Search found 4705 matches

by mediatechnology
Wed Jun 23, 2021 1:09 pm
Forum: Pro Audio Design
Topic: Super Low Distortion Ultra Pure Audio Oscillators Revisited
Replies: 135
Views: 177002

Re: Super Low Distortion Ultra Pure Audio Oscillators Revisited

Using a 5532 I just checked the output offset on the first PC board and it's about -1.8V with the notch filter unbalanced and about -130 mV with the jumpers set to balanced. That offset is primarily due to Ib*100KΩ*Gain. I made Rbias large to allow a lowish value polypropylene film cap and let the o...
by mediatechnology
Tue Jun 22, 2021 5:23 pm
Forum: Pro Audio Design
Topic: Super Low Distortion Ultra Pure Audio Oscillators Revisited
Replies: 135
Views: 177002

Re: Super Low Distortion Ultra Pure Audio Oscillators Revisited

Mike you're right about the output offset. That 10mV number was from cut and paste. The 1.5V that does develop shouldn't be too much of a problem since the output is AC coupled and the INA doesn't see much level due to the preceeding notch filter. I actually anticipated that and AC coupled it for th...
by mediatechnology
Sat Jun 19, 2021 3:04 pm
Forum: Pro Audio Design
Topic: Transistor Vbe Matching Using A Commutating Chopper-Based Circuit
Replies: 32
Views: 68831

Re: Transistor Vbe Matching Using A Commutating Chopper-Based Circuit

I had used up my stock of matched ZTX-851 transistors for the flat MC preamp and the time had come to match some more up. The ZTX851 for this run was from a different lot. Out of 30 devices I had no problem getting 12 pairs matched to <1 mV which is adequate for the MC preamp. This lot had higher ga...
by mediatechnology
Sat Jun 19, 2021 12:48 pm
Forum: The Peabody Lounge
Topic: The Corona Virus Hoax of 2020
Replies: 406
Views: 167944

Eric Clapton Details How The COVID 'Vaccine" Paralyzed Him

Eric Clapton Details How The COVID 'Vaccine" Paralyzed Him https://banned.video/watch?id=60c921e9384b080b2bf5dc83 The full Eric Clapton interview form Oracle Films can be found here: https://www.youtube.com/watch?v=4OHmMKrVbNk Eric Clapton details how he was duped into getting the Astra Zeneca vacc...
by mediatechnology
Mon Jun 14, 2021 5:59 pm
Forum: The Peabody Lounge
Topic: The Corona Virus Hoax of 2020
Replies: 406
Views: 167944

"Vaccine" Deaths Off The Charts

https://waynekirkwood.com/images/jpg/VAERS_Deaths_0621.jpg The VAERS reporting system only makes public the initial report. If a physician reports to the VAERS system that a patient had a bad headache as an adverse reaction and the patient then dies a week later from a brain aneurysm only the "bad ...
by mediatechnology
Mon Jun 14, 2021 9:28 am
Forum: Pro Audio Design
Topic: Super Low Distortion Ultra Pure Audio Oscillators Revisited
Replies: 135
Views: 177002

Re: Super Low Distortion Ultra Pure Audio Oscillators Revisited

Here's a link to the THD calculator I use to interpret ULDO/Nacho's FFTs. https://proaudiodesignforum.com/calculators/ULDO_Nacho_THD_Calculator.xls I plugged in some typical measurement data into the xls. The gray cells are for measurements and test conditions. https://proaudiodesignforum.com/image...
by mediatechnology
Mon Jun 07, 2021 5:09 pm
Forum: Pro Audio Design
Topic: That1580 mini mixer
Replies: 92
Views: 206518

Re: That1580 mini mixer

For some reason I was thinking each pair of channels fed an A/D. Forgot you were analog summing. For the single modulator driver the Birt might still be advantageous. The Cirrus circuit requires anti-polarity inputs. The Birt can be fed single-ended or differential but still provides differential ou...
by mediatechnology
Mon Jun 07, 2021 7:43 am
Forum: Pro Audio Design
Topic: That1580 mini mixer
Replies: 92
Views: 206518

Re: That1580 mini mixer

It also occurred to me that you might consider combining the 124X common mode stage with the modulator driver. Use a "Birt" topology similar to those shown in THAT's DN-140 (figure 11 basic Birt) and the THAT 5263 data sheet figure 12. http://www.thatcorp.com/datashts/THAT_5263_Datasheet.pdf I did t...
by mediatechnology
Mon Jun 07, 2021 6:16 am
Forum: Pro Audio Design
Topic: That1580 mini mixer
Replies: 92
Views: 206518

Re: That1580 mini mixer

Nice work!

Could you perform polarity reversal in software and save a bunch of switches/relays?
by mediatechnology
Thu Jun 03, 2021 9:18 am
Forum: The Peabody Lounge
Topic: The Corona Virus Hoax of 2020
Replies: 406
Views: 167944

Engineered protein crystals make cells magnetic

Can you attract and hold a magnet at the injection site? WTF are you smoking? magnets.... um no. Have you tried it? Seems to be related to the Pfizer product. Engineered protein crystals make cells magnetic: https://www.sciencedaily.com/releases/2019/09/190925083802.htm September 25, 2019 Source: A...