Blocking phantom

[peter purpose]

Thanks Dave, I was hoping to avoid a switch as I don't have the panel real estate, but I may have a re-think.

Cheers
peter

 

[NewYorkDave]

No room even for a teensy-tiny toggle? :razz:

 

[peter purpose]

Well, I could squeeze a togglette in there I suppose.

Cheers Dave :guinness: :sam:

 

[PRR]

> I was hoping to avoid a switch

Then can you go further up the chain and implement mic/line switching there? You said the box has a relay for that; I think that is where you want to tap-in your new line jacks.

 

[Mark Burnley]

Yea, steady on Kev, I'm emotional enough after reading the Pets thread in The Brewery!

:sad:

Peter,

What/when/why/how does the relay switch between mic and line in the module? Surely it's a p.o.p to take a DC feed from this switch and use this to switch a DPDT relay in place of the DPDT togglette in Daves schematic above?

Mark

 

[peter purpose]

Mark, I'm going with a panel mount dpdt and dassdatt.
As for 'What/when/why/how', it's a top secret Audix gizmo that's buried deep within the bowels of the module which I'd rather leave well alone.

Ayethengyaw
peter

 

[squib]

Peter

I rack these modules a while back and had to deal with the mic and line inputs being on the same pins. My solution was quite different and i also added a unbalanced DI input. It avoids having to decouple the line input with caps. If you don't want a DI input the solution is quite simple. Just move the wires to the input of the line transformer to the spare pins ( say 5 and 6 ) of the edge connector. The gain switch will pick up the line input as per usual. This is far better ( and easier ) than fiddling around with caps etc, you just have to open up the module and move a couple of wires
:grin:

 

[soundguy]

you guys are ALL tea drinking pirates.

dave

 

[Kev]

[quote author="Mark Burnley"]Yea, steady on Kev, I'm emotional enough after reading the Pets thread in The Brewery![/quote]

YEP
I've read but not posted
yes the memories of a pet can hit hard and when least expected
perhaps I'll post my story in there ... but not today.


PIRATES
did some one say Pirates ??? :shock: :green:

 

[SSLtech]

a-HAAA-Rrrrrrrrrrr!!!

Ahoy there, scurvies!!!

harrrr...-ha-HAAARRrrrrrr!!!!

Keef

 

[peter purpose]

Air, hellair.... :green:

 

[Mark Burnley]

[quote author="squib"]Just move the wires to the input of the line transformer to the spare pins ( say 5 and 6 ) of the edge connector. The gain switch will pick up the line input as per usual. This is far better ( and easier ) than fiddling around with caps etc, you just have to open up the module and move a couple of wires
:grin:[/quote]

Peter,

Are you going to give this a go, or have you drilled that hole for the dpdt now! :wink:

Shiver me timbers, landlubbers, sounds like a good mod to me.

Mark

 

[peter purpose]

Mark,
The hole is in the panel, with a switch in it and wired up to Daves specs.

Thanks for the suggestions squib....why I don't think of these things is anybodys guess....but maybe I'm just as thick as shite.

Thanks everyone.

pooter

 

[squib]

Peter
bummer you've put that hole in the front panel, cause it would be so much more elegant to just move the input of the line transformer to the spare pins. However, why don't you use the switch to select the mic input around to select a DI input? Also, what are you doing with the output? The output doesn't have much drive capability and certainly won't drive 600 ohms. Changing one resistor can fix this.

 

[peter purpose]

[quote author="squib"]what are you doing with the output? The output doesn't have much drive capability and certainly won't drive 600 ohms. Changing one resistor can fix this. [/quote]


Rob,
Currently running unbalanced.....sounds sweet as a nut, but am toying with the idea of hanging a Phoenix Audio TF1 Class a output stage off the back.
Tell me more of the resistor fix..oh OZ master.

peter

 

[squib]

Change R150 from 75R to 39R. It increases the standing current of the output transistor, enabling it to deliver more current in class A to a load.
easy!

 

[peter purpose]

Kinwellaahnsum..!!

Cheers Rob :guinness:

 

[ytrehalf]

[quote author="squib"]Peter

I rack these modules a while back and had to deal with the mic and line inputs being on the same pins. My solution was quite different and i also added a unbalanced DI input. It avoids having to decouple the line input with caps. If you don't want a DI input the solution is quite simple. Just move the wires to the input of the line transformer to the spare pins ( say 5 and 6 ) of the edge connector. The gain switch will pick up the line input as per usual. This is far better ( and easier ) than fiddling around with caps etc, you just have to open up the module and move a couple of wires
:grin:[/quote]


Hello Squib, I'm racking a pair of these (35102) myself and I'm wondering if you could share your mod for the D.I. input.

Also if anyone could point me to the schematics for this channel it would be much appreciated.

 

[Sleeper]

I was reading that you can increase the value of the 47 uf caps in the phantom supply and decrease the chances of overloading the p48 supply.

I'm also curious what the range needs to be on the 6.81k resistors, I know they need to be closely matched, but I'm just curious why that particular value? would a pair of 6.5ks work just as well?

reason I ask is I have to fix a couple of dodgy phantom supplies. these work on some mics and not others... the supply is
more than adequte to handle the milliamps required. I'm assuming these are probably just poorly matched resistors as I made these very early on in my diy learning curve. Anyhow I'm all out of 6.81ks so I'll have to order unless perhaps I can use the 6.5k holcos that i have.

Thanks
Sleeper

 

[jrmintz]

Mouser has 0.1% Holcos which I use for phantom. Part #279-6.81K They're expensive, relatively speaking, but I figure it's one less thing for me to screw up.

:green:

:guinness: :sam: