Search found 304 matches
- Tue Apr 30, 2019 12:21 pm
- Forum: Pro Audio Design
- Topic: A Low Noise Balanced Input Moving Coil Preamp Using the ZTX851
- Replies: 499
- Views: 783792
Re: A Low Noise Balanced Input Moving Coil Preamp Using the ZTX851
My tester for EMI, hum, thermal drift is a hair drier. A cheap tool that does it all. An anecdote about thermal stability: A design of mine about a test equipement to test TV reference monitors. When they put my proto, in thermal testing to check the compliance with requirements about stability of l...
- Sat Apr 27, 2019 8:06 am
- Forum: Pro Audio Design
- Topic: A Low Noise Balanced Input Moving Coil Preamp Using the ZTX851
- Replies: 499
- Views: 783792
Re: A Low Noise Balanced Input Moving Coil Preamp Using the ZTX851
First off, thanks to show all this nice work.
I am very interested about this.I do want to get some mu-metal....and I'll try lining the metal Hammond box with it.
- Wed Apr 17, 2019 1:59 pm
- Forum: Build
- Topic: Simple pcb design program
- Replies: 28
- Views: 109929
Re: Simple pcb design program
I see these software are mostly locked to: Output = Ordering PCBs to a specific manufacturer. PCB express has a netlist file, how could it not have it, however I found no way to import or export to LTspice for instance. Gerber files, same thing. Is there a true free software, open to alternate softw...
- Wed Apr 17, 2019 1:20 pm
- Forum: Pro Audio Design
- Topic: Op amp matching
- Replies: 44
- Views: 50017
Re: Op amp matching
I am not familiar about the effect of noise on an integrator. May be naive, I see integration, filtering out noise. I see the noise at the input averaged, buried in the integrating capacitor. 1/f noise looks scary because going to infinity for f going to 0 while gain of an integrator goes to infinit...
- Wed Apr 17, 2019 2:57 am
- Forum: Pro Audio Design
- Topic: Op amp matching
- Replies: 44
- Views: 50017
Re: Op amp matching
About low Vos balanced integrators I am afraid we are stuck with OPA2277 or go the route of choppers with adaptation board. I do not see how to use two OP07 with two trimmers. I see no way to trim correctly those two that will interact. OTOH. One trimmer for the two op-amp makes the adjustment possi...
- Sat Apr 13, 2019 5:11 am
- Forum: Pro Audio Design
- Topic: Op amp matching
- Replies: 44
- Views: 50017
Re: Op amp matching
From the data sheet, one can expect 5µV Vos with trimming using OP07E.
It comes in two flavors OP07E ( better ) and OP07C.
There is another flavor OP07D ( not so good, lower cost ).
It comes in two flavors OP07E ( better ) and OP07C.
There is another flavor OP07D ( not so good, lower cost ).
- Wed Apr 10, 2019 11:46 pm
- Forum: Pro Audio Design
- Topic: A Low Noise Balanced Input Moving Coil Preamp Using the ZTX851
- Replies: 499
- Views: 783792
Re: A Low Noise Balanced Input Moving Coil Preamp Using the ZTX851
LM4562/LME49720 and now-discontinued LME49860. I am shocked to see Texas Instrument continue publishing datasheets for these op-amps tooting low noise: 2.7 nV / rt Hz. And they continue to sell an op-amp they have discontinued without any warning like "not for new design". Clearly, they c...
- Tue Apr 09, 2019 4:19 am
- Forum: Test, Measurement and Repair
- Topic: entropy continued?
- Replies: 34
- Views: 155693
Re: entropy continued?
Bad contacts before, good after contact cleaning spray. So, there was some contact contamination: Corrosion, oily film, some residu left from manufacturing, storing, handling. Who knows wether the culprit is the socket or the IC. Well, you are stuck with those, all you can do is to keep the stabilan...
- Mon Apr 08, 2019 11:06 am
- Forum: Pro Audio Design
- Topic: A Low Noise Balanced Input Moving Coil Preamp Using the ZTX851
- Replies: 499
- Views: 783792
Re: A Low Noise Balanced Input Moving Coil Preamp Using the ZTX851
LM4562, LME49720, LME49860 the same chip. Better than NE5532, pin compatible.
2.7 nV/rt Hz THD 0.00003% 55 Mhz 140dB capable to drive 600 ohm ( Iout +/- 26mA ).
Please, double check.
2.7 nV/rt Hz THD 0.00003% 55 Mhz 140dB capable to drive 600 ohm ( Iout +/- 26mA ).
Please, double check.
- Sun Apr 07, 2019 8:35 am
- Forum: Pro Audio Design
- Topic: A Low Noise Balanced Input Moving Coil Preamp Using the ZTX851
- Replies: 499
- Views: 783792