Sennheiser SK100 Jack confusion

[Bill Baritompa]

Originally Posted by John Willett

This is *not* a mic. input cable, it's a *line* input cable.

The mic. input cable ie wired:-
XLR1 (ground) > Ring & Shield
XLR2 (hot) > Tip + a blocking capacitor
XLR3 (cold) > Ring & Shield

The mic. cable is not a Sennheiser standard and would be made up by a Sennheiser dealer - it requeres a blocking capacitor inside to stop the plug-in power getting to a dynamic mic.

Hi John, I'm want to wire up my own mic cable, what value, rating
and type of capacitor should be used? Thanks, Bill

[John Willett]

Originally Posted by Bill Baritompa

Hi John, I'm want to wire up my own mic cable, what value, rating
and type of capacitor should be used? Thanks, Bill

Mini jack:
positive to tip and negative to sleeve - short ring and sleeve together.

XLR 3F:
Use a 1μF tantalum bead capacitor.

Wire the -ve side to XLR pin 2. Connect the +ve side to the cable and connect the other end of the cable to mini-jack tip. I would advise sleeving this to minimise the possibility of a short.

Unbalance the XLR by shorting pins 1 and 3 and connect the screen here.

You can then connect a dynamic mic. to the SK 100 TX as the capacitor blocks the DC voltage from the transmitter.

[Derek Heeps]

Hi , I just bought an EW100 kit , with the SK 100 bodypack and the EK 100 camera receiver .

While the kit came with what I take to be the ME2 or 4 microphone , with 3.5mm mini jack connection , I also have some MKE 2-2r microphones from some older VHF kits we used to have in a hire company I worked for . These older kits used an unusual connector which was impossible to buy anywhere , and if the cables got damaged out on a hire , the mics used to get written off ; I kept a couple of them where the damage was near the end of the cable :)

I currently use the MKE 2-2r's as wired lapel mics with a couple of Audio Technica preamps which have mini XLR connectors - these preamps have what I presume to be balanced inputs with 5V phantom power across the hot and cold connectors ( pins 2&3 ) .

While I know the (unusual) pin assignment for the SK100 mic/line input connector , what I cannot see in any of the manuals is the spec for mic power . Even though the mic input is unbalanced , I wonder if it is still 5V ?

To confuse things still further , I had a trawl through Sennheiser's website and found the pdf manual for the SK 5012 , which shows the pin assignment of the mic connector to be ground , +5V and audio +5V : so it would seem that the MKE 2-2r is not a balanced mic anyway ?

I don't know if it would work to conect the two +5V cables together to the unbalanced +ve tip of the jack and the ground to the ground ; I suspect not , and I'm a bit wary of grounding one side of the mic which should have +5V on it , thus putting 5V across the capsule instead of both ends being equally suspended at 5V above ground .

I would most likely make up a short cable from mini jack to mini XLR , so as to still have the facility to use these capsules as wired mics with the preamps .

I just wondered if anyone has used these capsules with the newer transmitters , and how they might have wired them ?

I would prefer to use them as they are much smaller and better mics than the ME2 and ME4 mics , and so they should be as I recall they used to cost around £300 to replace about 15 years ago !

[Rick Reineke]

Lavaliere mics usually require 'bias current' (aka, "Plug-in Power") which is normally 2 to 5 volts... not to be confused with "Phantom Power" which is normally 48V and totally different wiring. The SK100 bodypack transmitter incorporates this so you do not need an external power supply. I do not know the wiring configuration for an MKE-2 mic other than the TRS plug's ring connector is floated.
Locking 3.5mm TRS plugs are readily available though. TecNec Locking 3.5mm Stereo Audio Plug Black 3.5, 2.5mm Mini Connectors at Markertek.com

[Derek Heeps]

I know the ring connector is for line level input ( against ground on the sleeve ) while the mic level input is tip/sleeve .

Yes 'plug in power' is typically a single low voltage , whereas phantom is two separate but equal voltages over ground applied to hot and cold so that there is no potential difference across the signal pins ; the spec allows for phantom to be anywhere from 5V to 48V , although requirements vary from one microphone to another .

Thanks for the link , the locking mini jack connectors are readily available from a number of places .

[Rick Reineke]

"Phantom Pwr to be anywhere from 5V to 48V" Would be for the XLR Phantom Power adapter, which would have an XLR connector. The MKE mic itself only requires bias current, so the PP adapter would not be necessary with the transmitter.

[Derek Heeps]

This is what I'm trying to determine . However , tonight I have spent a couple of hours doing a bit more research .

The link below describes the MKE 2-2r as requiring 12-48V Phantom Power

Sennheiser MKE2 miniature omnidirectional condenser microphone. Free data sheet by GB Audio

However , that is the website of a private company and may or may not be correct .

For more reliable information I went to Sennheiser themselves .

The spec sheet for the MKE 2 ( of which the 2-2 R is a variant ) lists several versions with differing power supply requirements ( this seems to depend on how the cable connector is configured - the lead is a screened cable with copper screen surrounding red and blue cores , which would seem reasonable to interpret as screen = ground , red = hot , blue = cold ) and , going by the connector options it can be configured as either a balanced mic with Phantom power ( the manual states on page 7 under 'technical Data' that Phantom power can range from 12V to 48V , however the Audio Technica preamp/power modules I have used them successfully with only supply 5V Phantom , as does the SK 5012 series transmitter ) .

The spec sheet for the MKE 2 series can be read here

http://94.100.244.130/sennheiser/old_manual.nsf/resources/MKE2.pdf/$File/MKE2.pdf

The confusion arises because we used them in supplied kits with both the SK 2012 VHF transmitters , and the later SK 5012 UHF transmitters .

The earlier transmitters ( 2012 ) had a coaxial Bruel and Kjaer microphone connector ( which Sennheiser would not supply as a part , nor could it be sourced elsewhere , hence the mics being written off due to cable damage ) - since this connector only had a single centre pole plus the screw down body it could never support anything other than unbalanced operation and single sided power supply .

The manual for the SK 2012 , link below , states on page 14 that a dc voltage of 7.5 volts is supplied via the connector , or can be blocked by inserting a capacitor .

http://94.100.244.130/sennheiser/old_manual.nsf/resources/SK_2012_33001_0394_Sp5.pdf/$File/SK_2012_33001_0394_Sp5.pdf

However , if we then look at the manual for the later SK 5012 transmitter , which used a three pin Lemo connector , and which were supplied with these same microphones as a kit , we see pins 1 & 2 each carrying +5.2V , and the pin 3 being ground , along with the body of the connector - this looks awfully like 5V Phantom powering , other than that only pin 2 is designated as carrying AF ! See page 36 of the link below

http://94.100.244.130/sennheiser/old_manual.nsf/resources/SK5012.pdf/$File/SK5012.pdf

Sadly , referring to the manual for the EW 100 series , while there is a pin assignment for the connectors on page 79 , and sensitivities quoted for the AF inputs on page 82 , there is no mention of what the voltage supplied via the mic input might be ! I may just need to plug a loose connector in and measure it .

The EW 100 manual is here

http://94.100.244.130/sennheiser/old_manual.nsf/resources/ew100.pdf/$File/ew100.pdf

Going by all of the above , I will measure the mic supply voltage coming out of the bodypack ; if it seems to be within an acceptable range , I will make up a short adaptor cable from 3 pin-mini jack to a male mini-XLR to mate with the connectors already on my microphones and I will wire it so that the red wire goes to the tip of the mini-jack and both ground and blue go to the sleeve , also shorting the ring to ground .

While I'm about it , I will also make up a line input cable so that I can use the transmitter to link from the output of my portable mixer ( Spirit Folio ) for occasions where I want to set up a few mics and link to the camera from a distance away .

EDIT - I noticed after posting that the links to the manuals don't come up as hyperlinks , but they seem to work fine if you paste them into your browser .

[Rick Reineke]

John Willett, who was employed by Sennheiser is more of an authority on the MKE-2 and Sennheiser products in general than I, and hopefully will comment on your issue. John?

[John Willett]

Originally Posted by Derek Heeps

Hi , I just bought an EW100 kit , with the SK 100 bodypack and the EK 100 camera receiver .

While the kit came with what I take to be the ME2 or 4 microphone , with 3.5mm mini jack connection , I also have some MKE 2-2r microphones from some older VHF kits we used to have in a hire company I worked for . These older kits used an unusual connector which was impossible to buy anywhere , and if the cables got damaged out on a hire , the mics used to get written off ; I kept a couple of them where the damage was near the end of the cable :)

I currently use the MKE 2-2r's as wired lapel mics with a couple of Audio Technica preamps which have mini XLR connectors - these preamps have what I presume to be balanced inputs with 5V phantom power across the hot and cold connectors ( pins 2&3 ) .

While I know the (unusual) pin assignment for the SK100 mic/line input connector , what I cannot see in any of the manuals is the spec for mic power . Even though the mic input is unbalanced , I wonder if it is still 5V ?

To confuse things still further , I had a trawl through Sennheiser's website and found the pdf manual for the SK 5012 , which shows the pin assignment of the mic connector to be ground , +5V and audio +5V : so it would seem that the MKE 2-2r is not a balanced mic anyway ?

I don't know if it would work to conect the two +5V cables together to the unbalanced +ve tip of the jack and the ground to the ground ; I suspect not , and I'm a bit wary of grounding one side of the mic which should have +5V on it , thus putting 5V across the capsule instead of both ends being equally suspended at 5V above ground .

I would most likely make up a short cable from mini jack to mini XLR , so as to still have the facility to use these capsules as wired mics with the preamps .

I just wondered if anyone has used these capsules with the newer transmitters , and how they might have wired them ?

I would prefer to use them as they are much smaller and better mics than the ME2 and ME4 mics , and so they should be as I recall they used to cost around £300 to replace about 15 years ago !

All MKE 2 microphones are unbalanced at the capsule.

There is more than one way of wiring the mic. as you can see from the KE 4 manual (the KE 4 is basically the raw OEM capsule that's used in the MKE 2).

So just contact Sennheiser and they will tell you which wire goes where on the 3-pole mini-jack for correct working on the G3.

[Derek Heeps]

OK , thanks for that suggestion - I will email their support section .

[Derek Heeps]

Just to update , since I hadn't been in here since the holidays , I connected the red ( hot ? ) wire to the tip of the mini jack plug and the braid to the sleeve of the plug , leaving the blue wire unconnected . I did this by making a short adaptor cable from a locking mini jack to a mini XLR to mate with the existing connectors on the mics - this way I can still use them as wired mics with the Audio Technica adaptors .

The mics work very nicely indeed with the EW 100 and are so much less conspicuous than the larger ones which came with the kit .

[John Willett]

Originally Posted by Derek Heeps

Just to update , since I hadn't been in here since the holidays , I connected the red ( hot ? ) wire to the tip of the mini jack plug and the braid to the sleeve of the plug , leaving the blue wire unconnected . I did this by making a short adaptor cable from a locking mini jack to a mini XLR to mate with the existing connectors on the mics - this way I can still use them as wired mics with the Audio Technica adaptors .

The mics work very nicely indeed with the EW 100 and are so much less conspicuous than the larger ones which came with the kit .

If it's a G3, you need to short ring and sleeve to switch off the line input.

[Derek Heeps]

Yes , I should have said I did that as well , thanks .

I also made up a couple of line input cables , one from 1/4" jack and one from XLR , for taking feeds from mixing desks at venues - in those cables I left the tip unconnected as I didn't want to short out the power ( I suppose I could short a cap to ground to block all but dc ) .

[Rick Reineke]

"I left the tip unconnected as I didn't want to short out the power"
> AFAIK, on the SK100 G2, one could get away without grounding the tip .. On the G3, the Tip terminal must be tied to the sleeve/ground.
Maybe John can clarify this.

[Derek Heeps]

Alas , mine is neither the G2 nor the G3 , just the plain old eW 100 kit ( Generation 1 ? ) with the grey metal cases which take a PP3 battery in the side , not the newer ones with the flip open cases which run on two AA batteries . We also have an eW 500 kit at work of the same generation as mine , the components of which seem to mix and match fine with mine .

I know my older transmitter is capable of operating outside the 863-865 MHz licence exempt range here in the UK , but I will just take care to remain within the legal frequencies .