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Summit and TACT SDAI 2175 Integrated Amp

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edwinr

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Out of interest, how many people have tried their Summits or Vantages with the TACT amplifier?

I tried the TACT at home with my new Summits and I was surprised to learn the Summits wouldn't switch these speakers from standby to active. As you know, the Summits are meant to switch from standby when they detect a musical signal. But with the TACT, they don't. What you get is a muted signal from the Summits and the speakers operate with the status light indicating yellow rather than green.

I switched amplifers to another s/s device, and the Summits operated as they should do. I checked with the local dealer, and he contacted TACT. There appears to be a consensus that the TACT doesn't send enough DC signal with the musical signal to activate the Summits.

If this is the case, either TACT or ML will have to consider this issue because there is an increasing move to so-called 'digital' amplifiers in the market.

I am hoping the TACT didn't damage my ML's. I don't think so, because they appear to be operating normally at the moment.
 
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Joey_V

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For one, are your Summits "modded" for digital amps? I know that older Summits dont have the modded circuits built in for proper digital amp usage... you need to contact ML to verify that your Summits are of the newer batch - ones which have the modded circuitry built in. If you're an owner of an older stock Summit, then you will need ML to send to you the mod so you can do it yourself.

If this isnt the problem, then the OP's question is beyond me.
 

edwinr

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Thanks for that. I didn't realise that ML had modified the Summit. I just bought them so I imagine they're from the new batch - but you never know. I'll contact ML.
 

garmtz

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I have been using a Lyngdorf SDA 2175 very succesfully with my Vantage speakers. In fact, the Lyngdorf really makes the Vantage sing and has no problems with the load. It saw off a €9000 Chord amplifier in some aspects, like focus and definition.
 

edwinr

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My dealer has advised, after speaking with Peter Lyngdorf (TACT), and Martin Logan, that the ML's run twin digital type amplifiers in each Summit. Therefore you can't run another digital amplifer unless you remove the ground from the Summit's power cable. Apparently there was a ground loop problem using the standard Summit power cables. I am now being supplied with modified power cables and my TACT amp is being returned after testing okay with the store's demo Summits. Cool... :)
 

garmtz

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Strange... My Vantage also have an earth, but they do work fine with my Lyngdorf/TacT. Maybe the ground is not connected internally?
 

edwinr

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It is strange. But I have to take the explanation at face value. I get my amp back tday so I'll see if their explanation has any validity.
 

JonFo

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garmtz said:
Strange... My Vantage also have an earth, but they do work fine with my Lyngdorf/TacT. Maybe the ground is not connected internally?
Could be, I was mildly surprised when I opened up my 'Donor' SL3 to find that the three wire EIC plug had nothing connected to the ground wire internally. So even though it had a three-prong power cord, it essentially was wired as a Line / Earth arrangement, no ground.
 

Peter Hogan

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JonFo said:
Could be, I was mildly surprised when I opened up my 'Donor' SL3 to find that the three wire EIC plug had nothing connected to the ground wire internally. So even though it had a three-prong power cord, it essentially was wired as a Line / Earth arrangement, no ground.
Hi,
Your SL3's have no built in amp, as the Vantage does. My CLS's have no ground connection either. I'd be pretty certain that they would use the ground pin with the built in amplifier.

Peter
 

JonFo

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Peter Hogan said:
Hi,
Your SL3's have no built in amp, as the Vantage does. My CLS's have no ground connection either. I'd be pretty certain that they would use the ground pin with the built in amplifier.

Peter
Peter, quite right. I keep forgetting that ML is now putting amps in more of the line. A good thing, as we all know that bi-amping is a benefit.

But it will introduce opportunities for ground loops.
 

edwinr

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Okay, I've got my Tact amplifier back. The dealer provided modified power cords with the ground pin removed from the wall plug. They also provided a pair of Cardas balanced interconnects to try with my CEC belt drive CD player - which is optimised for balanced operation.

I am now pleased to say the entire system is operating as it should. The Summits are switching on and off as they should with a musical signal, and I can now hear the Tact amplifer driving the Summits in their full glory. Obviously it will be a fairly lengthy 'burn-in' period. Maybe a couple of weeks or so as the Summits are brand new.

But frankly, I just could not believe that the solution to the Summit's inability to activate with musical signals could be solved by such a simple fix.

One thing I will say, after auditioning the Vantage in my home as well, the Summit is a totally different loudspeaker. I know that sounds banal, but that's how I call it. The Vantage is vastly more room friendly and probably more accessible to the casual listener.

Now the Summit sounded a little ordinary when I finally got it going. But I started moving the things around and adjusted my listening position until I felt more comfortable with them. Finally I acheived a sweet spot where the soundstaging and imaging began to take some form. I played a few CD's through them and they started to loosen up quite a bit. The shock was, that the CD's I was playing were the limiting factor. The Summits were merely reproducing what was on the discs - I thought they were good recordings. But guess what? The quality as reproduced on the Summits would have done Mr. Hoover proud.

So I dragged out a few more Cd's I hadn't heard in a while, fullpriced CD's from Telarc and Philips and a couple of other well respected labels. Now we were starting to gell. I adjusted the bass controls with a zero on the 25hz and minus 3 on the 50hz. The everything started to make sense. I had top to bottom coherency, a full and beautifully extended bass without boom, and detail that started to leap out of the panels. Yum!

I pulled the Summits a little further out from the wall - around 4 feet (measured from the top of the panel) and the central image locked into the centre. These speakers are incredible and they still have lots of room for improvement. This is not to suggest the Vantage is less of a loudspeaker. I'm just suggesting that the Summit is so much more - if you get my drift. ;)
 
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