# Uncategorized **URL:** https://forum.quantasylum.com/c/uncategorized/1.md [Latest](https://forum.quantasylum.com/latest.md) · [Categories](https://forum.quantasylum.com/categories.md) --- ## [Welcome to the QuantAsylum Forum](https://forum.quantasylum.com/t/welcome-to-the-quantasylum-forum/7)
**Author:** [@system](https://forum.quantasylum.com/u/system)\ **Replies:** 0\ **Last updated:** [December 5, 2019, 12:47am UTC](https://forum.quantasylum.com/t/welcome-to-the-quantasylum-forum/7 "2019-12-05T00:47:46Z")
The QuantAsylum Forum is a place to discuss QuantAsylum hardware and software. Have a question? Need support? Have an idea on how to streamline something? Want to share some measurements? This is the place. We’re using … --- ## [QA40xPlot Thread](https://forum.quantasylum.com/t/qa40xplot-thread/1795)
**Author:** [@MarkZ](https://forum.quantasylum.com/u/MarkZ)\ **Replies:** 423\ **Last updated:** [September 24, 2026, 10:34am UTC](https://forum.quantasylum.com/t/qa40xplot-thread/1795 "2026-09-24T10:34:27Z")
Now that QA40xPlot is stable I wanted a thread for help/upgrade requests and focused discussion. If you missed the thread while I was writing it… The QA40xPlot application is an open source Windows program that provides… --- ## [Wanted Quant Asylum dummy load](https://forum.quantasylum.com/t/wanted-quant-asylum-dummy-load/2397)
**Author:** [@Hector](https://forum.quantasylum.com/u/Hector)\ **Replies:** 0\ **Last updated:** [September 15, 2026, 5:38pm UTC](https://forum.quantasylum.com/t/wanted-quant-asylum-dummy-load/2397 "2026-09-15T17:38:08Z")
If anyone has a good working one and wish to sell I would be very interested. --- ## [Frequency response frequency](https://forum.quantasylum.com/t/frequency-response-frequency/2385)
**Author:** [@breedj](https://forum.quantasylum.com/u/breedj)\ **Replies:** 2\ **Last updated:** [September 7, 2026, 8:07pm UTC](https://forum.quantasylum.com/t/frequency-response-frequency/2385 "2026-09-07T20:07:35Z")
Hi, I am using the standard app quite some time and also build my own version some time ago. My version uses the API to do a EchoChirp. And I found that my amplifier was quite ok. But resently I started to build V2 of … --- ## [MCP Server for QA40x](https://forum.quantasylum.com/t/mcp-server-for-qa40x/2379)
**Author:** [@matt](https://forum.quantasylum.com/u/matt)\ **Replies:** 4\ **Last updated:** [August 20, 2026, 11:33pm UTC](https://forum.quantasylum.com/t/mcp-server-for-qa40x/2379 "2026-08-20T23:33:00Z")
I’ve been working on an MCP server for the QA40x software. MCP (Model Context Protocol) servers allow AIs such as ChatGPTs Codex and Claude Code to communicate with applications. But there’s also a discovery piece, where… --- ## [Python and QA40x](https://forum.quantasylum.com/t/python-and-qa40x/1464)
**Author:** [@matt](https://forum.quantasylum.com/u/matt)\ **Replies:** 13\ **Last updated:** [August 18, 2026, 3:37pm UTC](https://forum.quantasylum.com/t/python-and-qa40x/1464 "2026-08-18T15:37:31Z")
There are some Python classes I’m finishing that know how to use the calibration data inside the QA40x so that you can send/receive absolute values to/from the QA40x hardware. This will come in subsequent post. This post… --- ## [QA403 measuring 76 SNR is loopback test?](https://forum.quantasylum.com/t/qa403-measuring-76-snr-is-loopback-test/2376)
**Author:** [@turambar517](https://forum.quantasylum.com/u/turambar517)\ **Replies:** 5\ **Last updated:** [August 18, 2026, 1:21am UTC](https://forum.quantasylum.com/t/qa403-measuring-76-snr-is-loopback-test/2376 "2026-08-18T01:21:02Z")
Hi all! I got my QA403 finally out of the box and am trying to get a good baseline on audio measurements. I have a BNC to BNC looped from L+ Out to L- IN and all the other 3 inputs blocked with shorting caps. I am just … --- ## [Channel muting when mirroring (QA403)](https://forum.quantasylum.com/t/channel-muting-when-mirroring-qa403/1310)
**Author:** [@yegolebi](https://forum.quantasylum.com/u/yegolebi)\ **Replies:** 7\ **Last updated:** [August 13, 2026, 2:38pm UTC](https://forum.quantasylum.com/t/channel-muting-when-mirroring-qa403/1310 "2026-08-13T14:38:49Z")
Does the generator channel mute setting also work with mirroring? maybe I am doing something wrong, but despite the mute setting both DAC channels generate the same signal… --- ## [QA40x\_BareMetal](https://forum.quantasylum.com/t/qa40x-baremetal/769)
**Author:** [@matt](https://forum.quantasylum.com/u/matt)\ **Replies:** 7\ **Last updated:** [August 6, 2026, 12:11pm UTC](https://forum.quantasylum.com/t/qa40x-baremetal/769 "2026-08-06T12:11:47Z")
I’m not sure how useful this will be to most. But if you are working on a platform that isn’t supported and are able to write software, the code at the link below shows how to control the QA402, QA403 (and upcoming QA404… --- ## [Wow & flutter visualizer](https://forum.quantasylum.com/t/wow-flutter-visualizer/2333)
**Author:** [@Chicago](https://forum.quantasylum.com/u/Chicago)\ **Replies:** 10\ **Last updated:** [July 30, 2026, 2:29pm UTC](https://forum.quantasylum.com/t/wow-flutter-visualizer/2333 "2026-07-30T14:29:33Z")
Hi, I have a QA401 so older code 1.924. I have the W&F visualizer v0.83. I’m writing to verify this earlier version produces a valid measurement? I know it’s unweighted but the numbers I’m getting are actually better … --- ## [Unofficial open-source cross-platform tool for the QA402/QA403](https://forum.quantasylum.com/t/unofficial-open-source-cross-platform-tool-for-the-qa402-qa403/2331)
**Author:** [@raph29](https://forum.quantasylum.com/u/raph29)\ **Replies:** 11\ **Last updated:** [July 22, 2026, 9:55pm UTC](https://forum.quantasylum.com/t/unofficial-open-source-cross-platform-tool-for-the-qa402-qa403/2331 "2026-07-22T21:55:09Z")
Hi Matt, I’m a QA402 owner and I’ve built an unofficial, open-source desktop app to drive the QA402/QA403 from macOS/Linux/Windows — a from-scratch Rust + Tauri implementation of the USB protocol, with spectrum/scope/… --- ## [Any word on v2.0 software](https://forum.quantasylum.com/t/any-word-on-v2-0-software/2327)
**Author:** [@skipburrows](https://forum.quantasylum.com/u/skipburrows)\ **Replies:** 3\ **Last updated:** [July 7, 2026, 5:04pm UTC](https://forum.quantasylum.com/t/any-word-on-v2-0-software/2327 "2026-07-07T17:04:56Z")
Hey Mat, I was wondering if there’s been any further development on version 2.0 for the analyzing software. The feature set looked great but I haven’t seen any development in a while. Thanks. --- ## [TSP Measurement with QA403 release 1.223 - Issues](https://forum.quantasylum.com/t/tsp-measurement-with-qa403-release-1-223-issues/2286)
**Author:** [@AVO](https://forum.quantasylum.com/u/AVO)\ **Replies:** 2\ **Last updated:** [May 28, 2026, 4:27pm UTC](https://forum.quantasylum.com/t/tsp-measurement-with-qa403-release-1-223-issues/2286 "2026-05-28T16:27:46Z")
Hi all first I wanted to thank Matt for the new 1.223 release for the QA403. I have only tested the updated “SPKR Impedance” from the “Automated Tests” menu so far. With release 1.223 the results of the TSP measurement… --- ## [No signal from right input channel](https://forum.quantasylum.com/t/no-signal-from-right-input-channel/2281)
**Author:** [@kabae](https://forum.quantasylum.com/u/kabae)\ **Replies:** 1\ **Last updated:** [May 20, 2026, 1:11am UTC](https://forum.quantasylum.com/t/no-signal-from-right-input-channel/2281 "2026-05-20T01:11:42Z")
Hello, I’ve been evaluating the QA403 for testing on both a Windows 11 and Ubuntu 24.04 machine and had no issues working through the Quick Start examples and using the REST interface to get measurements from the unit. … --- ## [THD measurement lower than 127 dB](https://forum.quantasylum.com/t/thd-measurement-lower-than-127-db/2138)
**Author:** [@YvesLegault](https://forum.quantasylum.com/u/YvesLegault)\ **Replies:** 11\ **Last updated:** [May 18, 2026, 11:36pm UTC](https://forum.quantasylum.com/t/thd-measurement-lower-than-127-db/2138 "2026-05-18T23:36:04Z")
Maybe it is ghost chasing, but I tried to figure out the best “floor” readings I can get out from my QA403. Connecting a QA403 to a tower PC running Debian Linux 13, Trixie, I was also able to run the QA40x software. w… --- ## [QA40xPlot and QA462](https://forum.quantasylum.com/t/qa40xplot-and-qa462/2278)
**Author:** [@Thumb](https://forum.quantasylum.com/u/Thumb)\ **Replies:** 0\ **Last updated:** [May 13, 2026, 5:05pm UTC](https://forum.quantasylum.com/t/qa40xplot-and-qa462/2278 "2026-05-13T17:05:22Z")
Has any one use a QA462 with the QA40xPlot software ? How would I use it ? What ref. Resistor to use and so on ! Pro and cons --- ## [Is the Forum down?](https://forum.quantasylum.com/t/is-the-forum-down/2268)
**Author:** [@cfortner](https://forum.quantasylum.com/u/cfortner)\ **Replies:** 2\ **Last updated:** [May 10, 2026, 8:31am UTC](https://forum.quantasylum.com/t/is-the-forum-down/2268 "2026-05-10T08:31:10Z")
Hi, since 4 days no single post, are you all ok? Greetings Christian --- ## [Q403 grounding point](https://forum.quantasylum.com/t/q403-grounding-point/2102)
**Author:** [@skipburrows](https://forum.quantasylum.com/u/skipburrows)\ **Replies:** 17\ **Last updated:** [May 4, 2026, 7:42am UTC](https://forum.quantasylum.com/t/q403-grounding-point/2102 "2026-05-04T07:42:39Z")
Hi all.. I’ve finally built my rack box to house my q403. It brings all the connectors out to the front via xlr,b&c and even the usb and a ground. My question is where is best to attach a ground on the 403 so I can str… --- ## [Frequency respone trace](https://forum.quantasylum.com/t/frequency-respone-trace/2255)
**Author:** [@walge](https://forum.quantasylum.com/u/walge)\ **Replies:** 30\ **Last updated:** [April 22, 2026, 6:17am UTC](https://forum.quantasylum.com/t/frequency-respone-trace/2255 "2026-04-22T06:17:21Z")
Hi I have done some response of amps I got the picture in attach I can’t understand why from 1kHz to the high end the trace became thick With both sw Thanks --- ## [SPLMeter app now available on GitHub](https://forum.quantasylum.com/t/splmeter-app-now-available-on-github/2259)
**Author:** [@philipppaulklose](https://forum.quantasylum.com/u/philipppaulklose)\ **Replies:** 2\ **Last updated:** [April 13, 2026, 6:54pm UTC](https://forum.quantasylum.com/t/splmeter-app-now-available-on-github/2259 "2026-04-13T18:54:58Z")
I have solved a problem for me and think the world could also use that solution. :slight\_smile: SPLMeter is a Sound Pressure Level (SPL) meter, available as a macOS/Windows/Linux standalone app and as VST3 / AU plugin. … --- ## [Can I test a USB ADC with the QA403?](https://forum.quantasylum.com/t/can-i-test-a-usb-adc-with-the-qa403/2078)
**Author:** [@DavidR](https://forum.quantasylum.com/u/DavidR)\ **Replies:** 5\ **Last updated:** [April 13, 2026, 1:59pm UTC](https://forum.quantasylum.com/t/can-i-test-a-usb-adc-with-the-qa403/2078 "2026-04-13T13:59:14Z")
USB ADC products are common. An example of such a product is a box that converts the output of a phono cartridge into a stream that a computer can capture via a USB connection between the box and the computer. A USB Audi… --- ## [Qa40x\_V2 Version 0.1](https://forum.quantasylum.com/t/qa40x-v2-version-0-1/2246)
**Author:** [@matt](https://forum.quantasylum.com/u/matt)\ **Replies:** 26\ **Last updated:** [April 4, 2026, 3:25pm UTC](https://forum.quantasylum.com/t/qa40x-v2-version-0-1/2246 "2026-04-04T15:25:24Z")
The next version of Qa40x is getting close, and it would be a big help if those on non-PC platforms could try and report what they see. The zip is located HERE. 1. Download and Unzip Download the zip and unzip. There’s … --- ## [QA402 Software on Linux and Mac](https://forum.quantasylum.com/t/qa402-software-on-linux-and-mac/330)
**Author:** [@matt](https://forum.quantasylum.com/u/matt)\ **Replies:** 51\ **Last updated:** [March 24, 2026, 9:14pm UTC](https://forum.quantasylum.com/t/qa402-software-on-linux-and-mac/330 "2026-03-24T21:14:47Z")
The QA402 software binaries are hosted on GitHub here. Theoretically, the images should run as-in on Linux and Mac under Mono. Most of the time, we’re all used to downloading different images based on our platform (and s… --- ## [Abnormal Graph on Crown Amp](https://forum.quantasylum.com/t/abnormal-graph-on-crown-amp/2244)
**Author:** [@Balahid](https://forum.quantasylum.com/u/Balahid)\ **Replies:** 8\ **Last updated:** [March 16, 2026, 3:48pm UTC](https://forum.quantasylum.com/t/abnormal-graph-on-crown-amp/2244 "2026-03-16T15:48:14Z")
Hello, I have an amp made by crown that is multimode AB & B when testing the amp, I noticed a strange dip in THD+N on the channels. It consistently occurs at the 1.4kHz and recovers at the 3.3kHz. Is this graph normal? … --- ## [SPKR Impedance - Vas measurement issue](https://forum.quantasylum.com/t/spkr-impedance-vas-measurement-issue/2240)
**Author:** [@AVO](https://forum.quantasylum.com/u/AVO)\ **Replies:** 2\ **Last updated:** [March 13, 2026, 12:06pm UTC](https://forum.quantasylum.com/t/spkr-impedance-vas-measurement-issue/2240 "2026-03-13T12:06:31Z")
Hi today I was using the QA403 (SW release 1.222) and the QA461 transducer driver to measure the Thiele Small Parameters of an Audax HM210G6 woofer chassis (new chassis, no burn-in). I was using the SPKR Impedance autom… --- ## [403 and ARTA sw](https://forum.quantasylum.com/t/403-and-arta-sw/2242)
**Author:** [@walge](https://forum.quantasylum.com/u/walge)\ **Replies:** 2\ **Last updated:** [March 12, 2026, 7:50pm UTC](https://forum.quantasylum.com/t/403-and-arta-sw/2242 "2026-03-12T19:50:17Z")
Hi one strange question But ARTA sw can run with 403? Walter --- ## [Testing an audio compressor](https://forum.quantasylum.com/t/testing-an-audio-compressor/2231)
**Author:** [@skipburrows](https://forum.quantasylum.com/u/skipburrows)\ **Replies:** 3\ **Last updated:** [March 7, 2026, 3:33pm UTC](https://forum.quantasylum.com/t/testing-an-audio-compressor/2231 "2026-03-07T15:33:12Z")
Hey all… I’m currently in development of a new audio compressor. I’ve been tuning the attack and release time mostly by ear. However now that I think it’s sounding nice I’d really like to dig in and try and get the actu… --- ## [My custom Q403 case](https://forum.quantasylum.com/t/my-custom-q403-case/2232)
**Author:** [@skipburrows](https://forum.quantasylum.com/u/skipburrows)\ **Replies:** 4\ **Last updated:** [March 5, 2026, 4:32pm UTC](https://forum.quantasylum.com/t/my-custom-q403-case/2232 "2026-03-05T16:32:37Z")
Hey all. I finished my custom Q403 case. I have 2 outputs and inputs per channel for added flexibility. I also took the +side of each input and “Y’ed” to b&c connectors so you can put a scope from the DUT. Works well. … --- ## [Adding a switch to the 403](https://forum.quantasylum.com/t/adding-a-switch-to-the-403/2227)
**Author:** [@peppermint](https://forum.quantasylum.com/u/peppermint)\ **Replies:** 13\ **Last updated:** [March 3, 2026, 1:20am UTC](https://forum.quantasylum.com/t/adding-a-switch-to-the-403/2227 "2026-03-03T01:20:43Z")
It drives me absolutely crazy that I have to plug and unplug the USB cable every time I need to use the 403. Quite frankly, adding a simple switch would cost next to nothing. It could even be at the back of the unit, nex… --- ## [Verifying Calibration Automatically](https://forum.quantasylum.com/t/verifying-calibration-automatically/2153)
**Author:** [@matt](https://forum.quantasylum.com/u/matt)\ **Replies:** 9\ **Last updated:** [February 26, 2026, 10:06pm UTC](https://forum.quantasylum.com/t/verifying-calibration-automatically/2153 "2026-02-26T22:06:14Z")
Release 1.221 is up HERE This release has a new feature that is discussed HERE This allows you to generate a calibration report for your QA40x hardware if you have a recently calibration 6.5 digit DVM. You really do ne… [Next page](https://forum.quantasylum.com/c/uncategorized/1.md?page=1)