Yamaha A-U671 Integrated Amp & DAC Review

[Doodski]

Are you asking abou the tone control characteristics?
I would opine (and that's all that this is, an opinion based on anecdotal information & memory!) that they're not uncommon, although the range is (or may be) somewhat more subtle than tone controls of the old days (to wit, the 'seventies). The turnover frequency is on the high side, though, similar to the old days' typical tone controls.

Since I just happened to look this up yesterday for a tone control question Someplace Else Here's a pretty typical, slightly high-ish-end tone control scheme for Yamaha's ca. 1978 CR-2020 receiver. This one has two different turnover options: 500 Hz (pretty typical) and 125 Hz (more subtle and 'audiophile', with respect to this component's era). This graph (from the owner manual, and I apologize for the quality of the reproduction) shows the maximum range of the controls -- which is pretty unsubtle.

View attachment 50735
Note that this receiver also has a boost/cut "Presence" (midrange) tone control as well (and for better or for worse).

CR-2020 is on the right in this glamour shot of two almost-super-receivers from the mid/late 1970s

Semi-monstrous 1970s soiled state receivers by Mark Hardy, on Flickr
(as befits the stature and maturity of these two grandes dames, this photograph was taken with 35 mm film ).

Yamaha made up for their fairly ordinary tone controls, to some extent, by offering a variable loudness control in most of their components for quite a few years. The variable loudness was (is), arguably, more useful in the real world. But, again, that's just an opinion, too!

I remember using that Yamaha 2020 receiver well. It was a party machine battleship

 

[mhardy6647]

I've only had one for 10 or 12 years; I did buy that one restored so it wasn't... ahhhh... cheap.
I thought I had the vertical tasting of that era of Yamaha receivers, until I realized that there actually was a CR-3020
The CR-3020 came - as best I can tell - a little later than its CR-**20 brethren (sistern?), and a little before the CR-**40 family of receivers.
I was (inexplicably) unaware of its existence when it was new.
They're not terribly common (although it's not particularly to find one for sale nowadays in the usual venues)... but they also ain't cheap. I.e., I am not likely to ever add one to the collection (not that I really even have any place that could actually accommodate its size or its weight).

(borrowed image, needless to say!)

 

[AudioJester]

Minidsp SHD comes to mind: https://www.audiosciencereview.com/...nts-of-minidsp-shd-dac-dsp-and-streamer.4286/

I am told they fixed the jitter issue post review.

If they did this , they should send the new revised version to you to remeasure. Would be in their best interests as there is not much in the market that has all those features.

 

[anmpr1]

.. Compared to the pots in the 70s that had the detent built into the pot-body itself, it's a roundabout way to get the "feel" they wanted.

I recall owning a then 'high end' tube preamp from an outfit called Counterpoint. Had that era Mark Levinson preamp look--with tubes! The volume control made little clicks as you turned it, making you think it was somehow 'calibrated' in accurate fractions of a dB. I found out that it was just a metal ratchet washer giving it 'the feel' of something special. It was easy to pop off, allowing for a smooth turn of the wheel. LOL

 

[Toku]

YAMAHA has several product development groups. Audio group, AV system group, home appliance group, etc. WXA-50 is a product of the AV Group.
I think that this A-U671 is probably a product of the Home Appliances Group. When I first saw this product, is this a YAMAHA product? I was surprised with.
The old YAMAHA products you have shown in the photos are products from the days when the YAMAHA audio group was most brilliant.
My favorite YMAHA products are CA1000, CA2000, NS1000M. I used a $ 600 / pcs YAMAHA JA-2070 alnico magnet 20cm full range unit for my old homemade speaker. That was when I was most crazy about audio.

 

[mugbot]

So I'm a new member, and I happen to own one of these so I thought I'd look it up on this forum and yeeeesh. That is not exactly a glowing review!

My question is whether upgrading this amp to something better (I'm considering the Peachtree Nova 150) would audibly improve the sound? It's driving a pair of DALI Zensor 3's. I also have a minidsp DDRC-24 on the way to experiment with Dirac if that is of relevance.

 

[Brit on a Budget]

Hello.

I have the Yamaha A-670 (UK) [the non DAC version of the A-U670/A-U671] and did a teardown of that for comparison, if anyone is interested.
The 4 photos show; top down view, inside front of daughter boards, close up of chip package, and a bonus image showing metal weights.

Yamaha could have easily packed this whole amp into the space of the Topping PA5, so to give it the illusion of being packed with heavy components, they screwed in 2 heavy steel plates to each side (see figure 4) to give the false impression of heft. Note, the metal plate is rusting.

Regardless, the design is lovely and simple but if it wasn't for the poor noise performance it could be a stellar amp.

Regards.

 

[khaliss]

I found a good deal on one from the local FB marketplace (appears to be in pristine condition). It looks great, and matches the theme of my little music station in the bonus room. Got it hooked up last night and paired with a set of Definitive Tech Demand D9 bookshelf speakers, so far it sounds great! The source is an old all-in-one PC (converted to Windows 11)... the only minor issue so far is Yamaha's driver for the DAC unit is limited to 32-bit/192k =(

Yamaha's website specifies this can go 32-bit/384Khz, but I'm not seeing that as an option in Windows sound settings... anyone else have the same issue? Also, the Yamaha windows driver is from circa-2017 (windows 10), very outdated... disappointing that Yamaha hasn't put out a newer version of the driver.

 

[Toku]

I found a good deal on one from the local FB marketplace (appears to be in pristine condition). It looks great, and matches the theme of my little music station in the bonus room. Got it hooked up last night and paired with a set of Definitive Tech Demand D9 bookshelf speakers, so far it sounds great! The source is an old all-in-one PC (converted to Windows 11)... the only minor issue so far is Yamaha's driver for the DAC unit is limited to 32-bit/192k =(

Yamaha's website specifies this can go 32-bit/384Khz, but I'm not seeing that as an option in Windows sound settings... anyone else have the same issue? Also, the Yamaha windows driver is from circa-2017 (windows 10), very outdated... disappointing that Yamaha hasn't put out a newer version of the driver.
View attachment 429774

Have you installed the dedicated driver downloaded from the YAMAHA website on your PC?

Have you set the output destination of your audio player to the installed driver?

When playing through the Windows audio system, the audio is resampled to the sampling rate that you have set in Windows, and then output. Therefore, it is not played back at the original sampling rate.

 

[khaliss]

Have you installed the dedicated driver downloaded from the YAMAHA website on your PC?

Have you set the output destination of your audio player to the installed driver?

When playing through the Windows audio system, the audio is resampled to the sampling rate that you have set in Windows, and then output. Therefore, it is not played back at the original sampling rate.

* Yes, I downloaded the driver directly from Yamaha's website <link>
** I'm just using Youtube Music from the web-browser to test it out, here is the setting in Windows > Control Panel > Sound (screenshot below). As you can see, it only goes to 32-bit 192000 Hz maximum rate (it can't go higher to 384Khz). I know about how Windows resamples whatever audio source is playing to what it is set here:

I know Windows can do 32-bit, 384Khz... I can do it with my LavaAudio DS-600 DAC, which has a much newer Windows driver. The manual for this Yamaha shows specifically that it can play PCM at 32-bit 384Khz (highlighted in red), but it seems Windows 11 can only be set to 192Khz (in green):

 

[Toku]

* Yes, I downloaded the driver directly from Yamaha's website <link>
** I'm just using Youtube Music from the web-browser to test it out, here is the setting in Windows > Control Panel > Sound (screenshot below). As you can see, it only goes to 32-bit 192000 Hz maximum rate (it can't go higher to 384Khz). I know about how Windows resamples whatever audio source is playing to what it is set here:
View attachment 429941

I know Windows can do 32-bit, 384Khz... I can do it with my LavaAudio DS-600 DAC, which has a much newer Windows driver. The manual for this Yamaha shows specifically that it can play PCM at 32-bit 384Khz (highlighted in red), but it seems Windows 11 can only be set to 192Khz (in green):

View attachment 430008

When playing using the Windows 10/11 audio system, you can set the output sampling rate up to 384kHz, but for older PCs, it is limited to 192kHz. When playing using the Windows audio system, the installed YAMAHA driver is not used. To avoid this, install a music player such as Foober2000 and set the YAMAHA driver as the output.

 

[khaliss]

I did try it on a much newer laptop and it's still limited to 192Khz, so it's definitely not a Windows OS or computer hardware issue... same computer I can run my DS600 at 384Khz. As far as using Foober2000, I've never used that before but I will definitely try it out.

 

[khaliss]

It was the Windows driver!!! I contacted Yamaha Support, and after a day of waiting... a support specialist responded and provided this link to a much newer Win11 "Steinberg" USB driver <LINK> With that, I'm now able to set the sound output to max rate with the DAC's spec:

Feels like there's a difference now with the new driver (could just be my ears LOL)... I played the entire Alice in Chains MTV Unplugged album, audio was so clean & the acoustic instruments were life-like (at least to my ears)! Below is a pic of my modest mini-listening station: speakers are Definitive Tech Demand D9 bookshelves, supplemented by a Monoprice 8" subwoofer (not much of a sub, but it does the job for casual listening).

I tested using the RCA analog inputs of the Yamaha from the PC's 2.5mm analog audio out, and I could almost hear a little hint of noise(?) when playing loud... but when I switched over to pure digital (USB-DAC)... night & day difference: clean, more detail, overall just much better sounding! Happy I found this little gem on FB marketplace... the guy I got it from said he purchased it from ebay a year ago (think he mentioned he only used it with the analog input). I'm really digging the classic Yamaha look of this thing, plus the motorized volume knob is a bonus!

 

[Knobstler]

Can I run 4 ohm speakers of the Yamaha? I want to pair it with some scandyna minipods for a familie member. So only causal listening no party.

 

[cybernaut667]

The scandyna minipods are 4ohm??