What route to choose? External DAC amp soundcard. Options galore.

skaz

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My Situation - Bought a pair of polk monitor 30 bookshelf speakers to use on my computer. Also bought a lepai lp-2020a+ tripath amp to power them.

My problem - I can hear every piece of electronic noise from inside my computer through my speakers. Hard drives, webpages loading, mouse movement, etc.

Possible solutions -

1. External DAC --to-- AMP --to-- speakers
2. External Soundcard/DAC --to-- AMP --to-- speakers
3. External DAC/Amp --to-- speakers

Items within budget are (other suggestions are welcome)...

a. DAC/amp - Topping TP30 This only has the tripath 2024 vs the 2020 that can be had in other amps.
b. Soundcard/DAC - Soundblaster THX SB1095
c. Amp - I'll probably replace the Lepai as I want one with a muted on/off. Maybe the Topping TP20-MK2 This one has the Tripath 2020 chip.

Side Notes: I am using my on board audio chip but from the research I did I concluded that even when some people upgraded to a dedicated internal sound card they still could hear the electronic noise through their speakers. Never had this problem previous to buying the speakers and amp. Use to use logitech 5.1 system.

SUM - What solution do you think is best based on my situation, problem, and selected solutions?
 

skaz

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Thanks for the reply. I did think about the receiver route but after comparing prices and size too I thought at that point I mine as well get a dac/amp. Although it is a great way to get the digital sound out of the EMI filled box. :)
 
my audio technical knowledge isn't superb when it comes to home theater as i just got into it a year ago myself but i believe receivers have an integrated amplifier. since you are only using one source then you "should" only need an amplifier and not any of the post-processing that is done by a receiver.

i was just saying that i've had superb luck and zero issues by going with a receiver. then again i had to go the receiver route as i have two input devices.

exactly as you said: i'm thinking that the emi from inside your box is jumping onto the audio-output ports of your sound module and then being amped up by your dac/amp making it sound worse.

i'm not sure if i have less emi than you since i have a full tower case (corsair obsidian) and stock 120mm fans (no fancy high output ones) or if the receiver is filtering out any emi. i'm using a shielded dvi-hdmi cable which helps also. the speaker wire coming out of the receiver isnt shielded i dont think but its rather heavy grade (the monster cable stuff, actually it was a good price!)

---

perhaps you can do a few tests to see where the emi is coming from.

it doesnt help at this point but i know some receivers are less than $50-75.
 

skaz

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Yeah the electronic noise is happening during the DAC stage on the sound card within the computer case. Then traveling up the analog 3.5 to RCA cable to the amp and then outputting its ugly head through my speakers.

I order the amp/dac combo and will return the lepai amp to see if that solves my problem. It should, because the digital signal will be converted outside the case relieving the conversion of any interference from the internal components. At least I hope so. =)

I guess what I was ultimately trying to figure out was which one of the specific items listed for the external amp/dac combo or the external sound card would be a better option.

~

Just out of curiosity where did you find receivers in the 50-70 range!? All I could find was the sherwood 4105 at 100 bucks. =)
 
Did you have these noises with typical PC speakers? If so then there is a problem in the PC. If not then the amp may be picking them up via RF so you can try moving the amp away from the PC. If it is coming through the power cord then you can try lifting the ground with a 3-2 ac plug adapter. Borrow another amp or receiver to try. Good luck.
 

skaz

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Just got my Topping TP30 today and it the electronic noise from within the computer is no longer exiting through my speakers. =)

On TOP of that I think the Topping sounds better then the crappy Lepai I was using.

 

stordansker

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Hey I just wanted to let you know I just built a new PC using the lepai lp-2020a+ and have the same problem. Sounds awful.

Was your solution simply to replace the 2020 with the TP30 and run sound from your pc via usb to the DAC?
 

skaz

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Hey, yeah my goal was basically to avoid the internal DAC (on board sound chip) and to move the digital source to an external DAC. The tp30 is both an amp and dac so that worked for me. I'm sure the fact that the lepai was cheaply built and the power supply for it was cheap (vonage?) Too didn't help the situation.

On top of that the lepai had no mute and the speakers would sort of pop when turning on and off. That drove me nuts. Tp30 has a mute and doesn't do that. Good luck bro.

Ps: also for what it's worth to you the tp30 uses higher grade components inside
it. 5 way binding post vs the clips and a convenient headphone Jack on the front. The spare analog input can be used with a mp3 player too.
 

stordansker

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So I just got home and tried "lifting" the ground and wala it got rid of the noise without having to throw down $130 for the TP30! Big thanks to americanaudiophile for the idea. It looks like the problem was a ground loop issue caused by the AC/DC converter. OP if you still have your 2020 I would definitely try this.