Add me to the ST-120 “fan” club please.
I finished mine just over 6 weeks ago. It’s been playing pretty steadily ever since.
I made the mistake of not getting the low gain driver board originally so I ended up buying the kit for one and swapping it out.
Right now it’s running a Psvane 12AU7 in the center position and Electro Harmonix 12AU7s in the outboard positions. For the rectifier I’ve installed a Weber “CopperCap” WZ68. Output tubes are a matched quad of Tung Sol KT120s. All available options have been installed. The time delay board is an absolute essential here in Central Florida with our blinkie-blinkie power. The stepped attenuator is especially nice in my system as my preamp (McIntosh C32) has a good bit of gain.
There are only 2 places where I “strayed” from the original kit components. (1) Since the low gain driver board specifies .33uF coupling capacitors rather than .22uF I installed a set of Mundorf .33uF 630V. (2) I purchased off of eBay one of the bias point kits to replace the normal octal sockets. The reason for this is that I have a set of specially constructed leads for my DVOM that fit these connections. If I ever decide to sell the amp (no time soon) I’ll put the octals back in
I am very VERY pleased with what I’m hearing. Mine spends most of the time in triode mode but every now and then I’ll flip it over to ultra-linear. Several people have now been to my house and heard my system with the ST-120. To date everyone has been very impressed.
If you’re “on the fence” about getting any one of the three offerings my advice is DO IT. Today. In kit form it’s easy to build and the step-by-step instructions are excellent. If you’re not comfortable with a soldering iron then get Bob to build one for you. Either way you’ll end up with an amplifier that sounds WAY better than it has any right to at its price point.
Many MANY thanks go out to Bob and Roy for their fine products, excellent support, and dedication to the audio “niche” known as Dynaco/Dynakit.
Here’s a picture of mine singing…