EE people (again!) please...

[digital desire]

I have an older sony es receiver that is still pumping strong, and is currently feeding an emotiva xpa -5. So I only need it as a pre/pro. But the output is too high, I can only use the first 1/5 of the volume knob. I was going to make some diy attenuators/ voltage dividers. But here is the cool part -
A few years ago I picked up a spare exact same receiver that was dead from a neighbor, and I tried (unsuccessfully) to fix it. I think it has a blown main digital board. Anyway...
In that process, I bought a service manual, and am looking at my spare pre out board. I want to drop (guessing!) about 10 or 12 db.
So I want to change just one resistor on each channel if possible, they are smt (I have a hot air work station). But I am not great at it, and only want to do this once.
Just looking at say the top (left channel) I have a choice of 3. 380, 373, and 367. Which one, and what value? Also, those caps are not on the -30 board, only the upgrade model. What would they be there for? Just to shunt off very high freq stuff?
Thanks for any suggestions! I would of course only do this to my parts pig, if I screw it up, no harm/ I'll just do it externally...

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[Johnloudb]

I think the caps are there to filter high frequency noise. I would change R380 - R385 from 1k ohms to 250 ohms. This would give 11.6dB more attenuation. I think that's reasonable given where you are turning the volume control. You don't want to attenuate too much of course.

Strange that they would put so much resistance at the output. This pre/pro was clearly designed with too much gain and it looks like they were also attenuating the gain at the output? I don't know.

[digital desire]

I thought the same thing, but maybe this is the way they can lower the noise floor? Dunno. But I'll change out those resistors and see how it floats!

Thanks!

[digital desire]

Well those little resistors scared me, so I had someone who knew what they were doing do solder them for me. Ended up using 267 ohm.
I guess I missed my guess on how much I needed to pad down, I would have thought 10db would have done it! But there is not much difference in the knob. I use maybe 10* more arc of it.
So maybe 50 ohm?

[Johnloudb]

Hmm ... without knowing the gain of your pre/pro it's hard to say. Your guess is as good as mine. But, 50 ohms would probably get you significantly more rotation on the knob. Your amp/speaker system probably has a high sensitivity as well. What about a good passive preamp? Sorry, you probably need the surround sound processor or tone controlls which I think are good to have.

[digital desire]

Speakers are not too sensitive, sealed wwmts from here.. The amp has a 32 db gain structure. I may just keep it the way it is for now.
I do appreciate your help!