DIY Hasimoto HM-3 SUT

[ZZMoko]

Well these transformers are now becoming very Fashionable on LH so here's my effort

All ready to get started



Drilling all the holes



Now ready for the hard bit

[ZZMoko]

Thanks to Graham and his brilliant wiring circuit even I was able to wire everything correctly first time



And now the finished article in proper Shindo Green for the full Japanese SUT effect



Now for some serious listening.......

[gthang]

Very nice David.  

The copper lining looks good, are they sufficiently hum free?

I found dropping in the stickers in place very difficult, I could'nt bring myself to let go for fear of miss-aligning.

[ZZMoko]

Yes hum free I'm not sure how much effect the copper has I just copied it off that HiFi Heroin site as they seem to know their way around SUT building.

In regards to the stickers I couldn't get the backing off so had to use some double sided tape instead I think they are straight but it's hard to be exact.

[difool]

Since I do have a HM-3 and Problems with hum: can you link me to the wiring circuit, please?

[rfgumby]

Magnetic hum shielding requires ferrous metals to shield.  That would more specifically be electromagnetic not electrostatic hum.  Iron needs to be present for metal to be ferrous, copper and aluminum are non-ferrous so don't help appreciably with hum.

Copper and aluminum shielding works well for RF shielding however.  So it will help keep stray RF from being modulated in your gain stages.

[low pitch]

The stickers have a thin protective layer on the front as well (if you didn't already spot it).  Quite hard to get off, but they look beautiful without and will of course sound MUCH better.  The best way to get the back and front layer off is a sharp modelling knife to find the edge.  I think the best way to get the position right before you drop them on (whcih I never thought of until just now) is to use a bit of bluetack and a stick, rather than just your fingers.  I dont have the SUTs but some other Hasimoto trannies. Interested in your impression of them.
martin

[ZZMoko]

I think I will stay with the double sided tape I would hate to damage the stickers with a knife....and I know with my clumsiness that's exactly what would happen 

The case is aluminuim lined with copper, Graham used MuMetal to line his but I've no idea where he got it from. Positioning wise I have put my SUT as far away as possible from any electrical sources to try to limit any interference

I can't seem to load the drawing up to the site but if you PM your email I can forward it to you.

As to how the transformers sound I can only add to what Graham said they just seem to add more air and space to the sound.... With Blue Note records the studio appears to be bigger with more space between the instruments if that makes sense

[low pitch]

leave the double sided tape, but pick at the top with your finger nail to get the protective layer off - it is like what aluminium sheet comes with. Shame to leave it on, looks really nice.
martin

[gthang]

David, I've just picked the top layer off with my nail, dead easy and they look 100 x better.

[ZZMoko]

Mine are now off as well, yes a bit of finger nail and a smidge of courage did the job....thanks for pointing it out they now look much better

[ropie]

Love that turquoise, David

[jervill]

Looks nice David!

[ZZMoko]

Well I finally managed to figure a way to upload Graham's wiring diagram for anybody else who wants to follow this for themselves.



Thanks for Graham for drawing this out for us beginners  that can't follow proper electric circuit diagrams 

[Chris65]

Very nice David. Have you guys got a good source for the HM-3's?

(and I won't make any comment about this thread being in 'Amplifiers'.................. )