Bm-600 mod samples

Icantthinkofaname · Apr 5, 2020

I finally got around to modding a BM-600 without destroying it. I don't have any measurements of them yet, since one is still stock. I do have samples of each here, it's just a quick sibilance test though.

https://www.gearslutz.com/board/low-end-theory/1304846-isk-bm-600-mod-demo.html

I think the modded one is a bit flatter and midrangey sounding to me, but that might just be confirmation bias since I haven't measured them, and I don't trust "frequency analysis" plug ins as being a scientific way to check frequency response.

There are a couple blankets on a couple of the walls and part of the floor, and there's a bed in the room, so it's not completely untreated, but it's less than ideal.

Khron · Apr 6, 2020

The mod involving... increasing the value of the low-pass (or rather, high-shelf attenuation) capacitor, or..?

RuudNL · Apr 6, 2020

The modded version sounds 'strange'. Could it be the difference in placement?

(I tried to invert the polarity of one microphone to hear the difference, but it seems impossible to 'null' the signal.)

Icantthinkofaname · Apr 6, 2020

Khron said:
The mod involving... increasing the value of the low-pass (or rather, high-shelf attenuation) capacitor, or..?

Yeah, it's a 680pF capacitor now.

RuudNL said:
The modded version sounds 'strange'. Could it be the difference in placement?

(I tried to invert the polarity of one microphone to hear the difference, but it seems impossible to 'null' the signal.)

They were in about the same spot. Is it possible to use too high a voltage rating? The easiest ones for me to get were 1000v so that's what's in there. The vowel sound definitely sound noticeably darker to me, but that's all I'm hearing, but I don't have the best ears.

Icantthinkofaname · Apr 6, 2020

Maybe I did something wrong, but I just replaced the one capacitor (C1 on the schematic in the DIY C414 thread), the one right beside the resistor. I'll get a picture in a bit.