Dynaco St-70 or Dynaco Mark III?

[chadbang]

Does anyone have an opinon on the sonic advantages of either amp?

 

[SteveA]

Hi!

As always, the correct answer is "it depends". What do you plan to do with the amp?

Best regards,
Steve

 

[chadbang]

Opps, sorry. I'm going to use it (them) to run my main speakers -- Spica TC-50s (87 SPL 4 Ohm). The Spica's are already blessed with a fantastic midrange, but I feel if I can take the vocals up another 20% with just a touch more fullness and the fabled tube "bloom", I'll be happy for awhile to come.

 

[SteveA]

Armed with that information, it is a little easier to compare how these two might do. I think the Spica will present a challenge to either amp unless you have a small listening room and don’t expect high SPLs. For what it is worth, I used a modified Stereo 70 to drive my E-T LFT8s (84 dB for 1 watt). This pairing sounded great on small scale works but ran out of steam very quickly as could be expected.

I’ve always preferred the EL34 (Stereo 70) midrange to that of the 6550 (Mark III) although the latter generally provides better bass definition and impact.

Do you plan to leave them stock or will you take some measures to shore up some performance shortcomings?

Very best regards,
Steve

 

[chadbang]

Man, I just lost a half page post because of that last Head-fi crash .....grrrrrrrr



Anyway, the gist of it was:

I'm not a DYIer, so I guess I'm going to take what I get. Hopefully any mods for safety or longevity's sake will already have been done (there seems to be a lot of modded one for sale, but there are also a lot of unmodded ones. Which would you suggested going for?) I think the most I'm cable of is plugging in a tube. As far as power, I don't ever push my speakers loud, so I guess that isssue isn't much of a problem. It's generally me sitting in the sweet spot, eight feet from the speakers, with Frank Sinatra and a glass of scotch (that's me with the scotch, BTW). Although the 60 per channel of my Adcom GFA 535 seem just about right. Still, my last question would have to be: why do you prefer the midrange of the ST70 over the Mark III? A significant improvement?

Boy, that is a lot less entertaining of a reply than I had previously written. Sorry, Steve.

And thanks for your help, BTW

 

[rickcr42]

even though you are not a DIYer the "stock' dynas can use some help

The front end is not the best and should ideally be replaced with an updated circuit

Also the power supply caps may be leaky due to age and should be replaced,something you live with when you pursue vintage audio gear

some good stuff here :

http://www.triodeel.com/dynaco.html

http://store.yahoo.com/triodeel/index.html

http://www.quadesl.com/schematics.shtml

http://www.curcioaudio.com/dynadr_3.htm

Manuals for free download with full schematics and a dyna dedicated forum is here :

http://www.audioasylum.com/forums/dynaco/bbs.html

Not trying to scare you away , i own a LOT of dyna gear-including the very first dynaco amp :

The MK-ll !

BTW-your spicas will do well with either due to the extremely smooth impedance curve of the design

As for volume ,they were never intended as "Rock The House" loudspeakers anyway but are more for intimate listening at medium volume.

If you can manage to scare up an original Janus subwoofer you will have a system to not be ashamed of 1

vintage rick ,aged to perfection