Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Equipment & Tools From test equipment to hand tools

QuantAsylum QA400 and QA401
QuantAsylum QA400 and QA401
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 4th August 2018, 01:17 PM   #2511
miklos is offline miklos  Hungary
diyAudio Member
 
miklos's Avatar
 
Join Date: Jul 2004
Location: Budapest/Toronto
I would rather dedicate less powerful laptop for the QA400.
__________________
miklos
  Reply With Quote
Old 17th August 2018, 11:10 AM   #2512
dennismiller55 is offline dennismiller55  United States
diyAudio Member
 
dennismiller55's Avatar
 
Join Date: May 2011
Location: Clifton, Maine
Well, as other here have experienced, my QA400 no longer works after the Windows 10-1803 update.

I am thinking of running a dual boot Windows 10 & Windows 7. It is not clear (to me) on the QA website whether or not the latest QA400 software will work with Windows 7.

Anyone have any trouble running the QA400 software with Windows 7 OS?
  Reply With Quote
Old 17th August 2018, 12:55 PM   #2513
MarkS is offline MarkS  United Kingdom
diyAudio Member
 
Join Date: Jun 2004
QuantAsylum QA400 and QA401
I run a QA400 with no problems under Win7 but you need to have the last issue signed drivers otherwise it turns into a mess.

If you get stuck finding the drivers pm me and I'll stick them in a dropbox for you...
  Reply With Quote
Old 10th September 2018, 10:46 PM   #2514
blueglow is offline blueglow  United States
diyAudio Member
 
blueglow's Avatar
 
Join Date: Nov 2012
Location: Winston-Salem NC
I just ordered the QA401, anxiously awaiting the delivery.
Curious, I currently run two Dale 8 ohm 250W 1% non-inductive resistors in my bench dummy load. I currently us an HP 8903B that I simply feed via a BNC cable tapped across the 8 ohm load with a switch to vary between L & R channels. I mostly use it on vintage stereo gear I've restored.
Time for something new though...

Anyways, how are you guys connecting the QA401 to your dummy load?
What are you using for a dummy load?
Using any sort of resistor divider network as an attenuator?

Just curious what others may have already figured out worked well.
Thanks in advance for your input
Mark
  Reply With Quote
Old 11th September 2018, 01:52 AM   #2515
anatech is offline anatech  Canada
diyAudio Moderator
 
anatech's Avatar
 
Join Date: Jun 2004
Location: Georgetown, On
QuantAsylum QA400 and QA401
Hi blueglow,
I use the same resistors that you do. I recently bought an RTX 6001 and it has balanced inputs. This allows me to not worry about ground loops due to connecting wire between the loads.

Before doing this, I would measure one channel at a time using an HP 339A. Connecting the load grounds together is bad news. Having that connection made inside a piece of test equipment is even worse news.

As for attenuators, you can make one from resistors, but you will have to compensate them much like an oscilloscope probe must be.

-Chris
__________________
"Just because you can, doesn't mean you should" my Wife
  Reply With Quote
Old 11th September 2018, 10:09 PM   #2516
dennismiller55 is offline dennismiller55  United States
diyAudio Member
 
dennismiller55's Avatar
 
Join Date: May 2011
Location: Clifton, Maine
Quote:
Originally Posted by dennismiller55 View Post
Well, as other here have experienced, my QA400 no longer works after the Windows 10-1803 update.

I am thinking of running a dual boot Windows 10 & Windows 7. It is not clear (to me) on the QA website whether or not the latest QA400 software will work with Windows 7.

Anyone have any trouble running the QA400 software with Windows 7 OS?
Quote:
Originally Posted by MarkS View Post
I run a QA400 with no problems under Win7 but you need to have the last issue signed drivers otherwise it turns into a mess.

If you get stuck finding the drivers pm me and I'll stick them in a dropbox for you...
Thanks Mark but I got it working.

Well I am happy to report that I did set up a dual boot laptop (Win10 & Win7). The Q400 runs perfectly in Win7. I decided to install all my bench programs in the Win7 partition. ARTA and Pete Millett's HP8903 Analyzer Software. I will continue to use the Win10 partition for web browsing and email.
  Reply With Quote
Old 12th September 2018, 01:37 AM   #2517
1audio is offline 1audio  United States
diyAudio Member
 
Join Date: Mar 2004
Location: SF Bay Area
QuantAsylum QA400 and QA401
Input attenuator-
First check the max input for the QA401 @ 56V P-P or 28V peak to confirm that is not enough for the amp you want to test. The input is full differential but the peak with respect to the ground at the input is 28V. if you are using 8 Ohm loads (and I see no reason why they need to be exceptionally non-inductive but that is a separate discussion) you could build an attenuator using a 720 Ohm resistor and an 80 Ohm resistor. You would not need any compensation for this and any frequency this system will operate at. The 20 dB (10X) attenuation will make the arithmetic pretty easy from there.Actually I would use 2 360 Ohm resistors from each end of the load with the 80 Ohm resistor in the middle so BTL or single ended will work fine.

Matt at QA is working on an interesting load box. Since its controlled by the software it may be able to do more.
__________________
Demian Martin
Product Design Services
  Reply With Quote
Old 12th September 2018, 03:50 AM   #2518
anatech is offline anatech  Canada
diyAudio Moderator
 
anatech's Avatar
 
Join Date: Jun 2004
Location: Georgetown, On
QuantAsylum QA400 and QA401
Hi Demian,
Good to know. I was working with sound cards whose impedance was (very approximately) 10 K. The network did require compensation due to the higher resistances involved. I was pretty surprised at ow much compensation was needed due to the high input capacitance on some sound cards.

-Chris
__________________
"Just because you can, doesn't mean you should" my Wife
  Reply With Quote
Old 26th September 2018, 07:14 PM   #2519
jlind54 is offline jlind54  United States
diyAudio Member
 
Join Date: Nov 2012
Location: Kansas
Does anyone have YouTube content showing their setup and test measurements of an amplifier using one of the QA401's?
  Reply With Quote
Old 26th September 2018, 07:48 PM   #2520
MarkS is offline MarkS  United Kingdom
diyAudio Member
 
Join Date: Jun 2004
QuantAsylum QA400 and QA401
Quote:
Originally Posted by jlind54 View Post
Does anyone have YouTube content showing their setup and test measurements of an amplifier using one of the QA401's?
Have you read this blog post on their site about testing a D-amp with a QA401?
First Look: Evaluating Class D Power Amps with the QA401 – QuantAsylum
  Reply With Quote

Reply


QuantAsylum QA400 and QA401Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
QuantAsylum 401 & 405 B&W_arthur Equipment & Tools 5 22nd March 2016 04:27 PM
QA190 and QA400 Gains sgtnoah Equipment & Tools 4 17th July 2015 03:46 AM
Question on QA400 Alan0354 Equipment & Tools 7 10th July 2015 06:34 PM
FS QuantAsylum QA400 audio analyser jan.didden Swap Meet 3 29th September 2014 05:10 PM
New Quantasylum QA190 Differential Input Probe stellavox Equipment & Tools 3 20th March 2014 06:06 PM


New To Site? Need Help?

All times are GMT. The time now is 07:36 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki