Monday, April 25, 2011

Kenwood KT-6040 through MSB PAD-1 w/o gain lacks bass muscle

Somehow, I'm not finding the current tuner setup with Kenwood KT-6040 being fed straight (1 foot solid core coax from Blue Jeans cable) into MSB PAD-1 to sound as solid as it did when I fed Kenwood through Lavry AD10 (in one of various less-straight configurations).  It has a distinct thinness now.

I'm wondering if this is just coincidence (the music KPAC has been playing most recently perhaps?) or quasi-psychological (the gain is 12dB lower, so although in principle I could boost gain exactly to match, perhaps I just don't because the numbers look too high) or something technical.

One ready technical explanation is that while I could boost the gain on the Lavry (and did so, about 10dB) I cannot do so on the PAD-1 as it has no gain adjustment.  As described earlier, I ONLY use the balanced input on the PAD-1 (since the other inputs are very inferior) which means I have to use a RCA-to-XLR adapter and either boost the gain with external preamp or not.  (Currently, I am not boosting the gain, though it appears my Aragon 28k is still working after all, so I could use that, except there's no room for it in the current physical configuration.)

By not boosting the gain, I am loosing about 12dB gain (peak output is at -12db), and comparable S/N and dynamic range.  That's equivalent to two bits, so I don't really have much better than 16 bits actual S/N in my digital encoding.  My previous argument was that should be sufficient for a tuner anyway.  But perhaps I was wrong.

It would be nice if there were a tiny stereo lineamp based on OPA-2604 or other high end opamp (IMO 5534 might be good also).  Such a thing could be built in a small hammond box with external DC supply.

But nobody seems to make anything like that.  You can find various gain boxes intended for musicians of non-high-end quality, or fancy and incredibly expensive preamps which have features I don't need.  But not a the combination of stripped-down-features and high-end-quality and low-price.

The PAD-1 used through balanced inputs seems about as good as I am able to measure, distortion about 0.001% or less, and it seemed perfectly adequate for Denon 5900 when used with Aragon 28k to boost gain.

Better improvement might come from better antenna than buying high end preamp.

Other option might be routing all analog inputs through Lavry.  In that case, I need a balanced selector, and made with premium components those can be as high as $375.

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