At 0.5 mv output I would think that is normal if the VTL and your amp both have moderate-high gain.
7 responses Add your response
I looked at the Helikon's specs and see that the recommended load is from 100 ohms to 47k-ohms. The MM section of the VTL is probably loaded at 47k-ohms. So if the cartridge sounds "bright" to you in the highs, that is the probable cause... But that shouldn't hurt anything as long as you like the sound.
This also probably means that if you ever try to use a high output cartridge you'll be back to barely being able to move the volume control, even on the lower gain MM inputs.
It would bug me if: 1. The high output phono stage was sarurating the first amplification stage on your pre-amp (signs could be loss of dynamics, blown fuses or speaker damage due to clipping). 2. I thought there was a chance that I'd really hammer my power amp and speakers if I forgot and left the volume in the cd player position and then dropped the needle. Were it I, the high gain would make me crazy from wondering about sound degradation and worrying about blue smoke. I'd drop a couple hundred in some attenuators if needed, after contacting the vendors to ask about the best/cheapest way to drop gain a bit.
Obviously, the combination of linestage gain, plus the MC stage gain, and the sensitivity of your amplifier are too much for use with the Helikon. The Helikon is not a high output MC, but it is not low output either. Use the MM stage as you have done, there is no way this physically harms anything.
The only issue is that MM stages tend to have adjustment capabilities suited for MM cartridges (e.g., adjustable capacitive loading and fixed 47k ohm resistive loading). MC cartridges are insensitive to capacitive loading so any adjustable setting of capacitive loading will not do much. In order to change the resistive loading, you will have to probably add your own resistors. This can be done by experimenting with good, high quality low wattage resistors. You could open the preamp up and solder the resistors on to the inside of the RCA jack (between the center pin and the outer part of the jack).