Is 60dB gain enough for Kleos?


At age 52, after years of technological philandering, I am once again courting my old vinyl flame. I just bought a VPI Classic 3 because it looks like it was built in the fifties, like me. Now I am obsessing over the selection of cartridge and phono-amp. Every man needs his irrational, unsubstantiated religious beliefs, and mine include vacuum tubes (very fifties-ish) and a transformerless signal path.

So let's say that for the moment I am enamored with the Fosgate Signature phono-amp, which having a 60dB gain without any input transformer. Now I have read that this works best with a high-output MC in the 0.8 to 1.0 mV range.

Here's the rub ... I am very intrigued by the Lyra Kleos, my fascination with which is due in no small part to the musings in these pages of J Carr himself. Alas, the Kleos has an output of only 0.5 mV. So I seek the advice of those who might have pertinent experience!

Dave
david_pully
Some 60db phono stages will be fine, and others will not be.

Assuming that your line stage preamp provides a reasonable amount of gain, say 10db or more, and that your power amp has a typical sensitivity number, say 1.5 volts or less (unbalanced), you'll have enough gain. The more important question is the signal-to-noise ratio (s/n) provided by the phono stage. If that is not particularly good, you may wind up with objectionable hiss levels.

I couldn't find a s/n spec for the Fosgate Signature. The last paragraph on this page, from the TAS review, is encouraging though.

However I would suggest that what would constitute the "pertinent experience" you are looking for would be specific experience with the Fosgate. Perhaps someone using it with a 0.8 to 1.0 mv cartridge could try turning up their volume control to a level around 6db higher than they would normally listen at, and indicate what kind of hiss levels result while no music is being played.

Regards,
-- Al
What Al says makes sense. My phono pre is an ARC PH-7 which has 57.5 db of gain. The noise and hum stat is 70db. My line-stage is an ARC Ref-5 which has 12 db of gain if the XLR output is used, which it is in my case. The noise and hum stat is 109db. So total gain is almost 70db.

ARC advised me that I should not use a cartridge that produces less than .5mV of gain, and more would be better. So far, I have used high output MC and MM cartridges that produce more than 2mV so I can't personally vouch that .5mV is ok, but what I can say is that what Al says is consistent with the advice ARC gave me.

FWIW