Friday, August 18, 2023

Ortofon STM-72 + Weller WTCPS repair + Hakko FX-888D



One morning, I discovered the right channel of my Ortofon STM-72 was dead. While waiting for the Weller WTCPS soldering station to heat up, I carefully peeled the foilcal to pull apart the 2-piece tubular housing so I can resolder the broken cable connection(s). 


After a couple of minutes the Weller's tip was still as cold as room temp. Sure enough, the heating element retired without giving any notice. This is probably the third or fourth element I've installed since I started using it in the Angela Instruments work bench 30-some years ago.

To compound matters, it was out of stock at the Amazon store. Did I really want to wait?


Since I had other projects lined up and encouraged by Amazon points saved by Tish, I decided to splurge on a brand new Hakko FX-888D, which would be at our doorstep the next day.

The solder pads (red arrow) are where the cable connection typically breaks. Proper adjustment of the cable strain relief (blue arrow) should prevent future cable disconnection.

After completing a few more projects, the replacement EC234 heating element arrived.

 Fortunately, I had a newer BA60 barrel nut in my parts bin because the original barrel nut didn't fit. The WTCPS is back in service, albeit, as a backup to the Hakko FX-888D soldering station.👏

Back to the Ortofon...

Anatomy of the STM-72

As warm as Ike Quebec's tenor sax is a fitting description of how this MC step-up transformer sounds. If I'm deciphering it right, it's also echoed in the translation of the Stereo Sound article pictured above. 

This MC step-up device is definitely NOT for audiophiles who analyze the minutest resolution of detail in the soundstage!

 However, for those who love music, the Ortofon STM-72 complements the classic SPU or an ultra low output moving coil cartridge like the Fidelity Research FR1 MkII. It may even be the antidote to harsh sounding low Z/low output MC cartridges. That's IF, it can be acquired in the $150 price range. Beyond that, go for an Altec 4722 (or maybe the Cinemag equivalent?), which offers two levels of gain (1:18 + 1:36), wider bandwidth + better overall sound, IMHO!

It's perplexing that along with the Sony HA-T10, sellers are asking too much money for these entry-level MC transformers when both are pretty common. What gives?🤔




 

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5 comments:

  1. HamingredientAugust 21, 2023 at 9:26 AM

    Those are some TINY little transformers! I suspect the high asking prices for these little SUTs is a function of brand cachet and the "vintage & vinyl revival"...

    Nice job reviving the soldering iron! No more cold solder joints! ;-)

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    1. JEAugust 21, 2023 at 10:31 AM

      Thanks!

      I think the vintage/vinyl crowd is best served by Redboy MC step up transformers - https://www.flickr.com/photos/152614846@N06/albums/page1/ -👍🍻😊

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  2. rappaportJune 23, 2024 at 11:10 AM

    Hi Joseph
    You didn't consider replacing the captive IC with its cheap RCAs for something superior? It doesn't have to cost more than the SUT itself. Currently I'm having the time of my life with some ol' school "tweed" covered yellow/ black dotted "Studer/Sommer" ready made ICs.
    They fit right ind with their lovely warm tone yet transparent and natural top end.
    I'm seeking one of these STM-72s out and thought of replacing this with std.item.
    Cheers from DK

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    1. JEJune 24, 2024 at 3:41 PM

      I just prefer to hear the STM-72 in its original form first, then take it from there. Right now, I listen to my FM-MCT1, TKS83 and 4722 more than the STM-72.

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  3. AnonymousJuly 1, 2024 at 11:20 AM

    Thanks Joseph!
    That you found it worth toying with the STM-72 and mentioning it here, was the last gentle push I needed, having had my scepticisems about its provess😄👍

    Mine arrived today and was duely connected right away replacing an A23 SPU SUT running.the #1S (aswell being previously heard through my ANJ S-7Cz)
    The STM-72 is rather interesting prioritizing everything quite differently.
    The soundstage, width especially, shrunk immediately, with a lot less emphasis on reverb besides the anticipated reduction in "detailing" and recording artifacts.
    In exchange I got a nice weighty n' meaty center image and organic tonality with very natural voices w/o any trace of thin hardness, having enough of what matters the most - if wanting to return to what got me into this hobby; the love of music, w/o being sidetracked by all manner "irrelevant" studio gimmicks.
    Besides - most surprisingly given the size of this wee thingey - it having this big generous weighty warm organic bottom end.
    So a very welcome addition to my other SUTs.
    But to appreciate the STM-72, I guess you'll have to've been around the audio block enough times, to have grown tired of the ever increasing brightness of today. Often causing a pale thinness without enough flesh and blood. Well:
    Here's your antidote

    P.S.
    I might give it a go later with replacing the stock IC for something better. It being the kind we discarded aeons ago.

    Best regards
    rappaport










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