A-40 Transformer

croat47 · 7th June 2005, 08:00 PM

Hello,

So, AudioXpress sells boards for the A-40. There seems to be active builders of the A-40 (?). What tranny are you using?

I can't find a Signal 88-8. 2 custom pieces are going to run me a few hundred. If that's what I'm looking at, cool. But, I would prefer to know what (stock?) iron could be used.

Thanks!

Aaron

gl · 7th June 2005, 08:51 PM

Signal doesn't list the 88-8 anymore but they do list an 80-8 that would do fine. However, their transformers are simply too expensive these days.

I've built 2 A-40's using the 88-8. If I were buying transformers for a new A-40 project I would buy 2 Avel 330VA 25-0-25 toriods from PartsExpress. They're $47.00 each. The voltage is a bit high but it gives you an opportunity to build a CRC or CLC power supply and then end up with the voltages you need.

GL

Eric · 8th June 2005, 03:39 PM

Hi Aaron,

The Avel 330VA 25-0-25 toriods that GL recommends will do just fine for your a40 - one per channel. I had John from Victoria Magnetics custom wind a 600VA toroid for me with 4 secondaries, each rated at 24v 6.25A. I think it cost somewhere near $100. It gets a little warm after hours of use, so you might want to consider 350VA per channel.

After rectification and 65,000uF of capacitance, I get rails that run at about 32v - a little higher than specified, but not a problem at all. I have a web page written up on my a40 with lots of construction details here: http://www.facstaff.bucknell.edu/esa...ovies/a40.html

7th June 2005, 08:00 PM	#1
croat47 diyAudio Member Join Date: May 2005 Location: Eastern Shore, Maryland	A-40 Transformer Hello, So, AudioXpress sells boards for the A-40. There seems to be active builders of the A-40 (?). What tranny are you using? I can't find a Signal 88-8. 2 custom pieces are going to run me a few hundred. If that's what I'm looking at, cool. But, I would prefer to know what (stock?) iron could be used. Thanks! Aaron

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7th June 2005, 08:51 PM	#2
gl diyAudio Member Join Date: Dec 2003 Location: Sierra Foothills - California	Signal doesn't list the 88-8 anymore but they do list an 80-8 that would do fine. However, their transformers are simply too expensive these days. I've built 2 A-40's using the 88-8. If I were buying transformers for a new A-40 project I would buy 2 Avel 330VA 25-0-25 toriods from PartsExpress. They're $47.00 each. The voltage is a bit high but it gives you an opportunity to build a CRC or CLC power supply and then end up with the voltages you need. GL

8th June 2005, 03:39 PM	#3
Eric diyAudio Member Join Date: Nov 2000 Location: Central PA, USA	Hi Aaron, The Avel 330VA 25-0-25 toriods that GL recommends will do just fine for your a40 - one per channel. I had John from Victoria Magnetics custom wind a 600VA toroid for me with 4 secondaries, each rated at 24v 6.25A. I think it cost somewhere near $100. It gets a little warm after hours of use, so you might want to consider 350VA per channel. After rectification and 65,000uF of capacitance, I get rails that run at about 32v - a little higher than specified, but not a problem at all. I have a web page written up on my a40 with lots of construction details here: http://www.facstaff.bucknell.edu/esa...ovies/a40.html

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