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| Altec 15356 + UTC A20 |
While browsing at Books Kinokuniya in NYC in the 90's, this Noguchi ad from the November 1994 MJ Audio Technology issue inspired me to experiment with line transformers as digital sound enhancers. Since I was living on a post-grad assistantship budget back then, importing this pair from Japan was out of the question.
Instead, I settled for this surplus pair of Tamura line transformers.
Wired with a mild step up (via the center tap of the primary), I found my CDs a lot more enjoyable! Perhaps that's due to the iron "taming" the op-amps in the analog output signal path of my CD player and later, Audio Alchemy DAC in the Box.
Fast forward to 2023, I used a Google translate app to decipher the chapter about line transformers + digital in Stereo Sound Tube Kingdom Issue 107. The article discussed and evaluated various vintage and modern line transformers used in the same context, albeit they recommend a 1:2 step up ratio or 150:600.
The only Western Electric components in my Hi-Fi set up is this pair of WE111C repeat coils wired 300:600.
Even if I've eliminated all the op-amps and wired an all tube analog circuit from pin 6 (AOR) & 25 (AOL) of the non oversampling TDA1541 DAC chip, I still find the "digital sound shaping" abilities of these line transformers further enhance my enjoyment of digitized music.
Line transformers are a fun experiment. Try them!🍻
Been reading about your experiments with the transformers. The UTC A-20 sold for $14.40 each back in their 62-63 catalog. Found a pair semi reasonable on ebay, though saw them as high as $600 for one. That is over my head $$ wise, but going to try mine at 300:600 ratio on my Arcam Blackbox 2 that I converted to passive I/V with 47 ohm Mills wire wound resistors. I have the 8X TDA1387 substitute chip instead of the TDA1541. For some reason, the 8X chip distorted with the Arcam discrete I/V, but it sounds very good with the passive setup. Hoping for some good listening!
ReplyDeleteDen
Not familiar with the Arcam BB2 or TDA1387, but happy tweaking!
DeleteThe BB2 is basically the same as the Arcam Delta Black Box that you mentioned in your TDA1541 entry, in fact the circuit board looks the same as far as I can tell. The TDA1387 is another Phillips DAC chip. Here is a link if you wish to read a bit of commentary on it.
Deletehttps://www.diyaudio.com/community/threads/impressions-usb-dac-tda1387-nos-vs-pcm5102a-delta-sigma.319253/
I find it similar to the TDA1541, some ways I like it better.
Den
Thanks!
DeleteWell, Den here. Got the UTC A-20's wired up 333:500. Saxophone never sounded better! I wonder how long these transformers have been sitting
Deleteidle. Did you find that yours sounded better as they were re-introduced
to some signal running through them? ISo far, these are a keeper in my book!
I've been using Tamura, UTC line transformers, etc. for digital since the 90s, the latest being the WE111C 10 or so years ago. I don't remember any break-in for any of them.
DeleteThanks
DeleteEnjoy!
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