Sonic Frontiers Line 1

[AnalOg]

Hi Guys,

Maybe someone can guide me in the right direction. I've heard of nothing but great things about the Sonic Frontiers Line 1 pre, so I picked one up on the secondary market since they can not be had new.

My system is very revealing, and I have been going around in circles between cables & tube changes trying to eliviate to what I equate to a shreiky upper mid which makes it intolerable to listen to cds (on a Musical Fidelity A5) at moderatley higher levels. The analog front end is a bit more forgiving but can still be a bother.

I was ready to condem the Line 1 as just not being a good match for my system when I noticed those trim pots inside. I know I'm not suppose to adjust them, but since this a used unit with some history and having the problem that I'm having, I decided to turn them down. Taking note as to there original position I began to turn them down incrementally, the more I turned them down the more balance the sound became, even the highs became more detailed and focused, and was able to turn it up without wanting to run out the door.

I have concluded that someone on deafer ears than I turned these up, can anyone provide me with some assistance on what would be a optimal position for these pots or do I just adjust them until it sounds good?

Thanks,

Tom

[Deang]

What do the trim pots adjust (gain, DC bias, etc.), you shouldn't be adjusting them unless you know what they're doing, right?

"I have been going around in circles between cables & tube changes trying to eliviate to what I equate to a shreiky upper mid which makes it intolerable to listen to cds (on a Musical Fidelity A5) at moderatley higher levels."

Quit playing those CD's.

and get rid of the K-400.

[AnalOg]

I did some research on what those trim pots do, and all I found was this on Audio Asylum:

The pots are used to adjust output level of the + and - phase output for each channel. You need a sine-wave test CD as source and an oscilloscope to match the amplitube of + and - output.

I'm not sure about using a VOM.

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Play a test disc with a 1kHz tone and set the volume control to 75 on the display. Now set the VOM to AC setting and measure the voltage btw the phase + to ground and phase - to ground.

Now, turn the trimpot until both phases voltages are the same. Repeat the other channel. I got this info from SF.

I'm not sure what there refering to as to what phase + phase - is, can some one be more specific on what I'm suppose to be plugging my VOM leads into, it would be much appreciated.

Thanks,

Tom