RE: Re: Notes on Schems...update on grounding experiment

My mixer plugged to the line in gives me -55 and my K5 plugged to the line in gives me -55 too. I did the 147k hack but with 150k ones, I got a problem: the last 1/12 boosts the volume x3, and when I switch up and down from the 11/12 to the 12/12 part, I hear a pop between them(BTW it doesn't distort, except for crappy low W headphones.

"nelsonj_sce" <nelsonj_sce-/[email protected]> wrote:

>
>OK - I am note sure this is an apples-to-apples test but here is what
>I did.  I have a Yamaha DSP2416 mixer in my computer.  I hooked up my
>K5 to the mixer and then read the levels from the mixer.
>
>I did all tests while my K5 was in multi mode, I tested both the "mix"
>output and the "1" output and turned the mixer channel on my computer
>all the way up.  I did not hit any notes, so I was just looking at the
>noise level, and I did not run through any FX or noise gates, I just
>ran the K5 direct to the mixer.
>
>Results:
>
>1) With the K5 volume at minimum I was below -72dB on both "mix" and
>"1" outputs.  This was the same reading as when the K5 was not even
>plugged in, so there was no additional noise.
>
>2)With the K5 volume at MAX, the "Mix" output was just above -66dB and
>the "1" output was just above -72dB.  NOTE: I did the 147k resistor
>hack, so my MAX output is much hotter than a stock K5.
>
>I am not sure how my K5 would do if I used the same setup you used,
>but this was the best I could do with the equipment I have.  I hope
>this helps.
>
>
>
>
>
>
>--- In [email protected], Antoine Deschênes <antdes45@n...> wrote:
>> Could you do a little VU meter test, with mix output if you have
>changed
>> the opamp for it(The same opamp is for headphones) or single if not,
>> without a noise gate or anything else at minimum volume? I'd like to
>> know how many dBs is it now.(I sat my SBLive VOL adj. at -90dB on
>the VU
>> meter(Software) without anything plugged in the Live, then plugged the
>> K5 in the Line In and i got a -47dB.
>>
>> nelsonj_sce@y... a écrit:
>>
>> >
>> > Hack update:
>> > Since my last note I replaced the other two op-amps with socketed Burr
>> > Brown OPA4228.  Replacing these two other op-amps did reduce noise
>> > levels noticeably.  There is still some noise but with 1)the these
>> > four super clean op-amps, 2)using Multi, 3)routing everything to a
>> > sinlge output on the multi rather than mix, and 4)using my noise gate,
>> > noise is really not an issue any more.  I would love to try and
>> > replace the VCAs also, but I have not been able to track down a spec
>> > sheet (or any other info on the) on them so I do not have a clue as
>> > what might works as an upgraded part.
>> >
>> > If anyone can help, the VCAs are part M5222L and they are from
>> > the same off-brand Japanese JRC company that is used elsewhere in the
>> > K5.  If anyone can help me with details on the M5222Ls I will see if I
>> > can find a replacement parts.
>> >
>> > My bottom line: If you are willing to lay-out $30 for the four BB
>> > OPA4228 and sockets, and you if you are willing to remove some
>> > tough-to-remove parts, I highly recommend this op-amp replacement
>> > hack.  My K5 has much less noise and just sounds much warmer/classier
>> > with the new parts.  I would love remove more noise, but right now it
>> > sounds very good and I am not very motivate to continue hacking.  (I
>> > do still plan on replacing the headphone circuit though since I
>> > already made the new circuit and all I have to do is wire it up.)
>> >
>> > An interesting aside:  After I did the latest op-amp replacement,
>> > everything sounded great in multi, but when I went to single I had
>> > serious problems.  Various ranges of the keyboard worked fine, while
>> > other ranges sounds like a fried amp circuit.  It turns out that while
>> > I was removing IC8 I accidentally pulled part of the circuit board
>> > trace off that connected pins 1 and 2 on IC8.  This trace provides the
>> > feedback loop between the (-) and output of line G2.  Once I tracked
>> > down the problem I was able to reconnect pins 1 and 2 and then
>> > everything in single mode worked great.  What I conclude from this is
>> > that the K5 in single mode is splitting different ranges of the
>> > keyboard to different op-amps.  I am not sure what K% is doing in
>> > multi but multi (ouput 1) DOES NOT use the opamp in IC8 pins 1-2-3.
>> >
>> > Hack on.
>> >
>>
>>
>> --
>> antdes45@n...
>
>
>
>


-- 
Antoine Deschênes
aka DragonMaster
http://thehotcom.deep-ice.com/
Files:http://angelfire.com/ca7/hotcomcenter/


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