So, now that I have completed my A3000 Fix project, I think
now it is good to sum things up in a single post, so as to serve as a guide for
other users to fix & improve their Yamaha sampler.
CONCLUSIONS :
A) REINFORCING PLATE
Problem : Due to the Yamaha
A3000 inherent design, the encoders PCB is prone to broken solder joints and
lifting of copper traces, because the encoder push-action force is transferred
to the PCB solder joints .
Solution : Yamaha solved
this in the A4000 sampler by mounting the PCB on a metal plate and securing the
encoders with M7 nuts. For the A3000, a
special metal reinforcing plate has been constructed so that the push-action
force will be transferred to the plate instead of the PCB.
B) ENCODERS’ SELECTION (basic specs start-point:
30-detent-15 pulses with switch)
Problem : The stock Alps
encoders of the A3000 do all the hard work for the A3000, and they are used a
lot, so at some point they start to behave erratically and with no precision
whatsoever. Some say it’s Yamaha’s software problem, others say it is just
fatigue.
Solution: After a lot of
research and also conversation with other users and their personal experience,
the correct replacement encoders readily available today are as follows :
{ How did I miss it the first time when reading the data
sheets ?? I got dizzy from reading so
many datasheets, probably, and my mind was stuck with the number “20” for the
shaft….
WRONG ! 20 mm is the total height of the encoder!! }
Dimensionally is exactly
the same as the stock encoder. It is
only slightly tighter when turning the knob (it has 150-200 gf.cm torque specs
compared to the NEW Alps models
which have about 100 gf.cm or 10 mN.m ), but the old stock encoders are also
tighter. So, along with reinforcing
plate, it seems to be be an exact
match ! (Not
tested, but I want to…)
2.) BOURNS PEC11L-4220F-S0015 : This was my
1rst choice to order. I have read some good reviews concerning the quality
of these Bourns encoders. Also, they can
be mounted on the A3K chassis with a reinforcing plate and M7 nuts (same as the
above). It is only slightly tighter when
turning the knob (it has 150-200 gf.cm torque specs compared to the Alps EC11E15244G1 which has about 100
gf.cm or 10 mN.m ). Something to be considered also is that it is 3mm bigger in total height than the old
Alps, but after cutting to length it will fit exactly. (Not
tested)
3.) BOURNS PEC11L-4225F-S0015 : This
was ordered from me by mistake (I intended to buy the ones above), so some modifications
needed to be made : Height should be
reduced (I cut’em off by 5 mm , and still are higher than the stock ones by
3mm), and also the lip on the shaft
is thicker than the Bourns above, so I was stuck with those which protrude from
the faceplate of the A3K by 3mm. BUT they work flawlessly. (TESTED by me = ok)
4.) ALPS EC11N1524402 :
This is a new model from
ALPS, and according to my conversation with another user who discovered this
one, this guy verifies that it is an exact
replacement for the old Alps encoder (dimensionally, anyway), and also the
switch has less push-force value from the BOURNS which would be very easy on
the Yamaha PCB. The only difference is that this encoder does NOT have threads,
so mounting an extra metal plate with nuts cannot be done (but might not be
needed, anyway). An almost perfect
choice!
5.) ALPS EC11E15244G1 : Another alternative by Alps, which was my 2nd choice to order. The user
(Anonymous) who bought it and tested it,
CONFIRMS
that after cutting 3 mm off the shaft length the encoder is almost identical to the
old stock encoders and works the same. It doesn’t have any threads, though, just
like the one above. Excellent job, my friend !!
(TESTED by Anonymous user = ok) - (check his photo)
6.) ALPS EC11E15244B2 : Has not been tested by me, but the user who
has states that it works flawlessly. BUT it has some differences with the
stock encoder :
a.
The
switch travel is longer than the stock one (1,5 mm vs 0,5 mm of the stock Alps)
b.
Total
height of the encoder is greater than the stock ones, and the encoder shaft
protrudes from the A3K faceplate. There is, of course, a correction route
(cutting-off).
c.
Also
No threads and nuts.
You might pass this by, mainly because of
the increased switch travel (1,5 instead of 0,5 mm).
And 2 more
alternatives (not tested) :
===>> To check the above encoders datasheets,
just click on their part nrs above.
So, I
think there is quite a selection of alternatives to the stock encoders, it is
just a matter of availability.
If you can find it easily, then get it!
In my personal opinion, these 2 options may be the best :
No cutting and grinding is needed and they
fit like a glove , the Bourns has also
threading for mounting with M7 nuts and the ALPS has a slightly softer action . But
you will be the judge and decide what fits better for you.
See the photos
below for comparison :
 |
| cut Bourns 4225 / stock Alps / Bourns 4225 |
 |
| Bourns PEC11L-4225F-S0015 : as bought vs the modded ones |
|
 |
| stock old ALPS encoders |
 |
| ALPS EC11E type drawing |
 |
| BOURNS PEC11L-series Encoder selection |
 |
| ALPS EC11-series encoder selection |
=>> Read the complete
story here (PART-4)
and also useful are the Anonymous comments at my initial post here
(A3000 FIX) .
C) ENCODERS PRECISION IMPROVEMENT (CAPACITOR HACK)
Board assembly : ok
and there you
have it :
 |
| complete kit |
 |
| the board installed in the sampler |
Well, the thing works ! Night
and day improvement even with old stock encoders.
---------------------------------------------------------------------------------------------
CREDITS:
Following pages were essential and very
helpful to my research for a better A3000, so I am obliged to give
credit to their information, and say a big THANK YOU to :
- https://todbot.com/a3k/knobs/ : deals with the(slight)
improvement of the encoders’ erratic behavior (IF, of course they are in good
condition, which in my case I can’t say that they were ). Was my first
detailed information source about the
A3K encoders problem.
- http://www.jsigle.com/musicol/emufix.htm : this is a modification of the EMU sampler that
improves vastly the encoders functioning precision (some people did this mod
and saw an improvement). It contains detailed technical information for those
who understand electronics (not me 😕 , but I finally got it!! 😸 )This mod CAN be applied to the Yamaha A4000
(SEE LINK BELOW)
- I have to give credit also to Anonymous , a A3000 user who commented in my blog,
and through our conversation and his testing, some very useful information came
out and conclusions have been made. A truly delightful collaboration, which I
(we) hope will help other users of this wonderful sampler to improve their own
machine. Thank you, my friend, for sharing your information!
I HOPE THAT ALL THIS INFORMATION WILL BE
USEFUL TO YAMAHA A3000 USERS.
IT IS MOST IMPORTANT TO SHARE OUR
KNOWLEDGE AND EXPERIENCES, SO THAT
MUSIC WILL KEEP ON
!!!
NOBODY ALONE KNOWS IT
ALL, BUT EVERYBODY TOGETHER KNOW A LOT MORE !!!
------------ Greetings !! ------------
THE END (maybe..........)
