Sure electronics ST508 amp: AA-AB32186 - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps
Home Forums Rules Articles diyAudio Store Gallery Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Chip Amps Amplifiers based on integrated circuits

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 October 2015, 05:16 PM   #1
CCU is offline CCU  Denmark
diyAudio Member
 
Join Date: Apr 2007
Location: Kgs. Lyngby
Send a message via MSN to CCU
Default Sure electronics ST508 amp: AA-AB32186

Hi

We are making some mobile speakers. For the electronics we want to use a 2x4 miniDSP for signal processing and 2 of sure electronics amps based on the ST508 chip(model AA-AB32186)

But so fair we canīt get any useful output from the amps. maybe a watt or two.
The problem seems to be that MiniDSP low output and we therefore want to increase the gain amp.
Iīve looked at the datasheet for the amplifier chip. But i cannot find out how to increase the sensitivity of the amp.
Can you guys and gals help me out?

Datasheet for the chip
http://www.st.com/web/en/resource/te...CD00003546.pdf

Would be so grateful for some help.
  Reply With Quote
Old 4th October 2015, 05:37 PM   #2
diyAudio Member
 
Join Date: May 2010
Location: Skokie Il
The signal from the DSP and the amplifier is analog, right? Then put a voltage amplifier between the DSP and the amplifier. A simple op amp based circuit would suffice. Do some back of the envelope calculations to determine proper gain structure.

These digital amplifier boards sure do boast of high performance in a small space with an attractive price. Too good to be true? Not really hi-fi, I guess. I can't deny that I've been tempted to buy one of these units and see how well I could make it work.
  Reply With Quote
Old 4th October 2015, 06:51 PM   #3
CCU is offline CCU  Denmark
diyAudio Member
 
Join Date: Apr 2007
Location: Kgs. Lyngby
Send a message via MSN to CCU
Yes. It is an analog signal.
I simply have no clue about how i would go about designing something like that.
I can do smaller modification or buy something pre-made to put in between. But what would something like that be called?
  Reply With Quote
Old 5th October 2015, 05:34 AM   #4
AlexQS is offline AlexQS  United States
diyAudio Member
 
Join Date: Jan 2012
Location: Pacific Northwest
Quote:
Originally Posted by CCU View Post
Yes. It is an analog signal.
I simply have no clue about how i would go about designing something like that.
I can do smaller modification or buy something pre-made to put in between. But what would something like that be called?
BTW, I'm using miniDSP nanoDigi. Your miniDSP 2x4 is a little different, so I can't give you specifics, but look into the literature about your 2x4 -because I think there's a jumper you can move to change your output voltage from 0.9V to 2V. That may help your situation. Also when you plug in miniDSP to your computer, do you have gains in the menus set right? I have my input about -10dB as to not clip the DAC, and give me a little headroom for any PEQ gain. On the output tab, the least efficient speaker runs at full volume, and the most efficient speaker has a few -dB to pad it down to match. Check miniDSP forums for more if this area is problem.
  Reply With Quote
Old 5th October 2015, 09:02 AM   #5
CCU is offline CCU  Denmark
diyAudio Member
 
Join Date: Apr 2007
Location: Kgs. Lyngby
Send a message via MSN to CCU
On the 2x4MiniDSP the jumpers are for the input side only. And with the gain cranked up as much as the software allows. Then it seems to be using roughly 5-10% of the amps potential.
  Reply With Quote
Old 5th October 2015, 09:04 AM   #6
CCU is offline CCU  Denmark
diyAudio Member
 
Join Date: Apr 2007
Location: Kgs. Lyngby
Send a message via MSN to CCU
Iīve done a lot of experimentation. From what i can gather i need some kind of hardware solution. some kind of modification or extra hardware.
  Reply With Quote
Old 5th October 2015, 10:42 AM   #7
diyAudio Member
 
Mark Whitney's Avatar
 
Join Date: Feb 2013
Location: Netherlands
How about measuring the outputs of the miniDSP or testing the amps with a known source. On paper this set up should work just fine without any extra gain.
__________________
Regards Mark.
  Reply With Quote
Old 5th October 2015, 10:54 AM   #8
CCU is offline CCU  Denmark
diyAudio Member
 
Join Date: Apr 2007
Location: Kgs. Lyngby
Send a message via MSN to CCU
Driving the amps directly from the bluetooth module is really loud in comparison to what i get, when the signal goes though the MiniDSP. Which means the amps should be okay.

Sending the MiniDSP signal to my Denon amp gives a great result too.

So in some weird way that i canīt figure out. there is a mismatch between the 2 components.
  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
Sure Electronics AA-AB33182 [4 x 100W] Class D Audio Amplifier Board +27V DC Power... fualcr Swap Meet 5 11th December 2014 09:32 PM
Sure TK2050 AA-AB32186 jedimind0 Class D 3 11th June 2014 10:12 AM
Heathkit AA-40 or AA-121 panheadchopper Tubes / Valves 1 5th February 2011 04:51 AM
FS: HIGH END Home Audio lot..Opera Louspeakers, Triangle Comete, AA Primo, AA, etc. JiggaD369 Swap Meet 6 22nd August 2008 02:32 AM
1959 Pilot AA-908 Amp into Guitar Amp aronaut Tubes / Valves 6 19th March 2008 09:38 AM


New To Site? Need Help?

All times are GMT. The time now is 07:28 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.
Copyright Đ1999-2016 diyAudio

Content Relevant URLs by vBSEO 3.3.2