• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Concept receivers - documentation posted.

Wow!! That's great, thanks to both of you for making the 16.5 documentation possible. The Concept Karma will flow for both of you. :tresbon::thmbsp:

Regards,

Bart
 
I just received first gen copies of what I think is the 1977 Concept lineup including 16.5, 11.0, 5.5, 3.5, and 2.0. I will be forwarding to NN for scanning for all to see. I also received the CE-1 brochure.

Thanks to Loudenuff for sharing.
 
Njord Noatun said:
Thanks to scans and donations by Fcarpcarp, the following documents have been added to the Concept Manual Scan database:

  • [*]Concept 16.5 Owner's Manual w/schematic
    [*]Concept 16.5 Schematic
Both documents have been scanned to ultra-high specifications - 1100 dpi for the schematic and 600 dpi for the text. The front cover is done in full color. This is by far the highest-spec scan I have ever seen for any vintage stereo component: The schematic is completely sharp and with no loss to resolution even at 800% magnification or higher.

The old, now inferior, 16.5 documents have been retired to make room for the new and improved versions.

Thank you, Fcarpcarp!
:thmbsp:

Best regards,
Click to expand...


I assure you the pleasure is all mine. All you folks have taught me a great deal in my short time here, it's a treat to be able to give something back.

fcc
 
SoCal Sam said:
I just received first gen copies of what I think is the 1977 Concept lineup including 16.5, 11.0, 5.5, 3.5, and 2.0.
Click to expand...
This brochure is quite a find: Conventional wisdom has always been that the 5.5 was the TOTL 1st gen. recevier, and that it was replaced with the 16.5 and 11.0 as the TOTL's in the second generation: Although the emergence of this brochure does not categorically refute the theory that the 5.5 at some point was the TOTL, it does create some doubt about it. It also proves that our perception of Concept as having three distinct, mutually exclusive generations, is inaccurate: It is now clear that there was at least some overlap between the "generations".

From a manufacturing and even marketing point of view, this makes sense: Just like Mercedes Benz and BMW, as an example, do not replace their entire lineup in one fell swoop, but instead gradually introduce and retire certain models in their lineup, it only makes sense that electronics manufacturers follow a similarly gradual renewal strategy.

Thanks, Loudenuff. :thmbsp:

EDIT: And thank you Sam!
 
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no problem, just wanted to share my little bit of history. glad you could find it helpful. i also have my 16.5 om. and a om for the quadraflex st-19 speaker.
 
Concept 4.5D: Owner'sManual, Schematic.

Thanks to further scans and donations by Fcarpcarp, the following high resolution documents have been added to the Concept Manual Scan database:

  • [*]Concept 4.5D Owner's Manual
    [*]Concept 4.5D Schematic
 The schematic is completely sharp and with no loss to resolution even at very high magnification.

Thank you, Fcarpcarp!
:thmbsp:

Best regards,
 
1977 Receiver Line Brochure. CE-1 Owner's Manual. 16.5 THD test.

SoCal Sam said:
Thanks to Loudenuff for sharing.
Click to expand...
loudenuff? said:
No problem, just wanted to share my little bit of history.
Click to expand...
Njord Noatun said:
I will scan once I receive the copies from Sam. Thanks again, and welcome to AK, Loudenuff?!
Click to expand...

Thanks to scans and donations by Loudenuff?, the following documents have been added to the Concept Manual Scan database:

  • [*]Concept receiver line brochure (1977)
    [*]Concept CE-1 Owner's Manual
    [*]16.5 THD test (third party) dated March, 1978 (seven months after purchase.)
 Interestingly, the test shows the following THD (Total Harmonic Distortion) levels at 165 wpc for Loudenuff's 16.5 in pretty much a perfect straight line:

  • 20Hz: 0.05%
  • 10 kHz: 0.02%
  • 20 kHz: 0.1%
The 16.5's published specs is for THD of no more than 0.1% at 165 wpc 8 ohm (250 wpc 4 ohm!!) from 20 Hz to 20 kHz. This third party independent test therefore shows that the actual measured THD for this unit is comfortably meeting the manufacturer's published specifications.

Thank you, Loudenuff?!
:thmbsp:

Best regards,
 
Receiver line-ups: Latest Reflections

SoCal Sam said:
Been trying to figure out the Concept receiver line-ups.

First Generation: 2.0, 3.5, 5.5
Second Generation: 2.5, 4.5, 6.5, 11.0, 16.5
Third Generation: 4.5D, 7.5D, 12.0D

Anyone know approximate dates of manufacture?
Click to expand...

AK member Loudenuff, who is the owner of the first Concept 16.5 on record in the database I maintain, has provided several historically significant documents to the Concept document database, including a receiver line brochure from when he bought his 16.5 in August, 1977, that I have never seen before: This brochure has provided valuable information as to Concept's various receiver lineups, specifically insofar that it has given us a glimpse of what I would consider an "interim" lineup in between the first and second generation as per Sam's research above. Regrettably, Concept brochures were rarely dated but based on Loudenuff's purchase date of his very early serial number specimen, we assume the brochure to be from that year - 1977.

Looking at this information as well as other documents available from the database, my current thinking is that the Concept lineups were as follows:
  • 1st lineup (1976): 2.0, 3.5, 5.5
  • 2nd lineup (1977): 2.0, 3.5, 5.5, 11.0, 16.5
  • 3rd lineup (1978): 2.5, 4.5, 6.5, 11.0, 16.5
  • 4th lineup (1980): 4.5D, 7.5D, 12.0D
​
This is unlikely to be the final word with regards to the evolution of Concept receivers, but this is what (I think!) I know at this point in time. I also want to emphasize that these were unlikely to be four discrete, non-overlapping line-ups: More likely, there were significant overlaps for all kinds of reasons, including the need to sell out old inventory. For example, one would likely to be able to have bought both digital (D series) and non-digital Concept receivers in 1980 and 1981.

Any further information on this would be appreciated: In particular, it would be very valuable if we could get a First Gen. brochure confirming that the three as per above (2.0, 3.5, 5.5) were indeed the only ones available in first gen, and that the 5.5 was indeed TOTL in the first generation. A "D" series brochure would be very valuable, as well.
 
Loudenuff, Thanks VERY much for this :thmbsp::thmbsp:

I've become quite taken with Concepts and filling in informational blanks is a great help.

And thanks to Njord of course, our superlative archivist :)

fcc
 
Hi NN,

Thanks for the scans and to all who have contributed. The 1977 scan has a small digital artifact on the last page so may need to be rescanned. Otherwise, very informative and interesting.

I need to check these lineups vs any listing in my Audio magazine equipment annuals. Other AK'ers who may have the corresponding annuals from Stereo Review, High Fidelity, or maybe others should help too.

Regards,

Bart
 
Specs are guaranteed minimums...!

I don't know of any other manufacturer who actually guaranteed their amps would meet or exceed the published specs.

Since my 16.5 arrived I've mostly been trying to discover speakers that can do it justice.

Susurus
 
Thanks for hosting NN! We will keep scrounging for more Concept material.

Bart: Great idea! There may have been a press release or maybe an item announcing the Concept line. I haven't seen a Concept included in a mag comparo...

Susurus: I agree, the 16.5 has the ability to drive demanding speakers. It is one of the very few receivers that can play my NS-1000M's with authority.
 
mech986 said:
The 1977 scan has a small digital artifact on the last page so may need to be rescanned.
Click to expand...
The last page has been rescanned and will be uploaded to the site by tonight. Thanks for alerting me before I had returned the docs to Sam.
Susurus said:
I don't know of any other manufacturer who actually guaranteed their amps would meet or exceed the published specs.
Click to expand...
I wasn't aware that Concept receivers were subject to any different "guarantees" than those required by the FTC: Would you care to elaborate?

On a related note, LBPete says in a PM:

Code: 
[I]I'm not surprised that the THD was lower than the published spec.
To meet the FTC requirements of the era, the published spec needed to
match the performance of any unit produced. Theoretically the FTC could
walk into any Pacific Stereo, buy a unit and test it. So the manufactures
were very conservative to ensure any one built would meet the spec.[/I]

SoCal Sam said:
I haven't seen a Concept included in a mag comparo.
Click to expand...
Pacific Stereo never submitted Concepts to audio magazines for review, for many reasons, one being that they did not want to unduly ruffle the feathers of the big electronics manufacturers whose products they were also selling in their stores, besides their own brands. It didn't exactly help that Audio Magazine was owned by CBS (PS' parent), either: Can you say "conflict of interest"?

Also notice that "Pacific Stereo" features nowhere on any Concept material: Instead, it says in small print CBS Inc. on the back cover: There is a reason for this......
 
AK member Leejunker bought his Concept 5.5 new at Pacific Stereo on Whittier Blvd. In La Habra, CA. He has now shared with us a copy of the Owner's Manual for this receiver: It differs from the 5.5 we already have in the database in that it has two extra pages ("Operations", "Useful Information") and has a white cover (as opposed to black). The OM is uploaded to the database.

We do not know why PS issued two different owner's manuals for the 5.5 - it could be due to line-up changes or build changes. However, we do know that the 5.5 are manufactured in four different serial number ranges:
  • 10,000 (somewhat common)
  • 20,000 (only one observation)
  • 100,000 (the most common range)
  • 200,000 (only one observation)
Leejunker's serial number is in the 10,000 serial number range, and it is certain that his white OM belongs to this series and possible, if not likely, that the black OM belongs to the 100,000 series: But this is guesswork at best at this point.

Thanks, Leejunker! :thmbsp:
 
Njord Noatun said:
AK member Leejunker bought his Concept 5.5 new at Pacific Stereo on Whittier Blvd. In La Habra, CA.
Click to expand...
Leejunker alerted me to a spec difference between the earlier and the later version of the 5.5 owner's manual. At 55wpc, and for the range of 20Hz - 20kHz, the older manual states a THD of "no more than 0.3%", the newer one
"no more than 0.1%": The difference in THD levels might also explain the different serial number ranges. Thanks, Loudenuff.
 
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