Matttcattt said:was my question missed? see post no. 2018. thanks
Matttcattt, open a new thread with your question.
People are two busy discussing other things and may have missed it.
And for future search on the forum it's easier with a new thread.
Re: Matching
As far as matching goes; I always use chips with the same batch-code. They seem to behave very identical
![Wink ;) ;)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
zygibajt said:Have You ever consider matching those LM3875 (to get similar parameters in both channels).Matched par would for sure improve imaging and clarity of the sound,but I have no idea how it would be done.
Bartek
As far as matching goes; I always use chips with the same batch-code. They seem to behave very identical
Hi,
I fired up my Gainclone yesterday.Everything seems to be allright.I have three diffrent pairs of speakers.One of them are Altec 891A,two way studio monitors.When I hooked them up they started cracking.They play the music but crack.Only when listened very silent they don't.I was investigating what is happening and figured that the couse was a speaker cable (quite expensive one,figh capacity-about 1nF per meter).Exchanged cable and everything works fine.It happens only with Altec's.Other speakers don't crack with this cable.Also when I unplug one of the Altecs from GC there is no cracking and I can listen as loud as I want.Is it possible that GC is so sensitive? But why there is no cracking when only one speaker is connected.There is no diffrance which channel and which speaker.
I used 800VA ,2*19VAC tr.,25A single bridge,2,2uF coupling cap ,220K feedback resistor.Also I have DIY Aleph P preamp so instead of 50K pot I put 47K resistor to ground.
Dc offset is about 50mV ,same in both channels.
Do You have any idea why does it crack?
Bartek
I fired up my Gainclone yesterday.Everything seems to be allright.I have three diffrent pairs of speakers.One of them are Altec 891A,two way studio monitors.When I hooked them up they started cracking.They play the music but crack.Only when listened very silent they don't.I was investigating what is happening and figured that the couse was a speaker cable (quite expensive one,figh capacity-about 1nF per meter).Exchanged cable and everything works fine.It happens only with Altec's.Other speakers don't crack with this cable.Also when I unplug one of the Altecs from GC there is no cracking and I can listen as loud as I want.Is it possible that GC is so sensitive? But why there is no cracking when only one speaker is connected.There is no diffrance which channel and which speaker.
I used 800VA ,2*19VAC tr.,25A single bridge,2,2uF coupling cap ,220K feedback resistor.Also I have DIY Aleph P preamp so instead of 50K pot I put 47K resistor to ground.
Dc offset is about 50mV ,same in both channels.
Do You have any idea why does it crack?
Bartek
zygibajt said:I fired up my Gainclone yesterday.
Bartek,
Wow that was fast... wasn't it just the other day, you were asking if i thot this was a good idea to try
And welcome to the forum.
dave
im post for 2 reasons:
1) to keep this thread alive
2) to tell everyone about my website
http://www.freewebs.com/matttcatttweb/index.htm
any comments?
1) to keep this thread alive
2) to tell everyone about my website
http://www.freewebs.com/matttcatttweb/index.htm
any comments?
Matttcattt said:
On your site you mention building GC for a car amp. But what do you do about voltage regulation?
Or do you use the simple 0-14.4 V voltage swing of a car? In that case the National LM chips would not work because they must have a +- supply, whereas the OPA chips will work (but I think that you use them).
But with 0-14.4 V you waste a lot of potential of these amp chips, since most of them are designed to work up to 80 V voltage swing...
And how will you stabilize the voltage? Simply with filter caps? I do not think that the solution will be sufficient...
If building a chip amp for a car I would stick to those chips now commonly used inside car stereo units... and not those for home use...
Bye,
Arndt
Matttcattt said:im post for 2 reasons:
1) to keep this thread alive
2) to tell everyone about my website
http://www.freewebs.com/matttcatttweb/index.htm
any comments?
I don't know why, I can't see the picture every time I linked to your site. However, I can copy the link and open it on spearate explorer
![scratch :scratch: :scratch:](https://files.diyaudio.com/forums/images/smilies/scratch1.gif)
S.C said:
I don't know why, I can't see the picture every time I linked to your site. However, I can copy the link and open it on spearate explorer![]()
I can't see your pictures whatever I try...
![bawling :bawling: :bawling:](https://files.diyaudio.com/forums/images/smilies/bawling.gif)
mike
fdegrove said:Hi,
I can...
What browsers and OS are you guys using?
Cheers,![]()
Internet explorer 6 & windows 98
fdegrove said:Hi,
I can...
What browsers and OS are you guys using?
Cheers,![]()
IE 6 and XP Professional
![cannotbe :cannotbe: :cannotbe:](https://files.diyaudio.com/forums/images/smilies/cannotbe.gif)
Hi,
Strange...I am using IE6.0 SP1 + a whole raft of sandbag updates on Win2K and have no problem whatsoever.
If you guys want that page in a different format I can convert it to *.doc (MS Office 2000) or *.PDF (you'll need Acrobat Reader for that, free at adobe.com).
Just send me a e-mail through the forum and I'll mail it to you.
Cheers,![Wink ;) ;)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
Strange...I am using IE6.0 SP1 + a whole raft of sandbag updates on Win2K and have no problem whatsoever.
If you guys want that page in a different format I can convert it to *.doc (MS Office 2000) or *.PDF (you'll need Acrobat Reader for that, free at adobe.com).
Just send me a e-mail through the forum and I'll mail it to you.
Cheers,
it should work... the files are hosted here: http://www.laserarray.com/ftp.cgi?a...DIO/;right=/;order-left=name;order-right=name
i will try hosting them with the site that hosts my page...
i will try hosting them with the site that hosts my page...
zygibajt said:They play the music but crack.Only when listened very silent they don't.I was investigating what is happening and figured that the couse was a speaker cable (quite expensive one,figh capacity-about 1nF per meter).Exchanged cable and everything works fine.It happens only with Altec's.
Hi,
Your amp oscillates, IMHO.
Place Zobel network on amp output terminals.
Regards
Hi,
At a nanoF/m this to be expected....can't imagine any half sane cable designer putting such a crazy cable onto the market.
A well designed OPT coupled tube amp would drive that without going belly up but that's about it.
It'll still be on the brink of stability and I doubt it would solve it entirely...beter than nothing, I agree.
Cheers,![Wink ;) ;)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
(quite expensive one,figh capacity-about 1nF per meter).Exchanged cable and everything works fine.It happens only with Altec's.
At a nanoF/m this to be expected....can't imagine any half sane cable designer putting such a crazy cable onto the market.
A well designed OPT coupled tube amp would drive that without going belly up but that's about it.
Place Zobel network on amp output terminals.
It'll still be on the brink of stability and I doubt it would solve it entirely...beter than nothing, I agree.
Cheers,
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