PD1 vs Scaler EQ
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
PD1
This app simulates classic analog delay pedals, offering a meaner grit with a ladder filter and random delay-line noise. It's an audio-unit effect designed for musicians seeking unique delay sounds.
- Analog delay simulation
- Ladder filter for meaner grit
- Random delay-line noise
- Audio-unit effect plugin
- Classic pedal sound recreation
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PD-1 is an analog delay simulation audio plug-in and app that recreates the sounds of classic analog delay pedals with the twist of significantly meaner girt from a ladder filter and random delay-line noise.
Scaler EQ
This application offers a unique approach to audio equalization by intelligently adjusting frequencies based on the detected key and scale of your music. It provides both musical enhancements and traditional EQ controls for detailed sound shaping.
- In-key EQ with harmonic band types
- Automatic key and scale detection
- Familiar EQ controls with added color
- Magic Shelf for enhanced low and high frequencies
- Mastering-grade limiters and meters
- Dynamic band control and sidechain input
- Standalone and AUv3 host compatibility
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Following on from the award-winning Scaler music theory plugin, Scaler EQ offers a remarkable new way to EQ with musicality and colour. By detecting the key and scale of your audio and enhancing only note frequencies in key with your song, and reducing only note frequencies that aren’t, Scaler EQ can provide a new spin on working with cuts and boosts, increasing the tonality behind your music and providing new harmonic avenues. And for when you just want a regular, fully-featured, modern EQ, Scaler EQ has you covered with its familiar workflow, large choice of band types, mid/side operation, dynamic bands, peak limiters, and stereo enhancement. You can easily apply classic mixing and mastering techniques used by professionals, with an extra optional musical edge. NOTE: We have designed Scaler EQ for iPad. It works on iPhone too with identical functionality but relies more on the two finger tap to zoom function. -The World’s First In-Key EQ -Simple Key Detection -Musician- and Producer-Friendly Band Types -The Magic Shelf -Mastering Grade Limiters and Meters -All the Mod EQ Cons Main Features: Patent pending musical EQ with harmonic band types that boost in-key frequencies and cut out-of-key frequencies Familiar EQ controls translate to a regular workflow – but one that adds more colour Choice of band types for traditional boost/cut EQ or harmonic EQ Magic Shelf bands deliver punchier low end and smoother highs Simple key detection identifies the key and scale of your audio and sets the EQ’s target scale Scale Switching allows for scale and key changes in your track Dial in dynamics for any band (Threshold, Ratio, Attack, Release) Control any shape dynamically via sidechain input Add or remove scale notes for a specific colour (eg, four-note chords or just fifths) Input And Output Peak Limiters Adjustable input and output levels with peak and RMS metering Create unique EQ responses by combining magic shelves, harmonic filters and cuts Each band can be set to work on stereo, mid or side channels Enhance stereo width and collapse low frequencies to mono Minimum phase, zero latency EQ Standalone and compatible with AUv3 host apps such as Logic Pro, GarageBand, Auria, AUM, and Cubasis. Closable Panels and iOS zoom functions What can Scaler EQ be used for? Music Production: Ideal for musicians and producers looking to enhance the musicality of their tracks by ensuring all instruments are in harmony with the chosen scale. Audio Editing: Simplify EQ processes by targeting and cleaning up frequency bands to remove audio that doesn’t belong and enhance audio naturally present with the chosen scale. Audio Engineering: Dynamically soothe audio by suppressing in-harmonic frequencies or expanding harmonic frequencies using dynamic compression and expansion. Mastering: Place on your master channel to broaden your stereo width, focus your bass, increase loudness, and enhance your mix. Sound Designers: Easily create playable instruments from any recorded sound source using the Sound Design presets and musical resonator FX. DJing: DJs can use it to ensure that the tracks they mix are in harmony by detecting the key and scale whilst balancing the mix of each track. -"Scaler EQ is plugin that offers an innovative way to equalise with musicality and colour. It is a plugin that deserves to be tried by anyone." DJ Mag Italia -"Scaler EQ is a groundbreaking advancement in the world of audio engineering. The harmonic EQ technology is a game-changer." Song Mix Master -"Scaler EQ can make subtle harmonic changes or be a hugely creative plugin, but either way it makes your mixes sound better." Computer Music July 2024 -"Scaler EQ delivers harmonic processing we didn’t know we needed, but once heard, we might just apply it to everything." Music Radar -"Scaler EQ is a valuable tool for musicians, producers and audio professionals. It just might be the only EQ you need going forward’ 24bit Electronic Music Production
Screenshots
Verdict
The clearest difference is review sentiment: PD1 at 100% against Scaler EQ's 50%. PD1 also leads on price ($3.99 vs $12.99) and update cadence (every 6 days vs every 2 months). Scaler EQ's advantage is chart position (#194 vs unranked) and iOS requirement (15.0 vs 17.5). On ads, in-app purchases, monetization model and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
PD1 costs $3.99 and Scaler EQ $12.99 up front. Neither carries in-app purchases, so what you see is what you pay.
PD1 ships an update every 6 days, Scaler EQ every 2 months. The most recent releases landed on October 15, 2026 and October 3, 2026 respectively.
| Parameter | PD1 | Scaler EQ |
|---|---|---|
| Price | $3.99 — better | $12.99 |
| Rating | — | 4.6 (27 ratings) — better |
| Positive reviews | 100.0% of reviews — better | 50.0% of reviews |
| Number of ratings | — | 27 — better |
| Update frequency | Every 6 days — better | Every 2 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Best chart rank | — | #194 — better |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 17.5 | 15.0 — better |
| Further details — not scored | ||
| Size | 10 MB | 27 MB |
| Age rating | 4+ | 4+ |
| Developer | Pedro Yamada | Scaler Music |
Customer experience
PD1
Scaler EQ
In-app purchases
PD1
No in-app purchases
Scaler EQ
No in-app purchases








