Harman Kardon Pre-Outs

[BJG718]

I was wondering if it would be possible to hookup an external amplifier to an HK AVR 525 receiver in order to get a bit more power. If so, what amplifier or preamplifier would be recommended to do so? Lastly, what type of power increase / sound performance should I be expecting?

[cbennet]

Yes you can. I have a HK5800 and a PA 2000 amp I'm using with the HK525. Significant improvement in sound quality. Your mileage will depend a lot on what speakers you are using.

I was wondering if it would be possible to hookup an external amplifier to an HK AVR 525 receiver in order to get a bit more power. If so, what amplifier or preamplifier would be recommended to do so? Lastly, what type of power increase / sound performance should I be expecting?

[markw]

Lastly, what type of power increase / sound performance should I be expecting?

...and this obviously would depend on the power amp you chose. The better and mthe more powerful, the better the sound may be.

Of course, as the previous poster stated, a lot depends on your speakers, too. You can't polish a turd.

[nightflier]

You can't polish a turd.

Well you can, but it wouldn't compare to fine silver... But who said the speakers are crap? Even if he has cheapo Athena bookselves from BB, or Infinity Primus from CC, they will sound quite a bit better with a good external amp. So no, they won't shine the same way, but you can polish them...

[bjornb17]

Well you can, but it wouldn't compare to fine silver...

brilliant!

[BJG718]

Yes you can. I have a HK5800 and a PA 2000 amp I'm using with the HK525. Significant improvement in sound quality. Your mileage will depend a lot on what speakers you are using.

So am I looking just for a preamp then? Or am I looking for a power amp? I never quite understand what the purpose was of each of them besides providing power... Thanks for all input!

[BJG718]

Oh, also...the wattage ratings for whatever I need...do I add the wattage to whatever my 525 puts out? Or do I only get power from the preamp or amplifier or whatever I need?

[E-Stat]

So am I looking just for a preamp then? Or am I looking for a power amp? I never quite understand what the purpose was of each of them besides providing power... Thanks for all input!

Perhaps I can help. Preamps, as the name suggests, are the first amplification stage in the pipeline. Traditionally, they have consisted of a phono stage and a line stage. The phono stage not only increased the signal level, but also provided the inverse RIAA equalization curve. On a power ratio basis, phono stages do the most work and offer up to 60 db of gain. My phono stage has 46 db of gain which relates to a factor of approximately 46,000. This is necessary due to the extremely low output of cartridges..

Most consumer receivers today only have the line stage part since turntables are becoming more rare. It takes what is typically a half volt signal and increases it to roughly two volts to drive the power amplifier. Line stages have anywhere from 10 db to 20 db of gain. That is a factor of only 10 to 100. Line stages are still low voltage devices and cannot drive speakers.

The "heavy lifter" is the power amp. It is what produces the current sufficient to drive a speaker. Consequently, power amps are usually the largest and heaviest components and employ large heat sinks (although there are newer so called switching or digital amps that are more efficient, but not yet world class sounding). While the voltage gain is not much greater than the line stage (somewhere around 26db - or a factor of 400), the level of current is much higher.

The answer to your first question then is to acquire an external power amp. When you connect an external amp via the pre-out/main-in jacks, it replaces the internal one so the power is not additive. Unless of course you use it separately to drive another pair of speakers. Hope that helps!

rw

[BJG718]

Okay, so power amp it is. I was thinking that I would pick-up a 150wpc / 2 channel power amp to drive the front speakers. I would let the receiver take care of the surrounds and sub. My final question is: If I were to get Klipsch F-3s, which are rated at 150 maximum continuous watts / 600 peak watts, would a 150 wpc 2 channel power amp be what I want? Or could/should I be looking for more wpc? Thanks for all input again!

[clwarner]

A quality amp on the Used market is the NAD C270 or C272. You can find them on ebay or audiogon for roughly $300+. I currently own four of these units. I used them with my HK AVR 525 as the preamp, before I purchased the B&K 50 preamp. The HK did a great job, while I saved for the B&K. You will notice an improvement in your sound stage with running a quality external amp. It is money well spent In my book.

C.

[royphil345]

Yes, I have a Harman Kardon AVR-310 and adding an external power amp for the two main channels resulted in a noticable improvement in sound quality. As well as a huge improvement in power output. Even seems to increase the power available to the surround channels. Maybe less load on the power supply since the main channels aren't being driven by the receiver.

A 150WPC amp sounds about right for your needs. You could go a little higher. Always better to get a larger power amp than needed rather than a smaller one. A lower powered amp driven into clipping (distortion) will damage your speakers much faster than a few too many clean watts.

I use a 380WPC amp with 250 watt peak speakers and have never damaged a speaker. Don't quite turn it up all the way of course!!! With clean power, you can usually hear when your speakers are sounding a little "stressed" and turn down the volume before any damage occurs.

[BJG718]

I have been pulling my hair out looking for an external power amp. I am very hesitant buying something used and I am also very against spending more than 400 bucks for a new one. I have an HK 525 and I love it. I just think I could use a little bit more power than 75 watts. It occurred to me to get a new HK 3480 just to use as a power supply for the HK 525's main speakers... Is this possible? If so, what type of connections would I need?

[royphil345]

The HK 3480 won't work. Some receivers have preamp-out and main amplifier-in jacks joined by short "horseshoe" connectors. When the connectors are removed, the preamp or amplifier sections of the receiver may be used separately. Most of the HK receivers only have a preamp-out with no input jack to the main power amp. Wouldn't probably improve the sound quality anyway.

Klipsch speakers are famous for their efficiency. You may find that 75 HK watts (compares to 100+ watt receivers from some other manufacturers) are enough for you, unless you really want the ability to play the Klipschs as loud as they will play. (careful with your ears!!!)

In that case, an AudioSource AMP-300 may work out for you (around $425.00 delivered) http://www.digitallyunique.com/amp-300.html Alot of people on a budget say great things about AudioSource amps.

I probably wouldn't be afraid to check out some used amps either. NAD, Rotel, Adcom...
I'd do my homework though, and try to buy a model that's not too old. Some amps seem to perform flawlessly for a very, very long time. Power supply capacitors can become weak after 10 years or so however.

This Carver looks pretty tempting. It's one of the last models made by Carver and one of the best sounding IMHO. I own the A-760X. Great sounding amp, never had any trouble with it. Price may go too high though. http://cgi.ebay.com/ws/eBayISAPI.dll...sPageName=WDVW

WOW!!! While I was writing this, the price of the AudioSource AMP-300 went up from $399.00 to $415.00 at that store. AND the seller ended the auction for the Carver early. ...I guess nevermind... lol

[Resident Loser]

...the HK 3480 does, in fact, have "main-in" and "pre-out" jacks...as per the photos and owners manual downloads at the HK site...one of the few that has this feature...Denon and Marantz two-channel receivers are the others...

The HK is rated @125Wpc...but be advised while that is nearly twice the rating, an extra 50Wpc will only be slightly louder. It requires 10X the power to sound twice as loud...

I have a vintage HK Citation 19 power amp which puts out 100Wpc and very inefficient speakers...most of the time the amp cruises at about 2.5 watts output(as per the LED level indicator on the amp)...75Wpc is really quite sufficient for most applications...

jimHJJ(...hope this somehow helps...)

[BJG718]

I just wanted to take some load off of the 525. I noticed that it is a bit louder with fewer channels running, which is why I thought of a separate amp powering the mains. The louder the speakers go, the better for me. I'm in college and this seemed to be the cheapest way to have some loud and crazy parties or just one kick*ss home theater setup.

[royphil345]

I think the 75 WPC will be fine with the Klipschs. I really can't see spending money on a receiver to use as an amp. Would be just a little louder with probably no improvement in sound.

I notice on my HK that there is less gain when using all the channels. This is just to make it less likely that you would seriously overdrive the amp while it's working harder. It's a protection feature. When my HK is in surround mode, my external amp won't put out it's full output even with the volume control all the way up. This is fine with me. Keeps me from damaging the receiver or any of the speakers. Could turn up level controls for all the channels to get more gain, but system seems to sound best when they're set near zero.