Speakerplans.com Homepage
Forum Home Forum Home > General > Amp Forum
  New Posts New Posts RSS Feed - a stonecold Matrix
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

a stonecold Matrix
 Post Reply Post Reply Page  123 11>
Author
Message
  Topic Search Topic Search  Topic Options Topic Options
SMP View Drop Down
Young Croc
Young Croc
Avatar

Joined: 16 March 2013
Location: East London
Status: Offline
Points: 1226 		Post Options Post Options   Thanks (0) Thanks(0)   Quote SMP Quote  Post ReplyReply Direct Link To This Post Topic: a stonecold Matrix
    Posted: 14 September 2014 at 3:58pm
I have here a Matrix XT1200 apparently modded by Matrix

there is a problem with it as I see it
It does not get hot or even lukewarm at idle with the fan disabled. very odd for a Class AB after an hour or so it is still cold to touch

Perhaps I am missing something here but think not I am beginning to realise it is not what it is said to be.
just a class B driven by a Pseudo class A driver VAS that isn't either

anyone any thoughts on this?
Back to Top
bee View Drop Down
Old Croc
Old Croc
Avatar

Joined: 14 June 2011
Location: Middlesex
Status: Offline
Points: 4553 		Post Options Post Options   Thanks (0) Thanks(0)   Quote bee Quote  Post ReplyReply Direct Link To This Post Posted: 14 September 2014 at 4:40pm
have you turned the amp on...LOL
 
 
sorry, could not resist....
https://www.elements-audio.com
Back to Top
kedwardsleisure View Drop Down
Old Croc
Old Croc


Joined: 20 January 2009
Location: Staffordshire
Status: Offline
Points: 4947 		Post Options Post Options   Thanks (0) Thanks(0)   Quote kedwardsleisure Quote  Post ReplyReply Direct Link To This Post Posted: 14 September 2014 at 5:02pm
not sure I understand, does it work ok?
Kevin

North Staffordshire
Back to Top
SMP View Drop Down
Young Croc
Young Croc
Avatar

Joined: 16 March 2013
Location: East London
Status: Offline
Points: 1226 		Post Options Post Options   Thanks (0) Thanks(0)   Quote SMP Quote  Post ReplyReply Direct Link To This Post Posted: 14 September 2014 at 5:22pm
Originally posted by kedwardsleisure kedwardsleisure wrote:

not sure I understand, does it work ok?


well that is the question it functions ie passes a signal with power gain but "working" that is the issue in hand  Hardly Class AB if there is little or no dissipation within the current stage
Either that or someone changed the Laws of Physics and I never got to hear of it.  LOL
Back to Top
ceharden View Drop Down
The 10,000 Points Club
The 10,000 Points Club
Avatar

Joined: 05 June 2005
Location: Southampton
Status: Offline
Points: 11776 		Post Options Post Options   Thanks (0) Thanks(0)   Quote ceharden Quote  Post ReplyReply Direct Link To This Post Posted: 14 September 2014 at 6:02pm
I would stick it on a scope or better still a distortion analyser and determine whether the cold biassing is causing an issue with crossover distortion or not.
Back to Top
RobinMatrix View Drop Down
Young Croc
Young Croc


Joined: 23 August 2013
Location: Kidderminster
Status: Offline
Points: 567 		Post Options Post Options   Thanks (0) Thanks(0)   Quote RobinMatrix Quote  Post ReplyReply Direct Link To This Post Posted: 14 September 2014 at 9:40pm
How does it sound?

They do have a fair bit of heatsink ... and only dissipate around 5 to 10W a channel in idle ... which may not be enough to detect by hand ... if you have a scope, a lack of bias current will be easy to detect on small signals.  It is unlikely that both driver chains failed identically, at the same time ... it could simply be working perfectly ...
Matrix Pro Audio ::http://matrixproaudio.com/"
Back to Top
kedwardsleisure View Drop Down
Old Croc
Old Croc


Joined: 20 January 2009
Location: Staffordshire
Status: Offline
Points: 4947 		Post Options Post Options   Thanks (0) Thanks(0)   Quote kedwardsleisure Quote  Post ReplyReply Direct Link To This Post Posted: 14 September 2014 at 11:17pm
All the matrix amps Ive seen run with little quiescent current anyway, that's got to be good. Never seen one with crossover distortion either. Dont forget you're dealing with lateral mosfets which have better current sharing across the current range from threshold to clip. (wot no emitter resistors!). Its an inherently stable design in that respect.
Kevin

North Staffordshire
Back to Top
mini-mad View Drop Down
Old Croc
Old Croc
Avatar

Joined: 13 July 2012
Location: london
Status: Offline
Points: 6903 		Post Options Post Options   Thanks (0) Thanks(0)   Quote mini-mad Quote  Post ReplyReply Direct Link To This Post Posted: 14 September 2014 at 11:25pm
Xt1200??!!!..... wen he start building them?
If it sounds like a gorilla is trying to escape, turn it down.
Back to Top
Heathrow_B_line View Drop Down
Old Croc
Old Croc
Avatar

Joined: 11 January 2006
Location: United Kingdom
Status: Offline
Points: 7344 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Heathrow_B_line Quote  Post ReplyReply Direct Link To This Post Posted: 15 September 2014 at 12:37am
Originally posted by mini-mad mini-mad wrote:

Xt1200??!!!..... wen he start building them?


+1

is it 1u???
Produce a killer sound. Take no prisoners.
Back to Top
SMP View Drop Down
Young Croc
Young Croc
Avatar

Joined: 16 March 2013
Location: East London
Status: Offline
Points: 1226 		Post Options Post Options   Thanks (1) Thanks(1)   Quote SMP Quote  Post ReplyReply Direct Link To This Post Posted: 15 September 2014 at 2:04am
Originally posted by mini-mad mini-mad wrote:

Xt1200??!!!..... wen he start building them?


my mistake "GT1200FX"  I am aware of the device type as well to add I am given it's setup as per the owner who paid to have it specially done as class AB. but not class AB in my book. either way a very bad utilisation of the "Hitachi Circuit"  as it is clear to hear. replaced with an amp that is sonically better but opened it up to be nosey to find cheap nasty inside got more nosey disabled fan see what went on
Which brings us here to Cold running "Class AB"   Which is also how come? I will get some kit on it take some data and see where it is at.  just a piece of junk someone else needs to be owning as it will end up on ebay soonTongue
Back to Top
AM55 View Drop Down
Old Croc
Old Croc
Avatar

Joined: 16 August 2007
Location: Matlock
Status: Offline
Points: 1728 		Post Options Post Options   Thanks (0) Thanks(0)   Quote AM55 Quote  Post ReplyReply Direct Link To This Post Posted: 15 September 2014 at 6:14am
Facepalm.
Back to Top
James Tengo View Drop Down
Old Croc
Old Croc


Joined: 09 May 2008
Location: Brighton
Status: Offline
Points: 2155 		Post Options Post Options   Thanks (0) Thanks(0)   Quote James Tengo Quote  Post ReplyReply Direct Link To This Post Posted: 15 September 2014 at 6:39am

I quite like the sound of an Xt1200.... They run fairly hot though LOL


Edited by James Tengo - 15 September 2014 at 6:41am
Back to Top
 Post Reply Post Reply Page  123 11>

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.06
Copyright ©2001-2023 Web Wiz Ltd.

This page was generated in 0.313 seconds.