Dynaco ST-70 and Magneplanar 1.6QR


I just got into this with an entry level system consisting of Magnapan 1.6 and a dyna st 70. I love the sound, and they work fine together ,but I dont get enough gain out of the Dynaco. Should I be getting more?, if not, is there anything I can do, short of swithcing amps that would solve this issue?

If not , do you have any $1000 amp or less alternatives to recomend?

Very grateful for any advice in this matter.
By gain do you mean volume?
I got more volume out of my old dyan-70 by getting rid of the lamp cord power 'cable' and hard wiring a 14 gauge cord with a heavy duty plug.
No doubt,it played louder.
Also,make sure your output tubes are good and dont have high hours on them.The Svetlana EL-34 is a great tube and can give you a cleaner presentaion...clean = increased percieved volume. Also,Have you tried the 4ohm tap?
The Stereo 70 will run out of steam quickly with the 1.6's, I had Rogue Magnum 120's (120 watts) and they were not enough power for my taste.
My MG 1.6 sound much better with a 350 watt Adcom amp than with a 100 watt Adcom amp having similar specs except for power. The message is clear...get more watts.
Maggies need much more power. You could try a good powered sub. If you run from the pre-amp to the sub to the amp, you can filter out all signals below a certain level (100hz?) which will greatly alleviate the strain on the 70. According to Janis Subwoofers, if you eliminate all bass below 100hz, you effectively quadrupal the power available to the speakers!
Thanks for all the great advice. I am a novice in the hi fi area, but I realize that I am plummeting into the rabbit hole fast. ... I got the Maggie 1.6, loving the open sound, but felt that they needed some warmth, and therefore combined them with the Dyna - 70. It actually sounds good, as long as the music is not to demanding, and kept low...

So here is my probem I guess, is there any tube amp I could afford that provides 100W per channel or more? , ( would that do the trick?)
budget is about 1k....

alternatively, on the same budget, is there a solid state amp with warmth...? , again, thanks alot for all your advice..
As far as solid state in your price range, you might want to consider something like a McCormack DNA 1 (100 wpc)or DNA 125 (125 wpc). Check the archives for other people's opinions on these amps. Perhaps you could introduce tubes via a preamp? Good luck and have fun.
If you are open to experimentation, you could try a pre-owned B&K ST140 @105 wpc. Another possibility is one of the older SA series hybrid amps by Counterpoint.

I drove an older pair of MGIIIs with an ST140 for several years, in a smallish room. As long as your volume demands aren't huge, it can do a very adequate job. Buying a used one will still leave lots left over in your budget for quality cables.
As stated here above unfortunately the 1.6's do require a lot of watts. Further because of their flat 4 ohm load impedance they also require a lot of current which really means a good SS amp with a beafy power supply. Also due to the Magies' single ended magnet arrangement and the large driver surface area, good amounts of damping factor is also a requisite for control of the diaphragm.

A lot of Magie 1.6QR owners, myself included are using Odyssey Stratos amps that go around $1,100 new and $800 to $900 used. They pretty much meet the above requirements putting out 150W into 8 ohms and 280W into 4ohms and most imortantly having a good size power supply for current delivery. It's a very nice and sweet sounding amp with very good bass response albeit not a tubey sounding one (don't know any SS amp that sounds like tubes anyway) that is higly regarded many audiophiles. Paired with a good tube pre the stratos will let the warmth from the tubes come through and again that's what a great number of Magie/Stratos owners have in their systems. There's also an upgrade to the Stratos that costs about $75 and which doubles the storage capacitance of the power supply for even greater current capability.

You might also want to check, if not having done so already the following two forums for a lot more info on Magnepans and Odyssey respectively:



Happy listening!
I tried 3 defferent tube amps with my 1.6s and never got them to liven up, though the Manley Stingray did pretty good and with only 50 watts too.

I ended up going with SS and even then, with a Plinius SA100 MKIII 100 watts per channel class A, I wanted more power. I believe with Maggies you end up craving more and more power, and finally I decided I did not have enough money to get what I wanted for an amp and I sold them.

The moral of the story is: Learn to live with limited dynamic range unless you can throw some serious cash at a high power amp with any Maggie speaker.
I am sure that the various audiophile 100 to 150 watt amps mentioned above may improve performance in subtle ways. However, for the same, or less money, you can have 350 watts of Adcom amp. The difference will not be subtle.
By the way, when you get your new amp I'll take the Dynaco off your hands!

Seriously, the Dynaco is a nice piece, but just doesn't have the muscle needed for the Maggies. However, before you dispose of it, you might try biamping the MG 1.6. The Dynaco would suffice to power the tweeters, and you would retain that "tube sound" (warm-sounding harmonic distortion).
Eldartford, thanks for suggestion, but I have a question, do you mean that ,if merely running the tweeters, the dyna could deliver more volume?

also , it does indeed seem like I have to sell the dynaco, so if you are interested, here is a link to the closed ebay auction where I bought it.

I will try the tweeter setup tonight. Thanks;
Andersd...Volume means voltage gain (not really power) so it's possible that your preamp is just not driving the power amp with enough signal. One thing that you could try would be to connect your 4 ohm speakers to the 8 ohm outputs of the power amp. This will get you more voltage to the speakers although the power amp wattage capability (which may not be the limiting factor) will be less.

It's a long time since I played around with tubes, but I suspect that there is a 12AX7 input stage in the power amp. I hope you don't have a 12AU7 pluged in by mistake: that would lower gain. The driver for the output stage is probably a 12AU7: they might be swapped around.

You really ought to be able to play those speakers loud with your amp, and the symptom of insufficient power would be distortion, particularly clipping, rather than low volume.

All this being said, I still suggest you try a much more powerful amp, and find out how good your speakers really are.
Eldartford, which adcom amp are you using?

Andersd...My amp is the GFA-5503, which is the three-channel version of the GFA-5502 that you probably want. These amps are rated at 200 watts into 8 ohms, and 350 watts into 4 ohms (which is what the MG 1.6 are). I paid only $875 for my amp which was "B stock" (demo or mfg repaired) and it came from an authorized dealer with full warrantee, and I have no problems. (Someone "broke it in" for me, if you believe in that).

Magneplanar speakers are a very "easy" (resistive) load for the power amp, so I doubt that some of the very expensive amps would do much better than the Adcom when used with Magneplanars. If you were driving the MG 1.6 with the Adcom you would have a valid basis of comparison if you ever were to consider one of the very high end amps.

Go look at the Adcom website www.adcom.com for full details.

Thanks again, your advice is really appreciated as this is a "on a budget mission" .. I found some 5503's at better prices than the 5502, is there any drawback or benefit for me to go with the 5503 vs the other? ,
also what do you think of the 555?

Lastly, here is a curious thing. Some time ago I emailed Jolida to ask if they had a tube amp that could drive the 1.6s./. they answered as below.

The 502B, 801 or the JD 1000A could easily drive them.
Michael Allen

I dont know what to think?

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

you lost me here?

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.
 The 1,6qr maggies need power , i  have a musical fidelity nu vista m3  with the 1.6 its like 400w into 4 ohms with a monster supply.It sounds great ,i have had smg's,2's,3a with and without many different subs,velodyne,sunfire,etc. Imo maggies will get some substantial volume defintley better with a sub or even two smaller faster subs. either way ya pay for powered subs or amps.I biamped my mg3a cj and krell that was nice.( got the krell 150 for 1500,then added the cj later) 

Old thread, wish I could go back 13 years to chat with the op.

I'd recommend replacing or trading the 70s for a pair of Dynaco Mark IIIs,  replace all the 12ax7s with nos eico's, and replace the output tubes with nos Svetlana 6550s made from St. Petersburg Russia, and replace the speakers with a klipsch towers.  Will blow your 1000.00 a bit, but not by much.
agree with some of the post here on needing a ss amp with power.  if you want a warm sounding amp that would sound very good for the money you can not beat B&K amps.   a st140 is a good start but a st 202 and up would be better.  the amps are available for  $250 ---&400  on the used market.. very cheep for what they can do in sound quality.  odyssey audio are very good also but $1,000 is not going to get you one unless you find a stereo model.   an adcom 5500 would be another amp that would give you all the power and volume you want.   they are  for sale all the time and you can get one for $400 and up very easy.   so there you go,  amps with plenty of power and very affordable and would sound great with your speakers.  
When I mentioned replacement of all the 12ax7s with good nos, I forgot to mention that I was referring to my pas2.  Nothing has brought my 60wpc Mark iiis to life like a nice Dynaco preamp.   Running some pretty efficient speakers and the addition of a nice source, the Oppo 103d, soon to be replaced by a 95 which I purchased yesterday and also which brought me to Audiogon,  is what enabled me to bring that volume control knob down below 5 or so for my upper end.  I use the oppo to dial it in from there.

I'm admittedly a newbie to this audio stuff, but these tube amps sound so sweat, they put you in a trance and have you enjoying music you've heard before... but just somehow missed the whole deal.

Not knocking my old solid state system, powered by my Kenwood L-09s with an 07 preamp and an oppo 83 source, for full range sound, but nothing messages the brain like those dynacos. In my limited experience that is.