New PS for a New York Audio Labs SuperIt Phono Preamp

Here's a bit of audio work that I got done over the last few weekends.
The New York Audio Labs SuperIt phono preamp was a low cost tube/fet hybrid phono stage that punched way above its price point. It was well reviewed in the audio mags and had a bit of an underground following as a good unit to tweak. It uses regulated power supplies, FET/12AX7 cascodes as the gain elements, and an FET source follower on the output. With some tweaks to the power supply and some simple parts upgrades it can be a real giant killer. It was originally sourced with an external wallwart power supply which was just a big external transformer with 220v and 12v secondaries. I tweaked a couple of these a decade ago and kept one for myself and gave one to my brother-in-law. The transformer in the one that I gave away gave up the ghost so it got sent back to me for repair. I couldn't salvage the old transformer so I put together a new power supply using a couple of toroid transformers from Avel Lindberg. I put it in a nice small 8"x5"x3" box and it seems to work reasonably well. I included a fuse, and on/off switch, a polarity reversal switch which determines which side of the transformer primaries go to "hot" and a 5 pin connector from Switchcraft's Mini-Con-X series for the umbilical. I also added snubbers for the two transformers with values based on testing the actual transformers. Here's a sketch of the power supply schematic and a few photos of the finished unit. It's a bit of a rats nest because space was tight but it works fine.
 

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je2a3

Senior Member
I never owned a Moscode Super IT, but heard this preamp in a friend's system in the 80s, very musical! Back then a wall-wart still had to have iron inside, SMPS was but a dream. But that outboard power supply is really the proper way to go!👍

I remember one of the guys who worked for Moscode, Andy Fuchs. He set up GSI in Bloomfield, NJ. I used to hang out in his shop and bought the cascoded/differential 6922 PC board to modify my Dyna ST70. Right next door was a surplus store, Electronic Barn.
 
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The SuperIt is a modern take on the classic RCA phono stage that everyone seems to use as the starting point for their own designs. It just adds late 1980s variations on that theme - FET/Tube cascodes, regulated HV and filament supplies, and a bit more output "oomph" with an FET source follower. There's a schematic that's been floating around the web forever, which I've attached.

Regarding Andy Fuchs and GTI, I'd forgotten all about him. Looks he's still around selling guitar amplifiers under the company name Fuchs Audio. I never listened to modded gear with his boards but I do see that someone is selling a GTI Dynaco ST70 about 1 1/2 hours drive away. But now is not a good time to be driving around California meeting people, even for classic old gear :(.
 

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