Realistic Minimus 7 ID Thread

[VA1DER]

Thank-you so much for the information! You have a treasure trove of data. Do you share the entire database?

I can understand Radio Shack wanting to get numbers up on the initial order, but I would hesitate to think it was 40,000 per month. I think what we're seeing is the QC numbers go up sequentially month over month as the supplier fulfilled Tandy's initial order. I think likely for 40,000 in total. That's about 15 per store. That seems about right for what I remember about new SKUs when I worked there in the 80's. I know it's dangerous to extrapolate from so few data points, but seeing as we never see the number drop until November, this makes sense.

Even if mine aren't #81 and #88 total, they appear to be some of the best 7W's I've ever seen. I hadn't actually intended to order another pair. I already ordered six off eBay over the last week, deciding to treat myself to a little 5.1 system with a pair for center and four for surrounds (with an under-couch subwoofer). To that end, I ordered a pair of 40-2039Bs (Japan) and a set of four that has 2 x A's and 2 x C's (Korea unfortunately). But then today a saved search triggered on eBay and I didn't get past photo #2 showing the veneered front that I was clicking Buy It Now.

BTW, I have another data point for you: 40-2039A, 6A4, QC #721. Looks to be the earliest known 2039A. I'll post photos of all the rest when they arrive.

 

[Scott66]

Interesting questions. While researching Minimus-7 chronology I've logged nearly 250 examples of the Walnut version from images that offer discernible data (now including your pair -- thanks!). This is quite a small sample compared to data found for die-cast models.

For 1st issue, non-suffix 7W, I've logged merely 5 pair and a single. Data for this specific model has been scarce.

View attachment 3546973
The above indicates model production began at least as early as May of '82 with serial numbers less than 20,000. This steady progression to higher numbers through 1982 that abruptly drop in 1983 might, on its face, suggest serial numbers were reset yearly. But if that were true, we would expect a count well past 900's near the end of '83.

It's my thought that apparent steady numbers progression through the months of '82 is mere coincidence within this tiny data-starved sample. All other M7 models having far more entries show a clear pattern of numbers dropping back down in subsequent months, indicating serial number reset on a monthly basis. Even the small(ish) data sample for Walnut version 40-2039A shows this trend:

View attachment 3547018

It is interesting to find such high serial numbers for first version 40-2039 through the November '82 run. I've only occasionally found them that high or exceeded on black die cast models. For context, 40,000 /month equates to a production rate of roughly 1300 per day, 7 days a week. Tandy may have pushed production of their new walnut mini-speaker to ensure world wide shelf stock leading into the lucrative holiday shopping season.

Stuart, here are a couple more Walnut versions you can add to your database.
QC 3105/7A8
QC3110/7A8

Sourced from a private party for $15, when I bought my JBL L-100 and L-166 speakers.
Do you document metal versions, too? I also have a set of black and a spare.

 

[VA1DER]

I just ran into my second set of unicorns! For years I've been looking for original Minimus 7W's with the veneered face and despaired of ever owning any myself. Two weeks ago I ran into a pair and snapped them up counting my lucky stars. In fact, those were just delivered yesterday. Then today I encountered these and have just bought them.

Minimus 7Ws, original 40-2039, with date code 5A2 and serial numbers 12039 and 12230.

For 1st issue, non-suffix 7W, I've logged merely 5 pair and a single. Data for this specific model has been scarce.

Have I just found the earliest known examples?

QC 3105/7A8
QC3110/7A8

Scott, those stands you have for yours, are those the Sanus stands? How do you like them for the 7W? I'm considering those for mine building my surround system. They say they are rated for 3lbs and the 7Ws top off at 8lbs each.

 

[Scott66]

I'm not sure who made the stands. One set, I got from eBay and they're just listed as "universal speaker stands". I have another identical set that I found at a thrift store with some cheapo JVC surround sound speakers on them. The ebay set was about $40 and the thrift store set was $11.
They work fine.

 

[Hugis]

Howdy peeps!
2 more to add ...


Drivers/X over from the B


Now the big question, the tweeter isnt working (just tested and listened) , what can i replace them with ? (im in europe)
Havent opened the other up but the woofer is defo working.
I joined as this is the one place i kept finding info!

 

[baeron]

Howdy peeps!
2 more to add ...

View attachment 3728596View attachment 3728597
Drivers/X over from the B
View attachment 3728598View attachment 3728599View attachment 3728600

Now the big question, the tweeter isnt working (just tested and listened) , what can i replace them with ? (im in europe)
Havent opened the other up but the woofer is defo working.
I joined as this is the one place i kept finding info!

Welcome to Audiokarma

 

[Etj91]

Joining to add 2 more! These are my 3rd set of M7s but I never thought to date them before - this set, however, is a bit older than my previous pairs! I didn't pull the woofers yet but I have photos of the tweeters - I pulled those to fix the pushed-in diaphragm. Tweeter diaphragms are rounder now, but still dented - it looks like the grills had been collapsed in against the tweeters.

Date code 9A7, serial numbers 1553 and 1641, both with the SD-13 tweeter. From the chart these appear to be September 1977!

 

[Yodathedog]

Joining to add 2 more! These are my 3rd set of M7s but I never thought to date them before - this set, however, is a bit older than my previous pairs! I didn't pull the woofers yet but I have photos of the tweeters - I pulled those to fix the pushed-in diaphragm. Tweeter diaphragms are rounder now, but still dented - it looks like the grills had been collapsed in against the tweeters.

Date code 9A7, serial numbers 1553 and 1641, both with the SD-13 tweeter. From the chart these appear to be September 1977!

View attachment 3744366View attachment 3744367
View attachment 3744368View attachment 3744369

SD-13 are the best ones. Those are early speakers.

 

[Hugis]

Ok well as my sources for these parts are a bit more limited and no one chimed in( i also read numerous failed coil replacements into the excisting magnets- shame as they are lovley..)

Anyway heres a new way to keep them looking original....

These tweeters seemed within spec 8Ohm 10-20Watt

I also thought i should replace the caps, no worries 250v 4.7uf are cheap on the aliexpress.

Needed a soldering iron to fix the above ....


Then:

and the crossover



And to be fair everthing checks out , tweeters are 7ohms measured, etc
I have a drill and bits etc,vice,blah
Rear view:

NOTE: i used a sealer around the outer ring and in the 4 unused holes to keep it airtight

Front:


I also had some black computer screws that tapped themselves into the plactic really well.

and yes the soldering iron kinda worked (long story-needed fixing)....


Da-Dah! Thats it!

Now:


Fully working ( i did both as both coils were kaput)

They sound great TBH , Used in a 2.1 system.



Hope you enjoyed my journey ....Peace!