Pro Audio Design Forum

After spending about a week on IT support for the store I'm finally returning back to documenting Waveulator test. They say a picture is worth a thousand words so I'm posting some of the waveforms that will be in the test section of the pdf. Note that the input and output 'scope measurements are sin...

Looks like the OPA2134 is going end-of-life in DIP and perhaps SMT. Mouser https://www.mouser.com/c/?q=OPA2134 I bought a fairly large quantity from Mouser on 9/18 and by today Mouser's inventory is gone. Over at TI they show a few of the PA version in the store and no stock on Active UA SMT versio...

awesome for all the info. Looking to purchase the mastering insert switcher. torn between just getting a brick supply or the Meanwell RT-50C Triple Output Supply or Meanwell PD-2515. which one is recomended for use with in just one switcher. maybe 2 switchers in the future? and are the meanwells th...

There's a meta thread on power supplies here you might want to bookmark. https://proaudiodesignforum.com/forum/php/viewtopic.php?t=1123 I would follow the link to the Meanwell and take a look at the 24V 25W or 50W enclosed switchers. Another alternative is a common 24V desktop brick supply with a ba...

Thanks for joining us!

Yes, a power supply and switches would be needed.
The other item you would need for an assembled board would be the D connector breakout cable for the external devices you're going to insert which you can build or buy from Amazon and others.

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.

Bob Katz posted here back in July with questions about using the Insert Switcher to switch a transformer "color" box. Bob had some WE 111's he was interested in trying along with some vintage UTC and shared the results with me. Here are some of the pics and measurements... The box allows ...

Current-boosted Absolute Value, Average and Peak Detector Circuit Needs Only One Op Amp Adding two transistors lowers the output impedance and provides a high-charging-current peak output. D5 in the previous drawings is replaced by Q1, an emitter follower. Q2, which replaces D6, provides a high cha...

Improved Absolute Value and Peak Detector Circuit Needs Only One Op Amp Adding a single diode, D6, provides a peak detector output. D5 compensates for D6's forward drop. I raised R6 to 100KΩ to reduce gain errors at low level from D5's dynamic impedance. R6 can be ∞ . https://proaudiodesignforum.co...

Plan C. I confirmed that a BIFET (TL072) will peg to the negative rail in Spani's 1969 circuit when there is no input. A 5532 has enough Ib that it works. Here is a 2023 "improved version" of Spani's 1969 "Absolute Value Circuit Needs Only One Op Amp." https://proaudiodesignforu...