1

SK49 Multi-patern Tube Microphone / Shockmount elastic

« on: June 30, 2026, 11:53:50 PM »

Hi JPK,

I noticed the elastic band in the shockmount has started to wear, after one of the mics received a small impact. The shockmount did its job, and the mic is not damaged!

However, I would like to know where to get a new elastic band. Are you able to show me where? Or can I buy one from you?

Thank you,
Alex from NZ

2

SK49 Multi-patern Tube Microphone / SK49 pair on a live orchestra

« on: May 18, 2026, 06:09:45 AM »

Hi,

I thought you would like a sound sample of what the SK49s can do on orchestra. I built these mics, but I had to buy extra long 7-pin XLR cable to hang them from the ceiling of the auditorium. 

Last week I recorded the Christchurch Symphony Orchestra live in the Town Hall, Christchurch, New Zealand.

There is no reverb, EQ, or processing. 

They are absolutely fantastic microphones! Thanks Sound Skulptor!

https://soundcloud.com/harmerny-productions/sk49-in-ortf-on-a-live

3

SK49 Multi-patern Tube Microphone / Re: How long is the 7-pin XLR cable that comes with the SK49 kit?

« on: April 25, 2026, 08:59:29 PM »

I just made the test with five 6m cables connected together for a total of 30m.
The voltage accross R13 was still adequate at 3.61V and this include 4 additionnal male/female XLR junction.
So I think you are OK with the standard PSU and a 25m cable as long as it is a 7 wires good quality cable.

Thank you so much, that is incredibly helpful!

4

SK49 Multi-patern Tube Microphone / Re: How long is the 7-pin XLR cable that comes with the SK49 kit?

« on: April 21, 2026, 12:50:59 PM »

I think the best method would be to check the voltage across R13 in the PSU.
You want around 140mA in the tube heater so the voltage should be about 0.14 * 27 = 3.78V.
If the current falls under 133mA (3.6V accross R13) you can lower the value of R13 to increase the current.

Hi JPK,

I'm resurrecting this topic about the 25-metre long 7-pin cable for orchestral recording. 

Would you consider selling me two new power supplies with a specific value in R7 that would be appropriate for the voltage drop across this length of cable? 

The microphones are amazing - and rather than risk damaging the power supplies with some modifications that I don't understand, I'd prefer to have two dedicated power supplies for when I am using longer cables. 

What do you think? The microphones are amazing, and I'd like to use them for this task of longer cable runs. 

Cheers from New Zealand. 

5

SK49 Multi-patern Tube Microphone / Re: How long is the 7-pin XLR cable that comes with the SK49 kit?

« on: November 25, 2025, 10:57:37 PM »

Thanks very much for an amazing microphone design!

I've just finished building my pair in New Zealand. They are working perfectly, no issues. 

6

SK49 Multi-patern Tube Microphone / Re: How long is the 7-pin XLR cable that comes with the SK49 kit?

« on: November 09, 2025, 07:40:07 PM »

Thank you! Very helpful.

Here is the Telefunken M16 Mark II pinout:

• Pin 1: B+ (tube HT) 
• Pin 2: Tube heater (filament)
• Pin 3: Pattern control (remote pattern voltage) 
• Pin 4: Ground / chassis 
• Pin 5: Audio 
• Pin 6: Audio 
• Pin 7: Ground / shield 
  
  Will that be okay? It looks like Pin 4 is a double-up and could easily be used for the HPF of your SK49. 
  
  Cheers
• Alex

7

SK49 Multi-patern Tube Microphone / Re: How long is the 7-pin XLR cable that comes with the SK49 kit?

« on: November 08, 2025, 10:08:53 PM »

Thank you. 

Last question:

The cable you linked above has a lot of different variants, depending on the microphone. If you look at the drop-down menu, you will see. 

Which microphone cable is the SK49 compatible with, in terms of its XLR pinout?

Thanks,
Alex

8

SK49 Multi-patern Tube Microphone / Re: How long is the 7-pin XLR cable that comes with the SK49 kit?

« on: November 08, 2025, 12:15:01 AM »

Thank you, that’s fine.

My question now becomes… will I need to adjust the heater output voltage on a 25 metre cable run?

I think for 25 metres the voltage drop may be around 0.4v with 22AWG cable. Would it be safe for me to run it at 6.1v instead of the recommended 5.7v from your setup guide?

9

SK49 Multi-patern Tube Microphone / How long is the 7-pin XLR cable that comes with the SK49 kit?

« on: November 07, 2025, 07:15:38 AM »

I am hoping to hang the SK49 microphones for orchestral recording from our local town hall. 

The ceiling is around 18 metres above the stage. 

Will the 7-pin XLR reach down from the power supply (in the ceiling), to rigging drop length, which is about 17 metres?

If not, do you recommend a good cable supplier?

Thanks  

10

EQ573 Equaliser / Thank you - these EQs are so good!

« on: May 03, 2025, 02:20:00 AM »

Just wanted to say thank you the kits! The two I bought went together so easily; both worked perfectly first time (always a relief for a builder!).

Cheers, they sound great. They are paired with two of my MP573s, and then they go straight in to the pair of CP554s, completing my Neve channel strip

11

CP554 Diode bridge compressor / Re: What is the correct way to stereo link two CP554 units?

« on: August 31, 2024, 11:29:44 PM »

Thank you!
They sound incredible, by the way. Thank you for the amazing kit design.

12

CP554 Diode bridge compressor / What is the correct way to stereo link two CP554 units?

« on: August 20, 2024, 10:29:40 PM »

I have a Midas L10 power supply.

My CP554s occupy slots 7-8, 9-10.

I have selected the 'stereo' button on both units.

My inputs are 7 XLR in & out, and 9 XLR in & out.

Please let me know if my settings are correct  

13

CP554 Diode bridge compressor / Re: Can’t get 3v in step 5 in setup

« on: April 09, 2024, 09:07:48 PM »

All sorted JPK!

Both units working perfectly, and sounding amazing.

I'll do a demonstration for YouTube if you would like to look out for it

14

CP554 Diode bridge compressor / Re: Can’t get 3v in step 5 in setup

« on: April 08, 2024, 09:27:33 PM »

Check Zener D20. It could be dead.

I think you're right! I removed Z4V7 1W3 in D20 and my meter said OL in both directions on the diode test. I then put the diode back in circuit and tested it with normal power. Same result.

Is this the correct Mouser part?

https://nz.mouser.com/ProductDetail/Vishay-Semiconductors/BZX85C4V7-TAP?qs=yIvl1B2wDi7Hji4YUWzsdQ%3D%3D

I'm having trouble finding the right replacement part in my city. No local suppliers have 1W3.

Would it be okay to replace it with a 3W?

15

CP554 Diode bridge compressor / Re: Can’t get 3v in step 5 in setup

« on: April 06, 2024, 10:45:05 PM »

Thanks for your reply JPK! By the way - the first unit is sounding wonderful thank you!

(Without left PCB installed)
Check the connections to the output transformer.
What DC voltage do you get on the yellow wire, against 0V ? = 15.42
What DC voltage do you get on TP3, against 0V ? = 14.35
Check the solder joints on Q7, trimmer TR2 and R31. = completed! No issues. I de-soldered and reflowed just in case.

Step 5 result of VDC across TP2 & TP3 is 0.046 VDC with TR2 turned all the way clockwise.

16

CP554 Diode bridge compressor / Re: Can’t get 3v in step 5 in setup

« on: April 05, 2024, 11:19:43 PM »

Here are my results from your first aid test:

Threshold switch position		TP4 & TP5 AC voltage		JMP1 between pin1 DC voltage and +input on PCB 2 (I didn't know where else to put the probe)
+6dB		0.00 (supposed to be 0.11V)		1.8 VDC (supposed to be 0.14V)
0dB		0.00 (supposed to be 0.22V)		1.9 VDC (supposed to be 3V)
-6dB		0.00 (supposed to be 0.45V)		1.9VDC (supposed to be 10.8V)
-21dB		0.00 (supposed to be 2.4V)		2.03VDC (supposed to be 15V)

17

CP554 Diode bridge compressor / Can’t get 3v in step 5 in setup

« on: April 05, 2024, 08:39:43 PM »

Hi JP,

I initially successfully passed step 5 with this unit, and everything worked until step 11… when pressing down the BYPASS switch to get 0.98VAC produced no change.

After much trying, I decided to try from the beginning.

Now I can’t get past step 5.

I am getting +16vDC and -16vDC no problem.

But I only see 0.064vDC across TP2 and TP3. TR2 takes a lot of turns, and it only changes a little.

I have reflowed all solder on PCB1 and checked orientation.

Thank you!