Topic: Will SP Mod AD-20 Power Studio Projects C4s?

[jbsalt]

Hi guys.  I'm in the process of buying redbook's SP modified AD-20.  I noticed on the Sound Pro's page that the unit has "plug in power".  Notes that you can plug 9vdc phantom powered or "plug in power" mics directly into preamp without adapter cables or separate battery module. 

Will this have enough power to run a pair of C4s or will I need to buy a PS-2 as well?  Thank you all for your assistance... 

[lordbelial]

Hi guys.  I'm in the process of buying redbook's SP modified AD-20.  I noticed on the Sound Pro's page that the unit has "plug in power".  Notes that you can plug 9vdc phantom powered or "plug in power" mics directly into preamp without adapter cables or separate battery module. 

Will this have enough power to run a pair of C4s or will I need to buy a PS-2 as well?  Thank you all for your assistance... 

I don't know the supply specs of the C4's but I think the SP mod don't give "phantom power", they have only integrated a 2-wire battery box into the AD-20 so you can avoid the battery box + miniplug > XLR adaptor cable.

Here you can find a picture of my AD-20 with the adapter cable I made.

[Brian Skalinder]

Will this have enough power to run a pair of C4s or will I need to buy a PS-2 as well?

The C4's require 48v phantom power.  The mod-AD20 provides lower voltage (9v?) bias power.  The mod-AD20 will not power the C4s for two reasons:

• it does not provide sufficient voltage, and
• the wiring scheme for bias power is different than the wiring scheme for phantom power.

You're correct in that you'll need a separate phantom power source for your C4s.  The PS2 is one such phantom power source and will do the trick nicely.

IMO you're better of using a stock AD20 with the PS2 for two (maybe three) reasons:

• the PS2 outputs via XLR connectors, so with the mod-AD20 you'll need some adapters to convert the XLRs to the stereo mini;  with the stock AD20, you won't need any adapters; fewer adapters = fewer potential points of failure, fewer things to forget on your way out the door, etc.
• you'll go through batteries faster on the mod-AD20 because even though you're not using the 9v bias power to power your mics, I think the bias power is "always on"
• If I were you, I'd confirm with someone (SP directly is probably the best bet) whether or not running the 9v bias power from the mod-AD20 into the PS-2 will pose any problems;  I don't think so, but I'm not a technical expert

[jbsalt]

Thanks fellers!   

[Jamos]

Hi guys.  I'm in the process of buying redbook's SP modified AD-20.  I noticed on the Sound Pro's page that the unit has "plug in power".  Notes that you can plug 9vdc phantom powered or "plug in power" mics directly into preamp without adapter cables or separate battery module. 

Will this have enough power to run a pair of C4s or will I need to buy a PS-2 as well?  Thank you all for your assistance... 

I don't know the supply specs of the C4's but I think the SP mod don't give "phantom power", they have only integrated a 2-wire battery box into the AD-20 so you can avoid the battery box + miniplug > XLR adaptor cable.

Here you can find a picture of my AD-20 with the adapter cable I made.

Where did you get your knobs to replace the stock ones from the ad-20?
were they a direct fit?

thanks.
 

[Javier Cinakowski]

IMO you're better of using a stock AD20 with the PS2 for two (maybe three) reasons:


the PS2 outputs via XLR connectors, so with the mod-AD20 you'll need some adapters to convert the XLRs to the stereo mini;  with the stock AD20, you won't need any adapters; fewer adapters = fewer potential points of failure, fewer things to forget on your way out the door, etc.
you'll go through batteries faster on the mod-AD20 because even though you're not using the 9v bias power to power your mics, I think the bias power is "always on"
If I were you, I'd confirm with someone (SP directly is probably the best bet) whether or not running the 9v bias power from the mod-AD20 into the PS-2 will pose any problems;  I don't think so, but I'm not a technical expert

all of the above is not correct

The mod-AD20 has the orginal xlr input still intact and operational. 

The battery will not run down faster as the mod-ad20 has an extra 9v battery attached to it for 9v power.

The bias power does not pose any problems becasue it is only active in the 1/8" mini plug, not the xlrs

[Brian Skalinder]

all of the above is not correct

Thanks for the corrections, W, I should've indicated I was basing my comments on vague recollections.  I appreciate the correct facts. In light of the corrections, I'll amend my comments as follows:  not sure it makes sense to spend the extra cash on a modded AD20 (assuming you're not getting a super-duper deal) unless you're using both the XLR and mini inputs.  But that's neither here nor there - sounds like your mind's made up and the mod-AD20 will do what you need.  In which case, jbsalt:  have fun with your new gear!

[lordbelial]

Hi guys.  I'm in the process of buying redbook's SP modified AD-20.  I noticed on the Sound Pro's page that the unit has "plug in power".  Notes that you can plug 9vdc phantom powered or "plug in power" mics directly into preamp without adapter cables or separate battery module. 

Will this have enough power to run a pair of C4s or will I need to buy a PS-2 as well?  Thank you all for your assistance... 

I don't know the supply specs of the C4's but I think the SP mod don't give "phantom power", they have only integrated a 2-wire battery box into the AD-20 so you can avoid the battery box + miniplug > XLR adaptor cable.

Here you can find a picture of my AD-20 with the adapter cable I made.

Where did you get your knobs to replace the stock ones from the ad-20?
were they a direct fit?

thanks.
 

Uhm... Sorry, this Unit came modded. I'll try to figure out who was the one who modded this Ad-20...

[jbsalt]

Hi guys.  I'm in the process of buying redbook's SP modified AD-20.  I noticed on the Sound Pro's page that the unit has "plug in power".  Notes that you can plug 9vdc phantom powered or "plug in power" mics directly into preamp without adapter cables or separate battery module. 

Will this have enough power to run a pair of C4s or will I need to buy a PS-2 as well?  Thank you all for your assistance...