I need help finding a transformer for my board...

[sjaltenb]

Hello...

My cornish board has the following:

2x vintage Chandler tube Drivers (currently they both have their own transformers)
1x vintage electric mistress (has its own transformer)

then i also have about 10 9v effects, 4 9v external output jacks that i want to have power, plus all the other LEDs that will run off 9v.

Can i find a single toroidal transformer that can power all of these effects?? I know i need 12 volts for the GGG Ultra Clean Supply for my 9v. Is there a way to wire it that will power the two tube drivers and the mistress too??

One of the TDs is a Center tap (it seems to make more noise than the one that isnt) and the mistress has a center tap. I do not know the voltages, but they each had internal transformers that I am currently using. From what I can see by looking at the transformer, the one with center tap is 24v and the one without is 12v. not sure about the mistress.

I want to reduce all the transformers and use a single toroidal so it is quieter, more simple, and then i dont have to have so much AC120 running in the board to each transformer. I know that pete cornish does this somehow, and he has to power way more tubes etc. Please help! Worst Case, Can i have one toroidal power the GGGs for the 9v and then have another one for the other three?

thanks so much!!

[Ben N]

Not exactly what you asked for, but would this help?

[petemoore]

  Helped me...
  Floating DC voltage is the gifted one for PS's.
  take two 9v taps and create an 18v tap.
  Daisy chain some of those circuits, I'm sure you can find some that don't mind.
  that or build a larger PS w/more outputs, but I like first option better.

[sjaltenb]

hmmm im not really sure if thats what I would need or not.

like I said im not raelly positive what the requirements on the two tube drivers and the mistress are.... or how i would wire all those from one xformer.

[jakehop]

That weber transformer is IMHO awesome. The 9V 2A can easily be used with tube effects, and few analog effects use 300mA @ 9V.

Jake

[Ben N]

That weber transformer is IMHO awesome. The 9V 2A can easily be used with tube effects, and few analog effects use 300mA @ 9V.

Jake

With 2A you have enough juice to step it back up if you need higher voltage, or follow Pete's excellent suggestion to tie two taps together for 18v. (The 11v taps can be regulated down to 9v). If you need it, it is just as easy to get bipolar power.

Just sayin'.

[petemoore]

   Useful transformer for DIY pedal-ers, pro-gear-head-pedalboards.
  I have one here, built a Spyder with it, haven't had noise or had to look back at...funky noisy power supplies ever since, and got a VDLPP II also.
  Floating DC outputs are the bees knees of power supplies for effects,  compares sound wise to batteries which are a continuous hassle or failure risk.
    I wouldn't mind having an 18v tap to be honest, if I did I think a certain 'the last Mu, Booster in the chain' would be supplied by it.
  Consider MAX1044 for voltage doubling.

[sjaltenb]

Ok i have been reading up on this transformer, it might be the way to go for me!

im still kind of confused. i read this article:

http://www.geofex.com/Article_Folders/Spyder/spyder.htm

So, what i see is, that i use that transformer, and for my 9Vdc i use a couple GGG ultra clean power supplys with that transformer on a couple of the legs to obtain my 9v outputs for FX and LEDs.

Then, with the other legs, i can somehow obtain the necessary power for the two tube drivers and the electric mistress?

[Ben N]

How much voltage do you need? Just combine taps to get get close, then regulate to the exact voltage you need--more or less.

[sjaltenb]

well im not sure....

the two tube drivers are vintage Chandler types.

One has a Center tap and it appears that its 24v .2A.

the 2nd one has no center tap and based on the wiring of the trasnformer, it says its 12V.

Not sure about the mistress.....

[sjaltenb]

Here are pictures, maybe yall can help me figure it out: This is the setup i am currently using and you can see why it is not so good.:

the noise is not HORRIBLE but its not good. the TD with the center tap is the one with the most ac clicking noise.



This is the First TD (#71) This is the trasnformer and the circuit board that goes with it. There is no center tap, the green and black are the wires that go to the circuit.




This is the 2nd TD (#70) This transformer and the circuit that goes with it. There IS a center tap. its hard to see but those are the 3 secondaries coming off the trasnformer and there are also 4 diodes there.



This is the mistress xformer and board., there is no text on the xformer. There is a center tap.



I took pictures of the board because i thought it might help yall figure out the voltage required... I am trying to read as much as possible, im guessing the large 1n diodes are doing the rectifing on the board itself...am i correct? so we just need to figure out the necessary input voltage on these board and they should be good to go right off the trasnformer secondaries... correct?

[Ben N]

OK, beginning to see the problem. Is there a DEM schematic that gives you the operating voltage?

[sjaltenb]

i contacted Howard Davis who engineered it for electro harmonix, and here is the discussion:

Mr. Davis,

Thanks again for the mods and repairs, I love it!! Just a
quick question, what is the voltage of the transformer you
put in there? What is the necessary voltage for that
particular unit? I am trying to power all my FX in the board
with as few transformers as possible, and I know i'll need
9, 12, and 24 so far. I think maybe its a 15, is that
correct? Thanks!

I have not measured it in a long time, and don't have the specs available.
In a center-tap to ground two diode DC supply hookup, it delivers about
24VDC.

so.... i guess 24vdc?

Here is a schematic i Found:
http://www.generalguitargadgets.com/diagrams/dmistsc.gif

on the bill of materials it calls for an 18v transformer.
http://www.generalguitargadgets.com/bom/dmistbm.txt

is there a way i can measure it with a multimeter? i'm new to using them, but i have one.

[sjaltenb]

bumpage.