RMAA and T-amp: anyone? - diyAudio
Go Back   Home > Forums > Amplifiers > Class D

Class D Switching Power Amplifiers and Power D/A conversion

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 3rd September 2005, 10:44 AM   #1
antomas is offline antomas  Europe
diyAudio Member
 
Join Date: Feb 2003
Location: Torino, Italy
Default RMAA and T-amp: anyone?

Hi everybody!
Did anyone used RMAA to measure the perfomances of a SI T-amp (having separate grounds for left and right speaker)?

Thanks for your help,
Massimo
  Reply With Quote
Old 5th September 2005, 06:05 PM   #2
antomas is offline antomas  Europe
diyAudio Member
 
Join Date: Feb 2003
Location: Torino, Italy
Default Found???

Apparently, enough info to answer my question can be found in this RMAA forum thread:

http://forum.rightmark.org/topic.cgi?id=4:592

Ciao!!!
Massimo
  Reply With Quote
Old 8th September 2005, 12:31 PM   #3
mAJORD is offline mAJORD  Australia
diyAudio Member
 
Join Date: Apr 2004
Location: Brisbane Australia
ive used it to measure a TA2024 T-amp but not an si..
  Reply With Quote
Old 8th September 2005, 01:13 PM   #4
antomas is offline antomas  Europe
diyAudio Member
 
Join Date: Feb 2003
Location: Torino, Italy
Hi mAJORD, thanks for your answer!
Quote:
ive used it to measure a TA2024 T-amp but not an si..
That's fine for me. Would you please confirm me that you measured one channel at a time? Any other recommendation or tip?
Thanks a lot in the anticipation and have a nice evening (is it evening in Australia?)
Massimo
  Reply With Quote
Old 9th September 2005, 09:30 AM   #5
mAJORD is offline mAJORD  Australia
diyAudio Member
 
Join Date: Apr 2004
Location: Brisbane Australia
no mate sorry, single ended, and measured symultaneously. I didnt realise the Si amps were diff outputs on each channel?
  Reply With Quote
Old 16th September 2005, 01:17 PM   #6
antomas is offline antomas  Europe
diyAudio Member
 
Join Date: Feb 2003
Location: Torino, Italy
Hi mAJORD,
sorry for being so incredibly late in answering. We (me an my wife) had some health problems; nevertheless, I made some homework on this subject...

First of all, Tripath confirmed me that ANY TA2024 amplifier needs two differential buffers (one per channel) to be connected to a single-ended soundcard.

The kind guys of the RMAA forum told me that (but I'm sure you read that) a professional soundcard with a balanced input would allow measuring a TA2024 amp without differential buffer.

In the meanwhile I got in love with the idea that a balanced (H-shaped) attenuator with quite high input and output impedance could allow joining the L and R "cold" terminals together... maybe not

I guess many people (me included) would be happy to read about your setup. Which soundcard? Which attenuator?

Thanks for your answer and sorry for the delay.
Massimo
  Reply With Quote
Old 16th September 2005, 01:45 PM   #7
mAJORD is offline mAJORD  Australia
diyAudio Member
 
Join Date: Apr 2004
Location: Brisbane Australia
HI, hope you're both well now :P

No I didnt use a differential output.. mine is an AMP1 , using the TA2024, which has single ended outputs. hence not required.

im not sure how you'l get around that problem for your 2022. without making a low noise low distortion buffer to interface it.


-ed forgot to mention, card was at the time a crappy soundblaster Live, but now an E-MU 404.

I am using a voltage divider to attentuate the output over a range of gain. but that is all
  Reply With Quote
Old 16th September 2005, 02:55 PM   #8
antomas is offline antomas  Europe
diyAudio Member
 
Join Date: Feb 2003
Location: Torino, Italy
Talking Now I understand...

...why I got puzzled. It's just a matter of numbers.

You tested an AMP1 using a TA2022 that is single ended, so "joining grounds" is perfectly ok, while my T-Amp uses a balanced TA2024.

I should have built a AMP-1
Maybe in the future
Massimo
  Reply With Quote

Reply


Hide 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Measuring drivers - RMAA otto88 Multi-Way 3 4th March 2008 07:31 AM
Need help understanding RMAA results of CD player percy Digital Source 2 14th February 2006 10:55 PM
RMAA Help needed kimschips Digital Source 4 24th February 2005 07:02 AM
How accurate is RMAA distortion measurement? analog_sa Tubes / Valves 20 23rd May 2004 11:25 PM
RMAA Software setup maylar Digital Source 3 7th February 2004 04:18 PM


New To Site? Need Help?

All times are GMT. The time now is 09:07 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2