Go Back   Home > Forums > Amplifiers > Chip Amps

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 17th September 2009, 11:12 AM   #1
diyAudio Member
 
Join Date: Dec 2003
Location: brussels
Default input capacitor remove or not in tripath t2020

hello people

i have been upgrading my t2020 tripath very slow.
i'm running it on a smps psu for the last two years, it is a skynet 8080
i have been placing sanyo caps all over the t2020, and it does make a
serious (read hearable difference).

i was always reluctent to remove the input caps, because of fear of blowing up my speakers and the amp.

But here are my questions.

1)
a)i keep an dc coupling input capacitor. I have a 50kohm pot, i suppose that a 1uf - 2.2uf is good enough, knowing that my speakers are fullrangers and don't go much lower then 40hz.
b)i would buy a jantzen superior cap, obligato film oil or clarity dtac cap
these are still not to expensive and good.

2)
a) i give up the input cap. but can someone describe to me what has to be done then ? and what are the conditions you can do it.

i thought that the power supply ground and the signal ground may not be mixed. In the T-amp that is easy to do, but you could make this connection in other devices where the signal ground is attached to the power ground. But all the other devices i use (tuner, DAC) have no power ground or earth connection: so i suppose that this is not an issue then ?

(summarized: my tripath is grounded, and no other device connected to the amp may be grounded (well as the signal and ground is connected in this device). )
am i correct in this opinion ? if so i can loose the input caps without a problem.

b)can anyone explain me what to do when removing the input caps, the inputs have to be soldered to some pins, i think but i can't remember which.

thank you so much.
greetz

ps: i might build a 5v line for seperate power to the t2020,
but if i do that, i'm gonna loose the smps and build an analog psu, what do you think?

greetz again
  Reply With Quote
Old 18th September 2009, 04:07 PM   #2
diyAudio Member
 
Join Date: May 2008
1. a) The input stage of that amplifier is an inverting op amp. That means, the high-pass filter will be determined by the capacitor and Ri. The potentiometer should be before the capacitor to avoid interference with the gain setting.

2. a) If you skip that capacitor, you need some additional kind of DC protection for your speakers. You should also analyze all sources as to the effect their impedacnes will have on the inverting input stage.

The input capacitor does not help with grounding issues. It is there to isolate the different biasing potentials of source and amplifier, which means it blocks DC. Any DC from the source would be amplified and could lead to the destruction of your speakers without that capacitor or additional DC protection.

Your sources are pretty likely grounded. A tuner is usually even earthed through its antenna connection. Sources with floating ground are usually battery-driven, e. g. portable MP3-players.

b) Replace the capacitor with a jumper, if you decide to skip it.
__________________
If you've always done it like that, then it's probably wrong. (Henry Ford)
  Reply With Quote
Old 18th September 2009, 04:17 PM   #3
diyAudio Member
 
Join Date: Dec 2003
Location: brussels
thanks a lot pacificblue,

but maybe i don't understand not everything


so the input cap is there to block dc from the sources, i'm shure there is no dc on the source.

but there is something else ? the grounding issues ? they have nothing to do with the input cap ? (i don't get it completely)

a long story short: it would be better to use a very high end film cap in that place?

(i just wonder how the new version of the charlize ta2020 without cap is working so well, i mean you must use is with a battery, or battery dac to make it work ?)

thanks
  Reply With Quote
Old 18th September 2009, 04:28 PM   #4
diyAudio Moderator Emeritus
 
jean-paul's Avatar
 
Join Date: Sep 2002
Location: Germany
The input cap is there because the TA2020 itself has 2.5 V bias voltage on the input.
__________________
It's only audio. Official member of the Norske Brillegeit Gang.
  Reply With Quote
Old 18th September 2009, 04:32 PM   #5
diyAudio Member
 
Join Date: Dec 2003
Location: brussels
oh yes, that's true, but it is possible to remove them,

but then is there the issue with the grounding of other devices, or not ?

well to be simple, in my case, with a tuner it is not recommanded ?
then i will put a better cap ?

thanks
  Reply With Quote
Old 18th September 2009, 04:49 PM   #6
diyAudio Moderator Emeritus
 
jean-paul's Avatar
 
Join Date: Sep 2002
Location: Germany
The type/brand of your amp is unknown but I assume it is a ready made one with 5 mm pitched electrolytic input caps. In that case I would either use a decent 5 mm pitch film cap like Wima MKS2 ( no, they are not as evil as I often read, although they're MKT ) which sound better than electrolytic caps in most cases.

Even better : good old BG N series 4.7 uF. The latter are out of production for years now and thus they're hard to find but they're no doubt the best in that size.

If you are the kind of guy that uses car battery sized caps in amps that are smaller than the caps I can not advise you too well I also have read that the TA2020 can be used without input caps. I think it was Leo of the Charlize amps that found some way.

http://diyparadise.com/web/index.php...id=21&Itemid=5

Please check the negative side effects also !
__________________
It's only audio. Official member of the Norske Brillegeit Gang.

Last edited by jean-paul; 18th September 2009 at 04:58 PM.
  Reply With Quote
Old 18th September 2009, 04:59 PM   #7
diyAudio Member
 
Join Date: Dec 2003
Location: brussels
indeed, it is a 5mm pitch cap.

i have some BG lying around.

i have space enough in the amp, i was thinking about a big 1uf or 2.2uf film cap. and they are gonna be bigger then the amp. i was just wandering how much difference it would make. from a wima 2.2uf to an big film cap.

thanks
  Reply With Quote
Old 18th September 2009, 05:04 PM   #8
diyAudio Moderator Emeritus
 
jean-paul's Avatar
 
Join Date: Sep 2002
Location: Germany
When very large caps are used mechanical strength is compromised and it looks messy with melt glue, iron wire and cello tape.... Stray RF creeping in, coupling of output and input signals. Not my cup of tea. Well built and good sound go hand in hand.

Why bother if there is already a good Wima type in it ? Check the link, Leo is fond of BG N series too in TA2020 amps. No other series of BG can be recommended at that spot, just the N series !
__________________
It's only audio. Official member of the Norske Brillegeit Gang.
  Reply With Quote
Old 21st September 2009, 09:43 PM   #9
diyAudio Member
 
Join Date: Dec 2003
Location: brussels
thanks jean-paul
  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
Tripath Input Coupling Caps Davet Class D 427 15th July 2012 06:01 PM
charlize t2020 mod-topic then_dude Class D 4 22nd December 2007 04:13 PM
Why remove capacitor 'wrapping' ? Keyoke Chip Amps 50 6th December 2006 03:58 PM
tripath t2020 headphone then_dude Headphone Systems 4 9th September 2006 03:33 PM
Can I remove the input caps? Nightpuma Tubes / Valves 17 12th April 2006 11:21 PM


New To Site? Need Help?

All times are GMT. The time now is 08:46 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