Dynaco ST-70 and Magneplanar 1.6QR

If you can get the 5503 for less than a 5502, do it. The amp doesn't mind having one channel unused. Also, if you ever get into multichannel sound, the 3 channels will be useful.

The 555 was very well regarded when it came out, but that's a long time ago. I think you would be better off with a current model.

Regarding Jolida...any amp will "drive" the MG 1.6, but not all will do it in a way that extracts the full capabilities of the speaker.

the input tubes of a ST-70 are 7199's

David,

you lost me here?

A

Andersd...David says that the Dynaco st-70 uses a tube type 7199, not the more common 12AX7 which I mentioned. I assume he is correct. Whatever the proper tube is, my point is that you should make sure you have the right kind plugged in. Many small dual triode tubes will work, sort of, when substituted, but parameters like gain will be affected.

I have owned the Dynaco ST-70, (Cursio's version), and the Mag. 1.5QR for quite a long time. Many other amps came along then, yet I still own the ST-70.
The trouble with this combination is two fold.
1) Loudness level is limited
2) Yet within those limits, dynamic contrast is constrain
A fairly cheap and musical solution to these problems could be solve by bying a used 200 watts Rotel solid state amp.
Of course, many higher power tube amps will do the trick but will cost much more, yet most of them will use the 6550 output tube, so dont expect the sweethness and the thruthfull timbre and tonality to compete with an EL 34 based amp like yours.
I have own a Conrad Jonhson MV 100, EL 34 based tube amp delivering 100 watts. Althought the 1.5 werent around then, this could work very well indeed and might cost 1,200 or so.