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Epiphone Jack Casady Transformer

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Good evening, I am trolling every forum that may be able to help. I have a Jack Casady bass, which has similar wiring to the low impedance Les Paul signature bass. The circuit uses a transformer to boost the signal, and the part is covered in epoxy. The output wire broke at the epoxy. I dug a bit but could not find the lead. I have someone trying to extract the part to fix or fabricate, but the chance of success is low. Epiphone will not talk to me about the part, says I must use authorized dealers. Quite literally every major dealer in the country says they cannot help me. Does anyone here know where or how I can get a replacement for this part (the bass is still in production as far as I know)? Or even any info on the part, such as does it correspond to the Gibson onboard transistors for similar low impedance models? Kind of stuck. 

thanks for any help you can offer!

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  • 6 months later...

According to the Wikipedia page the transformer has 3 lower impedance settings. “The pickup is connected to a transformer with a three-position switch to select output impedance of 50, 250 or 500 ohms”


with that known, you could measure the output impedance of your pickup. With those two pieces of information, a transformer winder can calculate the appropriate ratios to wind a new transformer or search for an existing part with the right specs

If your tech doesn’t understand transformers you may be better off with a pro audio tech or amp tech

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Thanks for the reply! I actually resolved this issue with a lot of help from around the world. I traced the original transformer that Gibson used on its signature models, the precursor to the Epi JC. This was a UTC 0-1. The company stopped producing them in the late 60s, and later signature models used a transformer that looks exactly like the JC. I imagine they just had another company use the specs but the housing is very different from the original. Getting lucky on eBay, I sourced the original transformer and after some trial and error introduced it into the circuit. So my JC now has a 60s era transformer driving the circuit, it’s one of a kind! It was an expensive fix..


AND after months of bothering them, epi gave me the info I needed and I sourced the modern part (AFTER I fixed the bass). So I have a spare now. Part was cheap. No regrets though, it was a fun adventure, and I learned a ton of info that only a handful of people in the world care about.

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  • 1 year later...

Hey Mr Freddy 

I find myself in that very same spot any information you have on acquiring a transformer from Epiphone would be greatly appreciated because as of this moment my JC is DOA. 
   In the meantime I will try the eBay route but seriously any help would be hugely appreciated thank you

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