Topic: Church transformer based pre

[Chuck]

The dreaded screw driver... I used to have a Mini-Me and thats how I had to adjust the gain for line level signals... I have a DMIC-20 that I have to use a screw driver to change the toggled gain steps...  

Actually I'll bet most will be using this pre-amp into another pre-amp/ AD converter, so the balance can be controlled by the second unit.

[stirinthesauce]

The dreaded screw driver... I used to have a Mini-Me and thats how I had to adjust the gain for line level signals... I have a DMIC-20 that I have to use a screw driver to change the toggled gain steps...  

Actually I'll bet most will be using this pre-amp into another pre-amp/ AD converter, so the balance can be controlled by the second unit.

I would be using this into a mini me.  Double screwdriver action 

[Church-Audio]

The dreaded screw driver... I used to have a Mini-Me and thats how I had to adjust the gain for line level signals... I have a DMIC-20 that I have to use a screw driver to change the toggled gain steps...  

Actually I'll bet most will be using this pre-amp into another pre-amp/ AD converter, so the balance can be controlled by the second unit.

Well then we might have a bunch of options. I say use the fine adjustment on the preamp then you can "calibrate your stereo mics" so they are both the same level and not have to worry about doing anything on the second unit. Like I said before we cant please everyone. But maybe we can offer different options.. That might be a way to make most of the people happy.. I am all for that but I have to make sure I can get the "parts" when a customer says I want this or that.. It all costs money to have these things sitting on a shelf until a customer wants them. So I try to use off the shelf parts that are in high demand so that our supply chain never gets screwed up and the customer is never stuck waiting for "our" parts to come in.

[BJ]

The dreaded screw driver... I used to have a Mini-Me and thats how I had to adjust the gain for line level signals... I have a DMIC-20 that I have to use a screw driver to change the toggled gain steps... 

Actually I'll bet most will be using this pre-amp into another pre-amp/ AD converter, so the balance can be controlled by the second unit.

Well then we might have a bunch of options. I say use the fine adjustment on the preamp then you can "calibrate your stereo mics" so they are both the same level and not have to worry about doing anything on the second unit. Like I said before we cant please everyone. But maybe we can offer different options.. That might be a way to make most of the people happy.. I am all for that but I have to make sure I can get the "parts" when a customer says I want this or that.. It all costs money to have these things sitting on a shelf until a customer wants them. So I try to use off the shelf parts that are in high demand so that our supply chain never gets screwed up and the customer is never stuck waiting for "our" parts to come in.

Chris..honestly...build your prototype the way that you think would work best.  IF/When you get the demand for more...then you can worry about customization based on that customer.  until then...just a stock box would be great...b/c everyone can work with what they have.  no box will ever be perfect for everyone. 

[eclark]

+t to chris for helping me customize my st9100 preamp just how i wanted it! im really pumped to see this final project. keep up the work!

[it-goes-to-eleven]

I say use the fine adjustment on the preamp then you can "calibrate your stereo mics" so they are both the same level and not have to worry about doing anything on the second unit.

Would that pot be in the signal path as an attenuator or would it alter the gain?

I think the fine adjustment for balance is a good idea. Though I don't stress about mic balance much at all (my mics are matched).  Plus I switch between mics so any balance correction.  If you really wanted to get jiggy with it you could have resistor modules that inserted into the pre with each one having a different correction dialed in.. but again, I'm not sure mic imbalance is a common problem.

[roggae]

Regarding the stealthy preamp you are speaking of:

Would it be possible to make the preamp so that it could power both 48v and 9v mics (with a switch).  I realize the impedance would be off, but would it still work?  That would be fantastic for people with both types of mics.  Just a thought...

[Church-Audio]

I say use the fine adjustment on the preamp then you can "calibrate your stereo mics" so they are both the same level and not have to worry about doing anything on the second unit.

Would that pot be in the signal path as an attenuator or would it alter the gain?

I think the fine adjustment for balance is a good idea. Though I don't stress about mic balance much at all (my mics are matched).  Plus I switch between mics so any balance correction.  If you really wanted to get jiggy with it you could have resistor modules that inserted into the pre with each one having a different correction dialed in.. but again, I'm not sure mic imbalance is a common problem.

With 60 db of gain you need a true gain pot.. This preamp will have a true gain pot + a 20db pad.

[Church-Audio]

Regarding the stealthy preamp you are speaking of:

Would it be possible to make the preamp so that it could power both 48v and 9v mics (with a switch).  I realize the impedance would be off, but would it still work?  That would be fantastic for people with both types of mics.  Just a thought...

No if people want to use electret mics with it they will need impedance converters/phantom to 10volt adaptors.
The stealth preamp will be totally designed to drive balanced loads with a phantom powered mic..
The phantom power will be switchable on or off.. So people with powered mics that dont need phantom can use this preamp.

Chris

[roggae]

Regarding the stealthy preamp you are speaking of:

Would it be possible to make the preamp so that it could power both 48v and 9v mics (with a switch).  I realize the impedance would be off, but would it still work?  That would be fantastic for people with both types of mics.  Just a thought...

No if people want to use electret mics with it they will need impedance converters/phantom to 10volt adaptors.
The stealth preamp will be totally designed to drive balanced loads with a phantom powered mic..
The phantom power will be switchable on or off.. So people with powered mics that dont need phantom can use this preamp.

Chris

I figured as much.  Thanks.

[MLKLuke]

No if people want to use electret mics with it they will need impedance converters/phantom to 10volt adaptors.
The stealth preamp will be totally designed to drive balanced loads with a phantom powered mic..
The phantom power will be switchable on or off.. So people with powered mics that dont need phantom can use this preamp.

Chris

will it include also a small ADC inside or maybe it's asking too much for a stealth device? 

[Nick's Picks]

who needs that ?
all of the "stealth decks" have good A/Ds in them.

[silence]

Hey Chris, you should run this idea by the folks on Gearslutz location recording board and Yahoo Nature recordists. While the Gearslutz folks, many of whom  are on this site will probably have similar requests, the nature recordists are also looking for a small self powered stereo pre. These folks are looking for field rugged, low noise and high gain. As well as the pro's and hobbyists, there are several film/audio school instructors who are always looking for inexpensive recording options for their classes. 

Chris - This is an excellent idea.  and double your audience

[OOK]

June is approaching fast.. I can't wait to see pictures of the proto type!!!!

[Church-Audio]

June is approaching fast.. I can't wait to see pictures of the proto type!!!!

I think we are about 2 months away from a prototype. But one never knows...

Chris