Does anyone have a Heyboer Deluxe Reverb OT/ Mojo 773?

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lespaulnmarshall
Posts: 41
Joined: Thu Mar 26, 2020 7:00 pm

Does anyone have a Heyboer Deluxe Reverb OT/ Mojo 773?

Post by lespaulnmarshall »

Hi All,

I recently got a used Heyboer OT for a Deluxe Reverb. It came from a reliable guy, but the EIA/Model sticker is unfortunately gone. I've tested the ratio with my variac and it seems to have the winding correct ratio for a DR, however, the DCR measurement I'm getting with my DMM on the primary seems rather low. I'm getting about 160ish ohms from brown to blue. I was expecting more around the 400 ohm mark like other DR OTs that I've measured. I was curious if anyone has a Heyboer DR OT / Mojo 773, and if so what your measurements are?
I would greatly appreciate it if anyone could help!

Thanks!!
lespaulnmarshall
Posts: 41
Joined: Thu Mar 26, 2020 7:00 pm

Re: Does anyone have a Heyboer Deluxe Reverb OT/ Mojo 773?

Post by lespaulnmarshall »

In case anyone else ever finds themselves wondering about this, I just got the answer from Mojotone today. These transformers have a different stack made with thinner laminations that are a different material than the original. This then allows them to use a larger gauge wire with less turns, while keeping a somewhat similar tonal character and (of course) turns ratio. The correct DCR spec on the primary for both the MOJO 773 and 773SP is about 150 ohms DCR.

If anyone still has some closeup pics of a Mojo 773, I would really appreciate that though!
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