Here's the 2nd of my two original Dyna to VTA ST-70 upgrades. This one was a factory wired version. The factory rivets made getting things off the chassis a bit harder, but was otherwise pretty much the same process as the first build.
The two amps are now in a vertical bi-amp configuration, and sound wonderful together. I had a few bugs to work out on the 2nd amp. About the time I sorted everything out, a new porblem popped up on the first amp that been working great for about six weeks. Once that problem was fixed, my old Lazarus preamp acted up and needed to be recapped and some new resistors installed. All's well with the system now, and am happy to say it's never sounded better. There are some definite improvements with the bi-amped setup...especially with separation and soundstage. After some experimentation, I'm using EH EL-34s on the mid/tweeter channels in triode, and Nesstone EL34s on the woofer sides. There's a powered subwoofer hooked up too operating below ~ 50hz.
The two amps are now in a vertical bi-amp configuration, and sound wonderful together. I had a few bugs to work out on the 2nd amp. About the time I sorted everything out, a new porblem popped up on the first amp that been working great for about six weeks. Once that problem was fixed, my old Lazarus preamp acted up and needed to be recapped and some new resistors installed. All's well with the system now, and am happy to say it's never sounded better. There are some definite improvements with the bi-amped setup...especially with separation and soundstage. After some experimentation, I'm using EH EL-34s on the mid/tweeter channels in triode, and Nesstone EL34s on the woofer sides. There's a powered subwoofer hooked up too operating below ~ 50hz.