Tom Lauten
49 posts
Mar 15, 2019
5:15 AM
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Hi everyone. Could I get a second opinion on this mic and element please?
A Shure 707A with a 1949 shure 99a47 element?
Can anyone enlighten me in terms of the “type” of element this is? CR/CM? Impedance etc, etc?
Many thanks!
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Tom "Bad Paw" Lauten
Loch Ness, Scotland
www.nimbacreations.com
Last Edited by Tom Lauten on Mar 15, 2019 5:29 AM
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Bruce S
51 posts
Mar 15, 2019
5:53 AM
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That's a crystal element, which are always high impedance- you can see the label on it states that it's licensed by the Brush Development Company.
Here's a link to the datasheet for the mic;
https://pubs.shure.com/guide/707A/en-US.pdf
Some of the 707-A shells are slightly smaller than the 520 shells, other's the same size. Nice mic, especially if the crystal works
Last Edited by Bruce S on Mar 15, 2019 5:57 AM
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Tom Lauten
50 posts
Mar 15, 2019
6:09 AM
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Thanks for that. Well...it’s crystal as I had assumed. Maybe there is more info out there on the elements specs?
It’s exactly the same size as a 520dx shell.
The crystal does work although I don’t think it’s quite as hot as some CM elements I have. The output sounds fine but one has to cup it EXTREMELY closely to overdrive it. I’m wondering if it’s worth fitting a transformer to get that extra punch?
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Tom "Bad Paw" Lauten
Loch Ness, Scotland
www.nimbacreations.com
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Bruce S
52 posts
Mar 15, 2019
7:27 AM
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I wouldn't bother with a transformer. They don't work with crystal mics IME. The element contains a crystal of Rochelle salt; over time they absorb moisture and degrade. From the 2-49 stamp I'd guess it was made in 1949, so it's 70 years old! . I've had a crystal from one of the "new" JT30RH/Bluesblaster's fail in a couple of years, but a later MC151 in a JT30 that's lasted well, although I haven't played out with it much and keep it in a box with one of those little dehumidifying pouches in when not in use.
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jbone
2858 posts
Mar 15, 2019
8:00 AM
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Whatever else you do, keep that element from heat. I fried one many years ago and it was one like that. I did not heat sink when I was putting a new cable on and killed the crystal. If I was changing a cable or whatever I'd work well away from the element and heat sink as well.
Crystal elements are not the hot brown tone of a CM. They are more clean and clear yet warm. I hope you will appreciate what you have there!
I had a Ruskin custom built mic with a crystal from a JT30 some years ago and loved it. Sadly I had to let it go along with some other choice gear in hard times. If I had it to do over I'd have found other things to let go.
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Harpaholic
933 posts
Mar 15, 2019
9:56 PM
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If that's not an actual small shell with the grill screws on top and bottom then it's a Black label 47-48 model 707A (1940-1948) that came with a 99-131 Shure crystal which is not the R7. The shell color on yours is a darker grey/silver than the 49's. 1946-1947 was the last of the small shells.
The R7 is the replacement element for the 99A Shure crystal. Only difference is the R7 has an R7 stamped in blue usually on the white paper tag. Someone put a 49 crystal in that mic because 1949 was the first year of the silver 707A with the blue tag and the 99A crystal.
Ask anyone that owns or has owned a full strength 99A/R7 crystal. They are not clean. They push into crunch very easily. They have the fattest tone with the best bottom end of any element. They are without a doubt the best element ever made for harp.
I owned many 99A/R7's, three were full strength, two were the holy Grail of tone. If you can find a good 99-131, they are a real close second.
Last time I heard, Rod had been using
One as his main rig.
Last Edited by Harpaholic on Mar 15, 2019 10:14 PM
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Tom Lauten
51 posts
Mar 16, 2019
4:51 AM
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Well, it’s a standard shell with the screws on the r&l side of the grille.
The shell colour looks dark but is actually the classic silver/grey...just so little of the paint left! Don’t fully understand what that might imply re the crystal.
The sound is clean and silky as you described jbone...I like it but wish it as a bit more powerful with a teeny bit less headroom.
The grille almost looks painted but that might be a time worn satin chrome finish? Considering a complete restoration job...as good as I can do anyway...perhaps polishingbthe grille to a satin / brushed finish? Wish I could get a definitive standardised paint colour for the body.
Does anyone think I could clean that plate up at all...looks rough and worn / pitted...could use a little tidying.
Any ideas?
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Tom "Bad Paw" Lauten
Loch Ness, Scotland
www.nimbacreations.com
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Harpaholic
934 posts
Mar 16, 2019
10:14 AM
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Tom, the black tag implies the 99-131 crystal. The blue tag implies a 99A crystal..
Your element could be original since it's a late 40's mic which is the transitional period for the 707A.
The black tag 707 has darker paint than the 1949 blue tag model.
Last Edited by Harpaholic on Mar 16, 2019 10:17 AM
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Tom Lauten
53 posts
Mar 16, 2019
10:55 AM
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Hmmm...yeah, seems to be in flux between models. I’ll takr some snaps of the paint I can find...looks like the lighter shade to me.
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Tom "Bad Paw" Lauten
Loch Ness, Scotland
www.nimbacreations.com
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Tom Lauten
54 posts
Mar 16, 2019
11:04 AM
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Just found this...
Shure bullet mic ids
“...The third picture is a 1950’s model. I’m not exactly sure when the larger shells came into play but I think it’s safe to say right around 1950. It was at this time that the crystal element’s were changed to the larger sized R7 crystal which was used right up to 1970 when production of the 707A stopped. These tag’s were black with raised lettering. Most of them looked like they were a dark brown color and no longer had a serial # on them. The chrome grille was no longer being used and the grille’s were the same brushed nickel type as used on the 520 green bullets. The shells were now being painted light gray. These dark brown or black tag’s were not used for too long because the light blue tag’s as seen in the next picture were also used in the 1950’s....”
Mine seems to have an aluminium tag as opposed to what looks lik3 a brass one in the photo...apart from that...looks like a match.
 ”
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Tom "Bad Paw" Lauten
Loch Ness, Scotland
www.nimbacreations.com
Last Edited by Tom Lauten on Mar 16, 2019 11:16 AM
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Tom Lauten
55 posts
Mar 16, 2019
12:36 PM
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Here are some colour references of my 707A...
 ”
 ”
 ”
 ”
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Tom "Bad Paw" Lauten
Loch Ness, Scotland
www.nimbacreations.com
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Harpaholic
935 posts
Mar 17, 2019
5:47 PM
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You are correct, I forgot the small shell 707's are a darker color not yours.
All of the 1946 707's I've owned where small shell. I have two 1947's, one small shell, one standard. All came with 99-131 crystals. So my guess is 1947 is the transition of shell sizes.
I have owned a few 1949 and 1950 707's all were blue tag with 99A/R7 crystals.
The 707's also came in brown and in green paint, ( the C3). RCA made them in brown without a tag and probably other companies as well.
1949 is the first year of the blue tag 707 per Shure's data sheets/catalogs. So I assume by 1950 they were in full production.
The R7 was a replacement part, but Shure may have installed them due to lack of inventory?
From my experience, 99A/R7's tend to loose there bass at the end of there life and get real clean sounding. I have owned well over 30.
Last Edited by Harpaholic on Mar 17, 2019 6:16 PM
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Tom Lauten
60 posts
Mar 25, 2019
2:28 PM
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So I guess mine is 1949 with one of the last black/brown tags.
The element is weak and clean...such a shame but all things fade away I guess...my search for a strong replacement will have to begin.
The grill is near ready having been stripped of most of the tired old “chrome” and polished and the shell with its 2 square centimetres of original paint is being prepped for powder coating in as close a colour as I could find. I’ll be makin* up a nice new customer m gasket as well, all fresh, air tight and vibration reducing!
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Tom "Bad Paw" Lauten
Loch Ness, Scotland
www.nimbacreations.com
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indigo
556 posts
Mar 25, 2019
5:35 PM
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Hi Tom just curious on how do you make your own gaskets?
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Tom Lauten
61 posts
Mar 26, 2019
1:26 PM
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Short question, long answer!
I am a special effects artist by trade so model making, mould making, casting, plastics and rubber comes as second nature! Takes quite a bit of “jiggery-pokery” to set it all up.
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Tom "Bad Paw" Lauten
Loch Ness, Scotland
www.nimbacreations.com
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Tom Lauten
63 posts
Mar 28, 2019
7:10 AM
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Well, here we go. Not the IDEAL colour for the mic but even when holding the original paint up to a live sample things can turn out weirdly. The finish is a bit more “gold” than I would have liked. I wanted a bit of the yellow tone of the aged original but it came out more “champagne”...still, it has the 707 feel and the finish is nice and tough as old boots. Grill polished up nicely.
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Tom "Bad Paw" Lauten
Loch Ness, Scotland
www.nimbacreations.com
Last Edited by Tom Lauten on Mar 29, 2019 6:34 AM
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