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Mike_Schmidt's picture
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What to do what to do

Iam still in lingo land with a phone stage the more I read about step up's is that degrade sound but also gain for MC at 70DB is to much and adds hiss and unwanted sounds. I was looking at the Graham slee with the step up to go with my Dynavector Karot 0.3mv.

Any thoughts on this?

chebby's picture
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Re: What to do what to do

Trichord Dino with selectable gain steps of 74db, 70db and 63db

"We are currently awaiting the loading of our complement of small lemon-soaked paper napkins for your comfort, refreshment and hygiene during the journey."

Mike_Schmidt's picture
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Re: What to do what to do

thanks Chebby I was thinking of using the step up from Graham Slee along with my Rega fono MM for my MC cart. So thank you

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Re: What to do what to do

And lots inbetween soundwise if you fancy a tweak with the loading,you can get the sound that suits you. A bit forward in sound but not too bad. Very quiet mind.

Mike_Schmidt's picture
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Re: What to do what to do

I emailed Graham Slee for options, what a terrific response from Graham. I would just like to take this opportunity to thank him even though I dont know all of your lingo I do know cheeky LOL. Here is his response and for it I will buying a Graham Slee product.
Hi Mike,

Thanks for contacting me - let's take a look at your system....

0.3mV from your cartridge goes into a phono pre with 60dB gain which means there's 300mV out.

Your preamp requires 200mV input to give 1 Volt out.

And your power amp needs 1V to give 28V out

28V into 8 Ohms gives 100 watts.

But you have 300mV into your preamp, so that outputs 1.5V which converts to 42V into 8 Ohms = 225 watts

(decimal places have been knocked off in places to make this easier to read)

Your speakers do 88.5dB for 1 watt at 1 metre so sat at 5 metres that's 71.6dB sound pressure level, but to get concert hall level you'd need 100dB requiring 28.4dB more, but with 225 watts you only get 95dB, but this is two channel so a centre stage signal gives 3dB more making 98dB... close enough!

Must therefore only be an issue with volume control positioning (either that or your listening room is a ballroom).

12 o'clock gives approx. 1/10th output taking your sound pressure down to 88dB.

So, here again it's a case of CD output being 5 to 10 times more than is healthy (for power amp and speakers) and I bet you couldn't turn the CD much higher than 12 o'clock without clipping distortion?

Don't take this as an assault (I am being friendly jokey here - that's my character) but I believe you have exactly the same complaint as 99% of hi-fi listeners...

"volumecontrolitis" ;-)

It's a condition brought on by CD and all things digital - they're made to impress - they're boastful - they shunt out 5 - 10 times more voltage than is necessary, and it gives the poor vinyl gear manufacturer an undeserved baaaaad reputation.

You're only going to get another 2 or 3 dBU using the Elevator in front of the Moon set at 40dB gain (making 62 or 63 dB) where you really need another 14 - 20 (making 74 - 80 dB). If you could get this extra gain going into the Moon it's output would overload and clip like crazy (the extra 20dB - if you could get it - would take its output to 3V which is clip level in the Moon's spec).

The best thing would be to attenuate the CD player output by 14 - 20 dB, and learn to live with real world volume control settings.

I'm really sorry if you think my reply is a bit blunt but I'm a honest Yorkshire man and sometimes we come across that way.

Best wishes,
Graham

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Re: What to do what to do

Suffering succatash...what a reply from Graham Slee, yikes!

I use a Gramamp 2 SE with my LP12 and the music really rocks!  The gain is quite significant and i have to be careful with feedback on my amp.  Luckily, my Cyrus 8 has a protection circuit...you have to be careful to make sure the amp is on standby before powering on the stage! 

IMHO Grahams kit is great, there is no so-called degradation in sound from the gain but I do like a big sound so probably wouldn't notice.  These devices are meant to step up the signal afterall.

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