Dynamite ST-70

[Thoburn]

Anybody have experience with the Dynakit ST-70 kit. I have found a replacement for the 7199 tube. I need something with more umph that a 300B amp. I built a Frugelhorn MK3 with an Alpair driver that is only 85 Db rated and my Stereomour doesn't driver them well. This for a secondary system for down stairs and the room is large.

[Grainger49]

I still have one.  It did well with lower sensitivity speakers where my Paramours didn't.

What seems odd to me is horns and lower sensitivity.  That one is a head scratcher.

[Zimmer64]

Can't help with the Dynakit, but I have built the VTA St-70 (tubes4hifi.com), which I use in my main system. The kit is great and so is the sound. There also is a support forum: http://dynacotubeaudio.forumotion.com

Michael

[corndog71]

I second VTA!  They also sell a 60 watt stereo version called the ST120.  It's a great amp and can be made even better with some tweaking. 

[Thoburn]

Thanks guys for the input. The ST-120 is a little to expensive for this project. I'll start stashing away some of the beer money and get an ST-70 kit. Much appreciated.

[Thoburn]

Anybody have experience with the Dynakit ST-70 kit. I have found a replacement for the 7199 tube. I need something with more umph that a 300B amp. I built a Frugelhorn MK3 with an Alpair driver that is only 85 Db rated and my Stereomour doesn't driver them well. This for a secondary system for down stairs and the room is large.

Ok. The Alpair 7.3 have some hours on them now and I have to modify my first impression. At low to moderate listening levels with singer song writer music (Diana Krall, Nora Jones, Melody Gardot) they sound great with my Stereomour. Just don't try Beethoven's Ninth. I did. Maybe with a few hundred hours on them I'll try it again.

These Frugelhorn Mk3 with the Alpair 7.3 are an amazing speaker even though they are only 85 Db.

[Paul Birkeland]

I'll offer a little tidbit of thought on this matter. 

The maximum excursion on that particular driver is 4mm one way (noted for bass peaks, not sustained input), this would be 1 Watt of power at 55Hz.  Loading may or may not buy you a little more power handling.  At 75Hz, you can take more like 4W.

I'd still try a bigger push-pull amp, just for a point of comparison. 

-PB