Author Topic: Ribbon microphone  (Read 5573 times)

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Offline roberto.missoli

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Ribbon microphone
« on: November 13, 2011, 03:56:23 PM »
I have a ribbon microphone and I want to use it without the output transformer. If I remove the transformer I have this situation:

- the impedance is 0.5 Ohm and the output voltage is 0.04mV/Pa without the transformer

Do you think I can use one of the two RIAA amplifiers or the impedance is too low, than I still need a transformer?

Of course I need a DC input, but I think it is not a problem with these preamp.

Roberto Missoli
Italy

Offline roberto.missoli

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Re: Ribbon microphone
« Reply #1 on: November 13, 2011, 04:15:52 PM »
.... I forgot to say: with a RIAA bypass....

Offline peranders

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Re: Ribbon microphone
« Reply #2 on: November 13, 2011, 08:11:32 PM »
The QSXM2 would probably work.
/Per-Anders Sjöström, owner of this forum

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Offline roberto.missoli

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Re: Ribbon microphone
« Reply #3 on: November 14, 2011, 05:07:57 PM »
Thank you

I have these question:
1) In the input transistor array is it possible to use this type of component =>  http://www.thatcorp.com/datashts/THAT_300-Series_Datasheet.pdf
2 Do you think I need the input bias servo with a ribbon microphone?
3 Can I keep the signal directly for the Pre amplifier (PREAP-OUT to RIAA stage)? The idea is to use only this part with a new very compress PCB to install near (or inside) to the microphone. (Of course I need your authorization and I ready to pay the royalties)

Offline peranders

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Re: Ribbon microphone
« Reply #4 on: November 14, 2011, 08:34:42 PM »
1 Yes

2 Probably not

3 It might work depending of how much gain you want. Gut feeling says no.
/Per-Anders Sjöström, owner of this forum

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Offline roberto.missoli

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Re: Ribbon microphone
« Reply #5 on: November 14, 2011, 09:32:06 PM »
Thank you very much for your fast replay, you are too fast, probably faster that your preamp  :-)

About the question 3, are you able  to evaluate the gain? I think I need 70db (in this case I don't need an extra mic pre-amp) and I can  connect the system directly to a line input.
But if I need the more gain is it easy to de-select the RIAA network?



Offline peranders

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Re: Ribbon microphone
« Reply #6 on: November 14, 2011, 09:59:26 PM »
I think 40 dB gain per stage is good. It is just to remove the caps in the RIAA network if you want a flat frequency response.
/Per-Anders Sjöström, owner of this forum

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