Paul Wolff originally worked with Saul Walker at API and learned that in circuit design there are three ways to do things... the right way, the wrong way, and the Saul way... and as a result, once he bought API from Datatronix (who had run it into the ground) he carried on the same design philosophy approach as Saul as he moved the company forward. I met Saul once when I worked for Otari in the early 00s (he was on the design teams for the Otari Concept One, Concept Elite, and Advanta digital consoles). It was quite amazing to hear the answers to my questions about his approach... Paul was right as every answer was the Saul way! Saul's approach is one of the BIG reasons for the "API sound." As a note, look at the "bottom" edge of the circuit board for the 512C... the rows of double dots on the circuit board are there so that the input traces to the transformer mimic a twisted pair of write as would be in a mic cable. The attention to detail was remarkable. That was always on the 512 circuit boards, but it doesn't appear to be on the 515 circuit board. I'm glad I stumbled on to your channel... great informative videos and I'm a geek (and a former audio technical engineer) so I love them.
Great video! Electrical engineer here with a hobby in audio. This explained so much big picture stuff that I wasn’t able to find anywhere else. Thanks!
Thank you so much for these videos! I've been watching every single one! The level at which you interact with these pieces of gear is really helpful and educational! Thank you so much for your time, knowledge, and care!!!!
These videos are amazing. I wish there were workshops (live or digital) where you could learn how to build this stuff like you can do with tube amps. Not just a plug and play but actually learning the why you are doing it. I would pay for that.
I'd love to see ypu break down a more budget API type pre like Warm Audio and see how they differ. Even better if you could get your hands on a Silver Bullet to see how it's API and Neve style pre differ from the originals.
that might be getting into, uhh, manufacturer conflict of interest but I like the idea! one obvious difference is the "big blocks" will be different. Warm will have Alctron or custom Cinemag transformers, don't know what LTL's transformers are. They will have their own versions of the op amp, Brad's is the "Rogue 5." It's a "little different" to an API 2520 but these tiny differences add up. And obviously there are feature differences, the Silver Bullet can be overdriven, the Warm gives you "fun switches" and so on.
My friend Paul has 6 or 8 of those in a rack with phantom power added. I haven't had the opportunity to use them much so I can't comment on the punchiness. One of these days I am going to build some of the CAPI clones from Jeff.
Love your channel. It would be interesting to hear you explain the design of the DOA. To say the design is just transformer/DOA/transformer is only a part of the story. Fascinating channel, thank you.
I agree with your idea about the look of them. To me it's all a part of them being "American" the red/white/blue knobs and buttons, the punchy aggressive sound, it makes sense.
Soft request for a SSL-style vid at some point. You could probably go thru most of the heavily trafficked projects. These vids are great for us illiterate diy'rs.
Anybody got tech specs on input transformer, op amp, and output transformer, also where do you introduce your audio signal in this path? pretty sure ground can probably go to any ground, and you would probably want it after the input transformer since thats wall power?
Yeah, I always thought that how it looks (colors and shapes), and (sigh) how other people review it, is how I naturally associate how it sounds - good point. Its like a bunch of monkeys nodding their heads at a banana