Your choice for budget analog to digital converter

Thanks all, helpful discussion. I have a Graco headphone amp as well, the AC version, not the battery version. Using Grafo cans too. Thought I would go all-Brooklyn for a while.

How do I know what the right output level is, should I choose to run through my headphone amp as a Pre, trial and error? This reminds me of my days making tapes and learning how to deal with full dynamic range recording and tape saturation/undersaturation issues. kn

Thanks Al. Will do.

KN, yes it is analogous to optimizing the match between signal levels and the dynamic range of recording tape. The main difference, of course, being that a modest amount of analog tape oversaturation may still provide reasonable results, while any overload of digital recording equipment will produce very hard clipping.

There doesn't seem to be much meaningful technical information on the Grado headphone amplifiers. But assuming you are using the non-high gain version, that is intended for use with Grado headphones, unfortunately I suspect that its gain and output voltage capability are such that it would not provide enough voltage to fully utilize the dynamic range of the Linestreamer, when driven by a signal level corresponding to the output of a phono stage.

It appears that the high gain version was introduced for the purpose of driving non-Grado phones having impedances of 100 ohms or more, which require higher voltages than the 32 ohm Grado phones require, for a given amount of input power. And I did find some review comments indicating that the non-high gain version can't drive certain Sennheiser and other models to high volume levels. Finally, the fact that a similar model exists which runs on battery power, and is described as being able to run for 40 to 50 hours on two 9 volt batteries, would seem to indicate that the design is not particularly high powered.

All of that is speculative to some degree, of course, but the lack of technical specs on the amplifier precludes anything more definitive.

Regards,
-- Al

You might want to call Grado to try to figure out the output range, since both your cartridge and your electronics come from them. Also, how is the output of the phono preamp compared to a CD player, if you have one. If it is pretty comparable you might be in the 1 volt to 2 volt range already. You might check the CD output capability also.

Dtc, I suspect KN is using the high output version of the Platinum cartridge, which is spec'd at 5 mv under the standard test conditions. He would most likely be using, and have to use, the low gain setting of the phono stage with that cartridge, which apparently provides a gain of 40 db. That is a voltage gain of 100 times. So under the standard test conditions the phono stage will be putting out 0.5 volts.

Particularly high volume peaks on some recordings would no doubt put that into the 1 to 2 volt range, but many other recordings will be at levels that are considerably less than 0.5 volts most or all of the time.

The key questions to ask Grado, as I see it, would be what the gain of the headphone amplifier is, at the maximum setting of its volume control, and what its maximum output voltage is.

Best regards,
-- Al