Search found 5491 matches

by mediatechnology
Mon May 20, 2024 1:43 pm
Forum: Build
Topic: Quadrature Summing Filter Construction Information
Replies: 2
Views: 22366

Re: Quadrature Summing Filter Construction Information

Updated the board (QSF_4), schematic and BOM to add 22 pF compensation caps to use NJM2068, LM833, 4558 and other PNP op amps having a >750 kHz peaking response. The are not needed for the TL072, NE5532 or OPA2134.
by mediatechnology
Sun May 19, 2024 9:38 am
Forum: The Peabody Lounge
Topic: Gerber Text File Editing Fun
Replies: 5
Views: 506

Re: Gerber Editing Fun

I set aside this editing project for a couple of weeks while I soldered boards and dealt with the usual yard, household and auto entropy. The remaining Gerber Fun task was to move the Left channel "G" character 25 mils west. (Actually 24 mills to match the Right.) As you can see I got it d...
by mediatechnology
Fri May 17, 2024 7:12 pm
Forum: Pro Audio Design
Topic: Using The TI PCM4222 A/D Evaluation Module
Replies: 27
Views: 35377

Re: Using The TI PCM4222 A/D Evaluation Module

Glad you were able to put it to work!

I use 96 kHz since I primarily use it for test and measurement and occasionally for RAW (flat) vinyl capture.
by mediatechnology
Mon May 06, 2024 11:11 am
Forum: The Peabody Lounge
Topic: Gerber Text File Editing Fun
Replies: 5
Views: 506

Re: Gerber Editing Fun

I've used the Ucamco viewer and file checker. They're a great resource. Code for D21 defines a 0.065 x 0.065 pad: %AD D21 R,0.065X0.065*% The entire thermal pad, bottom layer, is 5 objects total. Square pad of 0.065X0.065 And four identical square polygons of 36x37 mils of negative polarity keep-out...
by mediatechnology
Mon May 06, 2024 10:38 am
Forum: The Peabody Lounge
Topic: Gerber Text File Editing Fun
Replies: 5
Views: 506

Re: Gerber Editing Fun

Thanks! Not sure I'm brave or just crazy. I've been using Gerbv : https://sourceforge.net/projects/gerbv/ and GerberLogix : https://easylogix.de/products_detail.php?prog_id=1 Every layer, except the .oln outline layer, requires modification. Top and bottom copper, top and bottom silkscreen, top and ...
by mediatechnology
Mon May 06, 2024 6:39 am
Forum: The Peabody Lounge
Topic: Gerber Text File Editing Fun
Replies: 5
Views: 506

Gerber Text File Editing Fun

I just sent off a revised layout to ExpressPCB that I had "stretched" 0.2 inches to add some additional compensation caps. The previous layout worked fine when reasonable op amps were used but peaky 4558-class op amps such as the NJM2068, LM833, MC33078 and NJM45XX-series were problematic....
by mediatechnology
Sun May 05, 2024 6:41 am
Forum: Build
Topic: Mastering Stereo Insert Switcher with Flip Construction Information
Replies: 33
Views: 118471

Re: Mastering Stereo Insert Switcher with Flip Construction Information

Who made that unit? I'd love to send them referrals. Have seen similar on Reverb. If you have contact info that would be great. I may be able to refer other custom work to them. Hi, i am new here, and i won`t be able to DIY a Mastering Insert Switcher, that is why i would like to buy one of these l...
by mediatechnology
Thu May 02, 2024 3:35 am
Forum: Pro Audio Design
Topic: The Studer "90°" Dome Filter Stereo to Mono Quadrature Summer
Replies: 52
Views: 200715

Re: The Studer "90°" Dome Filter Stereo to Mono Quadrature Summer

I've never listened to I-Q but I'm receiving another run of boards today and will be building another one.
I'll let you know.

L+R and L-R on a preamp are both useful when a stereo phono pickup is playing lateral and vertical cut recordings.
by mediatechnology
Tue Apr 30, 2024 8:32 am
Forum: Pro Audio Design
Topic: The Studer "90°" Dome Filter Stereo to Mono Quadrature Summer
Replies: 52
Views: 200715

Re: The Studer "90°" Dome Filter Stereo to Mono Quadrature Summer

I've listened to the mono sum quite a bit and like it.

I and Q presented in stereo as L and R has an image that's pulled hard in one direction.
by mediatechnology
Mon Apr 29, 2024 8:53 am
Forum: Document
Topic: The Panasonic MF-800 Motional Feedback Speaker-Amplifier System
Replies: 7
Views: 41220

Re: The Panasonic MF-800 Motional Feedback Speaker-Amplifier System

From AudioExpress: https://audioxpress.com/article/voice-coil-patent-review-controlled-passive-radiator In the realization of an active loudspeaker, one of the many useful techniques that has been applied is that of “ motional feedback ” (MFB)—the sensing of the motional output of the transducer di...