Denon PMA 920 and diminishing returns?

[Finnegan]

Howdy kind folks.

I am currently running a PMA 920 and Vienna Mozart Grands with a ML Dynamo 500 sub. I have a couple other amps, but I love how clean the Denon sounds.

In my current room I can't imagine the sound getting leaps and bounds better. Running in 4ohm supposedly the Denon has 180wpc. It is in a cooled enclosure, but I've never noticed it getting warm.

Curious if anyone has experience comparing the PMA 920 (or similar) against some of the fancier offerings. How much better can I make my sound by upgrading my power source? I know some separates are the way to go, but unless I can find a set of real pretty Marantz tube amps, I probably wont splurge there.

The rest of my equipment is as follows

Technics sl1200MK2 with Shure m91ED cart, EVG stylus, and upgraded mogami cables
If I am not spinning LPs I am streaming Tidal HiFi through an iMac and using an Apogee recording interface in reverse as a DAC (seems to work well, may upgrade this in the future I just record music sometimes, and it was here, and works)

Any thoughts or opinions? Much Obliged.

 

[bhunter]

I have a PMA900V that I use in my office. It is a very good clean sounding integrated amplifier. That said, I prefer every power amplifier I've had over it. Yamaha, ATI, Bryston, Krell, BK, and Adcom power amplifiers all sounded better regardless of what preamp I chose to use. There are some great integrated amps but all are high dollar. There are better values in the used market in separates IMHO. The added benefit of separates is the ability to change the sound signature via a preamp swap.

 

[rickb119]

I have the PMA 920 and my Pioneer SX-850 (recapped) runs circles around it. It's not a bad amp. It just doesn't have the detail and clarity that the Pioneer does. Of course my Sansui can run circles around the Pioneer, but it's in the shop now due to me installing a cap backwards.

Here's a thread that I commented on Denon. http://audiokarma.org/forums/index.php?threads/network-receiver-or-integrated-amp-with-dac.808774/

 

[Finnegan]

Well, that is good information. I find the PMA 920 to be good. Not great. Very clean and tight sounding. I think I am going the tube route. I enjoy the sound of the Denon, but I think I want a bit warmer, richer sound. I'd love to have an old Sansui, or Marantz.... But I am in Seattle, and the price of ANYTHING with those names on it is unreal right now. Just doesn't make much sense.

 

[Powertech]

I have a Denon PMA450SE (special edition - full of ELNA Cerafine caps etc) from the same era as the 920, which I bought new in about 1986. Denon had gone through a patch of dislike from Europe so set up a R&D base in the U.K. They set them selves up to design amps and CD players for the 'British sound', whatever that is. So a lot of this gear was designed in the U.K. and made in Japan. A particular little gem was the DCD820 CD player which has been called 'the one where they got it right'. I thought at the time that the 450 sounded very good other comparable gear around it.
A couple of years ago I bought a new Denon PMA720AE integrated amp as a stopgap while I was reworking my main system (it was cheap). I have to say that I was astonished at how good this amp is. The 720 was cleaner and more dynamic right across the range and the bass from the old 450 particularly showed up as being just wooly (if that makes any sense). I have a feeling that the Denons were voiced for British speakers of the time which tended to be quite bright sounding.

 

[rickb119]

I'd think that even an inexpensive stand alone DAC would make a big difference.

 

[Finnegan]

I'd think that even an inexpensive stand alone DAC would make a big difference.

Hmm. I have read a lot of conflicting information about DAC's. I think this apogee would best any inexpensive DAC on the market. It is a very high quality unit. I'd try a DAC if someone can show me that it is going to sound better than my Apogee Ensemble.

I could definitely see the PMA 920 having a British sound. The Bass that this amp plays through my Mozarts is impressive. It drives them at levels that I like to listen to (say 30-40%) and doesn't get hot. I am not sure. I may have found a nice pre/power amp that I could potentially pick up for a deal. I may give them a try just to see if they will best the Denon.

 

[rickb119]

Just looked up the Apogee. That's quite the set up. Would a DAC, specifically designed to convert digital to analog, best it?

 

[BilboBaggins]

Well, that is good information. I find the PMA 920 to be good. Not great. Very clean and tight sounding. I think I am going the tube route. I enjoy the sound of the Denon, but I think I want a bit warmer, richer sound. I'd love to have an old Sansui, or Marantz.... But I am in Seattle, and the price of ANYTHING with those names on it is unreal right now. Just doesn't make much sense.

Supply and demand.

I find my Denon sounds wooley compared to my Bose/Kef and Mc/Klipsch. It sounds good, just not great!

 

[Finnegan]

Yeah, the apogee is designed to convert analog to digital, Tidal recognizes it and sends it a digital signal like a soundcard. The ensemble then runs 1/4 out to RCA into the Denon. My assumption was that it does the same conversion either way, at high quality levels. Digital files played from tidal sound VERY good. Like I said, there might be a DAC that sounds better, but probably not in the realm of inexpensive.

As far as wooley is concerned, Because I have Vienna Mozarts, I am a bit worried about bottoming out the drivers. To combat that, I have the bass knob on the denon rolled all the way off, I then use the ML Dynamo to fill in the gaps. I'll have to procure a set of separates to compare. The combo in my room with minimal room treatment is extremely clear. Bass is tight and full.... I have no complaints. This isn't to say I can't do better, and those of you who've had this Denon are pretty sure I can do better. On the hunt I go.

 

[Finnegan]

Well, I picked up a Denon POA-1500 today for a song. Using the PMA 920 as a pre, I can't say the sound is a lot different. Definitely louder. I will have to do a Little tweaking here and there. I am hoping to pick up a decent tube pre. I have a late 80s marantz that I may try as a pre, but that thing doesn't sound great to me, fatigues my ears pretty quickly. I guess this POA-1500 will give me some headroom over the 920. They do make a nice sound together. Imaging is still good, not great. Might need to do a bit of tweaking with my speakers yet. It is quite possible imaging was better with the PMA920 alone. It is pretty cool having the big VU meters, Strange to know that at my normal listening levels I am using 10w or less.

 

[rjb5191]

I have a pma 720 and I find it to be a great sounding amp. I did refresh and upgrade it a bit but it hangs with my sansui and audire amps. I like the late 80's denon pma sound. Fast, clean, detailed but still smooth and a hint of warmth / euphony. You need to make sure these are biased optimally.

 

[cgutz]

I bought a PMA920 from someone who used them to power huge JBL speakers. Sounded really good at parties. He gave me a great deal.

As others indicate, I found the PMA920, while very powerful, wasn't as good as some other amplifiers for "detail" listening. While less powerful, I returned to my Sony Vfet TA4650 since I have pretty efficient speakers, and the details and soundstage are just so much clearer than the Denon. I have kept the PMA920 since:
a. I never really get rid of anything unless it is really bad
b. I would use it if I ever needed a "party" amp.

If you goal is loud and powerful, the Denon is great. If you goal is detail, soundstage and clarity, it can be bested. IMHO.

 

[rjb5191]

I bought a PMA920 from someone who used them to power huge JBL speakers. Sounded really good at parties. He gave me a great deal.

As others indicate, I found the PMA920, while very powerful, wasn't as good as some other amplifiers for "detail" listening. While less powerful, I returned to my Sony Vfet TA4650 since I have pretty efficient speakers, and the details and soundstage are just so much clearer than the Denon. I have kept the PMA920 since:
a. I never really get rid of anything unless it is really bad
b. I would use it if I ever needed a "party" amp.

If you goal is loud and powerful, the Denon is great. If you goal is detail, soundstage and clarity, it can be bested. IMHO.

Well,

The vfets are unique and special amps and are not really comparable to the late 80's denon pma series. They are also in a significantly higher price class. Also good luck mainaining those things as the vfet's go bad. I bought a pma-1060 locally in germany for $90. A pma 720 and 920 in the us for around $150 on ebay. Vfet's on Ebay are $400+. The higher end pma amps are actually pretty high speed and detailed in my opionion but not harsh at all. They kind of have that airy class a sound at low output power levels. I do some minor mods to them, biasing the IC's into class A operation and adding additional decoupling capacitance. This gives the phono section a pleasing sound that gives me the analog vibes I crave. I'm not saying that these amps are giant killers but they are very good amps for the price with a somewhat special sound. I compared my and to similar level Kenwood KA and it was no contest. Now, that kenwood was what I would call a party amp. Tight slammin bass, but an awful and veiled midrange and harsh highs. Perhaps your pma920 isn't biased optimally. I find there is a very narrow sweet spot with these amps. Try a broad range of 23-33 mV and zone in from there. I forgot where mine is at exactly right now.