Smooth tight bass
Laid back midrange
Slightly recessed treble but not in a bad way
A bevy of connections for just about anything

No loudness button
No remote

This review may not be a fair one.Soley based review with the preamp completely re-capped by me.I used nothing but good quality capacitors.In original form it was too dry sounding with not much dynamics.This applies to most commercial offerings in my opinion--they tend to have great designs but use crappy capacitors to cut cost.This in turn holds back the true potential of sound a lot of this equipment is capable of.

I purchased it in absolute mint condition.I re-capped all 3 main boards(power supply,flat amp,and eq board).Now,this preamp is showing some potential.It does not excel in any particular area.It's very quiet and smooth sounding.Neutral to the core in my opinion.Bass is now fast and tight with no overlays in sound.

The mids are not as forward as I would like but very acceptable and smooth.The treble is not elevated..in fact a little bit recessed and not so bright,however,the preamp is still able to retrieve detail in music which is always a good thing.

I'm not sure what year mine is from.I imagine somewhere between 1986-1992.I could be off by a few years.Upon,taking it apart I noticed it used nothing but Nichicon vx series capacitors.The entire circuit and design was thoughtfully laid out and professional.I used Panasonic fc,Rubycon zl,Blackgate,Elna Cerafine,and Elna Silmic II capacitors with some bypassed with polypropylenes.By doing this myself it brought out the detail that was normally suppressed in it's original form.

Now,it can breathe and perform as it should.Simply sounds much better and glad I am now the proud owner.I'm not one for neutral sound but this preamp changed my mind on that assupmption.It's very quiet and lets the music flow freely without and overload of coloration.

Similar Products Used:

Luxman tp114
Yamaha c-40
Adcom gfp 555

6 line level inputs with 2 tape loops in either direction and 2 quality phono inputs, what more can one want in a pre-amp of this caliber. The record outs and main preout can be switched on and off for serious headphone listening or Bi-amp, tri-amp applications which is how I presently have it set up. Good pre's of today are alot of money, so if you find one like I did. bring it home for the hell of it......Jake

Mine was mint, so cosmetically it was perfect. I removed the side panels and wished for it to be easily rackmounted, but no dice so far.

I brought this thing home on a whim, and after dusting it off, I can tell that it was hardly used. This P-304 blew away my Bi-fet pre-amps that I had modified for a pretty penny. A true no frills line level pre-amp, w/MC input for all you vintage guys. The tone control can be defeated, but they are actually usable, due to their unusual contour. The manual explains this feature thoroughly. If someone can modify mine to be rackmounted in a 19" inch EIA audio rack, call me today. 812-466-5952

Similar Products Used:

Van Alstine super Fet pre, modified pas pre, and other vintage pre-amps.

Deathly silent; no crosstalk; even frequency response

remote would be nice, but this is a matter of opinion

Truly, sound as it was meant to be heard. Before purchasing the 304, I had been using a $2000 plus preamp. After hearing my friends system, we swapped preamps. The 304 blew my amp away. I made him a swap offer which he refused. After a short search, I located a 304 for sale and jumped at the $300 ticket. Now, I experience sound - as it was meant to be heard.

Simple design. Solid construction.

No remote

This is the only preamp I have ever owned. From listening to lots of other demos I think I would desribe this preamp as neutral and plain. I get the best response from vocals and mid range with this. I don't have any real comparisons but I also don't have any complaints. I do wish I could use a remote with this.

System: Onkyo 304/504
B&W Naultilus 804

Excellent specs.,and the sound quality,build quality to back up those claims,plus great price!Like all Onkyo products,a real effort is made to channel the most important features into vital designs that offer major value and little nonsense.In the case of this preamp,it means clean design,clean sound.Defeatable tone controls,charging noise-filters,other features contribute to the sound quality.

For those who care(not me),no remote.Some would find the simulated-wood side panels a negative,but I think the look is subdued enough to counter the typical "industrial-black-box"look,without looking hokey.

I bought this preamp for 3 reasons:Reviews all around favorable,Price,and previous experience with Onkyo that indicated high value/moderate prices.I bought this item on sale at $200 below retail.Rich and all the guys at Star-Audio are the best.(We are lucky to have adventurous enough salesman in this cowboy state who actually will stock not only the Japanese brands, but also the best foreign,domestic brands like: B+W,Klipsch,Sunfire,Macintosh,Grado,RBH,others.I bought this preamp because the clean ciruitry to even the (Gasp!) headphone-jack would bring out the best sound from my Grado haedphones,and although I will buy a quality Amp for speaker use one day,most of my listening is via Grado.This is the best way to Great HI-FI sound rivalling Amp/Speaker combos worth thousands of bucks.The jack on this preamp will deliver ample power,uncolored sound,detail and smooth, balanced delivery of the sonics,more so than the jack found on my Onkyo receiver,which also gives a fine sound.No one can go wrong with this beautiful preamp,which will mate so well with even very Hi-end amps or other equipment.A rock-solid foundation on which to build your HI-FI dreams!And,what a steal...

Similar Products Used:

Onkyo TX-8210 receiver.

Sound. Clean, wonderful sound unmatched at the price.

Z-Roe

This preamp saved my system. I was using a B&K PT3 originally and the sound was terrible, I upgraded my amp from an Adcom GFA-5400 to a B&K Reference 4420 and there was no noticable difference! Then I tried the system with an Onkyo P-304 from the Circuit City demo floor and boy was I blown away!

Suddenly the power of the B&K reference 4420 was allowed to cleanly shine. I could not turn the volume up past 9:00 on the P-304 because it just became too loud. The same volume on the PT3 preamp, at about -35, was almost inaudible. In short, the clean efficiency of the P-304 showed me what a true quality preamp is all about.

Now I am using an Adcom GFP-750, and it too chokes my power slightly compared to the P-304. I enjoy its passive mode, but if rocking the house was first order I would slap the P-304 back into the system and get down! Sure, the Adcom sounds better, with better detail, and apssive mode is a gem, but the Onkyo is unmatched - hands down - for price and quality.

Bravo Onkyo!


Chris

Similar Products Used:

Adcom GFP-750, B&K PT3

Very smooth sound
Great specs, which in this case, translate into a great sound ( 116 S/N, 0.0003% THD, .1 to 160,000 Hz (from what I remember) )
Multiple tape loops
Great constuction
Good value

No remote

OK, I probably have the oldest P-504 reviewed here, so keep in mind that the P-504 that sells today might be slightly different than the one that I own. I feel that it is a testiment to the quality of the design of this pre-amp (and the M-504 power amp) that the same design has been sold for at least 12 years. A note to all of the present day purchasers: All of you are very lucky. When I bought mine, it was a bit more expensive. Luckily for you, over the last decade, the price has slowly decreased.

I bought my P-504 in 1989. For the last 11 years I have used the unit on a nearly daily basis. It has been a joy to own and I have not had any complaints in its function. The sound is pure and uncolored, just like the pre-amp itself. The unit is very spartan and narrowly focused. Its sole function is a sourse selector and volume attenuator. There isn't a tuner, no remote volume control (which is the only REAL weakness of the unit), suround sound processing, etc., just clean signal routing.

The only problem that I have EVER had with my P-504 is that one of the tape loop selector knobs loosened up slightly. A quick twist with an allen wrench fixed that in about 3 seconds. So with thousands of days of use and countless hours of use, you could say that I have had ZERO problems. The sound has not degraded with time. If you are looking for sonic excellence, and ammenities take a back seat to performance, buy this pre-amp. After living with it for over a decade I can whole-heartedly suggest the P-504 for an audio only system where quality and value are important.

***Please refer to my review of the Onkyo M-504 in the amplifiers section of this site.***

If you did read that review, you'll notice that the P-304 seems to be supplanted by the VSX-908S. I really have mixed feelings about this. The 908 has only 300 times the disortion of the P-304. :) In my system, the sound was much better the the P/M-504 duo. So for the near term, my P-504 is going to sit unused and dejected on my audio rack. It will make its return...

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Many auditioned in stores. Nothing directly to compare to in my own system.

crispy sound, silent, phono option, build construction is good

the only one i find is the lack of remote

got a new one at a bargain price at 199, got the last one which was available, it is very good. The good thing about,is the nice sound, detail, good bass, trebal and good vocals.I have NAD power amp, Infinity speakers, Cambridge audio CD PLAyer. The pre amp sound good in all types of music. The best was classical, and soul music where the voice is rich , but not too harsh...there is a softness to the voice..perfect what i Like.

The treble is also fine quite correct and the bass is good ..though i dont listen with too much bass I did like the nice tight focused bass.

The build is good with rosewood finish in the sides.. Lots of options with the inputs etc. Dead silent...that is great.All discrete pathway... you do not find this in this price.

The only thing bad is the remote ...had they made a remote it would been great. But if they had made a remote then the phono section would be missing..

Overall good deal

Really excellent design and value for the money,lots of features and inputs,an excellent stepped attenuator,decent looks,phono stage is very good for vinyl-lovers.

Minor weaknesses include no remote,non-detachable power cord,that's about all...

The operative phrase here is "Quality where it counts most." ...You will not find more bang-for-the-buck,which seems pretty typical of Onkyo and Integra product lines,all in all. Articulate,warm-but-not-soggy,tuneful,integrated flat response,tight-not-boomy,extended highs,black-silent,inner detail,fast transients,tracks the decay of notes way across and down,and more..,yes,yes,yes,yes,yes,yes,yes,yes,yes,yes! !! I bought this preamp primarily as a headphone-amp of sorts with the unusual advantage of numerous inputs for all needs inclusive. And boy,the jack on this baby really does deliver music that is clean and quiet and just...WOW! For Grado headphones I only need about 8 O'clock volume (about 30 ohms),and about 10 O'clock for my AKG K-501's (about 130 ohms),and I'll bet this preamp-jack has enough power to run Sennheiser 600's (about 300 ohms),although I have not tried this. The dead-quiet characteristics of this preamp make it ideal for headphone use. I plan to one day match it up with a tube-amp one day for speaker use,and I am sure I will be just as happy with the results then as I am now.

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Various brands auditioned.

Excellent power supply;utterly silent. Absolutely no cross-talk between inputs. Rich sound,correct tone controls,great mm phono stage. Build quality.

None at its price (even at its original price)

I have used many High-end preamps over the years,some sounded great most only so-so.Almost all of them were a pain in the rear to use;they either had no phono (rip off),no tape outs(contaminates the sound don't ya know,I guess buffers are beyond them),no switching to speak of,no tone controls (sacrilege!),are poor in reliablity (NAD and most tube preamps) or have horrible human engineering (twin volume controls ,weird box shapes so that no way can they fit on a shelf).Of all the High-enders that I have used, only the Spectral was worth the pain it put me thru. Its sound was truly first rate into almost any amp. Alas at the end of the speaker project it had to go home...

Then along comes this little Onkyo P-304. I have long known of Onkyo's rep in the Audio field (owned one of their better cd players,it was built like a tank and sounded fine). Circuit city had just put their demo unit up on the clearence rack for $129...no one there even knew what it was. So thinking what the heck,it can be a backup,I purchased it. Second best buy I ever made (got the Threshold for $30.

I set it up,turned it on,and went out to eat. After getting home I put on some music,it sounded nice but a smidgeon grainy like the Van Alstine pre-amp (bad tubes). I left it to cook for the night and came back to it the next day. Now it was singing! Bass was very deep,giving the subs something to work with. Bass attack was quite nice tho not in the Spectral's league ($5000). The suprise was in how good the bass decay was,the overtones were very natural and blended with the rest of the music beautifully. This was not one-note bass,it was very tuneful ,had really good pace and rythym and really made me want to dance (too bad I cant).
The mids were very nice with voices layering nicely,male voices sounded real with an honest low frequency foundation. Female voices sounded a little harsh on the very top,sort of mid fi, compared to the Threshold but still had nuance and subtlety. All in all very enjoyable.

The switching was silent and,amazingly,had no audible crosstalk between input;ie,I could have a CD playing on one input and have absolute silence on the one next to it. There was no hiss or hum,not even on the phono stage. And the tone controls! They actually work where they are supposed to! Amazing! I spent 20+ years living a hair-shirt existence of having to listen to badly recorded music on flat pre-amps because tone controls were only for the great unwashed masses...and yet, only the Spectral was good enough to justify their absence.

I opened the box and was very impressed. Mind you I saw no gold traces or wondercaps or unobtanium wire. What I did see was a massive power supply (It alone was worth more than I paid),neat wire layout,and nice, tho not audiophile grade,controls and switches. And I saw great engineering for the price point (the original $700+ one). I have no idea how they did it.

And then I tried the Onkyo with the Van Alstine Fet-Valve 300i....magic! Every good thing about the Onkyo got better,and the mid-fi harshness on the top vanished. Completely. The Threshold could still beat it on top,in terms of detail and ambiance,but the grit was gone. What was left was a sweet presentation of sound,involving to both the body and the mind,the sort of thing that I would have paid plenty for if any of the high-end stuff delivered. In fact it beat the Threshold rather badly in this department. The Phono stage was very quiet and seemed to love my audio-technica moving magnet cartridge,presenting good dynamic contrasts and excellent harmonic structure and ambiance with no trace of dryness...good enough at least to demonstrate the superiority of (some) analog over (some)digital. Sweet!

Now what was happening is that the Onkyo,in order to get those great specs does use pretty high negative feedback (by high end standards),which is one of the reasons for its absolute silence. This can react with the input of most solid-state amps,often producing that mid-fi sound (at least it was very slight on the Onkyo).But the Van Alstine presented an almost perfect resistive load,allowing the preamp to think it was on the test bench feeding a simple resistor.

Someday I will get around to modifying this preamp...but not anytime soon...The Onkyo P-304 has great sound,great flexibility,is pretty, and is a joy to use.
Which is exactly what a lot of high-end pre-amps arent.

Similar Products Used:

Spectral,Van Alstine Pass4,Threshold(various),PS Audio,Krell,Audible Illusions(pre 90's),SuperPhon,Conrad Johnson (various),NAD,Rotel,Parasound