[tfoust]

Tried something different tonight with disastrous results.  I wanted to play my Apple TV through the stereo but needed a Toslink to Coax converter to do it.  Got the converter today.  Connected Apple TV to converter to AVA dac to T8 ("Special" jacks) to 400R to Lascalas.  Switched it all on and turned the volume to 7:00, queued up a youtube video and what came out of the speakers shook the room.  It sounded like I had the volume set to 5:00.  It scared me to death.  My head hurt the rest of the evening.

I don't use a turntable so I'm not real familiar with phono input circuits and the T8 is second handed so I don't know what the original purchaser ordered.  But, do you suppose the "Special" jacks lead to a phono circuit and putting a line source into a phone circuit provides excessive amplification?  I was afraid to try it in another jack set without getting some advice.

Thanks in advance.   

[tvyankee]

Hey,

If you mean 7:00 o clock from 0 on the preamp thats not that high. I think what may have happened was that when you the toslink output i think it sets the volume output on the appletv to full level. If you have a iphone or ipod or phone with music on it then hook it into the preamp using the special input with the volume set to off on the device you are using in place of the appletv then just turn up the volume slowly. If it gets very loud very quick then stop and try a different input on the preamp and do the same thing. I think you will fine that everything is fine except your Head.

Good luck.

[Wayner]

The "Special" input is used for phono input when that option is included. That board looks for signals that are about 5 milivolts (.005 volts). Your "line" source has about 1 to 2 volts. So, you in essence way over drove that input. Use one of the other "line" inputs, and as alway, set your volume to zero when unsure of an outcome, then walk the volume up.

Wayner

[avahifi]

Wayner is correct, you inadvertently plugged a line level source into the RIAA phono preamp inputs of your preamplifer and overloaded this special phono cartridge amplification circuit and caused much higher output volume than you had expected.

In all AVA preamplifiers, the optional phono circuits, if installed, will always be on the first set of input jacks, marked either SPECIAL, or LINE 1 on our newest models.

You can usually tell if the phono circuits are installed by noting if there is a thumb nut ground installed on the back panel near the first set of inputs.  If the unit has the RIAA phono circuit option, the thumb nut assembly will be installed.  Without the phono section, this ground assembly will not be installed.  In that case, the first set of inputs are another set of line level inputs.

If in doubt, never plug any source into the first set of input jacks except the output directly from your vinyl record playing turntable. If you are using a separate RIAA phono preamp such as the Hegerman Bugle, its output goes into any of the line level inputs as the RIAA equalization and amplification has already be accomplished by the outboard unit.

And of course, your are welcome to call us for help about the operation of your AVA preamp (or any other audio device, AVA made or not). We enjoy providing you with good advice regarding your audio system use.

Our phono number is 651-330-9871. We answer the phone between 9 and 4:30 central time and you can catch me in the office on weekends often too.

Regards,

Frank Van Alstine

PS, if you purchased an AVA preamplifier used and it does not have the RIAA phono preamplifier circuits installed, we normally can add the phono circuits after the fact at a reasonable price.

[tfoust]

Thank you all for your input.

I did try the Tuner jacks with success.

Is this a great company or what?