supersize me, please. (powersupply)

kmj · 7th September 2004, 07:04 AM

Hi one and all!

I just wanted to ask a small question so here goes:
is there any practical advantages with an overdimensioning the transformer for the powersupply?

i have the choice between having one made to fullfill my needs and no more or buying one from hammond for a bit more and using a 20W caddoc resistor to drop the voltage and not using one of the 3 sec-windings. it seems to be kind of pointless so better be safe than sorry, there of the question.

kmj · 7th September 2004, 10:55 AM

after having my morning cup of coffee and reread this post so:

moderator, feel free to erase it

Bas Horneman · 7th September 2004, 11:35 AM

Quote:

is there any practical advantages with an overdimensioning the transformer for the powersupply?

Current wise yes.Voltage wise no.

If you wish...we could still delete this thread...

pedroskova · 7th September 2004, 02:48 PM

You never know what ideas will be popping up down the line, so an over-rated product might not be over-rated for long. Also, if you are making a cap input psu, switching to a choke input might be a better option for knocking down the voltage than a resistor.

ashok · 7th September 2004, 02:52 PM

Quote:

Also, if you are making a cap input psu, switching to a choke input might be a better option for knocking down the voltage than a resistor.

Never know, might sound better too !

kmj · 7th September 2004, 05:32 PM

well, i'm using diodes for rectification "full wave capacitor input load" i think it's called and it seems like i will have it wound for me, that way i can get it exaclly as i want it.
specs:
sec 200-0-200@300mA, 6,3V@4A.
that should be enough for 1 6sn7 and 2 6v6 (180V resp 250V). that and some headroom for another pair of 6v6 if the need arises.

I'm starting with a 6sn7-6v6 based amp from Boozhound but with different psu, it seems like a simple first project with many possibilities for modifications and tinkering. if it turns out ok then it's not so hard or expensive to add an extra 6v6 in parallell and buy bigger/better iron to avoid saturation.

bytheway, has anyone used those universal hammond irons? i read a test somewhere that even though the are rated 100-15kHz the acually have a range from 20-20KHz. Also Angela instruments had an review stating that you could get a richer bas

"by moving the connection from the bottom of the cathode resistor/bypass cap to the white secondary tap of the OPT instead of directly to ground"

but there's NO WAY that i'm doing that to my beloved speakers

anyway, i had my eyes set on the vdv3070 by menno van der veen but after some reading, and surfing this forum, it seemed to be quite an undertaking and there's probably better choices than a pushpull-quartet-EL34-triodemode-amp (peuh) when it comes to fidelity.

7th September 2004, 07:04 AM	#1
kmj diyAudio Member Join Date: Feb 2004 Location: Falkenberg	supersize me, please. (powersupply) Hi one and all! I just wanted to ask a small question so here goes: is there any practical advantages with an overdimensioning the transformer for the powersupply? i have the choice between having one made to fullfill my needs and no more or buying one from hammond for a bit more and using a 20W caddoc resistor to drop the voltage and not using one of the 3 sec-windings. it seems to be kind of pointless so better be safe than sorry, there of the question.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
0-30v 0-10a PowerSupply	gev	Power Supplies	16	24th May 2006 08:06 PM
PC PowerSupply	gev	Power Supplies	0	24th July 2005 01:00 PM
DC powersupply +-15V 2-3A	JensRasmussen	Solid State	9	22nd February 2004 09:42 PM
Powersupply	Kongen	Solid State	4	26th October 2003 03:19 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	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

7th September 2004, 10:55 AM	#2
kmj diyAudio Member Join Date: Feb 2004 Location: Falkenberg	after having my morning cup of coffee and reread this post so: moderator, feel free to erase it

7th September 2004, 02:48 PM	#4
pedroskova RIP Join Date: Dec 2002 Location: C'ville VA, USA	You never know what ideas will be popping up down the line, so an over-rated product might not be over-rated for long. Also, if you are making a cap input psu, switching to a choke input might be a better option for knocking down the voltage than a resistor.

7th September 2004, 05:32 PM	#6
kmj diyAudio Member Join Date: Feb 2004 Location: Falkenberg	well, i'm using diodes for rectification "full wave capacitor input load" i think it's called and it seems like i will have it wound for me, that way i can get it exaclly as i want it. specs: sec 200-0-200@300mA, 6,3V@4A. that should be enough for 1 6sn7 and 2 6v6 (180V resp 250V). that and some headroom for another pair of 6v6 if the need arises. I'm starting with a 6sn7-6v6 based amp from Boozhound but with different psu, it seems like a simple first project with many possibilities for modifications and tinkering. if it turns out ok then it's not so hard or expensive to add an extra 6v6 in parallell and buy bigger/better iron to avoid saturation. bytheway, has anyone used those universal hammond irons? i read a test somewhere that even though the are rated 100-15kHz the acually have a range from 20-20KHz. Also Angela instruments had an review stating that you could get a richer bas "by moving the connection from the bottom of the cathode resistor/bypass cap to the white secondary tap of the OPT instead of directly to ground" but there's NO WAY that i'm doing that to my beloved speakers anyway, i had my eyes set on the vdv3070 by menno van der veen but after some reading, and surfing this forum, it seemed to be quite an undertaking and there's probably better choices than a pushpull-quartet-EL34-triodemode-amp (peuh) when it comes to fidelity.