Glad I thought to ask. When you get a chance you might try it with a couple of 6K81s pulled up to 48V.
If you don't have an easily obtainable 48V supply you can get 45V from the IP27-18 by stacking all three or use the dual 20V and a 9V battery in series.
I'm curious about Bruno's TLM103s....
Search found 5469 matches
- Thu May 07, 2009 10:12 am
- Forum: Pro Audio Design
- Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
- Replies: 212
- Views: 413479
- Thu May 07, 2009 9:05 am
- Forum: Pro Audio Design
- Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
- Replies: 212
- Views: 413479
Re: A Direct-Coupled Input-Capacitorless Active Mic Preamp
Wow, cool - thanks! What we're looking for is the offset developed by the microphone when phantom is applied through the customary 6K81 pull-ups. It cannot be loaded by a transformer but an active input, or just the pullup resistors as load, will tell us how symmetric the current draw is. The DC pot...
- Wed May 06, 2009 9:01 pm
- Forum: Pro Audio Design
- Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
- Replies: 212
- Views: 413479
Re: A Direct-Coupled Input-Capacitorless Active Mic Preamp
Thanks. Looks like the 4050s may be the ones which are not transformer output.
Anybody got a TLM103?
The Vos is <<1 mV. Not a smoking gun. Anyone else want to measure some phantom-powered mics?Pair of 4050s
0.2mV/0.7mV
Anybody got a TLM103?
- Wed May 06, 2009 4:42 pm
- Forum: Pro Audio Design
- Topic: Mid Side M-S Matrix Uses No Precision Resistors
- Replies: 271
- Views: 634845
Re: Mid Side M-S Matrix Uses No Precision Resistors - Boards 5/1
I just wanted to thank everyone who has ordered boards recently!
Wayne
Wayne
- Wed May 06, 2009 4:41 pm
- Forum: Pro Audio Design
- Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
- Replies: 212
- Views: 413479
Re: A Direct-Coupled Input-Capacitorless Active Mic Preamp
Thanks Roger. Hardly a smoking gun.
You might check to see what the DC resistance is across pins 2 and 3. That should tell us if there's a transformer there.
You might check to see what the DC resistance is across pins 2 and 3. That should tell us if there's a transformer there.
- Wed May 06, 2009 11:57 am
- Forum: Pro Audio Design
- Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
- Replies: 212
- Views: 413479
Re: A Direct-Coupled Input-Capacitorless Active Mic Preamp
Roger - I haven't had a chance to re-explore the Murata modules.
I don't know for certain that AT3525 is transformer out, but the DCR was ~20 Ohms. I think I may have written 10 Ohms in the earlier post.
See what offset your 4050s have when you get the chance.
Wayne
I don't know for certain that AT3525 is transformer out, but the DCR was ~20 Ohms. I think I may have written 10 Ohms in the earlier post.
See what offset your 4050s have when you get the chance.
Wayne
- Sat May 02, 2009 2:07 pm
- Forum: Pro Audio Design
- Topic: A Discussion About True Power Summing for Stereo Compressors
- Replies: 65
- Views: 135666
Re: A Discussion About True Power Summing for Stereo Compressors
Crusty - Just saw this. Check your-email.Wayne, do you have access to a copy of Attack and Release Time Constants in RMS-Based Compressors and Limiters, by Fred Floru?
- Sat May 02, 2009 1:51 pm
- Forum: Pro Audio Design
- Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
- Replies: 212
- Views: 413479
Re: A Direct-Coupled Input-Capacitorless Active Mic Preamp
I found the 1/f component to be quite high in a number of caps I tested even with the input terminated in 150R and Rbias at 1k. These samples were Panasonic SU-series so as you often say YMMV. For new never-before-powered caps it took them 30 minutes or more to get "quiet." I did find the ...
- Sat May 02, 2009 9:39 am
- Forum: Pro Audio Design
- Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
- Replies: 212
- Views: 413479
Re: A Direct-Coupled Input-Capacitorless Active Mic Preamp
John - Thank you for bringing that to my attention. I think the comment made was for a topology that didn't provide correction of differential offsets from mic-induced errors. I saw that problem from the get-go and the posts here deal with that issue in great detail. I wrote early on: 7) Because DC ...
- Fri May 01, 2009 5:13 pm
- Forum: Pro Audio Design
- Topic: Mid Side M-S Matrix Uses No Precision Resistors
- Replies: 271
- Views: 634845
Re: Mid Side M-S Matrix Uses No Precision Resistors - Boards
Thanks Paul! Yes, they're in. Note that postage is going up Mother's Day and all rate bets are off. I hope to have an early BOM posted here soon and there are those schematics to get drawn for Roger to tidy up. Here's the link: http://www.ka-electronics.com/kaelectronics/MS_Matrix/MS_Matrix.htm Rath...