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OrthodoxBluesDec 11, 2009 7:32 PM GMT
I've avoided crystal mics because I live where it is hot. There are many places on our island where it also is very humid. Where I live tends to be more on the dry side. In any case, I've been reviewing information on crystal elements, and while everyone seems to agree that most or all are quite prone to breakage if dropped, there seems to be a difference of opinion regarding their longevity related to heat, and separately, humidity and dry weather. I'm hoping someone here knows more than me about this topic.
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I dislike crystall mics as they are fragile and unresistant to climate condition (it's often cold here) and they have twice less frequencies than SM57. It seems, that I can produce any crystall tone with my 57 and EQ (just reduce bass and highs).
Well, only slightly impulsively, I bought an Astatic JT-30 with a M-151 element in it. I figured that if the element fails, I'll get a Shure element put in it. I'm just not sure why I didn't ask about it (especially you, Joe) before I bought!
Crystals are sensitive to room temperatures and body heat as well. Ceramics arebasically man made crystals that are much more impervious to that.On my JT30's, I set the volume control onthe mike at about 3/4 of the way up and the volume on the amp at the feedback threshold because I know the output is gonna change from room temperature and body heat and so when the volume on the mike drops because of this, I can turn it up on the mike. when that same mike is given to a player who hasn't sweated, the volume will automatically go up. Also, the Rod Piazza mod was setup for when you turn the mic volume down, you don't lose the mids and highs, and when the crystal gets subjected to room temperature extremes and body heat, the extreme highs and lows get jacked up and the middle tends to fade out and here's where the low value cap on the volume control comes in, and it doesn't work when the volume control on the mike is all the way up.
Joe, it would be very funny for me to have a humidor because I am more allergic to tobacco smoke than anything else in the world!
BBQ Bob, I didn't know that crystal mics actually respond to the heat of the room and body temperature in terms of volume drops. I love the approach that you have, leaving some volume room for when you need it later in the performance. It reminds me of when a guitar player goes from rhythm to lead, and boosts his or her volume at that point, through a switch in pickups, a pedal or a flip of the guitar's volume knob. Can you tell me more about the Rod Piazza mod?
Thanks, now I understand, the capacitor allows more highs and mids through when the volume control is turned down, as normally that would squelch some of the highs. Again, my brain goes to a guitar comparison, in which you turn the tone knob up on a guitar when you turn the volume down, to do (i think) something of the same thing. It also leads me to wonder if a guitar treble booster pedal would work for the same thing ... well, I'm sure an equalizer would. I love learning this sort of thing. Thanks, Joe and Bob
Just gotta make sure the volume control on the mike you have has the correct impedance. Crystals are ultra high and the right pot is a minimum of 1meg. CM/CR is no more than 500K, and many dynamic mikes are 100-250K. That Rod mod was, I believe, originally used on Fender Telecasters from 1950-56.
Did Rod Piazza copy his mod from a fifties Telecaster? If so, that is a very cool piece of history for us who play both guitar and harmonica. Cool way for old school technology to travel. My Telecaster is a mongrel, it has a '69 neck, and a '64 body. It is old, but not fifties!
A former guitar player of mine who has his own vintage instrument shop here in Boston had not only a real '52 Tele for awhile, but also its predecessor, a '48 Broadcaster. I messed around with those (I also play a little bit of guitar), and the '52 definitely has that circuit, but unlike the pot that you'd use for a crystal/ceramic mic (minimum 1meg, ideally 5mg), it had that low value capacitor in the back of a 500K pot (the pot most commonly found in a guitar, but also used on the JT30/Blues Blaster when they started to finally put volume controls in them, but those are the wrong value/impedance for a crystal, but for CM/CR cartridges, they're the right ones) and it does that very same thing. I doubt that he stole that idea, but probably it was suggested to him by a good electronics guy or guitar repair guy. The idea of the the original Broadcaster/Tele was for use as a jazz guitar and many of those had much better bottom end than most Strats, and the top end was fatter than a lot of strats, and were great for playing jump/swing stuff as a 2nd choice to a Gibson with P-90's.
Thanks for the cool information, Bob. I received my new-to-me 70's or early 80's Astatic JT-30 with a M-151 element, and it sounds fantastic. I hope it lasts a very long time, because I love the sound. I read somewhere that crystal elements are supposed to have more of a treble response than the CM/CR Shure elements. I heard that, but it wasn't at the expense of a bass response. Perhaps my Shure is a bit more "boomy," but the Astatic had a full bass sound to my ears.
The elements in those JT30's have a surprising amount of bottom end, and the midrange presence rise isn't as heavily exaggerated as it is with the CM/CR cartridges. If you have the JT30 with the screw on connector and the threaded hole for a mike or a desk stand, those are pre-1984. The inside of the grills on those doesn't let in anywhere near as much body heat and moisture that the ones made after 1984 (anything from 1984 and later has either a mini-XLR or a regular XLR. The older ones you can get an adapter to use a guitar cable with them and I much prefer this setup to the XLR setup. The Astatic actually has more bottom end range than those CM/CR's do.
I use to get those with the screw on connector setups brand new back in the 70's for as little as $8-11 US brand new in the box, and with the desk stand that they often came with, about $14-15. Now the prices on Ebay for those is so freaking outrageous. Even when those were brand new, each crystal was different from each other, with some being almost too hot and some less hot.
Thanks for the cool information. My mic is pre-84, and it sounds like I got lucky with the element. How do these mics sound in comparison with the older mics?
Do you the newer mics??? The JT30's prior to 1984 are better, and the setup behind the grill is a superior setup that doesn't allow anywhere near as much heat and moisture that the ones since 1984 uses, which is just a cheap piece of paper behind the grill and they let way too much moisture and heat/cold in.
The cartridges from 1984-1989 were terrible, tho the present crop being made in Japan (buy Kobitone, I believe) are far worse and way too trebly and thin sounding.
I should also mention regarding older JT30 elements, is that there are two different crystals and ceramics. The MC-151 crystal and the MC-127 ceramic, which are the most commonly known, have a midrange presence rise in them, and the MC-101 crystal and the MC-126 ceramic have, as described in older Astatic literature as being substatially flat in its response, meaning that these two, which are rarer, do NOT have a midrange presence rise (for some amps, this, if you can find it, may be a better option).
Thanks, Bob, I meant how do the 70's and 80-84 sound in comparison to the 50's and 60's ones, which you answered regarding the elements. You also answered a question I should have asked, which is how they sound compared to the newer ones. I love learning about this stuff. I guess I have to face it, I really am a geek!
Like the 80's elements, some are hotter than others. The MC-101 and MC-126 were more common in the 50's so those are gonna be different because they don't have a midrange presence rise. Crystals have been noted for being inconsistent in terms of output (AKA hotness). Ceramics are basically man made crystals that ar more consistent, less susceptible to temperature extremes and some have been hotter than some crystals.
However, since Astatic stopped making the JT30's because their source for the crystals stopped making them entirely, the stuff being used now I believe are made by Kobitone of Japan, and they are clearly inferior as well as a lot more trebly.
I believe that I understand. I think that you said that you have more than one JT-30. What do you have, and what is your favorite, or does it depend on the situation and the amp?
I've really gotten into these vintage mics; they have as much of a story as the vintage amps and guitars, but usually are less expensive!
A good crystal element is a tonal thing of beauty. However too many are so crappy. Since Astatic stopped production good crystals are few and far between. I'd recommend either a CM element or a good dynamic element these days. Just because they are infinitely more reliable.
There is a guy in Germany called BBHarpy who apparently repairs crystal elements. I think he can be contacted through either Harp L or www.harponline.de
For the curious or addicted, I do have several MC-151's in good shape. Of course I have many more that rattle when you shake them - so my cost to get a good one is up there these days, and so they are not cheap. But they won't get any cheaper - I ask $215 for them right now.
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Given the fact that they are not made now, it seems like a reasonable price to me. It also makes me feel very lucky because I wound up with my 70's-early 80's JT-30 with an M-151 for less than that price.
Have you heard any of the crystals repaired by BBHarpy?
Ralf, aka BBHarpy has a cool site at www.harponline.de. You can press the British flag in the upper left of the home page and read it in English. I'm going to write to him to see if he repairs crystal elements. From his description of making custom mics, it appears that he does repair them, and perhaps Shure CM/CR elements as well.
I have several different JT30's with both crystal as well as ceramic elements. The older ones with the screw on connectors I still much prefer. If I have to user an amp with unusually high midrange strength that could make me feed easily, here's where using the crystal/ceramics without the midrange presence rise makes more sense (MC101/MC126). For most Fender tweed amps, the JT30's with either MC151/MC127 works better because the impedances match perfectly.
With an amp from the Black Face era, like a pre-CBS Twin or Super Reverb, the Green Bullets with either a CM/CR match better because of the impedance (black face amps have a lower impedance than the tweed ones, unless in the BF amps, you plug into the channel that does NOT have effects like tremelo and reverb in it).
No matter what, it doesn't phase me to go thru the PA because unlike too many players who freak out because they can't go thru an amp to get "their tone" (and if you have that for an answer, you never had any to begin with), I look at it the way many of the old masters did, just whatever to get my sound across. Many of those old guys would just burst out laughing at 99% of these gear infected players.
Yes BBHarpy repaired a Turner crystal element for me a few years back. Whilst not as strong as an original it did have a lot more output than before he repaired it. . It was definitely worth the money. I can't remember what I paid but I do remember thinking that it was dirt cheap.
Thanks for clarifying, Kingley. Ralf hasn't written back to me yet. I think that www.harponline.de actually is the site of Michael Timler, and Ralf writes some things on the site.