If CV2 is already 0, you can’t make it any slow with any sort of speed table, you need to work with the Back EMF CVs and adjust the motor control.
–Randy
Randy, can you be more specific in terms of CV adjustments? CV 2 at 1 provides acceptable speed for me, but the stops are really abrupt.
Do you have any magic combination of CV values to do your BEMF suggestion?
For abrupt stops or starting you should be looking at momentum CV3 for acceleration and CV4 for deceleration. Start increasing CV4 until the stopping is what you want or expect.
Peter
I’ve tried the deceleration momentum, which is CV4. Cranked up the value to near its maximum. It works and looks good when taking the throttle from, say, speed step 5 of 128 down to 0. The deceleration over a longer period masks the abrupt stop when going at low speed.
But going from step 1 of 128 to 0 looks abrupt. CV4 doesn’t seem to matter. Loksound and
If CV2 is already 0, you can’t make it any slow with any sort of speed table, you need to work with the Back EMF CVs and adjust the motor control.
–Randy
Randy, can you be more specific in terms of CV adjustments? CV 2 at 1 provides acceptable speed for me, but the stops are really abrupt.
Do you have any magic combination of CV values to do your BEMF suggestion?
For abrupt stops or starting you should be looking at momentum CV3 for acceleration and CV4 for deceleration. Start increasing CV4 until the stopping is what you want or expect.
Peter
I’ve tried the deceleration momentum, which is CV4. Cranked up the value to near its maximum. It works and looks good when taking the throttle from, say, speed step 5 of 128 down to 0. The deceleration over a longer period masks the
For example, I just watched the review JLWII2000 just posted on the IM cab forward. I hear no buzz. The thing just creeps along perfectly in step 1, both forward and reverse.
I know what I’m talking about. I just don’t know the cause or the remedy, unless its just a matter of settling for whichever brand of sound decoder is less offensive.
I watched JLWII2000’s review of the IM GP10. Its incomplete, as most reviews on the net are.
Any review posted on the net should include a part where the loco runs at speed step 1 through 5 on F8 mute. Especially switchers.
Switchers pull few cars and run slowly, which is different than an SD90M which would pull long trains at high speeds…creating a bunch of ambient noise. Switcher operations create low ambient noise and the volume must be turned down accordingly, which reveals any noises being generated by the loco.
Including traditional drivetrain noises.
Being the owner of 2 IM GP10s w/Loksound, I can tell you that JWLII2000’s review did not cover everything one needs to know before buying a switcher.
So you’re saying this buzz is even louder than the prime mover on a low volume setting? I always set my locos on a fairl ylow volume level, the stock 3/4 or full blast is WAY too loud to be realistic. The other side of the room is supposed to be many many miles away, you never hear a prototype that far away. I am a firm believer in low volume that can be heard near the loco only - not only is the quality often better, it also allows you to hear the sound increase as the loco approaches your viewing spot and trail off as it goes away.
Now, you did mention about the quality of the locos - the switchers I have are either Stewart/Bowser or the older P2K Alcos. The Bowsers always have been dead quiet, best and quietest running locos I have, hands down. They’re still quiet with TCS motor only decoders (T1’s from about 7-8 years ago, after they added BEMF) and the one with a Loksound. The P2Ks have TCS also, and are fairly quiet, certainly nothing objectionable. The worst loco I have in service is probably the Bachmann 44 tonner, though I do have an MDC boxcab sitting here on my desk and most of us know how loud they are - bit it’s getting completely reworked, including shell modifications, to better resemble the loco it’s going to be. The T-1 4-8-4’s when muted are a bit noisy with all the valve gear and lots of wheels making noise, the motors are rather quiet. I used to run those for hours at a time looping the layout at step 1 for background sound while working on something.
I’ve got a raft of Atlas/Kato RS3’s but thus far the only ones I’ve put decoders in are from years ago and have either NCE D13SRJ or old TCS T1 (prior to BEMF) and they all ran quietly as well, excepto for one that turned out to have a bad motor - somehow there was the glue used to hold the commutator segments in all over one of the segments, so it was very noisy when it ran but usually stopped on the glue insulated segment and then wouldn’t self-start. Scraping th
Randy, there is a CV that will help that buzz noise. Right now I can’t put my hands on my notes. CV ? is changed from a value of 20 to 24 . See if I can’t locate the CV later. Thought is was with my Lok Sound info> found it ! CV- might be set to a value of 4, change that to 20 or24.
Sometimes activating BEMF (CV29) will cause a locomotive to emit an slight audible buzz. I only had that happen with one locomotive and I can’t remember which one, or whether it was outfitted with a Loksound decoder.
CV29 doesn’t control BEMF. Most of the Euro decoders DO have a CV which you adjust for the ‘type’ of motor - this can have a drastic effect on the operation, since the settings vary from 3 pole open frame motors to coreless can motors and everything in between, and the optimal PWM drive is vastly different for each type. Loksound actually doesn’t have this, but the manuals for the Select and V4 give some recommended settings for the BEMF parameters for different motor types, plus they have the automatic adjustment.
I don’t recall what CV124 controls? All I know is that I had a Kato unit with the LokSound Select that the motor buzzed all the time. And this is after setting BEMF with there auto set mode. Changed CV124 to 20 through 24 and te Buzz went away
OK, that’s another one that is in the v4 manual but not Select, but should work on either. It’s another bit-mapped CV like CV29, it controls multiple things. Per the v4 manual, the default value is supposed to be 24, not 0.
One of the things it controls is the motor startup delay, that’s bit 2 in the CV. But the one that is probably meaningful for the motor buzz is bit 4. The choices are “adaptive regulation frequency” or “constant regulation frequency”. If the total value for CV124 was 0, then prime mover delay was off and it was on adaptive regulation. Changing the value to 24 turned on the constant regulation (and another setting that should only affect Marklin AC power) while keeping the prime mover delay off. Now, it doesn’t tell you what those two things mean, and it’s not a specific term, but based on what they call it I can guess it has something to do with the way the PWM motor drive signal is generated. It may be something like using a lower frequency PWM to get started (more torque, but also more buzz) vs. always using the high frequency (lower starting torque but no buzz).
Again, the v4 manual says this is the default, but any sound project creator can set the default CVs however they want, so this may not apply to all decoders. I’ll have to check mine where I hear no buzzing - I’d guess they are all set to 16 or higher (bit 4 is value 16, so if the CV is at least 16, the constant frequency setting is enabled).
I am sorry for the discussion triggered by my remark about the humming sound of ESU decoders. They do “work as designed” for those of us that hear them, eg. like me. There is nothing you can do. I discussed it lengthly with ESU developers a long time ago (this part of the hard- and software has never changed). I am glad most do not hear it or do not notice it and are happy with an extreme flexible sound decoder. I love the concept of customer sound uploading. I and my locomotives will join you again when ESU reworks it motor control. There are rumors they will do so with version 5. Have a great Christmas season!
I had the same discussion with ESU, Atlas, and IM; and they all acknowledge the buzz exists and that there is nothing they can really do about it. I’m simply surprised that so few others notice it. Hopefully the upgraded version will address it.
I too like the ESU motor control, and hope others enjoy their decoders as they seem to.
My new Christmas Athearn GP15 has the Tsunami2, but the slow speed performance hasn’t been upgraded like I had hoped it might.