DHO804

At a Glance

Best For

Overview

The Rigol DHO804 is an awkward product to review -- not because it's a bad oscilloscope, but because its sibling makes it almost impossible to recommend. At $439, the DHO804 delivers 70 MHz bandwidth, 4 channels, a 7-inch IPS touchscreen, 25 Mpt memory depth, WiFi, and protocol decoding for SPI, I2C, and UART. Those are legitimately good specifications for a modern scope. The problem is that the Rigol DHO924S costs $449 -- just $10 more -- and gives you 250 MHz bandwidth, 50 Mpt memory, a built-in function generator, and CAN/LIN decoding on top of everything the DHO804 offers.

That $10 gap is the defining fact of the DHO804's existence. It means this review is as much about helping you decide between the DHO804 and DHO924S as it is about evaluating the scope on its own merits. And on its own merits, the DHO804 is a good scope -- it shares the DHO924S's excellent IPS touchscreen, modern interface, and solid build quality. For basic Arduino work, learning electronics, and sub-70 MHz signals, it handles everything you'd throw at it.

The real question is: can you actually find the DHO804 at a price that creates meaningful daylight between it and the DHO924S? Because if the price gap is $10, the answer is obvious. If you find the DHO804 at $350 or $380, the conversation changes entirely. This review evaluates the DHO804 on its own terms, but the DHO924S shadow looms over every paragraph.

Pros & Cons

Design & Build Quality

The DHO804 shares the DHO924S's physical chassis -- same 350 x 210 x 120 mm dimensions, same 3.8 kg weight, same industrial design. This means it gets the same solid build quality, the same comfortable form factor, and the same excellent 7-inch IPS touchscreen. Everything I said about the DHO924S's physical design applies identically here.

The IPS panel delivers good color accuracy, wide viewing angles, and responsive touch input. The 1024x600 resolution keeps text and measurement values crisp. Multi-touch gestures (pinch to zoom, two-finger pan) work reliably. The physical knobs for vertical scale, horizontal scale, and trigger level provide the same satisfying tactile control. If you've held a DHO924S, you've held a DHO804 -- there is no difference in the hardware feel.

The fan behavior is identical to the DHO924S -- present and audible in a quiet room but not distracting during normal work. The included probes are also the same standard Rigol probes, adequate for general work within the 70 MHz bandwidth but worth upgrading if you want to maximize measurement accuracy.

Where the design starts to feel limiting is in what's missing versus the DHO924S: no built-in function generator. This means you need a separate instrument for signal generation, which takes up bench space and adds to your overall cost. For a standalone bench scope, the missing function generator is noticeable. For users who already have a function generator or don't need one, it's irrelevant.

Performance & Specifications Deep Dive

The 70 MHz bandwidth is the core specification that defines the DHO804's capability ceiling. For Arduino work at 16 MHz clock speeds, the 70 MHz bandwidth is more than adequate -- you're well within the passband with substantial headroom. For STM32 GPIO at 72 MHz, you're at the edge of the bandwidth and will see amplitude roll-off. For SPI at 25+ MHz clock speeds, you're working in a range where the bandwidth limitation starts to affect measurement accuracy.

To put this in practical terms: 70 MHz is enough for the vast majority of hobbyist Arduino and basic embedded work. It's not enough for faster microcontrollers, high-speed SPI, or any RF work. The DHO924S's 250 MHz bandwidth removes this ceiling almost entirely for hobbyist applications.

The 1.25 GSa/s sample rate is identical to the DHO924S and provides excellent oversampling at 70 MHz bandwidth. With Nyquist requiring only 140 MSa/s, the 1.25 GSa/s sample rate gives you nearly 9x oversampling, which produces very clean waveform reconstruction. This is actually better oversampling than the DHO924S achieves at 250 MHz (2.5x), so within its bandwidth, the DHO804's waveform quality is excellent.

The 25 Mpt memory depth is solid but half of the DHO924S's 50 Mpts. At full sample rate, 25 million points gives you 20 milliseconds of continuous capture. That's enough for most individual protocol transactions but may feel limiting for extended captures. If you frequently need to capture long sequences of bus traffic or monitor signals for seconds at a time, the memory depth difference between the DHO804 and DHO924S becomes meaningful.

The trigger system is identical to the DHO924S: edge, pulse, slope, video, pattern, duration, timeout, runt, window, delay, setup/hold, and Nth edge. This is one of the most comprehensive trigger systems at any price, and it's a genuine advantage of the DHO platform. Having pattern, runt, and setup/hold triggers at $439 gives you debugging capabilities that were exclusive to $2,000+ scopes a decade ago.

Software & User Experience

The DHO804 runs the same UltraVision II firmware as the DHO924S, so the user experience is identical. The touchscreen interface is modern, intuitive, and responsive. Menu navigation is shallow and logical. Autoset is fast and accurate. The entire software experience that makes the DHO924S such a pleasure to use is present in the DHO804 as well.

Measurement configuration, automatic measurements, math functions, FFT, and cursor operations all work the same way. If you've read the DHO924S section of this review (or our DHO924S review), you know what to expect here. The interface is the best in our lineup for intuitive operation.

WiFi connectivity is included and works the same way -- browser-based remote access, screen capture, and data export over the network. This is a feature that the similarly-priced Siglent SDS1104X-U and the slightly cheaper Rigol DS1054Z don't offer, and it's a genuine convenience for remote monitoring.

PC connectivity via USB works with Rigol's UltraScope software for deeper analysis, screen capture, and remote control. SCPI support enables automation with Python, LabVIEW, and other tools. The SCPI implementation is the same as the DHO924S -- reliable and well-documented for the DHO platform.

Protocol Decoding & Advanced Features

Protocol decoding on the DHO804 covers SPI, I2C, and UART. Notice what's missing compared to the DHO924S: CAN and LIN decoding are not included. This is a significant differentiator if automotive protocol work is in your plans. If you need CAN decoding, the DHO804 is not the right scope -- you need the DHO924S or the Siglent SDS1104X-U.

The SPI, I2C, and UART decoders work well within the 70 MHz bandwidth. SPI decoding handles clocks up to about 20-25 MHz comfortably, which covers most common SPI peripherals (sensors, flash memory, displays, ADCs). I2C decoding displays addresses, data, ACK/NACK status, and start/stop conditions clearly. UART decoding supports standard and non-standard baud rates.

The 4-channel capability is valuable for protocol work even at 70 MHz. SPI debugging requires clock, MOSI, MISO, and chip select -- exactly 4 signals. Being able to see all four simultaneously without swapping probes saves significant time during debugging sessions. Similarly, I2C debugging benefits from having SDA and SCL on two channels while monitoring power and an interrupt or enable signal on the remaining two.

The comprehensive trigger system works across all decoded protocols, letting you trigger on specific protocol conditions. Combined with the 25 Mpt memory depth, you can trigger on a specific I2C address and capture the surrounding context, or trigger on an SPI chip select edge and capture the entire transaction.

Real-World Use Cases

The DHO804 is well-suited for Arduino and basic microcontroller projects. Verifying PWM output, checking I2C communication with sensors, debugging SPI connections to displays or SD cards, and monitoring GPIO states -- these are all tasks that the 70 MHz bandwidth and 4 channels handle comfortably. The touchscreen makes these interactions quick and intuitive, and the protocol decoding shows you the data flowing over the bus.

Educational use is another strong fit. If you're learning electronics, the touchscreen interface minimizes the time spent figuring out the scope and maximizes the time spent understanding signals. The autoset function quickly configures the scope for whatever signal you connect, letting you focus on what the signal looks like and what it means rather than how to display it.

Basic analog work -- audio circuits, op-amp configurations, filter design below 70 MHz -- is handled without issues. The 1.25 GSa/s sample rate provides excellent waveform quality at these frequencies, and the automatic measurements give you accurate frequency, amplitude, and timing data.

Where the DHO804 falls short is anything requiring more bandwidth or CAN/LIN support. SPI at higher clock speeds, faster microcontroller debugging, RF work, and automotive embedded development all push beyond what the DHO804 can do. For these applications, the DHO924S's additional $10 buys you into a much wider capability envelope.

Who Should Buy This (And Who Shouldn't)

Buy the DHO804 if you find it at a meaningfully discounted price compared to the DHO924S. If you can get the DHO804 for $350-$380 (a $70-100 savings over the DHO924S), the value proposition starts to make sense -- you're getting a modern scope with an excellent touchscreen at a price that's competitive with the aging DS1054Z. At that price, the 70 MHz bandwidth and 25 Mpt memory are acceptable trade-offs.

Buy it if you know for certain that you'll never need more than 70 MHz bandwidth and don't need CAN/LIN decoding. If your work is exclusively Arduino-level projects with standard SPI and I2C, the DHO804's specifications are more than sufficient, and any savings over the DHO924S can go toward other tools or components.

Do not buy the DHO804 at its $439 list price when the DHO924S costs $449. A $10 price difference for 250 MHz bandwidth (vs 70 MHz), 50 Mpt memory (vs 25 Mpt), a function generator, and CAN/LIN decoding is the easiest decision in this entire buying guide. There is no rational argument for choosing the DHO804 at $439 when the DHO924S exists at $449.

Do not buy it if you anticipate growing beyond basic Arduino work. The 70 MHz bandwidth ceiling will limit you sooner than you expect, and upgrading later means buying a second scope rather than simply having bought the right scope the first time.

Alternatives Worth Considering

The Rigol DHO924S at $449 is the obvious alternative and the recommended choice for almost everyone. For $10 more, you get 3.6x the bandwidth, 2x the memory, a function generator, and CAN/LIN decoding. Unless the DHO804 is available at a significant discount, the DHO924S is the better buy.

The Rigol DS1054Z at $349 is the alternative for budget-conscious buyers who want maximum community support. It offers 50 MHz bandwidth (comparable to the DHO804's 70 MHz), 4 channels, 12 Mpt memory, and a massive ecosystem of tutorials, hacks, and forum answers. It lacks the touchscreen and modern interface, but the bandwidth hack to 100 MHz actually gives it more useful bandwidth than the DHO804 -- though the experience of using it is less polished.

The Siglent SDS1104X-U at $419 offers 100 MHz bandwidth with CAN/LIN decoding at a lower price than the DHO804. The trade-offs are a non-touch TFT display and a less intuitive interface. If you need CAN decoding and want to save money over the DHO924S, the SDS1104X-U is worth considering over the DHO804.

The Siglent SDS1202X-E at $379 offers 200 MHz bandwidth with 2 channels. If you can work with 2 channels instead of 4, the SDS1202X-E gives you nearly 3x the bandwidth of the DHO804 at a lower price. The trade-off is half the channels and no touchscreen.

For users on a tighter budget, the Hantek DSO5072P at $180 provides 70 MHz bandwidth and 2 channels in a basic benchtop form factor. It's significantly less capable than the DHO804 but costs less than half as much.

Frequently Asked Questions

Compare With Similar Scopes