Yamaha CR-1020 Vintage Receiver Measurements and Features

[MAB]

I want to provide an update. I have been enjoying the receiver, and am returning it to my friend tonight. I was concerned about the power amp performance measurements, and suspected my load wasn't performing well. I confirmed the load I was using has serious issues.

Retesting the amp with an 8 Ohm load of Dale non-inductive wirewound resistors gives much better performance. Here is the 5 Watt dashboard comparison:

The Dale Wirewound load is 85% lower THD compared to the Parts Express load I had been using. The Parts Express has lots of 3rd order and higher harmonics.

@RickS has actually seen the same distortion on these resistors before:

Using the QA451 with External Loads

not sure, looks like added noise and distortion… here is what I see with the plug-in…

forum.quantasylum.com

I initially wondered if this was Voltage Coefficient of Resistivity, or inductance despite the non-inductive claim. I measured inductance, not even close to explaining this. I tested for VCR with a bias adapter and LCR meter across frequency and DC voltage, VCR also doesn't explain. The elevated distortion is over 30dB of distortion at high power:

The new measurement also matches Yamaha's published spec much better (which I got a nice copy following an earlier suggestion from @LGD_ ):

I suspect I am thermally limited with my Wirewound load near 100 Watts. I'll address that, my findings on the Parts Express resistor, and all of the other load distortion details separately. For now the amp section of this awesome classic now properly presents a 5 Watt, 1 kHz SINAD result of 94.93 dB. If we compare the SINAD value to ASR amplifier rankings, this is on the threshold of Excellent, and is in some very nice company.

I'm happy, will PM @RickS to see if I should update the original post.

We can now get back to historical discussions and other nostalgia.

I'm going to go get a beer.

 

[mhardy6647]

Was therer ever an Empire 698? We had one, which had been reviewed well (tonearm effective-mass apart) and the thing, in a golden hue and solid wooden plinth, was to me a joy to behold and, like the equally rre Sony 8650, it helped records to *sound* as good as possible.

698! Maybe there was no 598 at all.

source: https://www.worldradiohistory.com/Archive-All-Audio/Archive-Audio/70s/Audio-1976-05.pdf#search="empire 698"

Kind of the polar opposite of the light and lovely, lean and jiggly LP-12, eh?
EDIT: also, other than the touch controls and optical auto-stop, rather at the other end of the spectrum from the GA-212, too.

 

[Ken1951]

I remember visiting Myer-EMCO down in or near College Park one day in '76 or 77. Klipschorns and the venerable old (even then, but still available) Empire turntable made significant impressions on me at the time. The Empire tt of that day (I think the model number was 598?) had touch controls a la the GA-212 and its kin (and the h/k-Rabco ST-7, and some of the better Thorens decks of around the same time).

Ahh, memories...

I worked at a competitor in the DC Metro area slightly before that time and had many friends still working there past that time. We sold GA-212s and Yamaha receivers by the truckload. Also the occasional 598 Empire and the original Rabco TTs and separate arms, usually on a TD-125 MkII. The Yamaha receivers were always great sellers and one of the more reliable brands as well.

 

[Ken1951]

View attachment 465909

698! Maybe there was no 598 at all.
View attachment 465908
source: https://www.worldradiohistory.com/Archive-All-Audio/Archive-Audio/70s/Audio-1976-05.pdf#search="empire 698"

Kind of the polar opposite of the light and lovely, lean and jiggly LP-12, eh?
EDIT: also, other than the touch controls and optical auto-stop, rather at the other end of the spectrum from the GA-212, too.

Empire Troubadour 598!

 

[DSJR]

If I knew then what I know now...

 

[bigolli]

@ MAB ,
first, thank you for the very interesting measurements which are really interesting for me as i restored in the past with a friend ( graduate engineer for electronics) vintage amplifier from the 70' s to the 90's.

One of my favourite is a set of Sansui B2101/ C 2101.

Only disadvantage is the smaller soundstage comparing against Revox amplifier from the 90' s or my NAD M33.

So with the B2101/ C2101 the soundstage sounds more compressed ( or smaller).

What is the technical reason for this?

Anything I can do?

Thank you?

 

[MAB]

@ MAB ,
first, thank you for the very interesting measurements which are really interesting for me as i restored in the past with a friend ( graduate engineer for electronics) vintage amplifier from the 70' s to the 90's.

One of my favourite is a set of Sansui B2101/ C 2101.

Only disadvantage is the smaller soundstage comparing against Revox amplifier from the 90' s or my NAD M33.

So with the B2101/ C2101 the soundstage sounds more compressed ( or smaller).

What is the technical reason for this?

Anything I can do?

Thank you?

Assuming the Sansui is working properly, likely none. Amps aren't typically responsible for soundstage, which is more of a property of the recording you are playing, and your room, and your speakers, in descending order.

This receiver is much more than an amp. For instance, if you adjusted the tone controls and compared to sound to a unit with no tone control adjustment, some people may remark they hear differences in "soundstage". If you used the variable loudness control to reduce the volume instead of the volume knob, some may report they hear soundstage maintained across volume better. Some may not like it, and say they hear worse soundstage effects. Stereo soundstage is a property of the recording, and the room and the speakers used to reproduce the recording. And a bit of our imagination to hear through the stereo sources. Sometimes frequency response will get in the way or alter that perception, but most amps have flat enough frequency response that they don't interfere or change our perception of imaging or soundstage.

Regarding amps sounding different, if they are all working properly, amps are boring, unobtrusive, and unidentifiable sources of voltage-gain. See page 78 for a classic test of how amplifiers sound:
https://americanradiohistory.com/Archive-HiFI-Stereo/80s/HiFi-Stereo-Review-1987-01.pdf
If they are working properly, are not driven to clipping, they are indistinguishable.. The rest of the magazine is great too.

David L. Clark organized many of these tests. A survey can be found here although it does require payment:

AES Convention Papers Forum » Ten years of A/B/X Testing

The AES Forum is where our members get to interact with each other in between conferences and section meetings.

secure.aes.org

Clark did a good job debunking the sound of amplifiers. None of this came as a surprise to me, since I had already discovered nobody in our store, and none of our customers could tell the difference between a Levinson Model 20.5 and a Niles installation amplifier. It's not like we were deaf, we were just human.

 

[Nicoff]

The first stereo system that I purchased was a Yamaha CR-820 receiver which was the junior version of the one reviewed here.
Thanks for the review; it brought back good memories!

 

[mhardy6647]

The CR-820 is also a nice piece of hardware, in my hardly-objective opinion.

"Put me in, coach! I'm ready to play..."

 

[RKV1]

Well, moving coupler switch worked great for a little while! Left channel eventually dropped out on all speaker circuits, but headphone jack works fine. Time for a deep cleaning. Any favorite contact cleaner?

You have a bad speaker switching relay. It's the only part in the signal path that's different between speakers and headphones. Replacements are likely unavailable but the relay contacts can be cleaned, if you are willing and able to do it.

 

[LGD_]

You have a bad speaker switching relay. It's the only part in the signal path that's different between speakers and headphones. Replacements are likely unavailable but the relay contacts can be cleaned, if you are willing and able to do it.

I just replaced the speaker relay on a CR-1020 that I'm working on. It's a drop-in replacement, works fine:

https://www.mouser.com/ProductDetail/Omron-Automation-and-Safety/MY2-02-DC12?qs=sGAEpiMZZMtSzCF3XBhmW1uKSon960XE227ogInLziM%3D