Any one with experience with Dynaco st70 and Magnepan.

[guitarlvr]

Hi all, Let me say thanks to any info you give me.

I have been eyeing a dynaco st70 amp. I have a vacuum tube audio pre (tubes 4 HiFi)
I want to run a pair of my trusty Maggie MMG speakers. It will be used for vinyl.

Any suggestions , Opinions or other wise. From you tube guys.
Thanks for any help. Peace. Tony

 

[ejman]

Don't know about the ST70 but my Jolida 502 P has no trouble running my 1.7's or my MMG's. The 502 P is about 60 W/CH and runs 6550's or KT (88, 120, 150). I think the ST70 runs EL34 so maybe 2/3 the power of the 6550?

 

[guitarlvr]

Yes, It runs 40wpc. I have never had a hard time with my MMG's but I was told they are power hungry. I have had them for 5 years and have tried all different amps and preamp's and never had any trouble. I thought maybe I was missing something. Thank you for your reply.

 

[ejman]

Yes some people like to use extremely powerful amps with Magneplanars and in fact I have a couple of of close to 400 watt into 4 ohm SS amps ( Conrad Johnson MF 2300A and Emotiva Monoblocks) but I actually prefer the sound with my relatively low power tube amp - go figure.

But of course, I suppose it depends on the type of music one prefers and how loud. I generally listen at 70-85 db levels according to my sound meter and I also have an HSU Subwoofer.

 

[a_retent]

From the Magnepan FAQ sheet supplied with my MMGs:

"How much power do the Magneplanars require?"
Many people are satisfied with 20 to 50 watt amplifiers, especially on the smaller models. 200 watt amplifiers are the maximum recommended for Magneplanars. Amplifiers with more than 200 watts can be used, but the fuse may blow before the maximum power is reached.
Keep in mind the power requirements in your dealer's showroom are much higher than a home situation. Typically, you will be satisfied with half the power in your home that you needed in a showroom demonstration.

So, whenever I see "Magnepans like lotsa power" I call
I currently run a pair of ARC vm220 tube monoblocks on my MMGs @ 200 wrms, 4 or 8Ω. An electronic xover removes signal from 70 Hz @ 18dB per octive and redirects to a separate amp and sub. I can EASILY get the mylar to slap with knob turn to spare. I get the same result when I used my ARC D400mkII SS amp, way more power than needed for even a pair of 1.7i @ 400 wrms per ch. 4Ω. I have only had the volume that loud twice and it was for a very brief moment as it was ridiculously loud and not at all comfortable to listen to. Why anyone would want to listen to music at that spL is beyond me. I don't need my hair blown back and if I did I wouldn't be using Magneplanars to do it...that's not what they were designed for.

 

[reed338]

I have a pair of 1.7i speakers. Ive used a Conrad Johnson MV-60...sounds okay, but no where near as good as it does with my Forte's. I have generally run my Magnepans with a Mcintosh MA6600...sounds good but something always felt lacking unless I turned the system up way loud, louder than I am comfortable listening. It wasn't until I tried a bryston 4b when the speakers seemed to truly open up and play with authority. Seriously, I dont know if its power, or the fact that my other two amps had output transformer, or what..... But the bryston is a total game changer with these speakers. Im guessing the same experience applies to the MMGs. You'll be happy with whatever amp you have im sure, but Magnepan demos with bryston amps and im pretty sure now thats for good reason.

 

[primosounds]

Hi all, Let me say thanks to any info you give me.

I have been eyeing a dynaco st70 amp. I have a vacuum tube audio pre (tubes 4 HiFi)
I want to run a pair of my trusty Maggie MMG speakers. It will be used for vinyl.

Any suggestions , Opinions or other wise. From you tube guys.
Thanks for any help. Peace. Tony

My last Maggy was a 2.7qr and before that the IIIa. I used a 75w/channel MFA M75 which is PP KT88 monoblocks on the 3a. That was an awesome combination for unbelievable soundstaging (well maybe the SOTA star sapphire turntable had a major contribution to the sound quality). I had to move on since the wires on the panel started to separate which caused a very annoying buzzing. The 2.7 never sounded as good as the 3a even with the same amplification and even a more powerfull 100w tube amp. This speaker also developed the same buzzing problem from the wires leaving the plastic membrane.
To get to the point i also tried Dynaco ST 70, EICO HF87 and 89 both PP EL34 amps on both types of speakers and they were ok. They were good sounding combos but i eventually matriculated to high efficiency speakers and low power single ended amps. BTW my current speakers are Altec 19 and they are at least 50 years old with absolutely no problems and 5 watt single ended el84 amp sounds very good too and will drive the wife out of the house when playing David Bowie, or Nirvana.

 

[SteevG]

Yes, It runs 40wpc. I have never had a hard time with my MMG's but I was told they are power hungry. I have had them for 5 years and have tried all different amps and preamp's and never had any trouble. I thought maybe I was missing something. Thank you for your reply.

A good ST70 is going to push about 20-25 watts per channel. They're rated at 70 watts total (35x2) but won't honestly hit that. The sound will have a lot to do with synergy as with any combination.

Let us know as we like follow up.

Also make sure your tubes are fresh and/or good and biased correctly and give it a bit of time to warm up (a good hour).

 

[Blue Shadow]

So, whenever I see "Magnepans like lotsa power" I call

I'm close to agreeing with you. I have already been very happy with the volume levels of DQ-10s with the sub using a pair of 50W mono tube amps on the 10s. Me getting close means the Magneplanars are in the system, now and will get the tube amps when this upcoming 70 degree days go away. Not that I don't like 70° days in Phila area in mid February.

The Dynacos will be just fine to the volume level they can accomplish. And at 40 watts, twice as loud is 400 watts so you won't be too far behind those guys with the measly 200 watt solid state amps.

 

[rickl]

there is a secret room at the factory with all the amps/pres are kept. they will never recommend one amp over another but they have tried many.

the first amp jim used was an st-70. I was offered it but just couldn't take it. it is part of the magnepan history.

i've used mark iiis with great success (imho). i'm currently using a big hafler and it sounds great. not sure if the little st70 will work but do know it was used in the first prototypes.

 

[jackmowbray]

I just plugged Andy's (NJ Phoenix) highly modded Eico St-70 into my main system. I normally drive my Gunned Magnepan 1.6's with a pair of Rogue Audio M-180's with excellent results. The progression of amps I have used with these speakers started with a Rogue Audio Cronus Magnum then I switched to SS power (Adcom, CJ) which definitely satisfied the Maggies thirst for current and finally to the M-180's because tubes just sound so good with these panels.

I don't know what it is - the iron, the mods, high current, synergy - but this amp can really drive these speakers! Not the last word in tight bass but it sounds great! In the process of rolling 6sn7's and 12ax7's to firm up the bass a bit.

The mono blocks will be getting a rest for a while....

Jack

 

[grundigger]

I ran MMGs with a modified ST-70 (Triode Electronics driver board) for a while. I ended up preferring a McCormack s/s amp with the MMGs as I wanted more dynamics. If I were going to try something like tubes + MMG these days, I'd buy Bob Latino's biggest amp(s). But now I prefer SET + high sensitivity speakers.

 

[Vintagegeek]

I have ran MG-1’s with my ST-70 with good results. I have replaced the can, rectifier, bias pots, terminal strip, caps (underside), bias resistors and circuit board with one from Dynakit. It is as close to original as it gets, sounded very nice. I was surprised as the MG-1’s are quite inefficient. With a change of the rectifier tube I can roll EL34’s or 6L6’s.

 

[loonlodge]

I have a Wright 70, a similar tube amp (4 EL34's) and ran SMG's and 3A's in a room that is 14 x 24 with no problems.