Topic: Zoom H2 modified to allow 4 line ins

[Ozpeter]

http://www.2090.org/zoom/bbs/viewtopic.php?t=11675&sid=a8a4b5e8dfb3364cf3f9f823195ca20a has the details.

Very interesting!

[widdly]

That's a great idea. 

I would have gone with stereo 3.5mm sockets.  If you could find full switching 3.5mm sockets, you wire it switch off the internal mics when something is plugged in and eliminate the need for the toggle switches.

I think there should be a capacitor on the line inputs.  Those feeds will have a DC bias for the electret mic elements.  Without a cap, that DC is feeding straight into the line out of whatever he plugs in. 

[illconditioned]

That's cool.  I (think) I may have asked that here before, but never had the chance to try it.  Anyway, that would be great for cheapo ambisonic recording!

Does anyone have pictures and/or chip #'s for the guts in the H2.  It is insanely cheap.  Also, does anyone know what mics are inside?  Probably something like Panasonic WM55.  It would be cool to just hack the thing and put something like Sennheiser MKE40 in there.  Even better to put a tetrahedron mount for Ambisonic .

Oh well.  Back to my omni recordings for now..

  Richard

[heyitsmejess]

i think i recall reading that the caps inside are primo caps...chris church took one apart, i believe

[widdly]

There is a guy on the micbuilders yahoo group called who has mounted a tetramic clone on the top of his H2....it looks great.  He is using those TSB-120 transound modules  http://www.jlielectronics.com/transsound/electrets/tsb-120a.htm

[fotoralf.be]

He is using those TSB-120 transound modules

Does anyone know of a source for these modules somewhere in Europe, preferably within the E.U.?

Ralf

[micmonster]

I'ld prefer 2 lines and 2 mix at once.

[cybergaloot]

i think i recall reading that the caps inside are primo caps...chris church took one apart, i believe

He told me they were Primo caps as well. His mod looked interesting but he gave up on it. He was going to cut the wires to the internal mics and install two 3.5mm sockets with built in switches so that when you plugged in external mics to the new sockets, it broke the connection to the internal mics. That way you could have run two pairs of external mics, or one pair internal and one pair external. That would have been cool for  A/B comparisons, trying two different configurations, cheap ambisonic, mid-side or Blumlein. I'm not sure what problems he ran into or why he gave up.

I'd prefer 2 lines and 2 mix at once.

.

I'd like that option too. A week or so ago I used the H2 line in to grab a soundboard to matrix with another recorder getting the ambient but haven't gotten around to it yet. I figured what the hell, if it doesn't work out I still have the ambient and can toss the H2 recording.

For the price the H2 is an ok recorder as long as you don't use the external mic connection. It makes a good backup recorder. Its also not as fragile as some will have you believe. I knocked mine off a bar and it hit the concrete floor hard. Not even a scratch!

[digifish_music]

Did you see this video on modifying a H2 with baffles...

http://www.youtube.com/watch?v=DoXxJuPRBrQ

and here is the line in mod video...

http://www.youtube.com/watch?v=N1vJq13ukrk

[popskull]

Wow.....so for $200 you can have a 4 channel dig recorder.....tempting

[popskull]

Now if we could figure out a spdif input mod, this box would be gold

[Church-Audio]

My Dad once told me "Son you cant turn a turd into a steak no matter how bad you want to" Although you might be able to get 4 inputs they will overload so badly and be so noisy that it will hardly be worth all that work and the many trips to radio shack to make it happen

[illconditioned]

My Dad once told me "Son you cant turn a turd into a steak no matter how bad you want to" Although you might be able to get 4 inputs they will overload so badly and be so noisy that it will hardly be worth all that work and the many trips to radio shack to make it happen

I agree that it might not sound great.  But this might be a fun experiment for people that want to do ambisonic recording.  I'm thinking of using four of your capsules, or just the existing Primo caps from the Zoom.  Or mabye some Sennheiser MKE40.  Put them on top in a tetrahedral pattern and record four channels.  Not great, but a fun and inexpensive way to get started.

BTW, this raises a general question about ambisonic recording: How good do the mic capsules need to be.  The capsules may be good, but, clean off-axis response is critical.  I think this is one place Len at Core Sound has the edge.  He has taken those capsules, measured them, and then presumeably tuned his software to fix the imperfections.  At least that is what I expect.  I would want to see some calibration data before I laid down any serious money for one of the mics...

  Richard

[popskull]

My Dad once told me "Son you cant turn a turd into a steak no matter how bad you want to" Although you might be able to get 4 inputs they will overload so badly and be so noisy that it will hardly be worth all that work and the many trips to radio shack to make it happen

Or a silk purse out of a sows ear

I hear ya......though I always encourage diy.........I know the results do not equal your craftmanship, but its how we learn

[Church-Audio]

My Dad once told me "Son you cant turn a turd into a steak no matter how bad you want to" Although you might be able to get 4 inputs they will overload so badly and be so noisy that it will hardly be worth all that work and the many trips to radio shack to make it happen

I agree that it might not sound great.  But this might be a fun experiment for people that want to do ambisonic recording.  I'm thinking of using four of your capsules, or just the existing Primo caps from the Zoom.  Or mabye some Sennheiser MKE40.  Put them on top in a tetrahedral pattern and record four channels.  Not great, but a fun and inexpensive way to get started.

BTW, this raises a general question about ambisonic recording: How good do the mic capsules need to be.  The capsules may be good, but, clean off-axis response is critical.  I think this is one place Len at Core Sound has the edge.  He has taken those capsules, measured them, and then presumeably tuned his software to fix the imperfections.  At least that is what I expect.  I would want to see some calibration data before I laid down any serious money for one of the mics...

  Richard

I would honestly say that calibration is EVERYTHING... with these mics and if the mics are not perfectly matched the whole thing is a waste of time. But its not only frequency response that needs to be matched its sensitivity and distortion and polar patterns that MUST be matched in order to make a great recording.

Chris