The $5 DIY Tube Condenser Microphone!!!

[Minion]

Hi Guys....I have been fooling with some Sub Mini Tubes and decided I would try to make a Tube condenser Microphone....

This Mic took me about 3 hours to put together Includeing etching the PCB and it only costs about $5 in Parts.....



It uses the 6418 Sub mini Power amp Pentode tube (the same Tubes as used in the AT3060 tube mic) and a generic Omni-directional Electret Condenser element and the PCB is only about 1.5in By 1.2in.....

I used the body of a Old mic that I killed by hitting to many times with a drum stick and it is a Fairly sold Mic even though it is Put together a Bit half assed.....

How does it sound?? Well it sounds very good actually...It has a very clear and clean Low end but is a Bit lacking in the High end but that is due to the shitty capsule, It also has very little noise and has a very nice Tubey sound, also the Output is EXTREMY Hot, It clip my Preamp if I have it above about 2 so i might add a 10db or 20db pad at a Later date, It might also be because I used a Very high gain NPN Transistor.....

I believe this design can also be easilly modified to work with a regular Condenser Capsule by omiting the Two 4.7k resistors comeing off the Capsule so the Capsule gets the full 48v polarizeing voltage......

I just thought that I would share this design with you and let you know that you can build a Good sounding Tube mic for very little money and without a Lot of Parts....


Cheers

[Albertb]

This looks interesting. Could you post a schematic? Well done for having the drive to put effort into making something that most people would just go straight out and buy. I have always found you often get a much improved piece of kit for a ridiculously small outlay that way.

I do recall someone posting details of a ribbon mike they had made on their kitchen table from scratch recently. He reckoned that was pretty good too. It made me remember experiments I did in the 60s with Reslo mikes, making new ribbons from very thin aluminium foil which used to line the inside of cigarette packets in those days. Saved a few pounds, ( a lot then), at the cost of a throw away bit of foil and an hour of time!

[Minion]

hi, here is the schematic.....





There is actually a Small error in the PCB design above but it instn"t enough of an error to render it non-working....If you look at the schematic you will probably find the error quickly enough and make the necessary changes......

Also depdending on the Transistor used you might try changeing the Value of the Biasing reisstors, also adjusting the resistors that come off of the Power pins of the tube could use adjusting to bias it correctly...I have noticed that from Tube to tube you might need to use different Values.....

This curcuit can also be modded for regular Condenser Capsules and Fetless electrets.....


Cheers

[aletheian]

Originally posted by Minion


I believe this design can also be easilly modified to work with a regular Condenser Capsule by omiting the Two 4.7k resistors comeing off the Capsule so the Capsule gets the full 48v polarizeing voltage......

I just thought that I would share this design with you and let you know that you can build a Good sounding Tube mic for very little money and without a Lot of Parts....

Cool little circuit! You should be able to use a regular large diaphragm condenser if you replace the input circuit with the 'usual suspects' as in a 1G resistor between the capsule and the phantom supply polarizing voltage, then feed it through a <1000p capacitor, followed by a 1G resistor to ground... don't see why that wouldn't work. I have a 6088 here that i could triode strap and build up with a 797 capsule... maybe I'll give it a try when i have a minute.

[colvan]

i'm seeking inspiration for a rebuild of a faulty rode nt2-a. the case is too small for the gyraf G7 build so this is a good change to design something from the ground up and learn the ropes..

curious to this circuit, though pic links are no longer.. can they be emailed?? tulczyn (at) gmail.com.. cheers

[Danjpiscina]

Hi. I'm new to this forum and I really want to build a mic! Just finished 2 compressors and a sub-mini tube mic sounds fun. i got the tube, just need the schematic posted again (it was deleted) and the bill of materials. Can anyone help me out? It would be much appreciated,

dan.

[mhelin]

http://www.naiant.com/microphonedesign.html
Notice also the DIY kit sold on this page! Can't beat that $9 mic.

http://www.naiant.com/images/MSH-4v2_Condenser_Mic.GIF

[WM]

Originally Posted by Minion

Hi Guys....I have been fooling with some Sub Mini Tubes and decided I would try to make a Tube condenser Microphone....

This Mic took me about 3 hours to put together Includeing etching the PCB and it only costs about $5 in Parts.....



It uses the 6418 Sub mini Power amp Pentode tube (the same Tubes as used in the AT3060 tube mic) and a generic Omni-directional Electret Condenser element and the PCB is only about 1.5in By 1.2in.....

I used the body of a Old mic that I killed by hitting to many times with a drum stick and it is a Fairly sold Mic even though it is Put together a Bit half assed.....

How does it sound?? Well it sounds very good actually...It has a very clear and clean Low end but is a Bit lacking in the High end but that is due to the shitty capsule, It also has very little noise and has a very nice Tubey sound, also the Output is EXTREMY Hot, It clip my Preamp if I have it above about 2 so i might add a 10db or 20db pad at a Later date, It might also be because I used a Very high gain NPN Transistor.....

I believe this design can also be easilly modified to work with a regular Condenser Capsule by omiting the Two 4.7k resistors comeing off the Capsule so the Capsule gets the full 48v polarizeing voltage......

I just thought that I would share this design with you and let you know that you can build a Good sounding Tube mic for very little money and without a Lot of Parts....


Cheers

Hi Minion, ...can you -pls!- post the schematic, again. thx, Wim

[impsick]

Minion i second the schematic request. Still got it? How did it come out?