Help - Very Strange Problem w/DynaVector 17d3

[JimmyEL34]

I have a "new everything" system. Custom built turntable with new SME M-2 arm, new DynaVector 17d3 Karat, Decware SUT unit using Sowter 1:20 SUT's and varible resistance loading pot, Decware ZP3 phono stage, Decware Z Stage pre-amp, Decware Torii Mk IV power amp, into my Klipsch KG4's rated @94dB. Completely all tube chain and hand wired. I have my CD player plugged directly into the Torii and it sounds glorious - very balanced and what you would expect a high-end tube amp to sound like.

However, for the first time in my life, my vinyl sounds worse than my CD's... I am getting opposite results of every single thread I've read across mutiple forums regarding the 17d3 cart. Everyone is loading the 17d3 anywhere from 100 to 1000 ohms. My 1:20 SUT's will let me max out at 117 ohms, but even that is too bright. Turning the load dial down to about 1/3 - 1/2 way mark sounds best, but am still getting upper midrange glare that hurts the ears to listen to. Everyone on the forums describes this cart as laid back with lush and velvety female midrange vocals to die for. Mine is anything but velvety or laid back. The midrange to upper midrange is way too forward and prominent. I have played with the SME by lowering/raising the tail, and it really doesn't affect that midrange glare. The best sound is obtained by setting up that arm perfectly level. My HTA is also set as per the SME alignment tool as well as the azimith.

The 17d3 is rated as .3mv output with internal resistance of 32 ohms, and recommended loading >100 ohms. I went to the Sowter website and their compatibitly chart recommends their 1:20 SUT's for the 17d3 cart. So, I am presenting 6mv to my 47k all-tube phono stage with varible resistance loading maxing out at 117 ohms. Everything I've read from the forums and Rothwell's articles regarding SUT's is that this is a perfectly acceptable mV to present. But I'm wondering if a 1:10 SUT might be better even if the signal would be lower than the ideal 4.5 - 5mv at 3mv, it would not be as hot and would allow me to take the resistance loading up to 470 ohms. But, on the otherhand, more ohms would make it sound even brighter, which is what I don't want, but perhaps this would be offset by dropping the mV down from 6mv to 3mv?

Any ideas on what could be going on here? What is better: to go with a 3mv signal or a 6mv signal to present to the phono stage? The Rothwell articles say either are perfectly acceptable. Anyway, this is a very strange situation. And one last question: The DynaVector 17d3 is brand new with only about 7 hours of play time on it - in some forums, people say that this cart breaks in at around 30 hours... The fact that it's new with few hours wouldn't make it overaccentuate the midrange would it? I mean the specs on this cart are ruler straight all the way accross the frequency range... Thanks in advance for your help.

 

[for_p1]

From my experience DV cartridges - they need about 50 hours to stabilize sound quality. You can always borrow MC phono stage from someone and try it instead to see if problem is with your setup. I also recommend to get test LP http://www.amazon.com/Ultimate-Analogue-Test-Lp/dp/B001GBA71Y and use it along with some measurements tools to see how flat is response of your system.

I would also try to replace all interconnects between TT and phono stage with different brand (even cheap one will do to test).

 

[mkane]

My 10x5 was a bit bright when new and didn't change much.

 

[dcmfan]

I dont use a SUT, so can't help there, but from your description it sounds like you're getting more of a 47k load than 100ohm.

I use a Dynavector Ruby and wouldn't describe it as velvety or laid back. The DV Karats used a short gemstone cantelever (ruby or diamond) to give a lot of energy and detail, especially in the upper registers. I don't think break in will change what you're hearing. Any chance you could borrow a MC phono stage and see how it sounds?

 

[rothwellaudio]

Your 1:20 transformer won't give you 6mV into the phonostage. The 32 ohm source impedance and 117 ohm load impedance means you'll get less than 6mV, but not much less. It actually works out at 4.7mV. That should be just about ideal.
My guess is that the cartridge just needs time to run in.

 

[JimmyEL34]

Your 1:20 transformer won't give you 6mV into the phonostage. The 32 ohm source impedance and 117 ohm load impedance means you'll get less than 6mV, but not much less. It actually works out at 4.7mV. That should be just about ideal.
My guess is that the cartridge just needs time to run in.

Thanks! Great website by the way and I enjoyed reading your in-depth articles. But tell me please, what is the formula you used for to come up with 4.7mV? I thought it was simply 20*.3mV to get 6mV -- so, I guess there's more to it than just that! I'd love to know the formula. I know the online KAB online phono stage calculator said the ideal gain for .3mV would be 61dB, is that correct, or is there a more exacting formula for that as well? Thanks for your insight --Cheers!

 

[jblnut]

I tried a 17D3 and passed - it was a bit too lively for my system. I would not call it "lush" by any stretch. It was lightning fast, and somewhat edgy and bright.
However I did note that its ride height was extremely low and that might have been part of the issue (collapsed suspension). Take a look at some pics of them on the web while playing. They do ride low, but if you're having trouble getting a sheet of paper in between the cart body and record, this might be your issue.

When my first AT33EV had suspension failure, it sounded like this.

jblnut

 

[rothwellaudio]

Thanks! Great website by the way and I enjoyed reading your in-depth articles. But tell me please, what is the formula you used for to come up with 4.7mV? I thought it was simply 20*.3mV to get 6mV -- so, I guess there's more to it than just that! I'd love to know the formula. I know the online KAB online phono stage calculator said the ideal gain for .3mV would be 61dB, is that correct, or is there a more exacting formula for that as well? Thanks for your insight --Cheers!

A 1:10 transformer will give you ten times the cartridge voltage, a 1:20 transformer will give you 20 times the cartridge voltage etc. if the cartidge's source impedance is zero. Of course, that's impossible, but many cartridges have such a low source impedance that it's a reasonable approximation. However, your cartridge's 32 ohm source impedance is high enough for a noticeable deviation from the approximation, particularly with a lowish 117 ohm load.
Basically, the source and load impedances form a potential divider with some signal being dropped across the source impedance and the rest being stepped up by the transformer. In your case the values are 32 ohms and 117 ohms. 117/(32+117) is the voltage seen by the transformer. That works out as 0.785. So instead of the phonostage seeing
0.3 x 20, it sees 0.3 x 20 x 0.785.

I've re-written the article on the website to try to be more accurate and less confusing. Maybe you read the old version. Here's the new one.
http://www.rothwellaudioproducts.co.uk/html/mc_step-up_transformers_explai.html

BTW, the interconnects between the transformer and phonostage can make a subtle difference to the top end of the frequency response. Go for low capacitance interconnects if you can, and have them no longer than they need to be.

 

[rothwellaudio]

I forgot to ask if the cartridge is sounding any more mellow since you've been using it a while?
Also, the difference between 6mV and 4.7mV is only 2dB, so it isn't very much different from what you thought it was - probably not enough to worry about anyway.

 

[JimmyEL34]

I forgot to ask if the cartridge is sounding any more mellow since you've been using it a while?
Also, the difference between 6mV and 4.7mV is only 2dB, so it isn't very much different from what you thought it was - probably not enough to worry about anyway.

Well, thank you again, "Mr. R" (shall we say) for the more exacting formula and the link to the updated page. I hate to say it, but I ended up returning my all tube phono stage and Sowter SUT's - the synergy was just not there with my Klipsch KG4's. So, I ended up purchasing a Sutherland 20/20 phono stage which allows me to use jumpers to set the gain and load. Turns out I was able to get the system under control by using 60dB of gain, and surprisingly, putting that cart under a 1k ohm load (most folks are loading that cart in the 300 - 475 ohm range). With this combo, I have airy highs hearing very delicate nuances without being un-naturaly bright and plenty of bass. I know that SUT's are the purest way to get the voltage up, but using that method to present to the 47k phono stage only left me with 117 ohm max load to play with, and it just didn't work.

Then there is a part II to all of this: after I got the upper midrange tamed down with the above swap of phono stages, I then substituted my KT66 power valves with 6L6GC valves, and that brought my system into the 3D sound stage that only a valve system can produce... So many factor's here, but I think I've got the right synergy for all my components now. The 6L6's also gave more "breathy" headroom to female vocals and light brushes on cymbals, a more liquid midrange, and more "umph" under the bass notes -- basically, the system sounded "dry" with the KT66's, and with the 6L6's, it's more "wet", shall we say, but certainly not loose or unfocused in anyway. Many audiophiles say the 6L6's are too sloppy for a stereo system, but again, it depends on the sum of all of your components, and for the Klipsch KG4's, they "just work" and bring an even keel to everything.

Oh, and to answer your original question, yes the cart is dialing down a bit now that it has more hours on it.

Thanks my friend for all of your well written articles on the Rothwell site and taking the time to educate me some more. Maybe one day I will return to SUT's, but it will require a lot more research on my end and demoing before I buy - I'm kind of worn out now from all the testing, experimenting, boxing up, shipping back, losing money on the restocking fees, etc., so for now, I'm just going to set back and enjoy the music! Thanks again - cheers!

 

[rothwellaudio]

Ok, glad you're much happier with what you have now. Time to sit back and enjoy some music instead of worrying about equipment