ST-120 - I completed the build of one of Bob's ST-120s about six months ago. The kit included all of the offered upgrades/extras. The build went smooth with only one glitch during initial testing. Following the initial voltage measurements, per the instructions, I installed the tubes and upon powering up, the rectifier tube fizzled and the fuse blew. After going over the wiring several more times, I finally had to contact Bob who asked that I check the mains voltage. Turns out it was 126.6v. The power company was contacted and they came out, measured 127v and stated, "that is high, but within tolerance." So, the ST-120 is now hooked up to a Variac with an output of 117.5v. I believe Bob said that the upper limit for the ST-120, and any tube amp without a voltage regulator, is about 122v. Bottom line, great kit and a great sounding amplifier. Until recently, it has been hooked up to a Heathkit AP-1800 preamp along with an AA-1600 and McIntosh MC-2105 power amp. The ST-120 is now the top choice. (Except maybe on those hot afternoons since the room is 90% glass on the west side) The only things unique are the brass legs that I turned on the lathe and the plugs I made that allowed mounting the LEDs from the Time Delay Relay circuit at the front sockets.
SP-9 - Following the ST-120 build I decided I wanted a full-tube system for listening to vinyl. So I chose the SP-9, with upgraded resistors and caps, that Roy offers. The kit went together quite well, with some reference to related books. (I'm just a hobbiest and not an EE by any stretch) The preamp sounds fantastic with no hum or background noise of any type. Here's what I found really surprising - I selected the SP-9 for the tone controls. For my current SS system, I use the tone controls as well as a graphic equalizer to get the sound I like. So, I was concerned with building a preamp without tone controls. Turns out, I get the sound I like from the SP-9 with the tone controls in their neutral position.
PH-14 - To complete the system I selected the PH-14 kit. Following the gain calculations that Roy did for me, for my particular cartridge, I decided to add a MC step-up circuit to the PH-14. This would save me some $ versus purchasing an MC step-up transformer. The kit went together quite easily and was an enjoyable project. I did change my mind during the build and upgraded the resistors and caps. The PH-14 also sounds great with no noise unless going through the MC circuit I added and then, only with the preamp volume pot nearly rotated to its extreme position. (this was tested with the phono arm held above the album, of course)
The above system components are outstanding and I found them to be a real bargain. Given the system performance, my next project will include Roy's SP-14 (now that I know I don't need tone controls), PH-14 and VTA Mk III circuit boards along with dynakitparts Mk III transformers, quadcaps and chokes. I'm planning an integrated stereo tube amp with all tubes on display. Did consider going with M-125s that Bob offers for the power stage but the weight of the transformers alone nearly take up the entire wieght target.
Anyway, here are some photos - I thought the descriptions added in photobucket would show up...