i see......
i will  set the trim to manual's value and then try to adjust again.
THANKS FOR REPLY

after 1 day burn in and play.....
i find something that i am confuse.
and i search the forum and a lots topic,and still don't understand.

1.does "presence" not make the tone big different??
i mean when i turn up to max or down to mini.
it does have something different,but i really feel it's not only just this level of different.
i use ethous pedal before,it's presence on poweramp really has a big effect to tone(maybe not advantage)
but i just wonder about this.


2. od eq don't has effective range,i know alots topics have tolk about this.
But when i turn off mid boost and pab boost.
od gain on 8.master volume on 3,i tweak these 3 pot and i have to really really listen carefully that maybe
can heard a little different.

sorry i never use d-like amp,so will feel confuse about this.
But the most lucky thing is that even have these two things.
It 's tone is still amazing.

The problem han been solved.
i measure the voltage plate,it's still have 446V
my friend tell me to test all the wire to ground.
And i find a wire from black probe to ground is vacation welds.
so i can't measure the power tubes's bias.
now i am playing
thanks!

i just got my hrm bm kit,and spend 3 weeks to build it.
now i am testing it.But my amp's bias just have 1~2 MV.
And of cause i have turn the biad pot up to max.
I can't set it to 35~38 MV,and my amp still have sound,but very vary small.
Did i wire somrthing wrong??Or which part i should check first??
THANKS~

i just think about a idea~
i can use my mixer to do this "buffer" thing??
usually mixer have aux function right?

ok,i see..
thanks for reply !!

my 1987 first use http://www.ceriatone.com/images/mods/FX-Loop.jpg style fx loop
i don't know why it doesn't use interrupt style loop at first.
so i have to use buffer........does anyone have a schematic??

my 1987 first come with fx loop mod(not interrupt style)
but when i use it,it will decrease so much gain and treble of tone.
nik say it is normal,so i just can use pedal in front of amp,not in fx loop.
over 2 years,i buy a g sharp and hope to use it on loop(because g sharp'tone is suck if use in front of amp)
so i check schematic and change wire for interrupt fx loop.
But it still the same!!althrought i turn the g sharp's input gain up to max.
it still lost so many tone,my friend tell me i must use buffer if i want to use FX UNIT in loop.
does Klein-ulator working??or i find metroamp has a fx loop kit too.
it seems to be using a op or tube to boost the singal??
what's everybody's way to use fx loop without tone lost?

THANKS~

my 1987 have a strange NOISE like phase.
when i use clean,everything is ok.
but when i turn up volume(use thd hotplate)to get overdrive tone.
every note's fermata(or sustain??)will become "FLOAT".
just like i use the phase padel.
this noise is not very serious.but you just can hear it.
i have try to change the tubes,but still the same.
my english is not good,hope you can understand what i mean.
THANKS!