Search found 5471 matches
- Sat May 02, 2009 9:39 am
- Forum: Pro Audio Design
- Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
- Replies: 212
- Views: 414054
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: 639328
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...
- Fri May 01, 2009 5:09 pm
- Forum: Build
- Topic: 1510 -- servo, or not ?
- Replies: 24
- Views: 75260
Re: 1510 -- servo, or not ?
Have you looked at this one? No input or Cgain caps. http://www.picocompressorforum.com/forum/php/viewtopic.php?f=6&t=14 I would do the offset servo differently now and change a couple of things but it's passed the proof-of-concept stage and works. Roger sent me some AT3525s to try with it. The ...
- Fri May 01, 2009 7:27 am
- Forum: Build
- Topic: 1510 -- servo, or not ?
- Replies: 24
- Views: 75260
Re: 1510 -- servo, or not ?
So I'll be OK using the two 3.3k resistors and 22k for the center resistor? Yes, to make my rather long story short that should work fine. :ugeek: Without coupling caps however that extra resistor doesn't bring much to the party. Have you considered using a 1512? It would drop in the same socket an...
- Thu Apr 30, 2009 7:29 pm
- Forum: Build
- Topic: 1510 -- servo, or not ?
- Replies: 24
- Views: 75260
Re: 1510 -- servo, or not ?
Using the T-bias scheme, what impedance will a mic see? I'm concerned about loading dynamic and ribbon mics. I have built a preamp around the 1510 using two 3.3k resistors to ground using the rule of thumb that the input impedance should be 10x the mic impedance (I do have a 600-ohm mic, AT804, and...
- Mon Apr 27, 2009 9:00 pm
- Forum: Pro Audio Design
- Topic: THAT1646 Operation From A Single Supply Voltage
- Replies: 6
- Views: 15731
THAT1646 Operation From A Single Supply Voltage
Here's one way to operate and bias a THAT1646 for single supply operation: https://www.ka-electronics.com/images/jpg/THAT1646_Single_Supply.jpg Image courtesy of THAT Corporation If the input is at or near the same DC potential as Vref (the one-half Vcc potential at the output of U2A) then C2 and R1...
- Mon Apr 27, 2009 6:13 am
- Forum: Pro Audio Design
- Topic: Using the THAT1646 As A Transistor Pre-Driver/Headphone Amp
- Replies: 80
- Views: 354443
Re: Using the THAT1646 As A Transistor Pre-Driver/Headphone Amp
They are an insulated TO-126 on a 2.28 mm pitch. 0.1" may be close enough.raf wrote:I need to re-pitch the output device pads... I used 0.1" thinking they were TO220, they are, what TO126?
Thanks Roger and Doug.
- Sun Apr 26, 2009 9:27 pm
- Forum: Pro Audio Design
- Topic: Using the THAT1646 As A Transistor Pre-Driver/Headphone Amp
- Replies: 80
- Views: 354443
Re: Using the THAT1646 As A Transistor Pre-Driver/Headphone Amp
I had a chance to check the PC board a few weeks ago and run a few measurements. The output Vos was <5mV. The orginal slew rate was thought to be ~4V/us but when re-measured turned out to be ~8V/us. This is consistent with the THAT1646 when driven in the "common mode" configuration. The RM...
- Fri Apr 24, 2009 8:25 pm
- Forum: Build
- Topic: Hum differences in toroidal power transformers...
- Replies: 2
- Views: 14761
Re: Hum differences in toroidal power transformers...
What was the harmonic content of the fields? Could it be an issue of core saturation?
- Fri Apr 24, 2009 11:46 am
- Forum: Document
- Topic: Phono Preamps
- Replies: 49
- Views: 206960
Re: Phono Preamps
Check out the Archiver USB preamp. This thing is full of 2SK389s.
http://www.hagtech.com/pdf/archiverman.pdf
The schematics are on page 7.
http://www.hagtech.com/pdf/archiverman.pdf#page=7
Cute the way the FETS are drawn as triodes.
http://www.hagtech.com/pdf/archiverman.pdf
The schematics are on page 7.
http://www.hagtech.com/pdf/archiverman.pdf#page=7
Cute the way the FETS are drawn as triodes.