Warbler Mk1D & Capi Vp 26/28 Issues

[geardude]

Curious, I've seem to encountered something unusual with my Warbler Mk1D.

When using my Warbler in conjunction with either a CAPI VP26 &/or a VP28 , I get insufficient gain and a loud hum. I'm talking I have to crank both the pre & output attenuater/fader full blast and I'm still not getting a sufficient signal and it's of course noisy as hell. This ONLY HAPPENS WITH THE WARBLER.

Anyone else encounter this?

Troubleshooting-

1) This issue is non -existent while using a 3u Black CM-1 on both CAPI's. So it's not my capi builds/ 48v channels not working properly


2) The Mk1D works flawlessly on my ISA one- no hum plenty of clean signal.

3) All tests using the same chords & xlr's so the only thing changing in the line is the microphone.



Could this be related to the powersupply of my 3 rack lunchnox not having enough juice or something of that nature( it's only a cheap 3 slot after all ) or is it possible I have a bonk warbler? 

 

[geardude]

Alright so after some reading over at geekslutz and with communication with the Mic maker( Thanks guoshung!) it's vital that these vintage style mics get the proper amount of phantom power to work properly. It's not getting enough juice on my Snackbox as proven by it working on my ISA one.

After being instructed to probe the pins between xlr's & the card slots of the Lunchbox itself, I found the voltage differences and there are some red flags.

Probing with DMM  the pin reading in the box between 13 & 15 should be +/-48- not anywhere low to the 16 I'm reading in the lunchbox slots.

This info is here of a similar problem can be found here...



This info is here
https://www.gearslutz.com/board/geekslutz-forum/481221-api-lunchbox-not-enough-phantom-power-km84.html

The mic builder is a guru  and according to him here's what he has to say about potential troubleshooting

"There is a +48 to +52 Vdc between pin2 and pin1, and there is a +48 to +52 Vdc between pin3 and pin1 too.

Some modern transformerless condenser mic can work when there is a +48 to +52 Vdc between pin2 and pin1 only.

But vintage transformer coupled mic must have a +48 to +52 Vdc between pin3 and pin1 too."

Well in the ISA one that checks out and works perfect- right in the sweet spot.

BUT on the snackbox I'm getting a puny 16- this with taking all the other preamps out.

The guy who posted on gearslutz turned out to have a bonk power supply- and I'm starting to think that this is my case or this snackbox is just not running enough juice and is noisey as hell.

I'm also noticing a loud buzzing interference with my pre's in the snackbox as well. For instance, the vp 28, it doesn't matter which microphone, dynamic or condenser, if I keep my channel knob at zero and move the preamp over two spots right from unity i get this building noise floor. Is this a symptom's of a bad power supply? Or a grounding issue? I've tested the units on other lunchboxes and they work fine.

 

[geardude]

Turns out there was a bad power supply in my Lunchbox- no issues here carry on.