Bottlehead Forum

Bottlehead Kits => Eros Phono => Topic started by: maarten on November 10, 2024, 10:05:51 AM

Title: Step-up transformers: where?
Post by: maarten on November 10, 2024, 10:05:51 AM
Hi,

I just started my Eros 2.0 kit.

I will probably need a step-up as I'm targeting low output MC cartridge.
I'm targeting the Audio Technica AT33Sa, so I'm not sure if I need one actually.

Regardless, the Eros 2.0 comes equipped with "mounting holes" for step-up transformers. But I'm a bit mystified, where are these "mounting holes"?
Thanks!

Title: Re: Step-up transformers: where?
Post by: Paul Birkeland on November 10, 2024, 10:20:29 AM
The two empty holes by the RCA jacks will allow for mounting MC step-ups.

That particular cartridge is going to work well with a 1:10 or something around 1:12. 

I'm somewhat partial to these for those intermediate Japanese type cartridges.  You'll have to drill your own holes for a Jensen though.  The Sowter 1:10 with the threaded bushing mount will drop right in. 
Title: Re: Step-up transformers: where?
Post by: maarten on November 10, 2024, 09:24:15 PM
Thanks,

I am indeed thinking about a Jensen, but the kit seems tuned for Sowter.
I'm still a bit confused about mounting but you seem to have some good pictures in the pinned thread -- which I only found after asking.
I started to worry about interference/noise though! I hope to first benchmark the kit without the SU, since I won't know where the problem is if something's amiss otherwise..
Title: Re: Step-up transformers: where?
Post by: Paul Birkeland on November 11, 2024, 07:12:33 AM
Cinemag can also make step-ups with a threaded bushing.
Title: Re: Step-up transformers: where?
Post by: maarten on November 11, 2024, 07:32:22 AM
Yes, these are nice, thanks for the tip.

I'm still doubting whether to just use an external Denon AU-320, because I'm not sure how good the shielding would have to be.
Title: Re: Step-up transformers: where?
Post by: maarten on November 11, 2024, 08:00:49 AM
Just discovered one can also try potting the transformers in wax. Not sure if anyone here has experience with this..
Title: Re: Step-up transformers: where?
Post by: Paul Birkeland on November 11, 2024, 10:09:23 AM
The Sowters at least are wax potted, the others may be wax or resin potted.  The wax/resin is not there for magnetic shielding.