MXL 990 condenser microphone capacitor upgrade MOD, body repaint, with sample audio

[@MicParts]

There is some misinformation here that I'd like to correct. By way of credentials, I've been manufacturing capsule and circuit upgrades for the 990 (and other models) for many years. I have personally modified 30-40 mics, including full circuit rebuilds, capsule replacements, power supply replacements, etc, from transformerless FET mics to transformer FET to tube microphones. I used to recommend the "single layer headbasket" mod demonstrated here. I loved the logic that the mic will sound "more open" with less mesh in the way. But then I did some audio testing (via swept sine wave using a measurement mic and calibrated speaker), and ABX testing, and concluded that this mod is usually a bad idea. One problem is that the audio effects are minimal, and not necessarily an improvement. The other problem is that you lose plosive protection and EMI/RFI protection. Sure, you can use a pop filter to avoid the plosive problem. But the pop filter won't prevent EMI/RFI from sneaking into your track through the open grille. The third and most critical problem with the single-layer grille mod is that the remaining layer of mesh resonates in the audio band. IIRC, I measured this at 13kHz for the 990. That means that your mic is making sympathetic resonance that YOU CAN HEAR IN EVERY TRACK you record. You can't EQ that back out of your mix. If you think you can hear a "more open" sound, but wish to avoid the problems with EMI/RFI and sympathetic resonance, do a Google search for [mxl 990 headbasket upgrade] to see a commercial alternative -- a 2-layer mesh grille that looks nicer than stock. We based the design on the Neumann M49. Regarding capacitor swaps: it's doubtful these would pass an ABX test. Said another way, I doubt most people would hear that capacitor change in a blind test. C3/C4 are the main signal caps, and they set the low-frequency response point of the circuit. I don't argue with using film caps there, although I'd go with polypropylene rather than polyester, which is what those generic box film types in the video probably are. But the reality is that the 990 has much deeper problems that these mods don't address, such as: - the capsule sounds pretty awful, with a 3-5dB scoop around 7-9kHz and a 3-5dB boost at 12-15kHz, accentuated by the single layer grille resonance - the JFET has huge input capacitance, which acts like a pad - the JFET wasn't biased properly, so it distorts prematurely - the DC oscillator under-powers the capsule, which negatively impacts sensitivity and therefore noise floor - Every 990 made since about 2013 has a surface-mount circuit board, which cannot be modified using the techniques described in the video. If you want an upgrade that EVERYONE will hear, replace the capsule with an RK-47. (Full disclosure: I make that capsule.) This one change will significantly re-voice the microphone. No circuit changes are necessary. This will give you a night-and-day upgrade and probably will addict you to DIY microphone upgrades for life. It did for me. :) If you have the chops and the tools to populate a circuit board, my company makes a drop-in replacement for the 990 that contains a full implementation of the Schoeps transformerless circuit. This kit has a full +60V DC power supply for the capsule, and employs low-noise parts throughout. The JFET is a NOS component with much lower input capacitance, and is properly and individually biased for each kit. The resulting mic has much higher output, much lower noise, and lower distortion. You're basically building something that competes with a TLM49, but it will cost you less than $500 instead of $1700. The MXL 990 becomes a "donor body," into which you're building a world-class mic. Some people say it's dumb to spend so much to "upgrade" a cheap mic. I disagree. If I can build a mic for $500 that sounds like it cost $1700 or more, that's a pretty great deal, no matter what brand name used to be on the mic body.

[@EricStrebel]

matthew mcglynn Thank you for your thoughtful post to the community. Great information. Can you contact me through www.Botzen.com ? perhaps there is an opportunity to make a new video and cover some of these details and get new information out there..

[@mexicanfrusciante]

great info

[@mexicanfrusciante]

+matthew mcglynn how will the RK-47 change the sound of the mic? does it give it a fuller/bassier sound? I'm trying to find a mic that will give a natural sound, as close to what you're hearing in the room without having to break the bank. Maybe this mod will do it? $600 is the most I want to spend.

[@MicParts]

The capsule in a condenser microphone determines 80-95% of the sound of the mic. Most microphone circuits are linear with respect to frequency, and therefore are not contributing much to the tone of the mic. The acoustic environment of the capsule -- meaning, the size and shape of the air cavity inside the grille, and the height of the capsule above the deck, the composition of the mounting post, the acoustic reflectivity of those surfaces, the placement of the body -- contribute some small percentage to the sound of the mic by filtering or increasing the amplitude of small bands of frequencies. But the bulk of the tone, meaning the frequency response of the mic, is determined by the capsule. Therefore, any question that addresses characteristics of tone, such as "fuller/bassier," have to be answered by changing the capsule. In some cases, it is theoretically possible to put EQ into the circuit to counteract or correct the sound of the capsule, but in the case of the 990, the capsule's goofy frequency response cannot be corrected by EQ. You'd need a multiband or parametric EQ, which is not feasible to build into a mic circuit. The RK-47 capsule (full disclosure: I make that capsule) is a nice choice because it works well on the stock circuit. It will sound fuller, because it lacks the high-frequency hype common to most cheap condenser mic capsules. By removing the excess response at 8-12kHz, the low end becomes more prominent, even without boosting it. This is a great low-cost upgrade to the 990 and many similar transformerless microphones. A nice alternative voicing is to use the RK-87 capsule, together with the circuit replacement kit from MicParts.com (disclosure: I designed and manufacture that kit). The RK-87 capsule does require in-circuit EQ that this circuit kit provides. The combination gives you a fairly linear-response microphone, with full low end and a very controlled and musical top end. This combination will beat most $1000 mics in a shootout, in my experience and according to customer feedback. There is no "better" option here; the two capsules sound different, and excel at different things. The RK-47 can be used with the stock MXL circuit, although the stock circuit has lower gain, higher noise, higher distortion, and a less cohesive sound. The RK-47 definitely benefits from a circuit upgrade, if you have the budget and the soldering chops to do it. The RK-47 is a more "colored" sounding capsule than is the RK-87. It is a fantastic contrast -- and I'd argue that a good mic collection would have examples of both, because as I mentioned above, these two capsules excel at different things.

[@endoffate5475]

@@MicParts Hey man where can i contact you?

[@gunslinger8130]

I couldn't really tell any difference in the sound to be honest. I do like the idea of removing the internal foam pop filter as I use an external pop filter anyway. Removing the internal foam pop filter opens up the mic and gets rid of that muffled sound that you sometimes get with these mics, especially with higher gain settings on the mixer or audio interface. Great video!!!

[@EricStrebel]

Tough to tell with all the compression that KZbin puts on everything, but its better in my opinion.

[@feverwar1466]

listen in good headphones or speakers. Clear as day difference.

[@reekrodriqguez6552]

Feverwar Eventually you still gotta put stuff on KZbin either way so what’s the point ?

[@GaryWalker]

@@EricStrebel It would be a heck of a lot easier to hear the difference (and yes, I can hear that the rolloff frequencies have changed) without the background music. I think if you're trying to compare microphones, having anything but the microphone's output in the channel is sort of working at cross purposes to your goal. Not trying to bag on you, I have one of these and am definitely going to see if I can make it a bit nicer on the ear by doing precisely this. I'm just trying to give you some advice about your production choices.

[@EricStrebel]

Fair point...

[@srbournival]

What song is in the background? Sounds like Robert miles

[@EricStrebel]

A version of his, correct

[@uriel-heavensguardian8949]

Awesome video!!!! Gonna mod mine as well! Just doing research and video watching before I do. Thanks for this

[@alexheyer3034]

Improve your soldering mate!!!

[@EricStrebel]

Glad you liked the video Heyer Alex. I will let Kris know. I think that is the second time she has ever soldered, I feel she did alright. Look for an upcoming video where I solder a circuit with out a board using leaded parts. Cheers!

[@brianboni4876]

What is the red ring? You didn't say if you painted the old one or if it is something else.

[@EricStrebel]

Brian Boni yup, painted the old one. glad you liked the vid, thanks for the comment

[@christopheguidemann6005]

Hello, What is the value of capacitors? Thank you

[@EricStrebel]

Honestly, I have absolutely no idea.

[@ronaldwhittaker6327]

they got third hand work holders or just plane work holders for soldering Eric but i know you knew that just saying

[@Tracks777]

Keep it up! Looking forward for more videos from you, don't stop!

[@EricStrebel]

MisterBassBoost Thanks for your continued support! I appreciate it

[@thepick5663]

Nice video. Do you know what capsule is in this microphone? Guessing it's a K67 type.

[@estheticmagazin]

how to painted this body ? like new mic

[@DVTOM]

can you provide a link to Silent Sky where you got those parts and their specs? Is it a recording studio because that is what comes up and I don't see any resources about the parts kit. thanks

[@EricStrebel]

Link added

[@jerrykooyman]

I see a lot of videos of modding the MXL 990, but I can't find anywhere what are the exactly type/value (pF) of these capacitors to replace. Do you have more details please?

[@fauxluv3170]

what type of paint did u use?

[@EricStrebel]

Rattle can paint, probably dupliciolor

[@suzukiax100rd3]

I removed the mesh and it generates a noise

[@reekrodriqguez6552]

Some people can say that this color is terrible, see how it’s all relative?

[@sourlito]

WHAT DID YOU USE TO PAINT THE BODY AND GRILLE?

[@EricStrebel]

Spray paint, probably a laquer

[@sourlito]

@@EricStrebel OK

[@Tracks777]

When is your next video? :D Keep it up!

[@EricStrebel]

MisterBassBoost Should be up very soon. Thanks for your support!

[@EricStrebel]

Credits at the end of the vid, made it with Figure

[@bloodwaytripbeats6162]

theres no way i do this to my mic :D

[@ArtistColony]

Who is here to know how to open the mic and just fix the dents on their mics?

[@alexurnous5682]

why why would you hurt sucht a expensive microhpne and who the frick is cris but just why you damaging the microphone by riping the mesh and soldering just dont

[@loveroflife1438]

Make me one please

[@EricStrebel]

If you have a unit you want painted and or modified, reach out and perhaps we can work out a fair price for the job

[@aldomanik3329]

Awesome! Please check the recording results by using this amazing mic condenser : kzbin.info/www/bejne/jni0aJSsqsh_f6M Stay healthy good people 😊 From Indonesia..

[@hosseinhos4963]

😂😂😂

[@Frank55]

Without changing the capsule, you will still have a pretty crappy microphone...

[@EricStrebel]

I agree, however I think it sounds halfway decent I still use it for every one of my videos working pretty good I think for the price good value, is it the best microphone ever. No but it ain't bad.

[@reekrodriqguez6552]

PPR Consulting & Solutions The capsule is 90% of the mic tho

[@jeremyfortunethe1st]

@@reekrodriqguez6552 some of the older mics had capsules that weren't as bad as others. It's a literal crap shoot which one you would get. But a good circuit behind a capsule with a decent frequency curve does make for a good mic. Maybe not a great mic. But the greatest mic in the world is still an extremely subjective thing. And to be honest, many many hit records over the years were made on far less superior equipment. There is a use for any mic that doesn't have a ton of noise in it.