from +/-80v to +/-70v rails

leander · 12th September 2005, 09:19 AM

Hey any ideas of how can I reduce voltage rails from +/-80v to +/-70v. I guess something like this as in the pic will work, any other ideas pls ?

Thanks

peranders · 12th September 2005, 09:36 AM

You could use a LM317/337 but notice that it can be a bit current consuming.

bocka · 12th September 2005, 09:42 AM

What's the reason you want to get down from +/-80V to +/-70V?

leander · 12th September 2005, 09:49 AM

What's the reason you want to get down from +/-80V to +/-70V?

Because the transformer I have is 55v-55v ac and the amp I have maximum voltage is +/-70v

bocka · 12th September 2005, 09:52 AM

Quote:

Because the transformer I have is 55v-55v ac and the amp I have maximum voltage is +/-70v

Do you have a schematic of the amp?

guytou · 12th September 2005, 10:44 AM

Don't you have 240V or 120V tap at the primary ?
That would be the most elegant way to drop about ten per cent of tension at the secondary .(i.e. , for a 220 V network ,you hook on 240V tap , for 110V network on the 120V tap .)

leander · 12th September 2005, 11:13 AM

http://www.ampslab.com/c300.htm

the transformer I have has both 240v, 120v primeries. whatis a tap ? should I hook it in series with the primary ?

paulb · 12th September 2005, 12:13 PM

Could you unwind a few turns from each side of the secondary of the transformer?

anatech · 12th September 2005, 12:14 PM

Hi leander,
The higher voltage may or may not be a problem. It is a good opportunity to install a voltage regulator for the amps. SOmething better than 317/337. Think of the Adcom vreg, or others.

-Chris

guytou · 12th September 2005, 01:18 PM

Leander , all you have to do is the 220 on the 240 and you should have 70V at the secondary instead of 80V . Try and check.

12th September 2005, 09:36 AM	#2
peranders Electrons are yellow and more is better! diyAudio Member Join Date: Apr 2002 Location: Göteborg, Sweden Blog Entries: 4	You could use a LM317/337 but notice that it can be a bit current consuming. __________________ /Per-Anders (my first name) or P-A as my friends call me

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12th September 2005, 09:42 AM	#3
bocka diyAudio Member Join Date: Jul 2003 Location: Hannover	What's the reason you want to get down from +/-80V to +/-70V?

12th September 2005, 09:49 AM	#4
leander diyAudio Member Join Date: Aug 2005	What's the reason you want to get down from +/-80V to +/-70V? Because the transformer I have is 55v-55v ac and the amp I have maximum voltage is +/-70v

12th September 2005, 10:44 AM	#6
guytou diyAudio Member Join Date: Mar 2005 Location: marseille	Don't you have 240V or 120V tap at the primary ? That would be the most elegant way to drop about ten per cent of tension at the secondary .(i.e. , for a 220 V network ,you hook on 240V tap , for 110V network on the 120V tap .)

12th September 2005, 11:13 AM	#7
leander diyAudio Member Join Date: Aug 2005	http://www.ampslab.com/c300.htm the transformer I have has both 240v, 120v primeries. whatis a tap ? should I hook it in series with the primary ?

12th September 2005, 12:13 PM	#8
paulb diyAudio Member Join Date: Jun 2001 Location: Calgary	Could you unwind a few turns from each side of the secondary of the transformer?

12th September 2005, 12:14 PM	#9
anatech diyAudio Moderator Join Date: Jun 2004 Location: Georgetown, On	Hi leander, The higher voltage may or may not be a problem. It is a good opportunity to install a voltage regulator for the amps. SOmething better than 317/337. Think of the Adcom vreg, or others. -Chris

12th September 2005, 01:18 PM	#10
guytou diyAudio Member Join Date: Mar 2005 Location: marseille	Leander , all you have to do is the 220 on the 240 and you should have 70V at the secondary instead of 80V . Try and check.

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