Using Photoshop to Understand Portastudio Schematics - Finding the Audio Path

In this video i discuss how colour-coding and annotating Portastudio schematics helped me to learn electronics.

I have a look at one of the first schematic diagrams I ever annotated, from a Tascam 244, then trace the audio path through a schematic I've never studied before , the playback amplifier of a Tascam 488 Mk II.

Along the way we talk about schematic conventions, roughly how operational amplifiers are used as volage amplifiers in portastudio circuits, how relays are used to switch the dual function magnetic head between the record and playback amps and oodles - yeah, thats right, OODLES - of other fun stuff!

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00:00 Introduction
00:48 Colour-coded Tascam 244 schematic
2:52 The role annotating schematics played as I was learning
3:28 How audio signals travel through operational amplifiers
4:17 Just enough Op amp theory to understand this video
5:19 Other components audio signals typically pass through
6:15 About the problem I am having with my 488 Mk II
7:24 Using an audio probe to find where a signal is blocked or changes
9:13 Don't have graphics software? Make lists.
10:00 Bringing a schematic into Photoshop for annotation
12:29 How identical circuits are represented in schematics
12:55 how reference designators vary on identical circuits
13:35 Locating the inputs and outputs on a schematic
15:56 Dual purpose magnetic heads in Portastudios
16:40 How relays appear on schematics
17:20 Tracing the audio path rule 1 - ignore paths to ground
18:31 Tracing the audio path rule 2 – ignore op amps' feedback loops
19:02 Coupling capacitors separate op-amp gain stages
19:47 Inputs & outputs CAN be on the top or bottom edge...
20:07 488 MK II playback amplifier topology in summary
21:03 Where I could test with the audio probe
21:25 Probing efficiently
22:27 Schematics - ignore most of the information most of the time
23:45 About exclusive patreon electronics videos
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