well, that was a super satisfying deep dive. I was fully prepared to dial in the sound of each tape mode through trial and error, but turns out some smart and ambitious people already did the work of analyzing and documenting the frequency responses of each machine.
bring on the nerd shit
for the love tapes pedal [1], I’m targetting sound profiles for three different types of machine; a multi-track device, a standard cassette player, and a microcassette player. each original tape player has documented and published frequency response ranges, derived from characteristics specific to the type of head, high and low pass filter ranges derived from the circuits, and acceptible wow/flutter ranges for servicing. on top of that, these metrics aren’t adding in the massively broad range of frequency changes the tape itself can introduce, although the research clearly documents which tapes are used in the data.
the data I found comes from service manuals, academic papers, magazine articles (what’s a magazine?), wikipedia, and fellow tape enthusiasts who just enjoy deep diving into nerd shit then graciously posting for others to enjoy. all data is freely available from publicly accessible sources.
the top models
apparently tyra banks is an abusive narcissist, but lucky for us, we’re not talking about those top models [2].
the reference devices I’ll be using for the sound profiles are:
TASCAM 424
even though it’s no longer being manufactored, the 424 is still a highly sought after piece of equipment, especially with lo-fi tape loop musicians. several pedal makers have reproduced the gain stage of the 424 because it just sounds so fucking amazing. I picked up the mxnhlt porta424 last year from marketplace and absolutely love it. I leave it on most of the time.
source information was taken from “TASCAM 424 MkIII review”, Sound on Sound, March 2001; the TASCAM service manual; Wikipedia: Portastudio.
I’m specifically targetting the TASCAM 424 with a Type II (CrO2) tape, no dbx.
Sony Walkman TPS-L2
the 1979 original Walkman is the canonical “consumer standard cassette” reference. it’s well-documented and represents the everyday lo-fi cassette sound.
I don’t personally own one since finding them is difficult and they’re crazy expensive (let alone usually not in working condition). I do own a Sanyo (Japan) Executive Talk-Book TRC-2500 (1984?) and it’s honestly the most solid and consistent handheld tape player/recorder I’ve ever owned. there’s a fair bit of noise while recording when sound isn’t coming through the input (which means I need to replace some capacitors) but otherwise it’s a great device.
the sony TPS-L2 is the walkman from guardians of the galaxy fame (which also lends to the super high price).
source information was taken from Wikipedia: Walkman; the Sony TPS-L2 product documentation.
I’m specifically targetting the Sony Walkman TPS-L2 with a Type II (CrO2) tape.
Olympus Pearlcorder L150
the Olympus Pearlcorder SD (1977) is one of my favorite microcassette devices. the sound it produces is narrow, with a high amount of artifacts and a noticable warble. I’ve used it to record and play loops for several tracks.
there isn’t a lot of information out there documenting the frequency response of the SD, but there is for the L150, a newer model Pearlcorder from Olympus. The documented frequency response for the L150 is a great starting point, and since the mechanical differences between it and the SD are documented, I can try to approximate the sound to the SD. for technical purposes, I’m saying it’s modeled after the L150.
source information was taken from Gough’s Tech Zone, “Tech Flashback: The Microcassette” Parts 1 and 2; Wikipedia: Microcassette; Olympus microcassette spec (2.4 cm/s, 200µs Type I EQ).
I’m specifically targetting the Olympus Pearlcorder L150 at the 2.4 cm/s setting.
plotting and storing frequency response information
programmatically analyzing the output of the sound profiles with the documented frequency responses is the next goal. I have three target reference devices and will create three selectable modes; clean, worn, and trashed. this makes nine variations total to accurately analyze and test to ensure I’m actually producing the right sound (and not just to my ears, but analyzed with software).
more to come.
[1] for the love of tapes… maybe? still playing with the name. irreverence is my favorite color.
[2] Tyra the great and benevolent is also suing Netflix for defamation. go watch the documentary before it gets taken down. I hope she loses her ass because jeesus christ what they talk about in that series is seriously fucked up. this lawsuit might just be for publicity knowing netflix will settle out of court, which was probably the intention all along. Tyra the kind planned for this all along, and so did netflix.