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  #16  
Old 11-06-2017, 08:46 PM
gitarro gitarro is offline
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Thanks for the reply sdelsolray. Looking forward to hear what is Wayne's experience using the trinity with his PMB.
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  #17  
Old 11-06-2017, 10:02 PM
gitarro gitarro is offline
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I found this on the k & k website on their trinity pro preamp:-

"Trinity Pro Preamp Features

The Trinity Pro Preamp allows for perfect balancing of a microphone and a pickup/transducer. Channel 2 is a designated mic channel with phase switch and supplies 9-volts to a lavalier type microphone. Each individual channel features volume, gain, +/- 20 dB bass, midrange, and treble filters. The EQ is accessible inside the box with trimpots. A convenient belt clip is included with this compact preamp, which weighs a mere ten ounces with the battery installed."

http://kksound.com/products/trinitypropreamp.php

From this, it looks like as long as your third party preamp supplies 9 volts DC to the microphone, it should be the same as the k & k preamp.
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  #18  
Old 11-07-2017, 06:13 AM
Ryan Alexander Ryan Alexander is offline
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I've gotten some strange responses from K&K when inquiring about using different preamps with the Trinity system. Usually some form of "why don't you use OUR preamps?". I think the only way we're going to settle this is to have someone brave enough give it a try on one of the "new" Trinity systems.

I was hoping to install a Trinity system in my Lowden to use with my Felix preamp, but that supplies 12v for the mic. Seems less likely that this would work compared to something like the Raven PMB if they have installed some kind of voltage protection.
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  #19  
Old 11-07-2017, 01:16 PM
wayne8 wayne8 is offline
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I'll be picking my guitar up this weekend and will check it out then and post back.
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  #20  
Old 11-07-2017, 04:09 PM
Mandobart Mandobart is offline
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Quote:
Originally Posted by tadmania View Post
The difference seems to be the operating voltage of the Meridian mic. It is 5V DC, which is different than the 9V or 18V current supplied by most preamps. It might be simple to alter or convert the voltage supplied to the proper levels when using the Meridian mic with non-K&K units. A 'step down' transformer seems the right term.
No it is not the right term. Transformers are for AC. Using a transformer for DC voltage will not work. It will be an open circuit. Running direct current 9 volts across the primary winding will give you 0 VDC on the secondary.

You need a DC voltage divider. Simple to build. Two resistors in series, size depends on how much current the mic draws. Let's simplify and say it is 1 A. Wire a 5 ohm and 4 ohm resistor in series. Connect the 9 VDC input across the series pair. Tap your output across the 5 ohm resistor. If the load is pulling 1 A, then the 5 ohm resistor is dropping 5 volts. Note you can use a 50 ohm and a 40 ohm, 500 ohm and 400 ohm, etc. so long as the ratio remains the same. But you do need to know how much current the mic draws, because you also need to size the resistors for power (1/8 watt, 1/4 W, etc.). This stuff is pretty easy for a guy with many years of training and experience as an electronics tech for the USN. But if this is not understandable to the reader I would not recommend trying to build and use your own power supply. Its impossible to put the smoke back into these components after you let it out.
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  #21  
Old 11-07-2017, 04:57 PM
gitarro gitarro is offline
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K & k has been very.fast in replying to my queries and so has John of Shoreline Music. It seems that the microphone's maximum voltage is 10v so the preamp that feeds it cannot exceed 10v.
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  #22  
Old 11-07-2017, 09:47 PM
tadmania tadmania is offline
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Quote:
Originally Posted by Mandobart View Post
No it is not the right term. Transformers are for AC. Using a transformer for DC voltage will not work. It will be an open circuit. Running direct current 9 volts across the primary winding will give you 0 VDC on the secondary.

You need a DC voltage divider. Simple to build. Two resistors in series, size depends on how much current the mic draws. Let's simplify and say it is 1 A. Wire a 5 ohm and 4 ohm resistor in series. Connect the 9 VDC input across the series pair. Tap your output across the 5 ohm resistor. If the load is pulling 1 A, then the 5 ohm resistor is dropping 5 volts. Note you can use a 50 ohm and a 40 ohm, 500 ohm and 400 ohm, etc. so long as the ratio remains the same. But you do need to know how much current the mic draws, because you also need to size the resistors for power (1/8 watt, 1/4 W, etc.). This stuff is pretty easy for a guy with many years of training and experience as an electronics tech for the USN. But if this is not understandable to the reader I would not recommend trying to build and use your own power supply. Its impossible to put the smoke back into these components after you let it out.
Thank you! Your post led me to look into the difference. Very interesting stuff.
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  #23  
Old 11-14-2017, 07:41 AM
Ryan Alexander Ryan Alexander is offline
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Paging wayne8! Did you have a chance to test your newly installed Trinity system with your Raven PMB?
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  #24  
Old 11-15-2017, 02:30 PM
wayne8 wayne8 is offline
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Sorry! I had to go out of town. Will be back in a day or so with an update.
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  #25  
Old 11-18-2017, 02:21 PM
wayne8 wayne8 is offline
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Finally was able to try this thing out. Tried the PMB with the AC adapter first. Worked fine on the pickup channel, nothing but hiss on the mic channel. Tried batteries instead of AC adapter and both channels worked fine. Main reason I was hoping to use the PMB instead of my K&K preamp was so I could eliminate the batteries. Oh well.
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  #26  
Old 11-18-2017, 04:47 PM
sdelsolray sdelsolray is offline
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Quote:
Originally Posted by wayne8 View Post
Finally was able to try this thing out. Tried the PMB with the AC adapter first. Worked fine on the pickup channel, nothing but hiss on the mic channel. Tried batteries instead of AC adapter and both channels worked fine. Main reason I was hoping to use the PMB instead of my K&K preamp was so I could eliminate the batteries. Oh well.
A properly working wall wart power supply should not do that. IIRC, that wall wart is a pair of 9v supplies put together to make 18v. Given your experience, it is likely the power supply is faulty, or its receptacle jack in the PMB unit or something else in the unit deal with delivery of external power. There are other 18v power supplies with the proper positive and negative connecting jack. Finding and trying one will either solve the problem or isolate it further. As an alternative, a competent tech should be able to figure it out easily.
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  #27  
Old 11-18-2017, 08:02 PM
wayne8 wayne8 is offline
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I'll try that. Thanks!
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  #28  
Old 11-18-2017, 08:09 PM
wayne8 wayne8 is offline
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I just checked the power supply. It says output 9VDCx2 300mA.
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  #29  
Old 11-19-2017, 11:58 AM
Ryan Alexander Ryan Alexander is offline
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Interesting. Sounds like the correct supply. I wonder if the Raven is generating 9v for the mic on battery power and more than 10v when operated via adapter?
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  #30  
Old 11-20-2017, 02:23 PM
wayne8 wayne8 is offline
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Well, according to the PMB manual, it says it puts out slightly more than 9 volts when using the adapter but doesn't say how much. I guess one 9 volt supplies the phantom and the other 9 volts supply power to the rest of the unit. The PMB uses two nine volt batteries if you don't use the adapter. In researching, trying to find a replacement, which I guess just isn't possible, I've read that it's fairly common for these adapters to be fried, something about unplugging them while the unit is on or something. Anyway, I'll either use it with batteries or continue to use the K&K belt pack preamp. Interesting that the K&K only uses one 9 volt battery and it, too, supplies phantom for the mic.
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