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

Anyone using a car audio amp in a home stereo set-up?
Anyone using a car audio amp in a home stereo set-up?
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 14th September 2020, 08:26 AM   #121
ginetto61 is offline ginetto61  Italy
diyAudio Member
 
Join Date: Sep 2009
Location: Milano
Anyone using a car audio amp in a home stereo set-up?
Quote:
Mismatched output transistors that are in parallel won't generally affect the sound (remember the global feedback) but it can affect the reliability when the amp is driven to its limits
i see ... the NGF takes care of everything ... ok no more doubts
Speaking of the amperes the max current delivered by an amp is very important because it tells about its driving ability of difficult loads
For instance two amps can have the same power on 8 ohm load ... but passing to 4 ohm load one can have more or less the same power and another one can double it. Usually the second one sounds more powerful in the bass.
It can deliver more current on a 4 ohm load while showing the same power on 8 ohm
This is the reason why some less powerful amps can sound more powerful that amps with higher wattage on 8 ohm ... because their current do not sag
Usually this is the result of some kind of current limiting circuit. They limit the current to limit the heatsink needs ... the parts grade ... i do not know why
There is an italian magazine doing this kind of test ( i am attaching a lab report)
Considering that the impedance curve of an average speaker can dip down to 4 ohm often i usually look to the power on 4 ohm .. or even 2 ohm I understand not many amps are stable on a 2 ohm load

Quote:
Why is testing important? (showstopper?)
if you do not test you do not know the power ... if an amp is stable Testing is fundamental in general
But the showstopper i was referring to is the fact that you mentioned that cables routing can have a huge impact on performance
I cannot accept the idea that if i move let's say a power wire the sound changes This was very surprising for me to learn as I have never experienced anything similar using home power amps ... maybe with some preamps but never with power amps
It seems that this kind of amps is very sensitive indeed.
Attached Images
File Type: jpg 066-71-Yamaha-3.jpg (593.4 KB, 62 views)
File Type: jpg mol.JPG (34.3 KB, 45 views)
__________________
“And is it any wonder That the monkey's confused” ― Roger Waters

Last edited by ginetto61; 14th September 2020 at 08:34 AM.
  Reply With Quote
Old 14th September 2020, 08:34 AM   #122
Perry Babin is offline Perry Babin  United States
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
You're mixing two things (at least). The ability of an amp to double the power in 1/2 the load isn't generally about the current capacity but the regulation of the rail voltage. The downside of this is that you limit the power into the higher impedance load to double the power. More snake oil.

You were talking about testing THD+noise. That's FAR different than testing for power. Power testing is relatively simple. You'll need a dummy load and a scope. THD+noise, you typically need a computer with a high-end sound card or a standalone piece of test equipment.
__________________
Anyone who purchased the repair tutorial, email me (babin_perry@yahoo.com) if you want to download the latest version.
  Reply With Quote
Old 14th September 2020, 08:50 AM   #123
ginetto61 is offline ginetto61  Italy
diyAudio Member
 
Join Date: Sep 2009
Location: Milano
Anyone using a car audio amp in a home stereo set-up?
Quote:
Originally Posted by Perry Babin View Post
You're mixing two things (at least). The ability of an amp to double the power in 1/2 the load isn't generally about the current capacity but the regulation of the rail voltage ...
Do you mean that what really sags is the power supply and not the output stage ? of course if the current is not limited by design with some kind of protections ? Thanks a lot now i understand much better.

Regarding the measurements no doubts ... i understand the points very well.
__________________
“And is it any wonder That the monkey's confused” ― Roger Waters
  Reply With Quote
Old 14th September 2020, 08:58 AM   #124
Perry Babin is offline Perry Babin  United States
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
Due to various losses in the circuit, the rail voltage drops as the load decreases in impedance, unless it's tightly regulated (really pointless, in most amps).

If you had a 2 ohm amp that was driven to full power (just before clipping) into 2 ohms and increased the load to 4 ohms or opened the load (no load), there would be no noticeable (and barely any measurable) difference in the signal at the speaker terminals.
__________________
Anyone who purchased the repair tutorial, email me (babin_perry@yahoo.com) if you want to download the latest version.
  Reply With Quote
Old 14th September 2020, 09:59 AM   #125
ginetto61 is offline ginetto61  Italy
diyAudio Member
 
Join Date: Sep 2009
Location: Milano
Anyone using a car audio amp in a home stereo set-up?
Quote:
Originally Posted by Perry Babin View Post
Due to various losses in the circuit, ...
if i understand well when the load impedance goes down the output stage has to deliver more current and then asks more current to the power supply
If the power supply cannot deliver that current the supply voltage sags ?
i have been advised to do a very simple test ... to put an analogue voltmeter across the PS caps and watch the needle ... as long as it does not drop everything is fine

Quote:
If you had a 2 ohm amp ...
do you mean an amp stable on 2 ohm ? that is really low indeed I really thing it would be better to avoid loads so low ... a very demanding load
Maybe having more output devices in parallel can improve the performance on very low loads ? if so that is also a very good point in favour of the paralleled output pairs design choice
I will study the link of switching power supplies you kindly provided to me even if i am very slow to understand things
My guess is that the last generation of smps should be much better also for audio purposes
I would like to thank you again for the very important lessons ... also the one about the preamps setting the sound as long as the power amp is rightly design. This is a very important point for me and mirrors my listening experience. I mean ... using the same preamp with different power amps provides very similar sounds ... much more than otherwise i.e. using a same power amp with different preamps (tubes in particular)
__________________
“And is it any wonder That the monkey's confused” ― Roger Waters

Last edited by ginetto61; 14th September 2020 at 10:03 AM.
  Reply With Quote
Old 14th September 2020, 10:16 AM   #126
Perry Babin is offline Perry Babin  United States
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
For most every amp, when the amp sends more power to the speakers, the rail voltage will drop. The drop will correspond to the power driven to the speakers. The rail voltage dropping means very little unless it collapses to nothing.

2 ohm 'stable' amps are the norm.

The term 'stable' was made up by marketing. In design, the term stable is used to express the amp circuit's resistance to misbehaving like oscillation.

I don't know if you're confusing the switching power supply in the amp and the external 12v power supply that uses switching to convert the voltage from mains to 12v.
__________________
Anyone who purchased the repair tutorial, email me (babin_perry@yahoo.com) if you want to download the latest version.
  Reply With Quote
Old 14th September 2020, 10:51 AM   #127
ginetto61 is offline ginetto61  Italy
diyAudio Member
 
Join Date: Sep 2009
Location: Milano
Anyone using a car audio amp in a home stereo set-up?
Quote:
Originally Posted by Perry Babin View Post
... I don't know if you're confusing the switching power supply in the amp and the external 12v power supply that uses switching to convert the voltage from mains to 12v
actually here we have two power supplies in series ... the smps providing the 12VDC and the dc-dc converter inside the power amp generating the dual voltage supply
And this actually confuses me a little more than usual
I still do not know precisely how to determine the current needed at 12VDC to power an amp properly ... i am aware that it depends on the amp's power but still it is not clear to me how to calculate the amperes
But 12VDC smps with high currents are quite available
Another one is coming ... too cheap to let it go

Alimentatore stabilizzato 12V 20A - Elettrodomestici In vendita a Roma

when i see Meanwell i cannot stop myself ... i respect the brand very much
I am preparing for the future
__________________
“And is it any wonder That the monkey's confused” ― Roger Waters

Last edited by ginetto61; 14th September 2020 at 11:00 AM.
  Reply With Quote
Old 14th September 2020, 11:04 AM   #128
Perry Babin is offline Perry Babin  United States
diyAudio Member
 
Join Date: Nov 2003
Location: Louisiana
We already covered current needed. The amps are about 50% efficient at full power. If you have a 100W amp running at full power, it's going to need 200w from the power supply.

At less than full power, it will require less from the 12v supply. At idle, it will require only about 1 amp of current.
__________________
Anyone who purchased the repair tutorial, email me (babin_perry@yahoo.com) if you want to download the latest version.
  Reply With Quote
Old 14th September 2020, 11:12 AM   #129
ginetto61 is offline ginetto61  Italy
diyAudio Member
 
Join Date: Sep 2009
Location: Milano
Anyone using a car audio amp in a home stereo set-up?
Thanks ! actually it is a lot indeed ... better not to exaggerate with amp's power then
No more questions ... i have also another one smaller amp and less powerful ... i will start with that one ... it seems that people in the car audio switch amps quite often Very good !
Kind regards, gino
__________________
“And is it any wonder That the monkey's confused” ― Roger Waters
  Reply With Quote
Old 15th September 2020, 09:59 PM   #130
Guerilla is offline Guerilla  Denmark
diyAudio Member
 
Join Date: Feb 2018
Location: Aalborg Denmark
2 ohm is only common when people put multible subwoofer drivers in paralel to produce very loud bass in their car.

Dont worry about wire-routing. Just connect plus to + and minus to -. put a lead from + to "remote" if you you dont have a 12 volt remote trigger signal from your preamp. Otherwise it wont power up.

Be prepared for noise when you power up. - Efficient speakers sound more noisy than less efficient ones - Moreso with a powerfull amplifier.

Noone knows if your amplifier has been repaired. Could very well be as new.

To learn modications you should just find an amp in a dumpster. Higher chance of hearing a difference when modifiying low quality amps.

Cheers!
  Reply With Quote

Reply


Anyone using a car audio amp in a home stereo set-up?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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Will this amplifier be able to replace my home audio stereo player? realflow100 Solid State 14 6th March 2017 08:35 PM
Dual 8" Sub for Home Stereo or Car Audio xpheolix Subwoofers 3 23rd October 2013 02:29 AM
any experience with car audio as a home stereo? gychang Car Audio 7 5th January 2013 12:14 PM
Car stereo home audio amplifier capcat Car Audio 8 25th April 2012 12:35 PM
Cheap Pro Audio Crossovers and EQ for home stereo? santiu Multi-Way 1 4th December 2005 12:15 PM


New To Site? Need Help?

All times are GMT. The time now is 03:31 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Copyright ©1999-2020 diyAudio
Wiki