Balanced Phono

Love it or hate it, it just won't stop
User avatar
Paul Barker
Social Sevices have been notified
Posts: 8876
Joined: Mon May 21, 2007 9:42 pm

#1 Balanced Phono

Post by Paul Barker »

I wander why Alan Wright changed this circuit slightly between 1998 and 2000
https://www.southampton.ac.uk/~apm3/diy ... tp3c_s.gif
Main difference of significance is b+ rail 300v rather than 200v.

Bugger I'd just ordered a bunch of the 170 devices when I saw the preferred dual bipolars. So had to then order those. I assume that the dual bipolars are inherently better matched. Pot luck for me as I wouldn't know where to begin matching them.

other differences seem insignificant.
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
User avatar
Nick
Site Admin
Posts: 15711
Joined: Sun May 06, 2007 10:20 am
Location: West Yorkshire

#2 Re: Balanced Phono

Post by Nick »

Well the toshiba parts were discontinued. Also look at

http://www.linearsystems.com/assets/med ... LSK489.pdf
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
User avatar
Paul Barker
Social Sevices have been notified
Posts: 8876
Joined: Mon May 21, 2007 9:42 pm

#3 Re: Balanced Phono

Post by Paul Barker »

Thank you.
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
User avatar
Paul Barker
Social Sevices have been notified
Posts: 8876
Joined: Mon May 21, 2007 9:42 pm

#4 Re: Balanced Phono

Post by Paul Barker »

Managed to get two of the mat02 pairs on ebay. Couldn't find the dual fets lsk489 for sale anywhere.
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
User avatar
Nick
Site Admin
Posts: 15711
Joined: Sun May 06, 2007 10:20 am
Location: West Yorkshire

#5 Re: Balanced Phono

Post by Nick »

The LSK389 is probably better for a phono

https://www.micross.com/ecommerce/shop-default.aspx
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
User avatar
IslandPink
Amstrad Tower of Power
Posts: 10041
Joined: Tue May 29, 2007 7:01 pm
Location: Denbigh, N.Wales

#6 Re: Balanced Phono

Post by IslandPink »

Looks like you're up to something, Paul .
Allen's RTP3C sounded very good at ETF 2005 .
"Once you find out ... the Circumstances ; then you can go out"
User avatar
Paul Barker
Social Sevices have been notified
Posts: 8876
Joined: Mon May 21, 2007 9:42 pm

#7 Re: Balanced Phono

Post by Paul Barker »

Well it's just common sense really Mark, no point reinventing the wheel. Good to het your feedback on the sound. Those of you who have used similar unbalanced have given good reports. I know of course that you Mark were geting very involved incorporating suggestions from Jo roberts et al. But I'm not wanting to do things on the extreme level right now. Maybe when I have a different home life.

Morgan was explaining on Saturday that there are few good balanced step up transformers, and with the dl103 I presently use he advised electronic gain as he put it.

I would use AW phono section, gain after that; I'll have to see how much voltage gain I need in front of Barbaric. Adust on test.
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
User avatar
Paul Barker
Social Sevices have been notified
Posts: 8876
Joined: Mon May 21, 2007 9:42 pm

#8 Re: Balanced Phono

Post by Paul Barker »

Thanks for that suggestion Nick? I've registered with them, just waiting for approval.
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
User avatar
Paul Barker
Social Sevices have been notified
Posts: 8876
Joined: Mon May 21, 2007 9:42 pm

#9 Re: Balanced Phono

Post by Paul Barker »

Valve Amplifiers 4th edition was waiting for me at home. Wider research mode begins.
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
User avatar
Paul Barker
Social Sevices have been notified
Posts: 8876
Joined: Mon May 21, 2007 9:42 pm

#10 Re: Balanced Phono

Post by Paul Barker »

OK I've read enough to prefer Morgan's version.

You would have to buy the book to know the schematic.

The salient differences are lower b+ greater first stage gain, smaller coupling caps by a factor of 10, simpler final gain stage. It's just more my thing.
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
User avatar
pre65
Amstrad Tower of Power
Posts: 21373
Joined: Wed Aug 22, 2007 11:13 pm
Location: North Essex/Suffolk border.

#11 Re: Balanced Phono

Post by pre65 »

Paul, I've got the Chinese version of edition 4 which Morgan gave me.

Can you tell me the chapter, and illustration number please ? My Chinese is a little ropy. :wink:
The only thing necessary for the triumph of evil is for good men to do nothing.

Edmund Burke

G-Popz THE easy listening connoisseur. (Philip)
User avatar
Paul Barker
Social Sevices have been notified
Posts: 8876
Joined: Mon May 21, 2007 9:42 pm

#12 Re: Balanced Phono

Post by Paul Barker »

In my book it's page 644 Figure 7_49 balanced hybrid riaa
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
User avatar
pre65
Amstrad Tower of Power
Posts: 21373
Joined: Wed Aug 22, 2007 11:13 pm
Location: North Essex/Suffolk border.

#13 Re: Balanced Phono

Post by pre65 »

Paul Barker wrote:In my book it's page 644 Figure 7_49 balanced hybrid riaa
There are less pages in the Chinese version, but I've found the diagram. Thanks. :)
The only thing necessary for the triumph of evil is for good men to do nothing.

Edmund Burke

G-Popz THE easy listening connoisseur. (Philip)
User avatar
Nick
Site Admin
Posts: 15711
Joined: Sun May 06, 2007 10:20 am
Location: West Yorkshire

#14 Re: Balanced Phono

Post by Nick »

Morgan was explaining on Saturday that there are few good balanced step up transformers
What is a balanced step up transformers? AFAIK, any step up can be used balanced as long as you remove the earth connection on its output.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
User avatar
Nick
Site Admin
Posts: 15711
Joined: Sun May 06, 2007 10:20 am
Location: West Yorkshire

#15 Re: Balanced Phono

Post by Nick »

You can see page 644 here if you are interested

https://books.google.co.uk/books?id=QdG ... &q&f=false
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
Post Reply