DIY USB-C microphone based on TSB 2555 capsule

[rock soderstrom]

Hi, youtube just suggested me the following video. The guy from DIY Perks builds a nice microphone and compares it to the Neumann U87ai. Serious craftsmanship and nice design ideas included.

 

[k brown]

I found that Transound capsule to be very bright - surprised the Neumann is just as bright.

 

[shabtek]

I disagree the 87 in the video sounds fuller and more balanced to me on macbook speakers--those transound capsules have a clear presence--whats that copper diy looking mike commercially made: eartrumpet? it uses this capsule iirc-- it has presence and some like it for live reinforcement.

 

[shabtek]

I'd be happy to explain exactly what's in there.

The circuit is a modified Schoeps-style - not simplified actually, but some unique component values and a few additions. Far from being SMD, the electronics are all discreet components hand wired point to point. Not even a printed circuit board. We use very high quality caps. We hand match the paired resistors and transistors. We bias each JFET individually with an oscillosope and distortion analyzer. The JFET and its bias resistors and 1G gate resistor are built on a small board and mounted directly to the capsule inside the headbasket to minimze any leakage in the super-high impedance section of the circuit (between the capsule and the JFET gate). I've attached the exact schematic. The coupling caps to the BJTs are quite small in the Edwina - .01uF - giving a counter to proximity effect with the chosen capsule to make the low end flat at 6 inches. We do other models using values up to .05uF there, which provides a rumble filter but is full range in the low frequencies for practical purposes. There's a feedack cap around the JFET that matches the high end to the capsule, similar to the U87 circuit.

The capsule is a Transound TSB-2555 26 mm single diaphragm electret. I like the sound. For our purposes, electret is much more reliable for a live-use mic, and the 26mm size is a great compromise between some LDC character and a very consistent polar pattern across a wide response, which larger dual diaphragm capsules definitely lack. That's the key to good feedback rejection. The only problem with these capsules is that they're not manufactured very consistently. Our QA on them rejects about 30% for not being within our target response. So for DIYers, I would definitely suggest getting ten and profiling them.

We build the mics all by hand in a small 5-person shop using pretty much exactly the methods I used to build the first ones in my basement as a hobbyist. The look reflects that. Some people love it, some don't. I do think mic DIYers are missing out if they don't get into playing with their own body designs. Most of the sonic character of any mic comes from the capsule and the headbasket and the acoustic interaction between them. We need more inventiveness in that area. I could post some pics of the guts if any one is interested.

 

[rock soderstrom]

Thanks for linking to the Edwina microphone. I had missed that at the time. Looks like the command mic from Captain Nemo on the Nautilus or the ideal stage mic for these guys:

 

[RuudNL]

The design is something for the 'phreakz'. (With ph and a z at the end. They are the worst...)

 

[Stew-D-O]

Hi, youtube just suggested me the following video. The guy from DIY Perks builds a nice microphone and compares it to the Neumann U87ai. Serious craftsmanship and nice design ideas included.

Speaking of TSB-2555 capsules, has anyone tried one of those similar-looking capsules as seen on Aliexpress?

 

[kingkorg]

If you are talking about these, they are absolutely phenomenal. I still cant believe they are so inexpensive. Be aware that mic project lacks 1G resistor gate to ground.

https://m.aliexpress.com/item/40000...7f08acc4a13f4118e4242d54fe21127e7ffa1d&gclid=

 

[k brown]

Also lacks a gate - as it has no FET!

 

[kingkorg]

What do you mean? I'm talking about the original mic project. It uses 2n4416 with no 1G gate to ground. Maybe i wasn't clear in my previous post.

 

[k brown]

Ah - got it. Didn't notice you said project.

 

[kingkorg]

I updated that, to avoid further confusion, totally my bad

 

[Stew-D-O]

If you are talking about these, they are absolutely phenomenal. I still cant believe they are so inexpensive. Be aware that mic project lacks 1G resistor gate to ground.

https://m.aliexpress.com/item/40000...7f08acc4a13f4118e4242d54fe21127e7ffa1d&gclid=

This brings me to a page that cannot be navigated. Can you just tell me what description they use.

 

[rogs]

If you are talking about these, they are absolutely phenomenal. I still cant believe they are so inexpensive. Be aware that mic project lacks 1G resistor gate to ground.

https://m.aliexpress.com/item/40000...7f08acc4a13f4118e4242d54fe21127e7ffa1d&gclid=

I agree - these are really good value for money capsule IMHO.
I don't have any 'raw' audio from one at the moment, but here's a short spoken word clip which I recorded through my dbx 286s channel strip a while back..... Quite reasonable for a £3 capsule I thought?

 

[rogs]

This brings me to a page that cannot be navigated. Can you just tell me what description they use.

THIS is the capsule

 

[rock soderstrom]

If you are talking about these, they are absolutely phenomenal. I still cant believe they are so inexpensive. Be aware that mic project lacks 1G resistor gate to ground.

https://m.aliexpress.com/item/40000...7f08acc4a13f4118e4242d54fe21127e7ffa1d&gclid=

I just bought one for 0,01€ plus 3,34€ shipping. First time buyer discount!

 

[k brown]

They are very, very bright though - unuseably so for my purposes. Shame, because they are very well-made.

 

[kingkorg]

Maybe you had a dud, i have about 30 pieces, not one sounds overly bright. +4db at HF, even, gradual, smooth boost. Flatter/darker than that you have yourself a measurement mic, which might be what you are after. At this dimension, it is almost impossible to make it flatter, simply due to physics.

The original Cad e100 has flater response, but it uses smaller capsule which is out of production, not the TSB one.

This is the "warmest" or darkest sounding readily available i came across.

https://a.aliexpress.com/_mN6hQOk

 

[k brown]

You must be right - my example is much brighter than TSB-2555.

 

[Erik2345]

https://groupdiy.com/threads/new-ish-electret-capsule.76460/