moota
7 posts
Mar 16, 2010
12:05 AM
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I've been using dynamic microphones for the longest time. I have both crystal (retro-rocket, hohner blues blaster) and dynamic (545SD, Superlux D112) mic but have been putting away the crystals because I find them too shrill, sometimes not even the tone control on the amp (a pro jr) can filter the shrillness out. Lately I've been playing with an Artec PEQ pedal in between mic and amp, I find that it works well filtering out the shrillness. It can boost up the other nice frequencies at the same time. I kind of like the result. Not too sure if it can match the MC151 elements (i never have one) but it sure is nice to me. Comparing to the dynamic mics i normally play thru, I seem to be able to cut thru better, articulation is more prominent and a lot more "character" if i may say. I can control with my hands how much/tight I want to cup the mic to get a range of tones from deep bassy ones (not as bassy as dynamics) to a cutting wail. This makes the crystals i have a joy to play.
Anyone here have similar experiences with PEQs to share? Or a similar approach?
I don't know enough about electronics but I'm wondering now if a good mic means that it has got a real decent output at all the right frequencies without using corrective devices like PEQ. I'm thinking too if this is so then a lot of these current mass production mics like the ones I have that seem to be not so popular with harp guys can see some serious usage provided you can somehow tame it through EQ either on board the amp or outboard.
for discussion pl
Cheers,
Louis
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MrVerylongusername
981 posts
Mar 16, 2010
4:04 AM
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A possible reason for the shrillness of your crystals is that their impedance may be too high. Astatic crystals have impedance measured in megaohms and other brands may well be higher than is optimal for an unmodded guitar amp input.
A simplistic analogy is trying to squirt a firehose through a keyhole, it's gonna be messy! a lot of the water won't pass through. In the analogy water=signal.
I've found a buffer circuit can really help - a unity gain amplifier between the mic and the amp - result the mic 'sees' a matched impedance and you get optimal voltage transfer = far less loss of bottom end frequencies.
I have almost zero knowledge of electronics, but I was able to make one of these UGA boxes in about half an hour with a soldering iron and £5 worth of components. Search the forum, there were some threads about buffer circuits and some links to schematics.
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moota
8 posts
Mar 16, 2010
5:32 AM
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MrVerylongusername, thanks for the tip. My search led me to this thread on this forum
http://www.modernbluesharmonica.com/board/board_topic/5560960/504459.htm
with a link to a post back in'02 by Ironman Curtis
http://www.harpl.com/2002101611.html
I can't quite figure out the heads and tail of the schematic drawn in ASCII though. Is there a clearer diagram somewhere? I might want to give this a try.
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MrVerylongusername
983 posts
Mar 16, 2010
5:35 AM
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I'm not sure if there is for the micmojo - that's the one I built. You might want to google "Jayphat" it's a slightly more refined and better documented circuit, although a bit of a more ambitious project.
Isaacullah also linked to some other circuits if I recall correctly. Isaac? you there? any advice?
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7LimitJI
23 posts
Mar 16, 2010
5:45 AM
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If you buy a LoneWolf pedal it has a buffer already built in.
There is another method, that I got from fellow forum member. 5F6H
If you're using a valve/tube amp.
Increase value of grid load resistor for V1, pin 2 from 1Meg to 5.6Meg or 8.2Meg
Hopefully Mark might jump in here with a better explanation.
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The Harpist formerly known as Doggycam
Those Dangerous Gentlemens Myspace
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MrVerylongusername
985 posts
Mar 16, 2010
6:36 AM
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I'v heard that would do it too, but I know nothing about amp-mods: 5f6H or any of the other amp-heads - any comment?
Back to buffer circuits: I have this habit of not deleting anything and I've found two versions of Ironman's schematic before he took them off his website. I've put them in my public dropbox.
I think this is the one you've seen, but this time properly laid out in a monospaced font so the ascii works!
http://dl.dropbox.com/u/3806988/MikeMojoPlans.txt
This is another version I got from Ironman's old website several years ago.
http://dl.dropbox.com/u/3806988/MMojo.txt
I recall needing both to really get my head round it, but like I say I'm not an electronics buff.
DISCLAIMER: this isn't my circuit. As far as I know it's public domain, but I'll withdraw the links if someone informs me otherwise.
Other than simple layman's terms, I have no idea how it works and can't help you if yours doesn't! (but I know there are guys here who can!)
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hvyj
211 posts
Mar 16, 2010
6:52 AM
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Parametric or semi parametric EQs are the bomb--since you can dial in the freq you want to boost (or cut), Typically, boosting low mids @ 240 hz fattens harp tone.
The problem w/ playing amped is that guitar amps are designed for guitars, not a signal produced by an open mic. Personally, I don't use bullet mics. My primary amp is an SWR Baby Baby Blue bass amp that has a 3 band semi parametric EQ that gives me almost total control over tone shaping and allows me to re-create the sound I hear in my head. Love it. i use pedal board electronics when i play through this amp.
But I will sometimes use my Princeton Reverb Reissue or my Super Reverb Reissue--on those amps, I set the volume on the amps for the sweet spot that gives the level of tube overdrive and tube compression i think sounds good and then i attenuate he input gain by rolling down the volume control on my 545 Ultimate to control feedback and then adjust the VC on the mic a little to set performance volume. No pedals when playing through these amps.
Never tried an Artec PEQ. It looks interesting--but it only has one band of EQ.
Last Edited by on Mar 16, 2010 6:53 AM
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5F6H
21 posts
Mar 16, 2010
7:08 AM
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It's worth considering that it's not necessarily the mic's that are the problem, the Pro Jr has a couple of caps that increase the high end that makes it through the amp, even with the tone control backed off. Have you tried the crystals in other amps & found the same issues?
Is your Blues Blaster the new type with the Kobitone element, or the old style with an Astatic...it could already be a 151 in there?
That said, if the EQ pedal is actually doing what you want, you may as well continue to use it.
Any crystal mic pluged into a 1Meg Fender input is to all intents & purposes "matched", a higher impedance load may improve detail & dynamic response on larger amps (with any kind of mic except the 520DX, so if you want to keep using this, I wouldn't recommend going higher on th input load) but I don't really know if it is something that is really going to help with a Pro Jr? They're already pretty lively, but it helps them cut & "punch above their weight".
The larger than 1Meg input load idea came from Shure's old crystal mic data sheets from 1934(?)...so the idea has been around a fair while.
I have installed an op amp buffer on a delay, it did crisp up the sound some, it worked just as well with CM/CR & dynamic mics as well...but I don't typically find such devices necessary.
Larger than normal impedance loads can be good for harp (almost irrespective of mic type) & accordian because they help keep more "front" to the note. Plucked string instruments (gtr/bass) already have this ability and can even sound harsh with higher than normal loads.
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HarpNinja
280 posts
Mar 16, 2010
7:18 AM
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I've been toying with the idea of getting something like the MXR ten band eq to run after a wireless unit. It would replace my Kinder on my pedal board. I use an Ultimate 57 and love the tone I get with a cable, but there are some times when using wireless really pays off. The idea is to boost some of the highs the wireless seems to dull.
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Mike Fugazzi
vocals/harmonica
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Album Ordering
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congaron
685 posts
Mar 16, 2010
12:00 PM
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I think my wireless unit may be helping me get the tone I want form my valve junior without the lonewolf mods, for the very reason Harpninja noted. I get less shrillness when I am wireless, a rounder sound when distorted and a nice raspy harp sound when on clean settings. I haven't investigated this with my latest pedal settings (they were made using only wireless), but in general I have had no trouble getting my tone with a vocal mic and wireless body packs ( i have two very different ones)
Regarding EQ, I am a firm proponent of EQ, parametric if possible, but graphic will also do well for harp in my experience as a sound guy. EQ is a serious tool for feedback elimination as well as tone-shaping, especially on a room for room basis if you have the capability and time for that. I just dial in my tone at home and let the sound guy fix the room, unless I am running our sound from the stage.
Last Edited by on Mar 16, 2010 12:01 PM
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moota
9 posts
Mar 18, 2010
6:40 AM
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Thank u everyone for chiming in on this. wow! lots of info to process at this point. My blues blaster has the Kobitone element, does it mean that its output impedance is > 1Mohm? So even when plugged into a so called guitar amp with high input Z it is mismatched? I also have the Shaker Retro Rocket, not sure wat is the element though.
on buffer circuits: would a MXR Microamp work in this case as well? Schematics can be found here http://www.schematicx.com/schematic/mxr-m-133-micro-amp-pedal-schematic/
Lonewolf Pedal: I've been wanting to get one of these for a long time esp a delay pedal (v1 or v2). Do all Lonewolf models come with the buffer circuit?
Wireless Units: I've never used one before, but if it does take away shrillness of a crystal mic then may be good to consider, any recommendations?
@hvyj: yes the Artec PEQ works on only 1 band and I use it only to snipe out the shrillness. do you know any other current production PEQ pedals that works on more than 1, that'll give more options?
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MrVerylongusername
1001 posts
Mar 18, 2010
6:58 AM
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If it's the Kobitone then no, so the buffer circuit thing might be a distraction. Sorry to confuse the issue.
Wireless with a bullet? not really sure, I think you'd be looking at a guitar system ideally.
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congaron
686 posts
Mar 18, 2010
8:15 AM
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I think so too. I use dynamic, so it is a simple wireless mic system. In fact, on of them is a singing machin i bough from radio shack, cut off the mic and wired an xlr female plug to match my vocal mic.
I still don't know how long the 9 volt batteries last after several 2 1/2 hour practice sessions with the band and home noodling. It's a long time though and the range is astounding for a $20 wireless system.
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