Pro Audio Design Forum

Walk into Jack White's Third Man Pressing record plant, and you're greeted by a burst of stylized sensations: A glossy sunflower-yellow floor. Tables stacked with a rainbow of colored LPs. An eye-catching mural by neighborhood artist Robert Sestok along a back wall. Music drifting across the acoust...

Wow, thanks for the feedback Greg! You sure can use a 1243 but I would recommend a 1240 for most headphone builds. I built most if not all of the line amp versions with 1246s but I never found a headphone application that required the added 6 dB attenuation of the 1246. Still, with some phones (e.g....

I was able to check the DF not the DA.

A Nichicon 22 uF UVR electrolytic measured 0.19 DF; a 22 uF tantalum 0.03 DF.

I was going to use a film capacitor anyway in my build.

Tantalum capacitors, which have tighter tolerance and lower DA excel as a Ct.

...compared to the commonly-used electrolytic timing cap.

My thinking is that a 22uF film (or a pair of 10 uF films) would be the ultimate timing capacitor. (And would be impressively big.)

Gary Hebert of THAT sent me a variation of the current rectifier which uses Q2 to pre-bias the rectifier in class A-B similar to the THAT2252. Gary liked JR's common base stage, Q9. http://www.proaudiodesignforum.com/images/jpg/THAT_300_Based_RMS_With_Current_Rectifier_800_BW.jpg THAT2252 replaceme...

Part will become a non-stocking item when stock is depleted Looks like that Sullins part is discontinued at Digi-Key. MicMix used a male right angle similar to the Sullins in some of their very early Studio C Reverbs. John Saul, one of the co-owners, had been an aerospace engineer and refused to us...

Someone may need to repair one.

Thanks Doug. I read Bill's articles. http://www.kenetek.com/OtherStuff/AboutT4units/AbouttheT4B/tabid/203/Default.aspx The one thing I've never seen discussed is the change in chromaticity of the EL panel versus applied frequency. The EL panels shift from yellowish green to blue versus frequency due...

This is the dBx 303A schematic showing the discrete transistor Blackmer® VCA and RMS detector based on a CA3083 array. https://www.proaudiodesignforum.com/images/jpg/dBx_303A_Schematic_Actual_800.jpg dBx 303A Schematic Large format: https://www.proaudiodesignforum.com/images/jpg/dBx_303A_Schematic_...

(I still like the idea of adding degeneration resistors to current mirror emitters if you use that rectifier topology and the emitters are separately accessible.)

I do want to try that.
It's in the 80s here today in February. Very hard to stay inside for long.