdf
I attach the 5V portion to this message.
Anders
The LT137A/337 are not really applicable since they only have a current-rating of 1.5A. I have 4A coming out of my toroid which is barely enough.
The full schematic is here: http://www.t.kth.se/andzak54/files/htpc_psu.pdf
I attach the 5V portion to this message.
Anders
Attachments
That sounds fine. The (Linear Technology) LT117T and 337T adj. regulators are lower in noise, but that would be more applicable to preamplfiers that draw less current than your applicaton. I'm sorry that I didn't pick up on what an HTPC is. For further noise reduction in power supplies (lower source impedances, etc.) especially for amplification of low-level signals (tape, microphone, phono) the "Super Regulator" stuff by Walter Jung and others that appeared in recent issues of AudioXPress looks like it could be very effective, but I haven't tried these designs yet, but intend to with my upcoming Ambisonic decoder/preamp project.
Those seem very interesting for me too, especially if the current rating could be increased to "normal" pc levels (>8A). Size isn't really a big issue in my application but complexity is, I don't like to complex things since I never seem to finish them...
However, I think my present design is good and simple enough to be tested so I will report once it has been built and tested.
Anders
However, I think my present design is good and simple enough to be tested so I will report once it has been built and tested.
Anders
A P.C. is such a "beehive" of R.F. interferrence that it may be difficult to go this approach. I'd take the approach of amplifying and conditioning the signals to as high a dB level as possible befire digital clipping at the A-D converter in the sound card by using electronics *outboard* (often called a breakout box) that is away from the computer's chassis, and powered by it's own, isolated power supply. Replacing a P.C.'s switching regulator with a lower noise linear regulator is only a small part of the battle.
The digital signals within a computer are pulses & square wave'ish stuff, that go rail-to-rail. The silicon is going into saturation turning on and off at incredible speeds. All this creates an enormous mass of R.F. energy (remember a square wave is an infinite series of odd-order sine waves that go right up the spectrum, and a speaker's pulse response, for instance, can determine it's frequency/phase response). Anyway, I guess I'm a little unsure about what your want to accomplish in using a linear power supply for a P.C. (if that's exactly what you are doing). The results could be a little disappointing if you factor in what I have just said--that a computer's digital circuitry is a vertiable minefield of RFI that no linear p.s. is going to remedy.
The digital signals within a computer are pulses & square wave'ish stuff, that go rail-to-rail. The silicon is going into saturation turning on and off at incredible speeds. All this creates an enormous mass of R.F. energy (remember a square wave is an infinite series of odd-order sine waves that go right up the spectrum, and a speaker's pulse response, for instance, can determine it's frequency/phase response). Anyway, I guess I'm a little unsure about what your want to accomplish in using a linear power supply for a P.C. (if that's exactly what you are doing). The results could be a little disappointing if you factor in what I have just said--that a computer's digital circuitry is a vertiable minefield of RFI that no linear p.s. is going to remedy.
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