Building an isolation transformer

Bill@LakeGeorge · « **Reply #20 on:** 12 Feb 2004, 08:49 pm »

Carl If you get one get a 20 or 30 amp one

JoshK · « **Reply #21 on:** 12 Feb 2004, 08:51 pm »

Quote from: bhiggins

It is not adaptive and would have to be manually adjusted using a multimeter to get the correct output. ...

Can you explain this point? I am not sure if I understand what you mean by this. If I dial it in to say 117Volts, am I always going to get 117V no matter what the wall is currently putting out?

bhiggins · « **Reply #22 on:** 12 Feb 2004, 09:10 pm »

Quote from: JoshK

Quote from: bhiggins
It is not adaptive and would have to be manually adjusted using a multimeter to get the correct output. ...

Can you explain this point? I am not sure if I understand what you mean by this. If I dial it in to say 117Volts, am I always going to get 117V no matter what the wall is currently putting out?

The dial allows you to select the output voltage as a percentage of the input voltage. I believe the unit we have goes from 0% to 120% or 140%. If for example your input voltage was 125V and you wanted 115V, then you would set the rotary dial for about 92%. If the input voltage dropped to 115V, then your output voltage would also drop to approximately 92% of this or 106V. You might want to keep a voltage meter permanently connected to the output, so that you could make adjustments as needed. Also, the graduations on the dial are not particularly accurate, which is why the meter helps to get an accurate setting.

JoshK · « **Reply #23 on:** 12 Feb 2004, 09:26 pm »

thanks for the explanation, wasn't sure how they worked.

Carlman · « **Reply #24 on:** 12 Feb 2004, 09:52 pm »

I may need to do this... I talked to Bill at Response today and brought this up... He asked if I had a tube amp.. I don't but, it made me immediately think about the tube preamp I was having trouble with... it went through tubes too fast. I haven't had a replacement long enough to test this theory but, I don't want to wait to find out.

Between the high voltage and RFI, I'm in an audiophile's nightmare.

Seems like I could call the power company and ask them to turn it down a little... I think I'll call for a laugh.

Thanks for the info on the VARIAC's. If there was a whole-house solution, I'd be even happier...

EDIT:
I called the power company and they're coming to check it early next week! Don't know if they'll fix anything but, it'll be interesting to see what or if they do anything... If they fix it, cost to me: 10 minutes of phone time. I'm not holding my breath, though. I'm sure they'll say it's 'within spec'...

RadioWonder · « **Reply #25 on:** 13 Feb 2004, 07:58 pm »

Hi all.....
For those who want to build rather than buy a Balanced Power Supply.

http://www.geocities.com/jonrisch/catch2.htm

http://www.transcendentsound.com/power_supply.htm

If you do not know about these.... Check them out...
I have a Transcendent Sound Balanced Power Supply kit on order.
Should be here next week..... Oh yes ..You can buy one assembled for
$50.00 more.....

Carlman · « **Reply #26 on:** 13 Feb 2004, 08:50 pm »

Quote from: RadioWonder

Hi all.....
http://www.geocities.com/jonrisch/catch2.htm
....

Thanks! The 'DU-2' isolation device is exactly what I was looking for. It has the capability of stepping down from 120 to 110. Nice.

Has anyone built this... or is the AudioAsylum a better place to find people who've done this...? I've seen JR's posts quite a few times on AA. I really would like a picture of a finished one because it seems too easy from reading it.

EDIT:
Just use a step down transformer!
http://www.transcendentsound.com/adjusting_transformer_voltage_wi.htm

Something like this:
http://www.alliedelec.com/catalog/pf.asp?FN=620.pdf

Wow. There is a way to fix it if the power company can't!

RadioWonder · « **Reply #27 on:** 13 Feb 2004, 09:37 pm »

Carlman....
Are you looking to build an "Isolation Transformer " or a Balanced
Power Supply? JR has both on his page. Here is the link to Signal Transformers. Download the PDF catalog and look for the DU-2 or SU-2
units they have a good picture of the transformer in question...

http://www.belfuse.com/signaltransformer/

JoshK · « **Reply #28 on:** 14 Feb 2004, 05:54 am »

Here is what I have been playing around with lately. I took the transformers out of two OneACs (1107, 1105), added some Hubbell outlets, the white one is cryo'd and unfiltered for the amp. Took me a long time to cut the back panel for those outlets by hand!!

and the bidniz end

bubba966 · « **Reply #29 on:** 14 Feb 2004, 06:03 am »

Looks nice Josh. Where'd you get the case?

JoshK · « **Reply #30 on:** 14 Feb 2004, 06:15 am »

thanks, got it off of ebay. Dude never got around to building his amp project. Its a par-metal case.

bubba966 · « **Reply #31 on:** 14 Feb 2004, 06:26 am »

Musta been cheap then. Lucky you, looks like it was $pendy...

JoshK · « **Reply #32 on:** 14 Feb 2004, 06:29 am »

Case was $40.

bubba966 · « **Reply #33 on:** 14 Feb 2004, 06:34 am »

Doesn't sound too bad. Forgot the $ of the Par-Metal cases as I've not looked in a while. But I seem to recall them costing a bit more than that...

RadioWonder · « **Reply #34 on:** 14 Feb 2004, 03:52 pm »

Joshk......
Your project looks great! Since you have cut out the chassis
for the electrical outlets, how about giving a few tips on the best way to do
it.....
I may get my Balanced Power Supply kit next week and would like to put two more outlets in the chassis....
Thanks for the help..... RW

Carlman · « **Reply #35 on:** 14 Feb 2004, 04:18 pm »

Josh,
That looks excellent! Please let us know if it makes a nice improvement in sonics.

BTW, if you already have a case, you can buy a single panel from par-metal. You can also have them do outlet holes for a somewhat reasonable price. Just call and ask. It would probably cost between $20-40 for a custom-cut panel like that.

-Carl