Kiwi with some queries

[Stereonerd]

Hi ML fans.
I live way down in New Zealand, and had heard and lusted over MLs several times while editing a local magazine that revolved around the subjects of home theatre and hi-fi.
I finally got the chance to buy myself a pair when the company distributing ML in NZ stopped doing so (sadly) and put their remaining stock on sale (happily for me).
I bought the powered PURITY speakers, which in most respects sound amazing - I've never owned speakers that are as forensically detailed, or have such a perfectly, pin-point placed sound field.
I could do with a little bit of advice as an ML and Purity novice, however. One of your members has already recommended I buy some room treatments to deal with the sometimes unbearable sharpness I'm getting from less than perfect recordings. But I'm thinking that this sharpness could also be reinforced by a few other factors, like my pre-amp, or the RCA cables that run from the speakers to the preamp. So...
* Does anyone have any recommendations for good quality RCAs?
* Does anyone have any recommendations for preamps that are particularly splendid with MLs, and particularly the Purity?
There are a couple of other things, too. If there are other owners of Purity's, or experts on this model, I'd love to know whether the onboard power amp is really the optimum amp, or if connecting an external power amp can produce better results? Also, I'd really like a definitive answer as to whether connecting conventional wiring to these speakers and running an external amp means the onboard amp is completely bypassed, or just passively processes the information (ie, colors it in some way).
I now co-run NZ's hi-fi/home theatre site www.witchdoctor.co.nz on which I have reviewed the speakers, but the questions above still nag me.
It's a real pity that ML now don't have a distributor locally in NZ, and I hope they appoint a new one soon!
Gary

 

[Krazikiwi]

The Edge

Hi Gary,

Welcome to the forum from another 'local'. The D Class type of amp used in the Purity sometimes gets the finger pointed at it because of the symptoms you describe.

A more "rounded" preamp tonally or even a valve design could take the edge off the sound, some " darker" sounding cables likewise ( I use Cardas).

Longer term, listening to a pre/ power amp combination that is not so "etched" might be better for you. Try listening to a New Zealand company like Plinius and you will probably solve a lot of what you hear.

What source are you using?

Remember, these speakers are ruthless in exposing the chain driving them, transparency is their forte.

fjeff

 

[projectormovielover]

Try some nordost blue heaven or some satori's for rca

Go for a mcintosh amp with a tube pre for smooth airy sounds

 

[Bernard]

Guys, am I missing something here ? I don't know the Puritys, so I went on to the ML site to check them out. They have an onboard power amp which cannot be bypassed, so why would anyone recommend an external power amp?

The ML site says that they can be driven with a receiver, but then it seems obvious that the signal is just dropped to line level before being amplified by the internal amp.

 

[MPS]

Based on you description I would recommend: EAR912 Professional Tube Control Centre
http://www.ear-yoshino.com/pdf/912%20Brochure.pdf

 

[Krazikiwi]

Amp? Watt amp?!

Guys, am I missing something here ? I don't know the Puritys, so I went on to the ML site to check them out. They have an onboard power amp which cannot be bypassed, so why would anyone recommend an external power amp?

The ML site says that they can be driven with a receiver, but then it seems obvious that the signal is just dropped to line level before being amplified by the internal amp.

Have a look here
http://www.hometheaterhifi.com/speakers/273-a-secrets-speaker-review.html
Interesting that he talks about using McIntosh amps.

Jeff

 

[Stereonerd]

Thanks to all for your advice.
I'm using a Rotel RC-1550 preamp, and think this may be my biggest problem.
Although, since I wrote to this forum, I have gone back to using my lovely Yamaha CD-S2000 SACD player, and that's warmed things up considerably.
It's interesting that, for all the information on the ML site, that there's nothing definitive (that I can find) written about the powered amp in the Purity speakers.
So, you can't bypass the inbuilt amp by using another amp. So, why are there binding posts, and why is there an option to use your own amp? Presumably, one would get SOME of the sonic benefits of your own amp, but the sound would be coloured by going through the inbuilt amp as well?
Also, would appreciate advice on whether members think I would benefit by having a subwoofer. My lounge is 19 (long) by 17 (wide) ft. The bass response of the MLs seems ample to me, but...

 

[Bigdaddynz]

Hi Gary, I've just come across and read your review of the Purities, and I can say that I agree with everything you say. I too got a pair off Trademe from the distributor for $3500 NZD, much cheaper than the normal price. It is a pity that Greg is no longer the distributor.

The Purities auto sense which signal source is being used, and switches to those inputs. If you have an RCA cable connected to them, they will use the onboard power amps, and if you wire up another amplifier to the speaker terminals, the Purities will use that signal source. As far as I know, the input not being used is switched out of circuit. They do need good room positioning, and there is a sweet spot for listening. They are far more detailed and bass extension is way much better than the Celestion SL6's I previously was using. I'm currently using a Craft C4 preamp and Audiolab 8000P power amp with a Linn Lp12 / Sumiko/Supex front end, with Audioquest interconnects. Some of that gear is quite old, and I wouldn't mind taking a look at some of the Cambridge Audio kit in the future. The Purities can be a tad bright at times, but I was putting this down to break-in time.

As to subwoofers, well the Purities go down to about 40hz, but I guess if you want that extra extension then a sub would be needed. ML have the Dynamo series subs, which seem to get a good write up. Having said that, I find the Purity bass very good - when 'The Pacific' mini series was shown here, I hadn't had the Purities for long, but some of the artillery explosions sounded pretty good to me.

As to comparing the amps, I couldn't tell much difference between the onboard amp and the Audiolab. However both the Audiolab and Purities are quite new, so again break-in time may be an issue (I haven't been using them much of late).

 

[MPS]

Consider investing in the best quality preamp you can, do not use high level inputs unless absolutely necessary. You will not gain anything using a power amplifier only deterioration of the input signal. This speaker will always use it's build in amplifier which can not be by-passed.

 

[Bernard]

So, you can't bypass the inbuilt amp by using another amp. So, why are there binding posts, and why is there an option to use your own amp?

Where you do not have a separate preamp and are using an integrated amplifier or receiver that does not have preamplifier outputs, you use the power amp output to the binding posts.

 

[Bigdaddynz]

The ML Purity owners manuals cautions you to not use both RCA and speaker terminal inputs at the same time, but it doesn't say whether the internal amp is switched out of circuit when using an external power amp.

I have sent an email to ML to get a definitive answer.

 

[Stereonerd]

Switcheroo

Thanks Bigdaddy, please let me know when/if you get a reply from ML.
I think they should clearly explain this to Purity owners, especially those who want to get the best possible sound out of their music (as opposed to the biggest bang for buck out of motion pictures).

 

[Bigdaddynz]

Here's the reply I got back from Martin Logan.

"Thank you for your inquiry and for your support of MartinLogan products. The internal power amp in the Purity's cannot be bypassed. The Purity will only take the signal sent to the speaker. The internal circuitry accepts the signal, but not the power. Please let us know if you have any further questions."


That reply would suggest that the signal from an external power amp is reduced to line level, and then fed to the Purity's internal power amp. It would also suggest that there is no point in driving these speakers with an external power amp, as that just introduces another unnecessary component into the chain.