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Cartridge gain overload - please explain

I am using a Lyra Delos on a JA Michell tecnodec, a Whest .30R phono stage,
an ARC LS25 linestage, ARC VT100 amp, and Rockport Mira Monitors.

I recently added the Whest to get more gain because the ARC PH3SE with 54dB was not enough, especially because the LS25 gives just 12dB of gain to single ended sources. By switching to the Whest, I was able to get more gain right from the phono stage, and also an additional 6dB from running balanced into the LS25.

Because I was coming in from a under-gain situation, I started with the Whest set to 66dB, thinking a bit more is good, and I could just turn the volume knob lower on the LS25. But there was that record pop / loud static discharge sound which was actually cartridge gain overload. When I changed the gain settings to 60dB, the problem ceased.

My question is, why does this happen? Whats wrong with an extra 6dB from the phonostage and just a little less output from the linestage to compensate? In my mind, that seems like it would work fine.

I would like to know more about this. Perhaps there will be even a benefit if I switch down to 55dB? But that seems counter intuitive, because I was getting too little gain before and I had to really ramp up the volume on the line stage, which caused a lot of noise.

thanks,
Mark
marktomaras

Showing 1 response by dover

dover
2,295 posts
 
I think somebody is confused here.
Using the balanced OUTPUT of the LS25 increases the gain by 6db.
I presume you plug the phono stage into the INPUT, at least I hope so.
There is nothing to suggest that using the balanced INPUT on the LS25 increases the gain.
Changing to a balanced INPUT on the LS25 does however increase maximum input from 14Volts to 28Volts which could give more headroom.

Funny thing is my old Quicksilver preamp could take 60volts up its jacksie on single ended before overload, and my 1960 Marantz 7 can take 30volts up its jacksie without overloading. I guess they dont make preamps like they use to.

The other thing I dont understand is that my Marantz 7 has 60db of TOTAL GAIN INCLUDING LINE STAGE and I can use a Koetsu with 0.4mV output with no noise and gain to spare. What has happened to modern tube preamp design - more noise, less gain and lower overload margins.
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