Advice on Jorgen schou transformer compability

[nickolas]

Not long ago I bought some tube equipment by chance containing components and two amplifiers, one el84 SE amp and a two channel EL84 SE amp. My plan was to build a something like a harp amp. I was a bit dissapointed on the looks hoping I could modify the existing design but it looks like everything has to come out and OT and PT tested for functionality. Anyway on the input there were three JS input transformers looking like this.

http://i228.photobucket.com/albums/ee45/nickebunker/DSCF6065.jpg (http://s228.photobucket.com/user/nickebunker/media/DSCF6065.jpg.html)

Searching the net I found this forum and that some JS trafo were made as SUT for turntables. JS made many different transformers though so I wonder if there is any application that fits these? Barry told me the impedance would be 30ohm towards the regular 47k input and MC pickups often wants more. I only have MM pickups for my PL12D turntable.
In a price list for schou there is listed a No.40 50ohm 80kohm for B&O pickup turns ratio 1:40. Perhaps this is similar. Have no idea what B&O pickup that might be though.

One of the transformers was hit a some point since the bottom lid was loose. Probably no damage done it seems since they all measure the same. The ends are just clamped together, looking inside there is another shiny metal canister which the wires enter through some wax. I didn't come out easily and I didn't want too pull on the wires so it stays inside. I can probably just push the lid tight again on with a tool.

Nicklas

[anubisgrau]

you have printed on the cans everything you need to know, it's 1:40 ratio, 20 ohm primary, 30k secondary. it's obviously an input transformer that can also serve as a MC transformer.

if you happen not to need these, please let me know. i'm a fan of JS transformers and would love to hear these in my system so i may buy them from you.

cheers!

[nickolas]

Ok, thanks for the interest I might sell them since I really don't know were to start. B&O made some pickups from the 1958-onwards but I can't find if they need any SUT with this high ratio. I first hoped that perhaps there was known suggestions on what cartridges or good vintage decks might go well with these so I could keep my eyes open if the opportunity presented itself.

I understand that both output voltage to RIAA preamp and impedance presented to pickup is of interest. So I did some digging myself and looking at the ortofon spec sheet, it looks like a Ortofon SPU classic mkII might work with these, >10ohm impedance and 200uV output. Though it seems I need a new tonearm and deck as well, in the end it is more than I am willing to spend at the moment.

What would be a fair price for these JS SUTs? One pair has the same date code, the one with loose bottom lid has another date code. They measure circa 2.7ohm primary and 2.7kohm secondary DC resistance all of them with just a couple percent tolerance between them. My component tester stated about 70mh on primary but I couldn't get a reading on secondary, it's a cheap tester though and it won't measure inductance on guitar pickups neither.

I guess it's hard to estimate the value for anyone without hearing them in your own system.

Nicklas

[anubisgrau]

i also have no idea, you would need to find that somehow.