Onkyo M504/P304....why can't I enjoy this??

onwardjames

Hoardimus Maximus
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Once jokingly told my now wife when she was but my gf that buying me the Onkyo M504 was "marriage material".

She called my bluff several years ago. Got the 304 pre, then the amp.

Imagine my surprise when after I got it set up, that it sounded lifeless and tinny. I was crestfallen. I can't sell it, you married guys get my drift...


I have had this amp connected to countless speakers, and I cannot find a good match with ANYTHING. Five minutes in, my ears are ringing like a bell. Shrill highs, dead-flat bass (comes out lifeless) and over-pronounced mids. ON every SINGLE speaker I connect to it.

Recapped HPM 100's. JBL L100T's with the T3 crossover mod. 2 pair of Advents. Marantz Imperial 6's. 2 pair of Yamaha NS690III's. Epi Model 20's. Boston Acoustic A-70's. Infinity's. The list goes on and on....


I simply cannot stand the sound of this pre/amp. Could there be something wrong? It runs quite normal temp (warm to hot after a long drive) and looks to be in great shape. Or has anyone else had experience with this gorgeous to look at, painful to listen to combo?

Someone here had a thread about recapping pre and amp, and sonically seeing a vast improvement, but my 40 year old Sony 7065A is stock, and has NEVER pained me like this one. I'm all out of ideas.
 
I'd find a service manual for the amp and check the alignment. (bias and offset).
That said, maybe your sources aren't up to snuff?
 
I've not tried any other thing for a pre...should do that, I guess.

My sources are pretty good, a Yamaha CDX1100U, Pioneer 9500 tuner, same stuff I plug into everything else.

I could use my sansui 9090db (rebuilt) for a pre....see if it's the amp or the onkyo pre..
 
I just wondered if anyone else has this combination and has been underwhelmed, because it's just flat. I cannot believe Onkyo allowed such a beautiful amp to sound so bad.
 
I have the M508 and it sounds wonderful. There is something wrong either in the preamp or power amp. Could be a bad ground. Try a different preamp first.
 
Are you able to improve things with the preamp tone controls?

I don't recall the preamp being that great, but the amp has its charms, even if its not quite exceptional.
 
I'm running a Hafler 915 pre-amp through my M504 and it sounds quite good to my ears. I recently was pushing recapped HPM100's and currently KEF 104/2 and both sounded great. I would make sure all your internal adjustments are correct and double check all connections, if that doesn't fix it try another preamp.
 
IMO, its very likely the preamp which is giving you grief; assuming a good quality system, I have found that changing the preamp impacts the overall sound much more than changing the power amp.

I'm pretty sure that the P304 uses 4558 op amps as active devices in the flat amp and the phono amp. These ICs are ubiquitous in Japanese designs from the 70s and 80s and compared to later op amps, are only average in performance. I recomend that you replace the flat amp op amp with a NJM2068 and the phono op amp with a NJM4580 and you'll be pleasantly rewarded for you efforts. I did the same to a very average Toshiba/Aurex preamp; details are here: http://www.audiokarma.org/forums/showthread.php?t=498670
 
Lucky it's the stereo that is shrill with a lifeless bottom.
Seriously, my 304/504 set drives the KLH 12s nicely. But, a GAS Thoebe pre and DCM TF 600 were a wow. Only draw back was too much power.
 
Are you able to improve things with the preamp tone controls?

I don't recall the preamp being that great, but the amp has its charms, even if its not quite exceptional.

Preamp tone controls help a little, but after a short while, my ears are still bleeding.

Best thing I've done is add a little eq, and I positively NEVER use eq.

I'll hook up something else as a pre, and se what happens. The 304 says "refurbished" or "remanufactured" or some thing on the side, so it was probably sick to begin with.
 
Can you bypass the preamp? Maybe plug in your ipod/phone or other music device (with volume control) directly into power amp and see how that sounds? Turn it down first lol.

If you've got a multimeter this very helpful thread can show if thee's something obviously wrong.
 
I can do that matteos. Thanks for the tip. After I finish in the yard (honey do list) then I'm going to get to the bottom of this.

Any tips on a good pre for not too much wampum, if that ends up being the prob??
 
Once jokingly told my now wife when she was but my gf that buying me the Onkyo M504 was "marriage material".

She called my bluff several years ago. Got the 304 pre, then the amp.

Imagine my surprise when after I got it set up, that it sounded lifeless and tinny. I was crestfallen. I can't sell it, you married guys get my drift...


I have had this amp connected to countless speakers, and I cannot find a good match with ANYTHING. Five minutes in, my ears are ringing like a bell. Shrill highs, dead-flat bass (comes out lifeless) and over-pronounced mids. ON every SINGLE speaker I connect to it.

Recapped HPM 100's. JBL L100T's with the T3 crossover mod. 2 pair of Advents. Marantz Imperial 6's. 2 pair of Yamaha NS690III's. Epi Model 20's. Boston Acoustic A-70's. Infinity's. The list goes on and on....


I simply cannot stand the sound of this pre/amp. Could there be something wrong? It runs quite normal temp (warm to hot after a long drive) and looks to be in great shape. Or has anyone else had experience with this gorgeous to look at, painful to listen to combo?

Someone here had a thread about recapping pre and amp, and sonically seeing a vast improvement, but my 40 year old Sony 7065A is stock, and has NEVER pained me like this one. I'm all out of ideas.

Try a different preamp. I tried a P304 back in the late '80s, and it did not remain in my system very long. Like so many other preamps, I found it fatiguing. Look for a Kenwood C-2, B&K PRO10MC or MC-101, Classe CP-30, CP-35 or SSP-25 (older pre-processor that has a reputation of sounding great operated in 2-channel mode), Phase Linear 3000 Series 2. I have direct experience with all of these models except the SSP-25.
 
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Nikko pre's are pretty cheap on the 'Bay and elsewhere. Very much the good match for my dry sounding Sony amp sections.

The thing is the engineers went way deep to get the FR as flat as board. Yeah, that's great for the advert and the specs geeks, but it is too dry until it's half way to the moon power wise.

None of the speakers you list are going to help either. They are also very flat'ish with good tweeters, but that makes for a very "analytical" system.

I'm not a proponent of throwing money at the issue. It's a good amp. You need to work around it to keep the wife happy and to learn how to get to the next level.

A tube pre would not be out of the question, but I'd be looking way out at the sources. Do you do vinyl? Grado cartridge or a Shure M75 maybe. Do you do FM, Nikko FT850 (with full service) is THE best most comfortable sounding FM tuner I have ever had in 50 odd years - and it's going into that flat'ish Sony and out to Infinities. It's just such a nice combination and so enjoyable to listen to, that it proved to me the amp section was OK and the speakers were OK, it was what you/I fed them. Pioneer tuners have always been a bit flat and dry to me, compounding teh issue. Besides the Nikko I mentioned, a earlier Sansui tuner might be a good choice?

I have the same issues with the CDP too. I'll solve it somehow... I tried some NOS TDA 1543 budget DACs. That didn't do it did for me, stuill looking. See if you can find an old 1543 based Magnavox CDP to try it with as a test? Maybe it will warm your CD Playback a bit. But I'm betting it will require a different direction. Or try a Sony Play Station. In other words, change stuff around, borrow stuff. Try this and that. Experiment. Use your headphones to get the room and the speakers out of the equation while evaluating.

Do you have a cassette deck? How does it sound with that source?

And swapping power amps may not be the right approach either, besides the wife issues ...

You need SYNERGY really bad :( I do too, but it's so hard to give up any of that great resolution and detail. It's doable and others have done it. It's hard to find, but once you do - bingo :music:
 
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Maybe the sound of the amplifier is simply not to your liking. Not all components are for all people.
 
A functioning amp doesn't have a "sound", it amplifies. If you're having problems, it is having problems. Have you checked dc offset and idle current? The former should be nothing, and the latter carefully calibrated as per the service manual. When that's done, it should behave normally, and not hurt your ears or the music it plays for you.
 
Nikko pre's are pretty cheap on the 'Bay and elsewhere. Very much the good match for my dry sounding Sony amp sections.

The thing is the engineers went way deep to get the FR as flat as board. Yeah, that's great for the advert and the specs geeks, but it is too dry until it's half way to the moon power wise.

None of the speakers you list are going to help either. They are also very flat'ish with good tweeters, but that makes for a very "analytical" system.

I'm not a proponent of throwing money at the issue. It's a good amp. You need to work around it to keep the wife happy and to learn how to get to the next level.

A tube pre would not be out of the question, but I'd be looking way out at the sources. Do you do vinyl? Grado cartridge or a Shure M75 maybe. Do you do FM, Nikko FT850 (with full service) is THE best most comfortable sounding FM tuner I have ever had in 50 odd years - and it's going into that flat'ish Sony and out to Infinities. It's just such a nice combination and so enjoyable to listen to, that it proved to me the amp section was OK and the speakers were OK, it was what you/I fed them. Pioneer tuners have always been a bit flat and dry to me, compounding teh issue. Besides the Nikko I mentioned, a earlier Sansui tuner might be a good choice?

I have the same issues with the CDP too. I'll solve it somehow... I tried some NOS TDA 1543 budget DACs. That didn't do it did for me, stuill looking. See if you can find an old 1543 based Magnavox CDP to try it with as a test? Maybe it will warm your CD Playback a bit. But I'm betting it will require a different direction. Or try a Sony Play Station. In other words, change stuff around, borrow stuff. Try this and that. Experiment. Use your headphones to get the room and the speakers out of the equation while evaluating.

Do you have a cassette deck? How does it sound with that source?

And swapping power amps may not be the right approach either, besides the wife issues ...

You need SYNERGY really bad :( I do too, but it's so hard to give up any of that great resolution and detail. It's doable and others have done it. It's hard to find, but once you do - bingo :music:


Broc, I feed it a Sony PSX60 tt with Shure M95EJ which sounds glorious on everything else. I have a Sony MD JE20ES, top of the line. The aforementioned yamaha....it all comes out just lifeless.

I just finished mowing, and the rest of the day is dedicated to beer and futzing with this beautiful, yet troublesome problem.

I once hooked my Yamaha M-60 power amp to the pre....

It sounded just exactly as bad, which leads one to believe.....:scratch2:


I have bottled this in for 4 years, so as to not hurt her feelings, cause she often joins me in the room when I'm on AK. I appreciate everyone's input, and will check DC in a bit.
 
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