Superlux S502 MK2 test, teardown and improvements

[MicUlli]

They look indeed quite similar, including the capsule to head amp interface.

What raised my eyebrows was how the mic was used with the capsule at one end of a boom stand and head amp at the other end. I'd expect he long wiring in between to add a lot of capacitive load, causing significant signal attenuation. Not to mention potential microphonics from vibrating cables in the boom, e.g. due to stage rumble or handling. Or would the capsules be electret types with built-in JFET? Has anyone seen such a set up before?

Jan

That is not correct. At least Schoeps devices include a JFET buffer in the capsule holder. Long wires are therefore no problem...

 

[MicUlli]

Hi All,
some questions arised regarding the output voltage and SNR with my "repair kit" in comparison to the original circuit.

S502 1st version:
Free Field Sensivity -40,3 dBV instead of -36 dBV
Electronics noise -127 dBV(A) instead of -114 dBV(A)
Self noise 16 dB(A) instead of 18 dB(A)
Max. SPL 140 dB instead of 134 dB

S502 MKII:
Free Field Sensivity -37 dBV instead of -38,6 dBV
Electronics noise -127 dBV(A) instead of -120 dBV(A)
Self noise 14,5 dB(A) instead of 16,5 dB(A)
Max. SPL 137 dB instead of 134 dB

So long MicUlli

 

[jp8]

That is not correct. At least Schoeps devices include a JFET buffer in the capsule holder. Long wires are therefore no problem...

Sorry, but now I'm confused... In your first post, you said the Schoeps and S502 MK2 capsules are interchangeable. And the capsules of the latter are without JFET and not pre-polarized, so then both should be regular condenser capsules. So do you mean to say some Schoeps capsules have a JFET or all?

Jan

 

[ubxf]

I think we might be talking about the active cable
https://schoeps.de/en/products/accessories/accessories-colette/kc.html

 

[MediaWorksOKC]

Hi All,
time to answer some questions:
1. I only sell the repair kits inside Europe.
2. The "repair kits" include pcb and ALL necessary components and a detailled assembly/test instruction.
3. Payment only by banking transfer, shipment via DHL, you get a tracking number.
4. MBC5X0 repair kits still available, S502 repair kits under construction.
5. Prices only upon request via PM, pls be so kind not to post them in public space
Thanks
MicUlli

I'm sure some of us here in the US would like to make our 502's better, I know I would. Is just the PCB available to the USA? Regards, Chris.

 

[pmfalcman]

This looks also similar to the Korean HMH CML-300 microphone,

I strongly suspect it's because this is a CML-300
As stated in Ali description

 

[mhelin]

I strongly suspect it's because this is a CML-300
As stated in Ali description

Yes but the Ali mic is HTDZ brand, http://www.htdzpro.com/ (however, you can't find CLM-300 there) and the HTH is the Korean brand, also the FR's are different. Is the Ali mic a Chinese copy of a Korean microphone which is a copy of a German microphone? Anyway, there is a third brand, Kateluo, with another identical CLM-300 microphone: https://www.kateluo.net/cms/show-30.html

Btw. you can use Google translate to read Korean or Chinese pages.

 

[mhelin]

Another variant from E-Image:
https://www.eimagevideo.com/E_mobile/pro_detail/tid/93/id/1250

Available in Europe (at least in UK):
https://proav.co.uk/e-image-professional-broadcasting-microphone

.. and France (Product temporarily unavailable):
https://www.videoplusfrance.com/fr/5138212-e-image-professional-broadcasting-microphone.html

 

[mhelin]

Also known as E-Image HM-55:
https://www.eimagevideo.com/E_mobile/pro_detail/tid/81/id/696

 

[janpanis]

I strongly suspect it's because this is a CML-300
As stated in Ali description

Where to buy? Can't find them in Ali nor anywhere else

 

[jeremynothman]

Another variant from E-Image:
https://www.eimagevideo.com/E_mobile/pro_detail/tid/93/id/1250

Available in Europe (at least in UK):
https://proav.co.uk/e-image-professional-broadcasting-microphone

.. and France (Product temporarily unavailable):
https://www.videoplusfrance.com/fr/5138212-e-image-professional-broadcasting-microphone.html

I agree that the specs/graphs are different, but the biggest difference between all these and the schoeps is the use of electret condenser capsules

 

[pmfalcman]

Where to buy? Can't find them in Ali nor anywhere else

I'm referring to Jan's post #77.
But beware! It may well be, as @mhelin said: " Is the Ali mic a Chinese copy of a Korean microphone which is a copy of a German microphone?" His remark is highly probable.

Also, first check links shared above by @mhelin.
He did a fantastic detective work.

They seem more trustworthy than Ali. Thread carefully.
Do not get carried away

 

[Emmathom]

Hi guys, I think we have deviated from original subject which was : is it possible to improve the Superlux S502 (and MkII) and how.

Let's summarize :
@MicUlli has done much measurements & tests and decided to design a original board which should improve the mic. Then he proposed to sell a whole kit board + components. We were 16 or so to "pre order"

Then @jp8 send the idea of using S502 1rst version capsules and marry them to a Schoeps-like circuit, and for that, he began seeking for a donor-body with a thread compatible with Superlux capsules.

Am I right here ?

For my case, I am concerned to know how things go for @MicUlli project, when we'll have to pay him and how much, and when will we be delivered...
Let's please focus on what we discuss here : a (very) nice & cheap mic which, plus that, could be improved.
(Korean - chineese stuff mics at ~70€ is another subject I guess)

Make it easy : spend 105~150€ for a really nice Superlux ORTF and get @MicUlli kit and you'll have an incredebile & unbeatable mic for its price ! (you can also use it as one mic only if you want so)

With respect

 

[jp8]

Then @jp8 send the idea of using S502 1rst version capsules and marry them to a Schoeps-like circuit, and for that, he began seeking for a donor-body with a thread compatible with Superlux capsules.

Am I right here ?

Yep

 

[jp8]

Yep

Uhm, actually, no... Not quite. My bad, I didn't read your post carefully. Assuming the S502 MK2 has capsules that are closest to the Schoeps MK4, I was looking for a (black) 20mm body with matching threads for these capsules. Best bet are 20mm SDCs from 797 Audio, but I haven't found cheap black ones yet.

Jan

 

[Emmathom]

Uhm, actually, no... Not quite. My bad, I didn't read your post carefully. Assuming the S502 MK2 has capsules that are closest to the Schoeps MK4, I was looking for a (black) 20mm body with matching threads for these capsules. Best bet are 20mm SDCs from 797 Audio, but I haven't found cheap black ones yet.

Jan

I thought only 1rst version can be used alone ?

Please @MicUlli coul you do for all of us a kind of digest of what can be done with these capsules (1rst & MkII) ? And a whole recap of the 2 versions ? Differences, similitudes, etc... if you please.

What I've understood :
* 1rst version doesn't need a DC/DC board but MkII does (does it mean that capsules polarisation of 1rst version deals with the phantom power ?)
* Capsules threads are not the same between 1rst & MkII versions

Edit : my bad. Post #31 @MicUlli says that MkII capsules are much more indicated for a Schoeps clone...

 

[Emmathom]

I also have tried the mic capsule with my MBC5X0 board with very good results. Because of the smaller pol voltage (39 V vs 60 V) the sensitivity is 3 dB smaller, but also the electronic noise. Therefore the self noise stays at 15,6 dBA and fortunately the max. SPL goes up to 140 dB . NO MESSY noise components above the audio range. Probably i will design a board with 2x MBC5X0 circuits that can be used as a replacement, stay tuned..

We stay tuned on that idea !

My verdict: Superlux S502MKII is a very fine mic, cheap enough and a must have for all mic freaks

Agree +++

 

[MicUlli]

I thought only 1rst version can be used alone ?

Please @MicUlli coul you do for all of us a kind of digest of what can be done with these capsules (1rst & MkII) ? And a whole recap of the 2 versions ? Differences, similitudes, etc... if you please.

What I've understood :
* 1rst version doesn't need a DC/DC board but MkII does (does it mean that capsules polarisation of 1rst version deals with the phantom power ?)
* Capsules threads are not the same between 1rst & MkII versions

Edit : my bad. Post #31 @MicUlli says that MkII capsules are much more indicated for a Schoeps clone...

Yes of course.

S502 1st version:
The capsule diameter is 22,5 mm. Capsule housing is connected to the diaphragm. Therefore the diaphragm is always connected to GND.
There is one pin in the center connected to the backplate.
The S502 1st version comes without a DCDC converter, polarisation voltage is applied at the backplate. Voltage is approx. 40 V.
The capsule signal coming from the backplate is amplified by a schoeps like circuit (connected to the gate of the jfet). This design has a very high noise level.

S502 MKII:
The capsule diameter is 20 mm. Capsule housing is NOT connected to the diaphragm. There exists a ring contact for the diaphragm. And it is explicitly used.
As usal the center pin is connected to the backplate.
S502 MKII has a DCDC converter generating the polarisation voltage of approx. 60 V, which is applied at the membrane. The membrane is also connected to the drain of the input jfet (for AC). The backplate is connected to the gate of the jfet. THIS is exactly the circuit configuration that became so famous (low noise level).

The Schoeps compatible capsules (3 contacts instead of only 2) of the S502 MKII offer a lot of opportunities for circuit tricks. One trick is to apply a positive polarisation voltage at the backplate AND a negative polarisation voltage at the diaphragm. That is exactly what my circuit does. The effective polarisation voltage is the difference (here +39 V - (-21 V) = +60 V).

Hope it helped a bit