Sony STR-DB930 - shocker !

Sony STR-DB930 - shocker !

Postby Axel » Thu Jun 16, 2016 10:39 am

Uh ? Ah ?
What's a home-theater receiver doing here ? Well, 1999 makes it 17 years old therefore fairly vintage now !

Real reason : I needed to streamline my video rig to do away with all the manual cable-switching to and from the monitor and the various sources and separately for the video and audio.
Further, if my Wega 42V is a sound bolid, it now needs restoration, and so does my Precise TA-P7F.

I needed something capable of passing through PAL and NTSC sources to the KX-27PS1 (most of my LDs and DVDs are NTSC - a format which spells, btw, "Never Twice the Same Color :), have some oomph c. 100Hz and below to push the small Technics SB-F3 which work so well with the Wega 42V, have sufficient i/os while remaining not too ugly, un-bulky, and cheap. And be Sony, too :)

I searched and stumbled upon the TA-AV670 (1991) but quickly found myself seriously doubting it would play NTSC signals as well, given its vintage and location, France, a spot which upheld its beautiful but useless SeCAM standard until much later on.
More searching brought the "recent" STR-DB930 as a quality item from the "QS" series - apparently everybody agrees on that so I'll follow, for once, the consensus. Search again. Find one in Paris, as new as can be, 80€. Done. Nice really-bigga trafo, non-resonating diecast AL heatsink, Nichicon FG caps everywhere (everywhere), enough video inputs, enough pre-outputs (just in case) - even if all knobs and switches and the front flap are made of plastic, this should be at least ok enough for my simple needs.


Unplug the old system, plug the new one. Clear all previous settings and presets ; set the monster on simple 2-channel, analogue, no sound fields or sonic whizz-bang from Pluto getting in the way.
Let it warm up for an hour, and fire it up.
... uh ?
Wazzat ?
Are my ears ok ?
Does this have a problem ?
Did I smoke grass without realizing I was (smoking grass) ?

Fiddle some with the 3-way semi-parametric EQ, and bass-boost switch, both barely making a difference on a film I know the soundtrack of by heart.
Alas, no go : this sounds like S_H_I_T. And I really mean that one particular word. No hiss, no noise, no crackling : technically this item functions as well as it looks.

I have to face the facts : my tiny Wega ADC-2 has more guts and clarity than this behemoth - impossible ! If you've seen the inside of an ADC-2, you know it should be impossible... but possible it is. When I think the marketing dept thought of putting in this monster a "dynamic compression" mode... it's an expander that should've been included. Make that two, in series !

Listen to the same soundtrack with my MDR-7506 headphones... AH ! THAT is more like it ! Not refined as, say, a TA-E86B but, still, perfectly listenable.
Put the speakers on again.... rghrgrhrgrhrgh : flat, blurry, muddy, unclear and as non-dynamic as can be. Headache in five minutes.

Email Discussion with Oscar (Ozzy), who confirms, circuit-wise, why I am SO disappointed as all I am hearing is a bass-less and closed-in muddy soup which makes me want to turn the volume down all the time. Not about to go hunt for something else (bigger, pricier, not in Paris), I decide to entirely bypass the power-amp section and give it another try.

So in comes one of my Falcon TAN-15F. Unplug, plug, replug, power-on, same soundtrack.
And a world of difference : regained is clarity, dynamics, depth, height, textures, spaciousness, and stereo that consists of infinite gradations between L and R and not just [L] isolated from [R] with some regurgitated soup troubled by bits of chewed carrots occupying the center.


So... WTF ?
Well, clearly : if the pre-amp and video sections of the STR-DB930 are beyond reproach, the power-amp is lousy. I mean LOUSY.
The SB-F3 are super-easy loads, 8 Ohm small speakers - not the tortured electrostats I had back then ! Using only the front amp section in 2-channel should be a breeze here.
I mean... the power transformer is as big as the F3's "bass" driver !

But, this very amp section is slashed, ridiculed and downright humiliated by a simple TAN-15F from 1978. Heavy hardware WASTED on stupid circuit design.
The STR-DB930 has "power" indeed, it has, oodles of it... but within that global envelope of volume, there is nothing worth listening : no dynamics and a soup of colorless mud.
I can't even imagine what this would output (or regurgitate ?) (vomit ?) if I were to use the "home-theater" sound fields options to widen my intergalactic space.
Whatever - I don't want to know.


If I had forgotten why I got into vintage after 1998… this STR-DB930 helped me remember why :)


(ctrl + click for full-size and large view)
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Finished ensemble, with a completely skewed iPhone perspective matching :)
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And views of the subject...
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(so much fine componentry for so little finesse)
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Re: Sony STR-DB930 - shocker !

Postby Stoffie » Thu Jun 16, 2016 2:28 pm

Hey Axel,

I have a STR-DB840 QS that I bought a long time ago (also secondhand), and is used for digital sources, some video switching and home cinema with a sub. Home cinema is fine, but stereo is indeed as awful as you describe. Good for people of the mp3 generation that have never heard a decent system.

I've tried it throughout the years with all kinds of speakers, mostly also very easy load but it never impresses even the tiniest bit as a stereo setup.

I have my TA-E88B/TA-N7B in the same room and when I do a back to back comparison of the same music on both systems, it's like a box is being lifted from over my ears.

I have honesty never tried it with another power amp, I guess I will!
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Re: Sony STR-DB930 - shocker !

Postby Ozzy » Sat Jun 18, 2016 10:50 pm

Besides sounding like s***, you forgot to tell the audience that it also has a very strong cat pee smell......
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Re: Sony STR-DB930 - shocker !

Postby Axel » Sun Jun 19, 2016 5:29 am

Ah - yes, but that is gone now, thorough cleaning inside out.
Indeed it was the surprising surprise of the find but you should have smelled the owner's apartment !
Gas-mask necessary... I guess people DO get used to everything and anything.

Still, there is nevertheless something screwy with the sound of that STR even with the TAN-15F replacing its power-amp section...
It's perfectly listenable, no headaches anymore ; but if the a/d and d/a IC, an AKM AK4526A, is specs-wise "perfection", I sure wish my Wega 42V could do video switching ;-)
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Re: Sony STR-DB930 - shocker !

Postby Sam Z » Thu Jul 07, 2016 10:42 am

Vintage Sony audio & Trinitron TV, cinema/art books, Stereo Sound mags, that room is heaven!
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Re: Sony STR-DB930 - shocker !

Postby Axel » Sat Sep 17, 2016 4:58 pm

And, of course, dry solder spots attacked my peace of mind : output speaker relays making front channels vanish and/or show creepy distortion at high levels and when bass is booming.
Relays which can be accessed easily by simply removing the bottom plate - lucky me.
The relays for the rear channels are elsewhere, on a sub-PCB really not as access-friendly as this one - lucky lucky me I don't use them channels.

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