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MyRef_C with Ultimate BOM

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Weather is detoriating so a chance to spend some time on the new arrivals.
Being one of the lucky ones with both PRP and Shinkoh resistors a final check and some questions:

-Positions are R10 (390) and R12 (3k3) and not R37?
-Alternatives are switches or soldering in and out. Would a switch detoriate the effect of such nice resistors?

Anyone alternative options for switching the resistors in and out?

Thanks

Michiel

Yes, swap R10 and R12 but not R37.

To allow the resistors to easily plug in and out cut up a machined-pin DIP socket like the ones Mill Max makes. Solder the individual pins to the board and cut and form the resistor leads to plug in. PRP 1/2W resistors have a 0.025" lead diameter and should just fit in a DIP socket pin. I have no data on Shinkoh resistors so you should check if they can plug in to the socket. There will always be questions about the validity of any comparison using switches and long wires to connect the switches to the board.
 
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This is my original question,

the final answer posted is CliveFreeman's answer verified by Jon to be a center tapped series connection.

If we need 24/25 vac to each MyRefC board, What Primary voltage transformer

do we select to get the correct output voltage when the secondary’s are wired in series?

My original 12 X 12 wired in series results in 24vac to AC1, 0v to PGND, and 24vac to AC2.

If I am correct the AN-2225 When wired in series will result in 50vac to AC1 and AC2.

What is the correct ac voltage to apply to each MyRefC board?

Thank you

I think I have it figured out now, what I was confused about was the way some books explain secondary series voltage.
 

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Hey guys,

I'm confused on how to wire my transformer now also. Could you tell me what wire goes where based on the data sheet of my transformer? It's in the link below. I use one transformer for each channel.

http://www.amplimo.nl/download/080xx.pdf

My best guess is that I have to yellow and grey to PGND, blue to AC1 and red to AC2. Can one of you confirm this?

Thanks a lot! :)

Cheers!

It looks like you want to follow the "serial operation to
double the secondary voltage" from you data sheet. Combine Yellow and Blue and use that as PGND, then use Red as AC1 and Grey as AC2.

This will give you the big voltage difference between AC1 and AC2 whereas the way you suggested would have a zero voltage difference between AC1 and AC2.
 
Transformer wiring

I'm new to this hobby... on my third build, but I managed to hook up the transformer for my last gain clone OK. All you need to make sure you hook up your transformer right is the data sheet or schematic. I found this one in the catalogue for my transformer manufacturer (attached .pdf). Colours vary by maker and transformer type of course.

Also, a little help like this link Wiring Transformers
(Site design, content and images © Daniel Clarke 2004)
This link cross references to the Antrim transformer link posted by Jon a couple of posts back... looks quite helpful though some of the secondary winding wiring notes are irrelevant for us.

If you are at all unsure, pick someone in this GB who seems knowledgeable, experienced (not me) and approachable and PM to ask for help (including as much relevant information as possible). Worst that can happen is they say no.

Bill
 

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Yup, I use 40W here too.

When you flip the switch, your bulb will flash as the reservoir capacitors in the amp charge. It'll then dim right down. I've tried playing music with it connected, and it's an interesting correlation between current draw (and bulb glowing brighter) and music volume. Sometimes, those beefy, underlying tones draw much more than you'd imagine....
 
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