Taperssection.com
Gear / Technical Help => Battery Boxes, Preamps, Mixers, ADCs, and Processors => Topic started by: acidjack on June 17, 2009, 04:12:54 PM
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I apologize as I feel like I have been posting about this and related stuff all over the place, but haven't really gotten quite the answers I am looking for. I also emailed Chris a couple of times, but have not heard back.
I am having 2 AKG ck91s modded out for an active setup. I need high SPL capability.
So far, I am having a hard time finding something to power these things. I'm in discussions with Sound Professionals about custom making something, and I love their gear, but if there is something commercially available and easier, I'm all for it, and the Church gear will cost less than having a custom job done, and is loved by many on here. I know the ST-9100 can already be built with 2xmini XLR inputs and a hardwired stereo mini out. But, I have heard that the 9100 doesn't output quite enough juice - that it doesn't output the 9v or higher that is needed for the ck91s, especially at higher volumes.
Is it the case that the 9100 doesn't quite provide 9v? Also, is this different for different versions of this preamp? I know Chris is swamped right now, so if I want one more quickly, it may make sense to acquire a used one instead of having a new one built...
Any other recs for something will do this and doesn't have to be custom built would be appreciated.
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The 9100 puts out about 97 % of what the total battery power is of the 9 volt battery your using.
This means the 9 volt battery would have to be putting out around 9.28 v. for the ST-9100 to provide 9 volts. I just tested one of my unused alkalines and it was putting out 9.33 v., but I doubt if it would stay above 9.28 long enough to be of much use.
Maybe one of the Maha 9.6 v. NiMh rechargeables from Thomas Distributing that Chris recommends would stay above 9.28 for several hours, but who knows?
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My measurements of the CA-UGLY with Maha 9.6v are below. Non DPA 4060 parts are in bold. Not sure how closely the UGLY compares with the 9100 but it's similar if not the same, adding features the UGLY lacks. Chris would need to confirm that however.
DPA 4060
33k ohms - resistance measured across mic
Church Audio UGLY preamp powered with '9.6v' rechargable NiMH battery measured at 10.2V charged
15ma - preamp's current draw through battery (mics attached, preamp output disconnected)
7.5V - open circuit mic power voltage
0.74mA - current draw through DPA 4060
2.8V - Voltage drop across DPA 4060
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My measurements of the CA-UGLY with Maha 9.6v are below. Non DPA 4060 parts are in bold. Not sure how closely the UGLY compares with the 9100 but it's similar if not the same, adding features the UGLY lacks. Chris would need to confirm that however.
DPA 4060
33k ohms - resistance measured across mic
Church Audio UGLY preamp powered with '9.6v' rechargable NiMH battery measured at 10.2V charged
15ma - preamp's current draw through battery (mics attached, preamp output disconnected)
7.5V - open circuit mic power voltage
0.74mA - current draw through DPA 4060
2.8V - Voltage drop across DPA 4060
Thanks. Hoping to hear from Chris eventually to confirm, as my other alternative involves having a custom box built at higher $$$.
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It won't work.
I asked Chris a while back and he said no, but he has a box he can make for you for this purpose. I just got an N Box, and am very happy with it.
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My measurements of the CA-UGLY with Maha 9.6v are below. Non DPA 4060 parts are in bold. Not sure how closely the UGLY compares with the 9100 but it's similar if not the same, adding features the UGLY lacks. Chris would need to confirm that however.
The 9100 will power your mics I have to get your mics here because there is a mod I have to do to the 9100 to make it work and I forget what I did lol.... but I have a few customers that are using 9100 preamps to power the mics you have.
Chris
DPA 4060
33k ohms - resistance measured across mic
Church Audio UGLY preamp powered with '9.6v' rechargable NiMH battery measured at 10.2V charged
15ma - preamp's current draw through battery (mics attached, preamp output disconnected)
7.5V - open circuit mic power voltage
0.74mA - current draw through DPA 4060
2.8V - Voltage drop across DPA 4060
Thanks. Hoping to hear from Chris eventually to confirm, as my other alternative involves having a custom box built at higher $$$.
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The 9100 will power your mics I have to get your mics here because there is a mod I have to do to the 9100 to make it work and I forget what I did lol.... but I have a few customers that are using 9100 preamps to power the mics you have.
Chris
There you have it. ;)
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I picked up a CA-9100 but according to my measurements it only delivers 4.7v +/- to the mics. (1)
Can I put a 9v battery box into the chain and prevent the brickwalling, or is there a chance for damage somewhere?
U~Ca, you're spot on. Here's your answer:
back then my preamps only put out about 4.6 volts now they put out 8 volts. That is a huge difference. I can upgrade your preamp for $79 that will give you a brand new preamp with the trade in of the old preamp.
So no need to mess around with an extra bbox, just send it back to Church for an upgrade!
To the OP:
Apart from powering your mics with "9100 active mod", did you know that they can also be ran with AT8531 power modules (or possibly AT8533/Samson PM4 if you have access to phantom). More details here:
http://taperssection.com/index.php/topic,57299.0.html
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^ I saw that... You missed my point. I *have* a battery box (costing way less than $80 BTW).
Is my idea a solution or a potential problem?
Sorry 'bout that. Sure, you should be able to run ck91>9V bbox>CA-9100>recorder.
You just have to work out the interconnects between the bbox and the 9100, depending on the jacks.
I guess the question is whether the bbox will be affected by the voltage coming from the 9100, but AFAIK this is no issue.
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^ I saw that... You missed my point. I *have* a battery box (costing way less than $80 BTW).
Is my idea a solution or a potential problem?
There should be no issues.
Chris
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The 9100 will power your mics I have to get your mics here because there is a mod I have to do to the 9100 to make it work and I forget what I did lol.... but I have a few customers that are using 9100 preamps to power the mics you have.
Chris
raising hand as one of those customers.
So far, everything's running fine with my 9100 preamp powering my ck91's....!
edit:
I did a show using that setup about 2 weekends ago, I'll try to post up a sample if anyone wants to take a listen and provide feedback
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ok, here's some audio samples for you with my ck91 > Church 9100 setup
The zipped file (rar actually) has 3 audio tracks, all from different shows, and it's related text file. So 6 files total once unzipped (or would that be unrarred?)
http://www.sendspace.com/file/spm1pg
If the link dies out from age and you want to hear them still, pm me