Modifying an SM57 - Removing the transformer (TapeOp Mod) and changing the impedance
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- Опубліковано 19 лют 2017
- Shure SM57
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Today we're looking at the trusty Shure SM57, in terms of recording guitars. We heard that you can modify them, so we decided to take out the transformer and see what difference that made. We then went one further, and wired in a resistor to change the impedance that the preamp would see.
8:57 - Stock SM57
9:10 SM57 TapeOp Mod
9:26 - SM57 TapeOp + Impedance Mod
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#SM57 #Transformerless #TapeOp
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In general you produced a fine video. A lot of good and interesting comments. Forgive me if i may do some myth busting regarding what you said and what others have commented. Many commenters noticed a pseudo stereo effect on the guitars. We do not know what other alterations you may have made during the comparisons which lead me to question the results of the tests. Your first statement suggests that the stock 57 has a transformer to offer a means to match the impedance of the mic to the first preamp and to increase gain which 'helps reduce Gain Before Feedback.' Only the mic capsule design attributes to better GBF. The xfmr has little to do with that. Yes the xfmr is there to match impedances and yes will affect the frequency response of a mic if improperly done. But not necessarily add gain. Regarding the presence of phantom voltage, A properly wired stock or mod 57 or any dynamic mic will be subject to voltage surge only while the mic is being connected or disconnected from the phantom source. But not when the mic is already plugged in. When the mic has already been plugged in and phantom voltage applied, no phantom current flows through the mic or xfmr. I'm sure everyone here has experienced hearing an audible click coming from a dynamic mic while plugging it in or upon unplugging. Actually I do not suggest trying this as it may eventually damage the mic. General rule is to leave the phantom off for all channel strips and pres until all microphones are connected. Then apply phantom as needed. As for adding a 680 ohm resistor, understand the impedance of the SM57 mic capsule is I believe about 50 ohms. The xfmr converts the capsule impedance to 150 ohm impedance. Rated impedance is 150 ohms (300 ohms actual). Adding a 680 ohm resistor in parallel is inconsequential and has little effect on the final audio. Yes loading a capsule or pickup with a resistance lower than its rated impedance will adversely affect the response. This brings us to the most important lesson. Most quality pres include a control to electronically 'match' the impedance of the pre's input to the mic. This is where significant tone and mic charestices can be achieved. Note: If you want the sound of a 57 without an xfmr, try an SM7. Thank you for your time.
Big difference in sound! Very different colors. Thanks for this. More tools to create a sonic landscape!
I love your channel man! great and some pretty unique tests ... amazing stuff !!
i was expectating a subtle almost inaudible difference, in reality its totally different tones, i dont think you can say one is better than the other, it depends on the material you want to record/color, good stuff.
Its 2 different capsules. Generally 2 SM57s will sound different. So essentially it isnt the best test. Its actually quite difficult to run a perfect test.
Hey, great video! On the amp comparisons, I'm curious what is your preferred way of getting that stereo sound? It is obviously some processing going on, to turn the mono signal into htsi funky stereo signal.
Removing the transformer smooths out the top end which doesn’t make it brighter, just cleaner and less harsh. It’ll allow you to push the high end more without being too harsh. In this case, you’ll be able to get a more pleasing bright tone as opposed to the stock 57.
I know this is an old video, but I recently watched your video where you compared a ton of SM57-ish mics, and I’m wondering if you have ever compared the transformerless one to any of the cheap copies since they also don’t have transformers.? Would be really interesting to know if it sounds similar to any of those.
IMHO the stock mic 🎤 sounds best. But everyone hears and appreciates sounds differently. 👍
Thanks for making this video. I came searching for the mod that converter from low to high impedances. I'm guessing that it's what was done with the 680 resistor. It's hard to distinguish on a very phone the change. Can you please include more in depth conclusions? Looking forward to the 'gizmo' edition.
Thanks
Really helpful for harp players who want their sm 57 to sound like a sm 545
great comparison. Try a shure unidyne III 545. It sounds like the best SM57 you've ever heard! Amazing on snares and guitar amps. not sure if they make them anymore, but they go on Ebay sometimes. You won't regret it!
I have one and I use it on my snare. The only problem I have with it is it has a faulty on/off slide switch that has ruined many takes.
I have come to understand that 2 SM57s will sound different, so their capsules are already different sounding. Hence the fact that these are 2 diff capsules means that can be contributing a lot of the sound already on its own.
Stock mic sounds best to me, I think using stock mic you could probably just change the EQ to sound like the modded one.
same
I preferred the stock SM57, but with the resistor added in, the mic had a fairly pleasant dark sound. Kind of a niche usage mic. I have a Tape-Op modded SM58, and I'm wondering if I should do the resistor mod now. Thanks for the video bro!
+Kadence yeah I wasn't aiming to say "you should use this one", more exploring what happens. I've been using the stock one more often, but this mod has its uses- I tried it on a piercing hi-hat recently and it worked a treat!
Did this to one of my 57s ...... very useful different flavour. Neither is 'better'. Each instance depends on the source. 'Choice' is good
OK this is a capsule related question....I have recently purchased a USA Shure SM58 (new old stock) capsule without the handle and transformer part so my question is until I can source the handle and transformer to go with it is there anyway I can test the microphone capsule to see if it's dead without using a multimeter which I have heard can cause voice coil damage? these USA Shure SM58's sound way better than the modern Mexican made units but these are bloody rare and expensive coz they were last made in the US back in 1984 so not easy to get a good one so I don't want to waste money finding a handle to go with it if it's not working
Both mods degrade the sound considerably in my opinion. The transformer's main function is to match the capsule's impedance to that of the preamp. The capsule requires a very low impedance, and removing the transformer puts too high a load on it, which ruins the frequency response. The resistor does little in terms of imedance and just lowers the signal even further.
Erwin Dokter are you even listening to yourself. Too nerdy for your own good. Do you know how many creative recording can come from this mod?
I agree withe Erwin, havin tested it... Also removing the transformer exposes the capsule to fatal damage caused by Phantom current on some old mixers
In order to properly modify anything, you need to understand how all the components work together, what each one does, and why it's in the OEM circuit. Basic electrical theory will help you.
I'm usually use standard SM57, for capture "SPIKE" you had said. I'm using another mic with good response for the mid-low frequency.
For my hearing reference for the amp sound, I'm using the original audio output from the amp that I want to record.
In the pre-record sound, I'm using the EQ section to match the recording sound and the reference from the amp.
Input equals output.
You could also just buy an SM77 which is a transformer-less sm57. They’re dirt cheap. If you blend the two microphones, they really make an awesome sound.
I think both mods took away some crispness. I preferred the sound of the stock 57 in this demo. But really, it all depends on the source material being recorded. Maybe if you don't have access to a ribbon mic, these mods might help someone find that middle ground between a 57 & R121.
+Remy R makes sense! It's worth knowing that you can undo the first mod by putting the transformer back, or wiring it into an external XLR cable
Thanks for this...
Very interesting. How is it stereo?
Yeah, that was confusing and distracting when trying to listen to differences.
Hi, what mic did you record this video with? sounds very clean.
Hey- my usual video mic is a Sennheiser MKH416 into an Audient ASP800
Hop Pole Studios I thought so) thanks!
A lot of you seem to be under the impression Phantom Power WILL Destroy a Non Tranformer OutPut Microphone Cartridge/Capsule when it is a Dynamic, Not so Unless, You Earth/Ground One side of the Microphone Cartridge/Capsule to Earth/Ground and Apply Phantom Voltage to whichever of the Two XLR Or The Small Screw Locking (Tuchel/Amphenol Made, Or Franz Binder Made versions or other maker's equivalent mating connectors with this type) DIN Plug PINS That Normally Pass The Positive Going AC Signal Output From The Cartridge/Capsule and The Negative AC Signal Output From The Other Equal and Opposite Polarity Terminal Of The Cartridge/Capsule, The Pins On an XLR Being Pin 2 For The Positive AC Signal Portion Of The Cartridge/Capsule Output and Pin 3 for The Negative AC Signal Portion of The Cartridge/Capsule Output , The same Rules Apply If a Transformer is Fitted, If it is A Small Din Screw Locking Connector As Found on 60s, 70s, Early/Mid Eigties,AKG, BEYER DYNAMIC, SENNHEISER, SCHOEPS Mics and a Host Of German and Austrian and Other European Microphones, Wired To The DIN Standard, which is Pin 1 Being, The Positive Going AC Signal Out Put From Either The Cartridge/Capsule and If a Transformer is fitted the Same Rules Apply As Stated for XLR Output Above and pin 3 Being, The Negative Going AC Signal Output From Either The Cartridge Capsule and If a Transformer is fitted the Same rules Apply as Stated for XLR output Above Too. Then Yes If one Of the Microphone's Cartridge/Capsule wires is Earthed/Grounded and the other to either of the Normal Balanced Output Pin's XLR Pin's 2 and 3, Pin 1 Earth/Ground and Din Pin's 1 and 3,Pin 2 Earth/Ground Has a Phantom Potential Difference Voltage between The Earth/Ground, (which is also the Negative DC Return for the Phantom Voltage Supply, with Respect to Either Phantom Power +12 Volts DC, Or Phantom Power +48 Volts DC) Being The Potential Difference In Both of The Two Standard Phantom Power Supply Voltages, Which are as Defined Under DIN Standard No, 45596, Standards, If my Memory Serves me correctly for the Standards Number, In Germany which is where The System Originated and the system is not Correctly Balanced With Respect To Earth/Ground, Such as the Pin 3 XLR Old Output Signal + Going Phase Standard in the late Fifties in some Countries, being internally connected to Ground in the Microphone PIn connector in the Mic or a Mic cable Internally connected such that Pin's 1 and 3 XLR are Shorted Together and a Phantom Voltage is Applied to Pin 2 XLR , Then either with a Transformer or without a Transformer, The Transformer Secondary Coil will Probably Burn Out Or The Microphone Capsule Coil Will Burn Out or be seriously cooked in either case causing shorted turns to either Coil structure, Further If Th Latest International Standard since The Late Sixties/Early Seventies Of Pin 2 XLR New Output Signal + Going Phase Standard is Earthed/Grounded and a Phantom Voltage is Applied to Pin 3 XLR, The Same Consequences Will Happen, Burn Out or Cooking Of Either Coil Trans former Or Microphone Coil without a Transformer Fitted to It. The Same would Happen In the Case Of The Small Screw Locking Din Connectors Where Pin's 1 and 3 carry normally a Balanced Signal + and - Respectively Balanced and Not Connected to Pin 2 Which In The Small Screw Locking Din Connector Case Is Earth/Ground, TheLarge Tuchel Connector found on some of The German and Austrian Manufacturer's Microphone and Have Different PIN allocations for The 3 Pole Versions But The Same Principals Apply. Ribbon Microphones and Dynamics Way Back in the Fifties and some of those Made,Till Sometime the Seventies Had A Centre Tap Sometimes, Earthed/Grounded on the Output Transformer built in to the Microphones and Also Mixers On the Inputs to the Microphone Amplifers An Input Transformer with an Earthed/Grounded Centre Tap, this also Known as Balanced with Respect to Ground, If the Centre Tap's is Unconnected and Is Insulated It is Known as Floating with Respect to Ground, Additionally the Centre Tap's On Both The Microphone Output and The MIxer Input Can be Used With an 8K2 Resistor In series with Thea Cetre Taps to Pass the Phantom Supply from The Mixer In to The Microphone and Out of It's Centre Tap Via It's 8K2 resistor toFeed The Powering and Capsule Biasing Circuits Within The Microphone's Preamplifier Handle Connector Assembly That The Capacitor/Condenser Capsule Is Either Fixed To Or Unscrewable for Swapping to different Polar Pattern Capsules. If No Centre taps are Available at either the Microphone Tranformer's OutPut Secondary Coil Or The Mixer's Input Transformer's Primary Coil, Then an Artificial Centre Tap is Derived By Using Two Closely Matched Resistors, of 6K8 OHMS to 1 Per Cent or Better Still. .1 Per Cent Tolerance To Mimic as If a Centre Tap was Available On The Microphone Transformer Output Secondary Coil or The Mixer Transformer's Primary Input Coil.
To Say when I first tried to Find out The Statement Phantom Lines To Earth, (Ground), Meant when I read it in a Journal of A UK Trade Repair Engineers Periodical E R T, Audio Fair 1968 Report and Review of what was Available from Ficord Microphone Companies models that Year, Was, almost if it was some Kind of Electronic Black art Known Only To Our BBC Radio/Telvision and Our ITV Television Station's and the Same Of American and European, Radio and T.V. station's. My FatherWas Ex WWII Royal Army Servie Corp's 49th West RidingInfrantry Division, Who went in To Radio,T.V. Brown and White Goods Repais and Doing Electrical Installations and other Related work, He could not tell mewhat it was, Phantom Power, but he brought me a Small reel to reel Awai TP 703 Tape recorder and a Book of The EMITAPE GUIDE TO RECORDING, Which started mhy interest in all things Sound, Recording and PA Equipment, I was also FascinatedBy Telephone and Now Know thatPhantom Poer Existed in their infancy via a Battery to Bias the Carbon Microphones Primary Transformer Circuit, and The Transformer's Secondary Gave The +and- AC Output Signal to go down the Telephone Line, different version of Phantom power and before the Transformer on it's Primary Widing/Coil, The Outputof The Transformer Being the Secondary at approimately Line Level, of 600 OHMS and Balanced But NO Earthing/Grounding/ Or Screening/Shielding, as it's a Hotter Signal of .775 Volts dBU,almost 1 Volt AC.
Everything we Do in Sound or Recording is Directly Related to the Evolution of The Telephone Sytems in the World as a Whole from The 1800s and Tied Up with Companies Such As Bell Alexander Graham, (db I Tenth of a Bell Unit), (to originally do with sound as Heard, Now an Electrical Voltage and Sound Power level dependant on which Log Base of 20 or 10, it is Referenced To).Who Taught Deaf Children as well as being an Inventor and Experimenter, Western Electric and IWE, International Western Electric, They were UK based and are Better Known As STC, Standard Telephones and cables, ITT/ATT also Related to Western Electric, IWE/STC and They ended Up Owning Jame P Cannon'c Company as ITT Cannon And STC Cannon Components PTY, The Austrailan Division of ITT Cannon USA and It's UK based Offices inSuussec Also variously Know as Cannon GB and ITT Cannon GB XL, XLR UA, O, P, America/USA/EP, in The UK Through F& E, Films and Equipments Wardour Street London, Pre Cannon GB/ITT Cannon GB and The X Connector, which is the original Format of The XL and XLR Connectors = X with a Latch is XL and FinallyX With LR with a Latch and Resilient Socket Insert is XLR.
All My Information and Knowledge Has Been Accrued Through Years of Research and Reading to Find out The History andEvolvement of all That I have Presented Here.
Leonard Sorrell, Sound Engineer Recording Engineer, Manufacturing and Repair Engineer, C & G 224 Electronics Qualification from The 198o/ 81 Terms at Technical College In Canterbury Kent UK
I dumped the metal grill and the foam insert, replaced with a strip of t-shirt to get rid of the mudiness.
I Added a dab of jb weld to the center of the plastic resonator to dampen the plasticy resonance of the resonator itself.
I changed to the yellow mod transformer from front end audio to get rid of the edgy distortion while keeping it bright and tight.
Lastly I will use a Cloudlifter Z to adjust the impedance to taste.
I love the compression of an sm57, but hate the indistinctness, the built in distortion and that it sounds kind of distant in a mix. I'm hopeful the mods will take it in the right direction.
I could have just bought a Heil pr20, but what fun would that be?
I just cooked it with some chilli beans to make it sound hotter. d= ;)
So I took out the transformer and disconected the wires , but I didnt take note of which colour wire was originally on which lead. What do you think I should do? If I get the wires opposite since I may have to guess, will the mic just not work?
If you get the wires backwards, the mic will work fine, but will be opposite polarity to the rest of your mics- you’ll have to flip the phase either on your interface or in software, but it’s not the end of the world. I have a vintage 421 wired like that, I just have to keep it in mind
right i see. is there a way I can test to see whether its normal or opposite polarity after I wire it? because its easy enough to flip em around while i have the soldering gun out!
You know, I’m not sure! If you have an interface with 2 channels, maybe put that mic and another one up next to each other, and record a clap. Look at the waveforms and if they go the same way, job done! If they do opposite ways, it’s rewiring time
ya, that makes sense lol. Ill try that! some engineer i am lol. thanks
Could you A/B these in a mix? That would be awesome.
+Matthew Mohr can do! I'll try and post that over the weekend
I play harmonica...which means I have different requirements for sound than guitar folks through my mics. I have an early 50's Shure 520 bullet, and my back up is an early 90's SM57. If you were to buy new 520's and SM57's today, you'd be getting different mics. They have changed the guts. And Shure won't tell you what or why. The older mics sound better for harmonicas. The newer ones seem to sound better for voice. Just my opinion.
awsome!
it's much more desirable to combine the sm57 with a royer imo, if you want low mids that sound really full, that is the way to go. but you have to be carefull with fantom power regardless
You're talking about changing the sound by adding a $1000+ mic, that's not a tenable solution for a lot of people
@@adamsteelproducer You're right, the focus of many channels is indeed the cheapest way to get sound, but than again... If Shure thought this mod was better for the overal sound they surely would have sold a modified sm57, Imo it's not worth the risk of damaging the microphone and losing the garantee. Just put on some low freq harmonic plugins and do some other tweaks and you'll have a simular sound, the overal sound is much like the stock one anyway...
With removing the transformer on the sm57 is make it high impendance microphone?
+Noki Januar no, much lower impedance
Hop Pole Studios thank you, great content video!
Interesting. I may do the impedance mod on of the Pyle SM57 knockoffs and *add* a transformer to it. I like dumb little projects.
Dude, I have watched tons of videos on this topic because I have quite a few mics that I use in my home studio, and trying to get the best sound out of them for recording. You video has got to be the BEST video I have seen on the topic...period. I have a Shure SM58 with the transformer in it, and I have three Pyle PDMIC78's, which are clones or copies of the SM57, and they do not have any transformers in them. So I have an external transformer that I use with all of my mics...it's from Radio Shack and it plugs into an amp or PA, I plug it into my vocal effects processor (a DigiTech RP100...don't laugh...lol, it might be a guitar effects unit but it works great for vocals as well). All it is, is a round tube looking thing with the transformer inside, it has the female XLR jack on the back end and has the 1/4" phono plug on the front end. You plug your XLR mic into the transformer back end, and then plug the adapter into whatever...an amp, PA...or in my case an effects processor. I just bought the PreSonus Audiobox USB the other day, I've had one before and they work really well as an audio interface. I'm going to try and use my transformer adapter and effects processor with it and try out all my mics and see how it sounds in my recordings. I never heard of the resistor mod, so I will definitely be trying that for sure!! Just wanted to say that you have the best informative video out there!! Subbed for sure...keep up the great work!!
+Gun Slinger thanks dude! Lots more videos to come :)
AWESOME!! Can't wait.
I found the stereo sound confusing and made it harder to compare in my opinion. But cool mod!
Beautifully present and chunky sounding amp my dude.
Also I think if you mixed both those signals together, you'd get a fat sound.
+f u n k j u n k . n e t cheers :)
+f u n k j u n k . n e t tried it, no luck in this case, sounded quite dull. If it was set up as a freeman technique it does sing!
Good point, definitely considering having an sm57 modded like this. Thanks for the video :)
No one hears some weird stereo thing going on?
Its been double tracked...
Andy Hosker yeah we know
the resistor should be in series ( in line ) not shorting the capsule.. the difference in sound is going to be in a transformer input mic pre, which needs the proper source impedance. The impedance directly from the capsule is very low, compared to normal
Those mods just add mud. It's like turning both the treble and the volume down (you instantly lose 12db of gain when you go transformerless which is huge if you don't have a super high quality preamp) One mod to consider is to put a better transformer or at this point... buy a better microphone!
Do they add mud? Or do they remove that 3k spike? All relative. Also losing that much output level shouldn’t be a problem with modern preamps unless you’re whispering from 12 feet away
@@adamsteelproducer It is a problem with most entry level preamps on the market. For example, the Sm7b is a wonderful microphone ... if you have quality preamp that gives you at least 60db of gain to be able to use it which is not the case for almost all entry level preamp on the market. The sm58 requires a few dbs of gain less than the sm7b, but still, quite gain hungry. Without transformer, you need more gain, therefore, you raise the noise floor. A lot a modern entry level preamps will have 50 db of gain (with noise). The best entry level interfaces will give you 60db of gain (with noise). Of course, in a studio environment, it's not an issue but at the same time, if you have the money to have a proper studio, why messing with that?
They use to make an sm57 without the Transformer but the problem was if someone switched on phantom power it would blow up the capsule🤟
only on xlr cable . ts cable don’t carry phantom
Who plugs a mic in with a TS cable in 2021?
@@adamsteelproducer why would you use xlr for dynamic mic!? Condenser yes. Dynamic no need I think
Where do you live? Pretty much every microphone has used XLR to interface with mic preamps for at least 30 years, the only equipment I have that works otherwise is from the 70s
Not interrupt .the only people who are probably using 6.5mJack connectors are home streaming people.
how many watts should the resistor be? theres different watt 680 ohm resistors!
+James Cassidy watts aren’t a big issue here, as it’s going to have tiny amounts of power going through it. Smaller is fine. In big circuits that use lots of mains power you might need higher wattage ones so they don’t melt. No mains here!
thanks buddy, ordering my 100 today lol. I guess I have -to mod 100 sm 57's!
+James Cassidy haha yeah you can’t get just a few!
Different colors for different results
The stock SM57 is a million time better.
Adding the resistor just made it sound like you put a sock over the mike, not an improvement.
But a change nonetheless. This was much more of an experiment
No, did'nt like the mods. Maybe next time, try a really good transformer.
Guitars are out of tune. Very strange.
That doesn't change the mic mods...
@@adamsteelproducer yes,but it's sounds weird and unpleasant.