[electronicgoo]

Good day to all!
 
I'm new to these boards just registered yesterday. I am clueless when it comes to audio equipment and I'd appreciate all the help I can get.
 
I have a set of Polk Audio Monitor40's sitting in my room right now: http://www.newegg.com/Product/Product.aspx?Item=82-290-203&SortField=3&SummaryType=0&Pagesize=10&PurchaseMark=&SelectedRating=-1&VideoOnlyMark=False&VendorMark=&IsFeedbackTab=true&Page=2#scrollFullInfo
 
I want to connect these to a desktop computer running Windows 7 and bypass the integrated audio. I was going to purchase Topping TP30 amp/dac but as far as I understand that won't really work because the amp only outputs 10W per channel while the Polk speakers are rated 20-125W, thus making the speakers/amp underpowered which can damage them, right?
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=310-312 <Topping TP30
 
 
My budget is pretty limited and ideally I'd like to find something around $100 but there is some wiggle room.  Also I do not intend to blast music as these will be set up in a small room and I usually listen to music at pretty low levels.
 
So could you guys recommend a dac/amp that will suit my needs and my price range?
 
And also if you guys have time could you tell me which cables/accessories I need to accomplish my objective?
 
Thank you so much.
 
 

 

[electronicgoo]

Also, could I use an audio interface as a dac/amp to power the speakers or is that something completely different?

 

[poeticEnnui]

This is totally doable!
 
The best bang-for-buck amp I could find that would be able to drive your speakers would be the Lepai Tripath TA2020. I've never used it but it has some rave reviews on PA, and with the ~$75 left in your budget, you'd be able to get a decent (read: much better than your computer's) DAC.
 
You could also go for a more powerful Dayton amp and go for a cheaper DAC, but I'd recommend the Lepai amp if this is for computer audio since you don't need terribly loud speakers for very-near-field listening.
 
I'm pretty sure that all the cables you need would come included with the DAC and amp. You'd connect the computer jack (be it 3.5mm or USB) to the DAC, then the DAC to the amp with RCA interconnects, then the amp to the speaker with speaker wire. All of that should come bundled with your equipment.
 

 

[trog]

One of my PC Audio set up happens to be an out of production Polk M3 and Lepai TA2020

With 89dB efficiency they go louder than i ever need with that amp. Also i suggest getting a nice X-Fi/Xonar PCI/PCIe sound card since your source is a desktop

 

 

[poeticEnnui]

Sick setup, trog. What's the bass extension of those things, anyway?

 

[electronicgoo]

Thank you all for your replies and thanks trog for providing images.
 
I'm still a bit confused about the amp though. Could someone please tell me the minimum specs of an amplifier that the Polks have to have?
 
Also based on the replies could I just get the topping tp30 and use that since it will act as an amp/dac? http://www.parts-express.com/pe/showdetl.cfm?Partnumber=310-312
 
The only reason I'm a bit skeptical about the lepai amp is because I heard that it does not have an auto on/off mute....
 
Sorry for so many questions but as you can tell I'm pretty confused.

  Any dac recommendations are also welcomed!

 

[poeticEnnui]

First of all, I mislinked the Lepai Tripath; I just fixed it in the original post. To answer your question -- you could use the Topping amp/DAC provided that you don't try and drive the speakers too hard. For very close-range listening, it shouldn't be a problem, but you'd have to be wary about the amp clipping at high volumes and damaging your speakers.
 
The Lepai is a little more powerful than the Topping, so it gives you more headroom for going louder. (I don't even think the Lepai meets the recommended power rating of the Polks -- 20-125W into 8 Ohms -- the Lepai doesn't specify what loads its 20W drives, so I'd assume that to be its 4 Ohm rating; the 8 Ohm rating would necessarily be lower.)
 
How close will you have the speakers, and how loud will you need them? I'd advise against the Topping if your speakers would be anywhere outside 2-3m away from you or if you like loud music. In short, an underpowered speaker is dangerous in that it can blow the drivers if you aren't careful. The safest option you'd have within your budget is the Dayton, but for super close range, it's overkill.

 

[trog]

Rated down to 60hz 
Quote:

Sick setup, trog. What's the bass extension of those things, anyway?

Btw the recommended wattage is just a guide - note that peeps have mated T-Amps with floor standers and i myself have tested the TA2020 with my Kenwood floor standers with awesome results! Those were 92dB though and my TV/HTPC room merely 12" x 10 "

 

[trog]

Quote:

First of all, I mislinked the Lepai Tripath; I just fixed it in the original post. To answer your question -- you could use the Topping amp/DAC provided that you don't try and drive the speakers too hard. For very close-range listening, it shouldn't be a problem, but you'd have to be wary about the amp clipping at high volumes and damaging your speakers.
 
The Lepai is a little more powerful than the Topping, so it gives you more headroom for going louder. (I don't even think the Lepai meets the recommended power rating of the Polks -- 20-125W into 8 Ohms -- the Lepai doesn't specify what loads its 20W drives, so I'd assume that to be its 4 Ohm rating; the 8 Ohm rating would necessarily be lower.)
 
How close will you have the speakers, and how loud will you need them? I'd advise against the Topping if your speakers would be anywhere outside 2-3m away from you or if you like loud music. In short, an underpowered speaker is dangerous in that it can blow the drivers if you aren't careful. The safest option you'd have within your budget is the Dayton, but for super close range, it's overkill.

Yep TA2020 via spec sheet belts out 20w x 2 into 4 ohms so about 10-15 into 8? More international free ship options for beefier T-Amps
 
 
TDA7492
http://www.ebay.com/itm/50Wx2-TDA7492-Class-T-Amp-Tripath-Stereo-Integrated-Amplifier-Gold-24V-Adapter-/250955775744?pt=LH_DefaultDomain_0&hash=item3a6e213f00#ht_6189wt_932
 
TPA3123
http://www.ebay.com/itm/MUSE-M50-TPA3123-2x50w-T-AMP-MINI-Stereo-Amplifier-S-/250879380212?pt=LH_DefaultDomain_0&hash=item3a69938af4
 
I had PMed the sellers and these put out about 30w x 2 into 8 ohms

 

[electronicgoo]

Hey thank you all for your responses I'm probably going to go with one of those tripath amps from ebay.
 
All I need now is a dac.... I was thinking about buying one of those Fiio dac/headphone amp units. How are they?

 

[trog]

Well if u needed portability and the ability to say use it on your desktop, netbook and work laptop, a USB DAC is an outstanding choice but for use with only a desktop a cheap and very capable used X-Fi/Xonar PCI/PCIe soundcard can be just what one is looking for ^^ 

 

[headfinoob]

Quote:

First of all, I mislinked the Lepai Tripath; I just fixed it in the original post. To answer your question -- you could use the Topping amp/DAC provided that you don't try and drive the speakers too hard. For very close-range listening, it shouldn't be a problem, but you'd have to be wary about the amp clipping at high volumes and damaging your speakers.
 
The Lepai is a little more powerful than the Topping, so it gives you more headroom for going louder. (I don't even think the Lepai meets the recommended power rating of the Polks -- 20-125W into 8 Ohms -- the Lepai doesn't specify what loads its 20W drives, so I'd assume that to be its 4 Ohm rating; the 8 Ohm rating would necessarily be lower.)
 
How close will you have the speakers, and how loud will you need them? I'd advise against the Topping if your speakers would be anywhere outside 2-3m away from you or if you like loud music. In short, an underpowered speaker is dangerous in that it can blow the drivers if you aren't careful. The safest option you'd have within your budget is the Dayton, but for super close range, it's overkill.

I just thought I'd chime in a bit.
Two things blow speakers.  Thermal or mechanical failure.  I have done both to various drivers on many occasions.  In any case, one wouldn't be able to drive a speaker into thermal overload unless the amplifier was capable of outputting greater than the speakers' RMS power rating.  If I am correct, the maximum output power of an amplifier that is fully clipped is just under 60% more output than the rated power of the amplifier outputting a sine wave.  I just integrated under the curve of a square wave and a sine wave.
Theoretically, one should be able to fully clip a 78W per channel amp and still not exceed thermal limits of speakers than handle 125W RMS per speaker.
I generally prefer more powerful amps if I am striving to get good bass out of the speaker.  Since low frequencies require more power to reproduce, combined with the nature of rapid bursts of low frequencies in drums or bass beats, I enjoy having extra power to retain the impact.
I suppose one should analyze their audio "needs" and habits.  Listening levels, speaker placement, music preferences, subwoofers or other drivers, and speaker efficiency all play a major role in determining how much power one should use.  The good thing is that 100W is roughly only perceptually twice as loud as 10W.  10W - 20W certainly be overkill depending on one's setup.  One thing to consider is that it is generally best for most amps to be run below their rated power output to reduce heat.  I also find it nice to "overpower" speakers so that any distortion is coming from the speaker before the amp.  That way you essentially eliminate one of the possible sources of distortion. 
IMO, there isn't really a substitute for power, but I'm sure this could be debated eternally.  The way I look at it, it's better not to sell yourself short on power if the budget allows it.  Auditioning and listening to various amplifiers would be the best thing to do if that is possible.  I personally find it highly inconvenient to try out products like that, so I generally try to learn as much about a product of interest before making a purchase.
 
 
 

 

[electronicgoo]

Quote:

The good thing is that 100W is roughly only perceptually twice as loud as 10W.  10W - 20W certainly be overkill depending on one's setup.  One thing to consider is that it is generally best for most amps to be run below their rated power output to reduce heat.  I also find it nice to "overpower" speakers so that any distortion is coming from the speaker before the amp.  That way you essentially eliminate one of the possible sources of distortion.  IMO, there isn't really a substitute for power, but I'm sure this could be debated eternally.  The way I look at it, it's better not to sell yourself short on power if the budget allows it.  Auditioning and listening to various amplifiers would be the best thing to do if that is possible.  I personally find it highly inconvenient to try out products like that, so I generally try to learn as much about a product of interest before making a purchase.
 
 
 

I am a bit confused about that statement. Are you saying that 10-20W amp would be more than enough to power the polks?
 
Just to let you all know I'm upgrading from cheap dell speakers that came with the desktop, so the polks will be a foot or two away from me.  As far as music goes, I listen to a bit of everything but mostly indie/alternative rock, hip-hop and electronic music.
 
As far as I see it anything I get will be an enormous upgrade from the cheap dell speakers.  I just do not want to spend close to $200 and then ruin my new setup because of the lack of knowledge about all the audio gear.
 
I would like to get a decent quality external dac as opposed to a sound card.  I was thinking of ordering this >>>http://www.amazon.com/FiiO-D3-Digital-Converter-Optical/dp/B005K2TXMO/ref=sr_1_2?ie=UTF8&qid=1333961525&sr=8-2
 
Would this work? What do you guys think?
 

 

[obobskivich]

Correct - very likely you will use under 1W in most domestic settings with most speakers. The situation with damaging your speakers would occur if you run the amplifier up to maximum (very loud) and push it into clipping (which can damage an unprotected tweeter (something very common with speakers)). 
 
The T-Amp is perfectly fine. At <3ft (1M) a 1W input will be quite intense (probably louder than you'll actually want to deal with) - I would say 250-500mW is probably more in-line with what you'll see as a continuous average. 
 
The "overpower" argument doesn't hold water either - the lowest THD band on an amplifier is not at it's minimal output stage, it's somewhat above that. Further, any properly designed amplifier will be heatsinked/cooled adequately for conventional use. Finally, if you do go off and buy a 200 or 400 or 1000W amplifier, it's still only going to be giving you that 250-500mW (or 1W or whatever) for normal listening - the extra power is unused extra capacity which may or may not waste power at the wall for no good reason. 
 
There's no reason for an external over an internal (or vice versa) audio controller - both are able to be good. The D3 cannot be an audio controller, it needs a source (audio controller, CD player, whatever you like), so you would be adding that on top of a sound card anyways. It's cheap though, so if you really want it, go for it. 
 
 
 

 

[headfinoob]

I would say that power "needs" should be truly auditioned first (if possible, its not always easy/convenient to try out different gear) because listening habits/behavior vary from person to person.  If  you are like me, then its hard to get enough power.  If you  are more normal than me and prefer typical listening levels, then the amps mentioned should work great.
obobskivich gives good advice, but I am certainly one of the few who that uses a substantial amount of power (granted, my speakers aren't very efficient.)
But yeah, perceptually, the human ear generally detects a 10dB increase in power as twice as loud.  A 10dB increase in power translates to 10 times the power.  So a 10dB from 20W would be 200W.  There are diminishing returns on power.
It's a double-edged sword.  It takes a lot of power to get very high levels, and it very little power to reach low levels.  It is good or bad depending on how you look at it.