AU999 Upper mid harshness?

afroaudio

Active Member
I have a very nice condition AU999 which I am using as my main amp at the moment. I have done ALL the mods on the unit and recapped completely including large filter caps. Couldnt have done it without all the info from the great AK'er Sansui heads!

I just did the final "mod" as suggested by AK'er Stereofun which was to balance the differential pair of transistors on the driver boards and replace their associated resistors with better matched tight tolerance variety. This has resulted in a noticeable improvement.. quite surprising really!

I am not really enjoying my AU999.... But, I have to say I am finding the sound a little fatiguing and the upper mids and highs a little harsh. There is a lot of detail here as well but I find there seems to be an emphasis in that area which is not really pleasant. Just wondering if others have experienced similar with the 999? I should say my speakers are 1970's Tannoy HPD 12 inch drivers in home built 100 liter cabinets. Until recently I was using an AU555A with these speakers which oddly delivers a fatter (maybe less accurate) lower end and none of the harshness in the upper registers.
 
That happend to me with some Sansui (G-8000, 9090, 9090db, 8080db, 999, 517) and Usher Audio speakers, but they worked awesome with Kef R series, so who knows, maybe it don't match very well with your speakers.
 
Its not the amplifier, I've never heard an AU999 have those characteristics.

Could be speaker + Source + human perception...

What is your source?
 
Based on my own experience with comparing the 555A and the 999, I do agree with you. However remember it takes a while to get used to an amplifier's distinctive sound.

I run my 999 thru Fostex Fe206En's, and these are fairly aggressively "middy" fullrange speakers. Your speakers may be the same. The sound of any amplifier is obviously going to change depending on the speaker match.

I did find the 555A fat and warm, but also silky in the mids (however unrefined) compared to the 999 (both were fully restored). If its too much with the 999, could you live with it by dialling down the mids on the 999 a bit? The 999 is my "reference" amp - I know that it will sound accurate, and with some recordings, that means its quite "middy".

Its like listening to reference studio monitors - sometimes the trade-off for accuracy comes at the expense of listening "comfort" I guess.
 
Put simply - when the resolution on the 999 goes up, it becomes much more sensitive or "unforgiving" toward A) harsh recordings B) sub par digital processing in your source. It wasn't before I put a world class DAC in its feed that I could really appreciate the depth and resolution without any harshness. I use Wharfedale speakers - they are known for their laid-back-ness. They have a modern slim/tall design with 2 x 6.5 " woofers that covers bass + mid and then a 1" tweeter. Some older speaker designs where you have a huge woofer and then a small mid and tweeter, often to my ears sounds a bit shrill, because the small diameter mid are pushed too hard to balance the large 10-12 inch woofer. This may even be more obvious with digital sources vs vinyl/tape that the speakers were designed around. The 555a almost always sounds good no matter what - but does leave some information behind when compared head on to a modded 999.
 
Put simply - when the resolution on the 999 goes up, it becomes much more sensitive or "unforgiving" toward A) harsh recordings B) sub par digital processing in your source. It wasn't before I put a world class DAC in its feed that I could really appreciate the depth and resolution without any harshness. I use Wharfedale speakers - they are known for their laid-back-ness. They have a modern slim/tall design with 2 x 6.5 " woofers that covers bass + mid and then a 1" tweeter. Some older speaker designs where you have a huge woofer and then a small mid and tweeter, often to my ears sounds a bit shrill, because the small diameter mid are pushed too hard to balance the large 10-12 inch woofer. This may even be more obvious with digital sources vs vinyl/tape that the speakers were designed around. The 555a almost always sounds good no matter what - but does leave some information behind when compared head on to a modded 999.

Ok have to ask...what is the name of that World Class DAC that you have used with your 999....?!?
 
Pink Floyd is known for having many albums that are pure, well balanced and exquisitely engineered to album/cd
How about the SACD remaster of Dark Side of the Moon in surround? I know that it sounds gimmicky but man that remaster brought out a lot of previously obscured detail.
 
Put simply - when the resolution on the 999 goes up, it becomes much more sensitive or "unforgiving" toward A) harsh recordings B) sub par digital processing in your source. It wasn't before I put a world class DAC in its feed that I could really appreciate the depth and resolution without any harshness. I use Wharfedale speakers - they are known for their laid-back-ness. They have a modern slim/tall design with 2 x 6.5 " woofers that covers bass + mid and then a 1" tweeter. Some older speaker designs where you have a huge woofer and then a small mid and tweeter, often to my ears sounds a bit shrill, because the small diameter mid are pushed too hard to balance the large 10-12 inch woofer. This may even be more obvious with digital sources vs vinyl/tape that the speakers were designed around. The 555a almost always sounds good no matter what - but does leave some information behind when compared head on to a modded 999.

Very very true.

One of the recently refurbished/modded/upgraded 999s that I did for a fellow audio nut here in Australia successfully saw off a number of highly fancied integrated and pre/power amps in a shoot-out. The owners of those other amps were very surprised indeed! A modded 999 is a formidable amp and is actually quite revealing of the source feeding it (which in my experience is fairly rare of a great many vintage amps!).
 
I enjoy reading the posts about the 999 and the mods by Kevzep/Stereofun...thank you!
(and am secretly hoping for more special mods! :) )
I have posted before and waxed lyrical about my modded 999...
I love its look...
I love its sound...thank you pete_mac...and Sansui!
I enjoy listening to my Sansui units in particular the venerable 555A/9500 and the considerable whack of my D11...
I do find though its the 999 that keeps drawing me back...
I am hearing resonances in its lower registers I never noticed before..
The audio shadows/nuances it brings forth are slightly more defined/discernible in the 999's audio inky blackness...
The lingering thwack of drums...fullness of tenor sax...the bounce of the bass..
The music breaths and its a detailed journey my ears can follow...
To my ears and in my humble opinion the 999 excels with detail...in particular the bass...
I do notice that I have the 999's bass control on neutral...but the mid is set on -2 and the treble at -4...
Any horn or trumpet playing is sharp as a razor...clear...detailed tending to brightness...piano revealing...
Ok the speakers are the SP5000 (the Wharfedales are undergoing cross-over work) and the listening room is smallish...
Definitely not a shy amp!
 
Ha ha - if the yard stick is the cost of a house, then everything is mid-class. I am not referring to price but performance. For a DAC the implementation is everything. Oppo hired in engineer legend John Curl to design the analog stage. When the professional reviews came out - the serious ones - the consensus and wording was "world class". The DAC at the time was simultaneously used in the $5000 McIntosh MCD500 as well as in a far more expensive Krell that I can't at the moment remember the name of. Thanks for sharing the beauty above, and I agree Oppo has really raised the bar for how good a bluray player can sound - that was the genius of their flagship BD105D, that for $1300 you get "world class" audio AND video processing, it even came with balanced XLR out, a separate power supply for the analog section and a 2nd dedicated Sabre ESS 9018 DAC for headphone out, which can be used as a pre-amp too.
 
Fair enough, these are somewhat subjective terms, even for the professional reviewers. The BD-105D, are by the majority of reviews a step up from previous models. Not sure if you have actually heard one.

Regardless of semantics, my point to the OP was that the quality of your digital source can greatly influence how you perceive your amp. When I got the Oppo, my lesser amps didn't quite benefit from the increased resolution - then the modded 999 went in and it was really an eye opener how that amp could "fill the shoes" and come to live.
 
I lived and worked in the recording studio many years ago
and one thing it taught me was to recognize good versus poorly engineered and recorded albums/music.

When I am uncertain of an amps performance and need to compare with a known benchmark,
I reach for an album or CD that was engineered (in the studio) to the utmost standards.
Over and above the original studio, engineer and production itself,
I look for albums with no added crunch, fuzz, distortion and/or overdrive etc.
particularly on things like guitars/bass.

If you have an album that was exquisitely engineered and recorded
that also lacks the addition of noise makers on guitars etc.,
Then you have an album that you can take with you to audition perspective or problematic systems.

Garbage in garbage out as they say.

Genesis - Tonite Tonite Tonite at or around the 2:12 instrumental is well balanced and beautifully clean onto record/CD.

Pink Floyd is known for having many albums that are pure, well balanced and exquisitely engineered to album/cd..
Just the first few seconds of hammer hitting drums on Dyer Maker at moderate to heart pounding volumes will tell you alot about the amp/speakers.
-If in playing back either of these two ultra squeaky clean selections at mid volumes you again hear harshness then you can at least eliminate the possibility that it's not because of your favorite selections which may or may not be distortion laden before it hits your record needle/CD.

-No offense but most people don't know how to differentiate between a well recorded album and one that is in itself poorly recorded which ultimately makes it hard to listen to


Eliminate the possibility that your fav recorded song/s are the culprit with distortion added to the original instruments and/or thru substandard record studio equipment, engineers and techniques and only then can you move on to finding where in else lays the culprit (speakers? amp? input device? etc.


regards,
moe of the North

.
Thank you someone else gets it. So many "audiophiles" do not seem to get this and chase their tails. Good, sounds great, not so good makes listening to some of my favorite songs not so good anymore. It's really is a bummer how you can hear so much garbage in them.
 
Thank you someone else gets it. So many "audiophiles" do not seem to get this and chase their tails. Good, sounds great, not so good makes listening to some of my favorite songs not so good anymore. It's really is a bummer how you can hear so much garbage in them.
If you're like me and you are an Audio Engineer and a Musician, you know how to listen past that sort of thing....There is so much great music which is recorded not very well, but why let it ruin the music journey? I am a realist, so the whole Audiophile thing is totally lost on me....
Music is music and I won't let the fact that something doesn't sound "perfect" ruin my enjoyment.
We live in the real world, not some fantasy world where everything is "perfect"....
My 2 cents anyway....
 
Hi Blah Blah - It is the 8 channel Sabre 32 ESS 9028 reference DAC. It is used in the flagship Oppo BD-105 with equally good analog section to match.

Hi Stereofun...I understand that that oppo BD-105 has two of those sabre 32 ESS 9028 Dacs inside..
How does the Unit sound?!? and in particular playing through the 999...?!? I am very curious about the pairing...
I'm also curious to know how exactly the BD-105 help's a listener to appreciate the depth and resolution of the music without the harshness...?!?
If the 999 only reveals the recording played...and it sounds harsh...how does the DAC help to moderate this harshness...
What is the process...?!?
 
To my ears the oppo has a very natural, detailed and non fatiguing sound with good low end gusto. It's very refined sound comes with a small (and quite acceptable) penalty in the department of attack and dynamics. For that reason the Oppo might be better matched up to either a faster livelier amp or ditto speaker - if that is your preference. The reason I still love it paired with the 999, is that you get to take full advantage of the modded 999's level of detail and strung out mid section as well as the oppo's ability to send some deep refined bass into the 999. For instance, the speedier more rhythmic Eight Deluxe matches the Oppo really well - keeps the Oppo on it's toes if you will - but the Eight D's more dry mid section don't come to life quite like on the 999.

Audio is all compromises eh ? but as Kevin says, we shouldn't get caught up in that. In short, I'd say that the oppo and 999 is a fantastic match if your preference is spades of detail and laid back refinement over punch and bravado.

How exactly the Oppo does audio so well, I cant tell. I do know that Oppo uses a separate ring transformer and subsequent power supply just for the audio section and that Audio legend John Curl was hired to design the analog part of the audio section. The build is impressive - a beautiful display of symmetry, organization and shielding, among a sea of red wima caps and otherwise Silmic II's .

I am really no expert in the DAC - Rather than say the 999 only reveals the recording played, I'd say the 999 eminently projects the signal it happens to receive to a nice authoritative sound stage. If that comes from a digital source that is sub par, well that is what you get, no way around that. It can't mask a bad recording - Back to black, by Amy Winehouse for all its great songwriting still sounds flat and harsh, even in 24/96 - But it does sounds flat and harsh projected eminently well...if that makes sense. What I have noticed is that some of my older disc that has been played on multiple systems through the decades sounds decidedly more refined on the Oppo, they may still have a late 80'ties harshness to them, but it is still more refined and can via the 999's excellent and clean tone controls become pretty darn good.

By the end of the day I think it is simply a matter of a very very good DAC (Happy now Botrytis ;-) - matched to a very well designed analog section by someone who really knew what he was doing.

BDP-105+XLR+Use.jpg

bdp105-analog-multichannel.jpg
 
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Hi Stereofun...

Thank you for your detailed reply...
I like the fact you do like the Oppo-BD105...for the reasons given...and that you also have it paired with a modded 999...
I guess that's reassuring for me cos i'm thinking of getting one for mine too...
Upon re-reading my post and yours I guess what I was really trying to say is...
Can a good Dac make harsh music listenable/enjoyable...ie...a silk purse out of a sow's ear!
I understand now that if you have an excellent recorded signal...and the better the Hi-Fi equipment one has...
The better it will take advantage of that signal...the same goes as you said for a bad recorded signal...bad in/still bad out...
So it would be fair to say that the Oppo may refine the harsh punch of a poor recording but not improve/eliminate it...
Cheers..
 
Your last paragraph is right on.

If the harshness perceived is due to the limitations of a previous digital player. Then it's fair to say that a well designet latest generation DAC can swoop in and process those same bits better, no different than a modded 999 can enhance your listening experience over a lesser amp. Now if the harshness you refer to is inate to the recording itself, then a high end DAC will only make that more obvious, however it will still deliver that awful recording in more detail and refinement, and that may very well get you more leverage on the excellent tone controls of say the 999. Case in point I have a very uninspiring early 90'ties CD featuring jazz guitarists Howard Robert. The Oppo, can't save it pr. Se, but the Oppo DAC extracts more detail and layers - still bland as heck - but at the hand of the 999's clean tone controls you can sauce it up pretty good and retain detail! That was not possible before where the tweeter would turn to foil paper, and the bass to mud if you tried ;-)

I think most cases are the first example where previous perceived harshness comes out more listenable with a new DAC, simply because of technology and engineers trial and error. Wasn't it a Sansui chief design engineer who once proclaimed that it was easy enough to get very good specs in an amp........But to make it actually sound great was pure art.
 
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Hi Stereofun...
Listening to Grant Green's CD...BORN TO BE BLUE...with Ike Quebec on Saxaphone...
Through a Marantz CDP to the modded 999 and out to Wharfedale E70's that have been recapped and had crossover work done...
One word Superb!!!
Fast...detailed...clean...sharp and authorative...Wide soundstage...
The raunch of Quebec's saxophone oozes out of the bottom end of the E70's...the punch to the guts when he hits those low notes...
Hard to imagine Solid State could get better...
Cheers...
 
Many things to consider here and honestly it hadnt really occurred to me that some of the albums I am listening to may have just been badly engineered to begin with (!) It does make very good sense to have some good reference material for evaluating equipment with. Also quite possible that my source which is the humble Cambridge Audio DacMagic100 may be showing its limitations with the modded 999. I think I was just surprised at the difference after the recapped 555A.. which was really making the Tannoys sing so nicely. I have now dialed down the tweeters on the Tannoys a notch and the sound of the fully modded 999 is starting to grow on me. Thanks again for all the input gents!
 
Ok...in regards to a Dac to accompany my Zep-999 in the end I went Local and bang for buck!
I still have a hankering for the Oppo...maybe when I win the Lottery!
So in the end I chose the GEISLER Klein Dac 11 in a loverly shade of Black! Costing $1000au posted.
Initial impressions whilst listening to Gigi Gyrce's 'The Rat Race Blues' with my Zep-999 and E70s...
Immediately noticeable Imaging...shade deeper musical separation...musical precision/clarity without the dreaded head ache fatigue...
Richard Williams trumpet playing soars and peaks to a laser sharp point of exhilaration without any fuzzy degrading...superb...
My understanding is the Dac can only play better after it burns in...so something for me to look forward too...
With all due respect to other system owners...
I think I have found my ideal listening system...
The Klein Dac 11 digs a tad deeper into the recordings...the Zep-999 is unfazed in effort and delivers to my E70's which finish without fatigue...
Time for more Richard Williams trumpet playing and a beer! :beerchug:

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