[BUILD] CAPI VP2X~500 Series~Preamp Kit~Official Support Thread

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kikovazquez

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Dec 7, 2020
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i have weird issue i have
two vp 26 and one is fine and working propertly the other one is half quieter even o. the loudest setting i dont know were to start the touble shoot i swaped in diffrent chassis same issue!!!!
 

Ricardus

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i have weird issue i have
two vp 26 and one is fine and working propertly the other one is half quieter even o. the loudest setting i dont know were to start the touble shoot i swaped in diffrent chassis same issue!!!!
Upload some hi res pics of the top and bottom of the boards.
 

Harpo

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... the other one is half quieter ...
doublecheck parts value of feedback resistor R5 being 20K for real (R4 was the part ID from a previous pcb revision), not mistakenly fitted 10K instead ... There are not so many possibilities on this pcb causing a factor 2 or 0.5 error.

edit: corrected part ID
 
Last edited:

jsteiger

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values on the resistors
and their position on the r7 and r8 the values as half of what is supposed!!!
Resistors cannot be measured with both ends soldered in circuit. You will get misleading results. At this point reading the color bands is the best way.

Was this pre working fine at some previous point and then stopped?
 

kikovazquez

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Resistors cannot be measured with both ends soldered in circuit. You will get misleading results. At this point reading the color bands is the best way.

Was this pre working fine at some previous point and then stopped?
no it never

i builded
and was
in storage
for a while
 

kikovazquez

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jsteiger

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OK, you've got 150k placed for R10 and that should be 160R. You basically flipped the locations for R3 and R10. That will indeed cause major level issues. R3 should be the 150k.
 

wjohn

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Mar 10, 2015
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Built my first CAPI pre (VP25) this weekend - it sounds great!
I built the very helpful extension jig also.
Thanks to Jeff and the team for a fantastic kit and documentation!
I've got a pair of VP26s, a VP28, a 312DI, and some DOA kits to keep me busy soldering over the next month or two. 😎
 

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wjohn

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Built my pair of VP26 kits this weekend and both worked. 🤘
Going through each step on two builds at a time seemed to make it go faster.
 

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