Pro Audio Design Forum

I'm looking at using a THAT1570 or THAT1583 in a design without the digital gain controller and needed a servo. ...So I came up with a fully-differential form of the Deboo Integrator we used to servo the THAT1510. You may recall that the THAT1510 provides a single-ended output to feed the servo but...

Thanks ricardo. My thinking was I'd take 66V to the actual preamp board and put the 48V ripple eater there so there is very limited opportunity for it to see a dead short. Glad you agree that it would not be required. I'm looking at what it would take to use a 1570/1583 in this application. I think ...

ricardo - Your 48V supply looks very clean. I noticed that you'd built in short-circuit protection since it appears to enter a cable. I'm thinking about feeding the preamp regulated 66V from the PSU and then putting the 48V ripple eater on the preamp board. Been mulling whether I should provide 48V ...

I took a break from tweaking the power supply I built because I wanted to use it to test a new "recovery" amplifier for the 1510 output. I came up with this: https://www.proaudiodesignforum.com/forum/php/viewtopic.php?f=6&t=557 https://proaudiodesignforum.com/images/jpg/Line_Input_AC-C...

I needed an AC-coupled, high impedance balanced line receiver with exceptional low frequency common mode rejection. I wanted to use a bipolar input op amp with low-value film capacitors for a "non-electrolytic" approach. This requires a high impedance input to reduce capacitor matching re...

Very cool! Looks like D18/D19/C53/C64 do the same (Self) deal by bootstrapping a halfwave doubler perched on top of the +Vbulk across C65. the heater was probably my most important contribution to the Soundfield project Funny. We were always told to the best way to dry the spit out of a microphone c...

$4k preamp... I have long wondered why we couldn't just shunt across electrolytic phantom caps for non-phantom mic operation. "Why have input caps at all?" has been my question since 2007. I would warn anyone considering shunting an input coupling capacitor with a relay the huge discharge...

I needed a replacement sponge and tray and stumbled upon Feld Electronics eBay store. I was so impressed with the extra sponges he threw in I gave him a very good review and visited his store. This guy has a lot of vintage soldering tips for Hexacan and Ungar. http://stores.ebay.com/feldelectronicsa...

Thanks John. If it were for a console I'd go for a second winding. C1 & C2 get big fast once you scale the current up. But, the second winding would only need to be 36-40V since it's "perched" on top of the V+ bulk supply. I'm thinking for two channels I'd want to use 470uF/100V for C1...

I was able to test the bootstrapped power supply and it works like a champ. This is the rectifier that derives +85VDC (unregulated) for the floating supply. https://proaudiodesignforum.com/images/jpg/DC_Preamp_Power_Supply_Simplified_BW.JPG DC-Coupled Preamp Power Supply Rectifiers I need about 20 ...