DC vs EQ550b
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
DC
This audio effect plug-in emulates a classic overdrive guitar pedal using advanced circuit modeling. It provides an authentic analog sound and integrates seamlessly with iOS Digital Audio Workstations.
- Circuit-modeled overdrive emulation
- Authentic analog sound
- Audio Unit Extension (AUv3) support
- Expands controls when touched
- Compatible with popular iOS DAWs
- Desktop quality algorithm
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DC-9 Overdrive is a circuit modeled overdrive plug-in that emulates the famous Ibanez® TS9 Tube Screamer. The DSP algorithms in DC-9 take into account the entire schematic, using the latest modeling techniques. This gives you an authentic analog sound that matches the character of the physical circuit. DC-9 is an Audio Unit Extension (AUv3) that works inside host apps. Just open up your favorite host that supports Audio Units and add it as an effect. The controls expand when touched so they can be easily seen while tweaking. DC-9 brings the distinctive warm overdrive crunch to your favorite iOS DAW. Compatible with GarageBand, Cubasis, Auria, BeatMaker, AudioBus, AUM, Modstep, and more. DC-9 gets its name from the Diode Clipper circuit used to create the distortion. Accurate modeling of the clipper by circuit simulation gives DC-9 an edge over the common distortion plug- in. The effect was carefully tuned using A/B comparisons to the original stop box. Blamsoft brings their experience creating top notch plug-ins for the desktop to iOS. The same algorithm is found in the popular Rack Extension for Propellerhead Reason. You get a desktop quality algorithm at an iOS friendly price. Tap Developer Website for sound examples. Note: Second screenshot shows the effect of touching a control.
EQ550b
This audio effect plugin emulates a classic American equalizer from the late 1960s, offering four bands of equalization with selectable frequencies and proportional Q. It provides a wide range of tonal variations for professional audio manipulation and can be used as a standalone app or an AUv3 plugin.
- Modeled vintage EQ
- Four bands of equalization
- Selectable frequency centers
- Proportional Q filter
- Stereo, Mid, or Side EQ modes
- AUv3 plugin compatibility
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EQ550b AUv3 plug-in — comes as time-limited Demo-version for you to try. It gives you 5 minutes of Free play time. (You can reload the EQ550b AUv3 plug-in as many times as you want, thereby you get the Demo period again and again.) Unlimited version of EQ550b AUv3 plug-in comes as In-App Purchase. Based on Classic American EQ from the late '60s, the EQ550b is a continuation of the EQ that played a major role in the history of music recording, but with an additional filter band and several new frequencies. With a surprisingly wide range of tonal variations, the EQ550b is an invaluable and professional audio tool with great flexibility and excellent sonic ability. Features: • Standalone and AUv3 plug-in; • Precise port of Rack Extensions plug-in; • Modeled vintage EQ; • Four bands of classic American equalization; • Each band offers seven selected frequency centers; • 15 dB of boost/cut per band; • EQ band 1 and 4 offer shelf/peak switching; • Proportional Q narrows filter Q at extremes; • Stereo (Mono), Mid or Side EQ modes; • Undo/Redo; • A/B comparison; • 2x/4x/8x Upsampling; • Macro controllers; • Built-in Gain Match; • Scalable GUI. Rather than offer a huge assortment of complex features, the EQ550b provides exactly the right number of controls. Its four EQ bands are overlapped significantly to aid in dual roles as problem solver and sweetening device with each band offering seven switchable filter frequencies that span four-to-five octaves. These frequencies, purposely selected to be musical rather than numeric. Making use of Proportional Q intuitively widens the filter bandwidth at minimal settings and narrows it at higher settings without the need for additional bandwidth controls. This unique feature minimizes the «phase-shift» sound found in many equalizers. The EQ550b extends the features of the original hardware and joins the flexibility of the digital world to the character of the analog processing. Allows you to choose between equalizer modes (Stereo, Mid, Side) and remove analogue saturation from the processing circuit to deliver pure digital sound. To use EQ550b as a plug-in, you need an AUv3-compatible host app like GarageBand, Auria, AUM, Cubasis and more — EQ550b will appear in the list of Audio Unit extensions for effect plug-ins in the host app.
Screenshots
Verdict
The clearest difference is price: EQ550b at Free against DC's $2.99. EQ550b also leads on rating (4.8 vs 4.2) and review sentiment (100% vs 67%). DC's advantage is in-app purchases (none vs 1). On ratings volume, ads 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
EQ550b is free to download; DC costs $2.99 up front. EQ550b sells 1 one-off in-app purchase. DC asks for nothing beyond the download.
EQ550b holds the better App Store score, 4.8 against 4.2. Both are backed by a comparable volume of ratings — 14 and 13 respectively. Written reviews point the same way: 67% of DC's written reviews are positive against 100% of EQ550b's.
DC ships an update every 6 months, EQ550b every 2 weeks. The most recent releases landed on October 9, 2026 and October 1, 2026 respectively.
| Parameter | DC | EQ550b |
|---|---|---|
| Price | $2.99 | Free — better |
| Rating | 4.2 (14 ratings) | 4.8 (13 ratings) — better |
| Positive reviews | 66.7% of reviews | 100.0% of reviews — better |
| Number of ratings | 14 — better | 13 |
| Update frequency | Every 6 months | Every 2 weeks — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 12.0 | 10.0 — better |
| Further details — not scored | ||
| Size | 17 MB | 19 MB |
| Age rating | 4+ | 4+ |
| Developer | Blamsoft, Inc. | RRS, OOO |
Customer experience
DC
EQ550b
In-app purchases
DC
No in-app purchases
EQ550b
- RRS EQ550b Unlimited$4.99








