[avahifi]

We still send out several free sets of our Ultravalve upgrade plans each week to those interested in improving their old Dyna ST 70 amplifiers. It seems like lots of people would like more for this very old amplifier.

Its pretty obvious that PeterCapo has never listened to our version of this amplifier (the Ultimate 70). I invite him to email me at avahifi.com and request the free rebuild plans.

We certainly don't want to discourage anyone from simply bringing an old ST-70 back up to good original working order, but they can make it so much better for low cost, especially since much of the needed restoration work is already included in our $445 rebuild kit (complete new power supply parts, all new capacitors and resistors, new double sided ground plate audio board and more).

[Tyson]

To answer the original question, I'd take a modern update of the Dynaco's over a chip amp any day of the week, and twice on Sunday's.  Great examples are the AVA mod mentioned above, and the Bob Latino version over at tubes4hifi.com - One thing I like about the Latino versions in particular is that if you like the sound of the ST70 (35 watts), but need more power, they have the ST120 (60 watts) which is the same circuit but more power.  And if even that isn't enough power they have the M125 monoblocks (125 watts) with the same circuit but in monoblocks.  Personally I love the sound of the modern updates of the old Dynacos.  Oh, I forgot to mention, the tube4hifi also offers an optional octal board (using 6SN7 tubes) which really ramps up the performance to another level.  With the octal boards, it's one of the best tube amps around, regardless of cost.

[PeterCapo]

We still send out several free sets of our Ultravalve upgrade plans each week to those interested in improving their old Dyna ST 70 amplifiers. It seems like lots of people would like more for this very old amplifier. ... Its pretty obvious that PeterCapo has never listened to our version of this amplifier (the Ultimate 70). I invite him to email me at avahifi.com and request the free rebuild plans. ...

I have listened to aged Dynacos in disrepair and know how awful they can sound.  But some time ago I restored Mark III monoblocks and they sounded terrific.  Much more recently, I restored a PAS according to the original circuit topology as well as built a new Stereo 70 to the original Dynaco circuit. In my living room I've compared them with my Parasound Halo JC-2 and Halo A21, Cary SLI-80 Signature, Cary SLP-98L, McIntosh MC275MkIV, a Jolida tube amp, an Antique Sound Lab tube amp and probably some other pieces I've forgotten about.

So, I think I've got some pretty good points of reference.  And how did they compare?  In most cases, the Dynacos held up quite respectably.  In the other cases the Dynacos were preferable and even my wife thought so.  And, no, neither of us is hard of hearing.  These original Dynaco circuits acquitted themselves well, against these more expensive, so-called "modern" products.  There simply isn't any need to change away from the original Dynaco circuit topology if you just install fresh parts 1:1.

I am not singling anyone out in this thread - hope this is understood.  Don't care to belabor the subject, either.  But, I do hope that the audiophile community, for its own sake, won't continue to be roped into specious notions circulating around on the Internet about the original Dynacos.  Hopefully, folks will feel free to explore and even realize the fine sonic potential of their original Dynacos, remaining as original Dynaco circuits.

[PeterCapo]

PS - Always happy to pick up another amp and have nothing against building yours, Frank.  Hopefully one of these days I'll find some time to get around to it.

[rollo]

 Peter a great circuit is a great circuit. Not many NEW circuit designs about. New and better parts available today. Maybe better power supply findings today, however that Dynaco circuit is still a winner every day it is heard and even better brought up to snuff.


charles

[Tyson]

I've always wanted to hear a Will Vincent restoration - they keep the original circuit & just update parts & stuff.  However the design/paint/casework looks very cool:

[PeterCapo]

That's really cool...