Rohde & Schwarz R&S UPL Review

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Rohde & Schwarz R&S UPL
0.00003% THD, DC-110 kHz (1996-2008)

Rohde & Schwarz UPL. enlarge.

Rear, Rohde & Schwarz UPL. enlarge. (about $10,000 used, depending on options).This free website's biggest source of support is when you use these links, especially this link directly to the R&S UPL at eBay (see How to Win at eBay), when you get anything, regardless of the country in which you live.

This sample actually came from Recon Test Equipment, (866) 855-0960, who offer not only great prices, but also extraordinary service and availability. This one shipped out and arrived overnight from across the country, and came fully calibrated and warranted. Recon Test can usually locate exactly what you need if you ask, and let them know I referred you if you get anything. They're also looking to expand their inventory if you have any no-longer-needed test equipment. Thanks! Ken.

November 2021 Audio Reviews All Reviews

The MADE-IN-GERMANY Rohde & Schwarz UPL is among the world's greatest laboratory audio analyzers. It's so stable that it has a two-year calibration cycle. It has state-of the-art-performance for both analog and digital measurements.

When introduced in 1996, the UPL was the "light" version of the state-of-the-art R&S UPD. Today, this UPL is exceeded only by the newest state-of-the-art R&S UPV. This UPL has the same audio performance as today's UPV, differing mostly in the internal computer used to control everything. An advantage of the simpler operating system of this UPL is that the entire instrument boots and is making complex measurements in less than 50 seconds from power-on!

If you're an individual who demands the highest possible audio performance, the UPL cannot be exceeded, and its used price is a bargain at only about $10,000. They sold new for about $40,000, well optioned.

A new UPV makes more sense for large organizations as it uses a more modern operating system, USB communication and CD/DVD drives, and is easy to order new, optioned for your exact needs, however the audio performance of the UPL and UPV are identical.

If you're running a laboratory on a shoestring, a used UPL offers the world's best laboratory audio performance, all in one box without needing any more computers or screens.

External sound cards like the American-made AP 2700 series have almost similar performance on paper, but they aren't stand-alone instruments and instead require a separate outboard computer. Actual performance of sound-card based analyzers often is much less when RFI and EMI from the PC is considered. R&S has been a specialist in radio, EMI and RFI design since they were founded in 1933, and has done extensive work in these instruments to ensure that the internal computers do not interfere with anything.

R&S audio analyzers are made without compromise. They are the world's best, and priced accordingly, so you don't often see them. Unlike Mercedes-Benz today, R&S is still a privately-held company run to make the world's very best laboratory equipment at any price, not to flood the market with less expensive products. You won't fully appreciate Rohde & Schwarz until you try to lift one of these heavy beasts of precision engineering: mechanics and RF shielding are very important to R&S as well. R&S equipment is still built to last a lifetime from a company that exists to build the best equipment, not to pander to investors.

The reason I'm so familiar with R&S, and specifically the UPL, is that I worked for the US company who represented R&S in the USA when the UPL was first introduced (Tektronix); R&S today has its own USA division.

WARNING: This is a professional laboratory instrument. If you lack the appropriate professional qualifications, you probably won't kill yourself working with this, however meaningful measurements require a great deal of skill to set up and perform. This is not a consumer device. Skill level required: Design Engineer, BSEE minimum degree.

The rest of this are notes to myself as I complete this review. Please read accordingly.

Performance top

Intro Specs Performance Compared Usage Recommendations

All these performance measurements are analog out to analog in.

Digital-to-digital measurements are pretty much perfect (it's just crunching numbers), and any mixed-mode tests would be testing the external converter that would be needed to change domains.

-130 dB / 0.00003% THD @ 1 kHz

R&S UPL intrinsic THD+N vs level

THD at 1 kHz at 2.4V RMS, UPL low-distortion generator, balanced 600 Ω output, generator crossed AC input as read by UPL analyzer, 22 kHz bandwidth.

Frequency Response

R&S UPL intrinsic level accuracy and frequency response

Frequency Response, UPL standard generator at 1 V RMS as read by UPL analyzer, DC-coupled, generator crossed, 10 Hz - 22 kHz. Channel 1 and Channel 2.

R&S UPL intrinsic level accuracy and frequency response

Setup for above.

Here's the actual response through a 99¢ stereo RCA cable:

R&S UPL intrinsic level accuracy and frequency response

Actual measured intrinsic frequency Response, UPL standard generator at 1 V RMS as read by UPL analyzer, DC-coupled, unbalanced 5 ohm output, RCA adapters into balanced inputs, 200 k ohm float, 10 Hz - 22 kHz. Channel 1 and Channel 2.

If that's not flat enough, R&S provides a setup file to get response this flat:

R&S UPL intrinsic level accuracy and frequency response

Ultraflat Frequency Response, R&S' FLAT_GEN.SAC and related files, generator as read by UPL, 2Hz - 22 kHz. Channel 1 and Channel 2.

For flatter results, one can store this curve as a calibration reference for even flatter response!

If you want to read down to 0.1 Hertz (one cycle every 10 seconds or 100 milliHertz), no problem, just set the generator's start frequency to 0.1 Hz:

R&S UPL intrinsic level accuracy and frequency response

At ultralow frequencies, the UPL is measuring slopes and slew rates to get amplitudes, so it sweeps through these quite quickly without having to wait for complete cycles.

Here's the response of the AC-coupled input:

R&S UPL intrinsic level accuracy and frequency response

AC-coupled Input response, unbalanced 5 ohm output, RCA adapters into balanced inputs, 200 k ohm, 0.1 Hz - 10 Hz. Channel 1 and Channel 2.

THD versus frequency