TTS steam decoders

[RAF96]

TTS chuffing is assembled from up to 18 separate but fixed chuff rate sound bytes, which swap one to the next as the throttle increases. BEMF is used to control when to chuff and when to coast hence on a decreasing throttle as speed rematches throttle setting and the load comes back on the chuff will recommence. The TTS chuffs are not triggered by say a wheel trigger/rev counter, therefore come in fixed rate ‘lumps’ across a speed band.

 

The CVs for altering the motor PI algorithm are more to do with how the motor reacts to throttle and nothing to do with how the sound reacts.

 

Chuff to wheel synch is set by the sound file assembler for any particular loco. The only way to alter this is by matching a TTS decoder chuff packet with a wheel diameter versus speed. I have a Tornado decoder in a GWR 2721 pannier tank and the chuff is well synchronised at my track speed range. My TTS A4 is well out of synch at my track speeds. In the absence of a wheel trigger as used on some decoders it boils down to the skill of the sound file guy matching a particular chuff rate versus wheel revs at slower speed where the eye can spot any mismatch.

 

Rob

[Merlin242]

TTS chuffing is assembled from up to 18 separate but fixed chuff rate sound bytes, which swap one to the next as the throttle increases. BEMF is used to control when to chuff and when to coast hence on a decreasing throttle as speed rematches throttle setting and the load comes back on the chuff will recommence. The TTS chuffs are not triggered by say a wheel trigger/rev counter, therefore come in fixed rate ‘lumps’ across a speed band.

 

The CVs for altering the motor PI algorithm are more to do with how the motor reacts to throttle and nothing to do with how the sound reacts.

 

Chuff to wheel synch is set by the sound file assembler for any particular loco. The only way to alter this is by matching a TTS decoder chuff packet with a wheel diameter versus speed. I have a Tornado decoder in a GWR 2721 pannier tank and the chuff is well synchronised at my track speed range. My TTS A4 is well out of synch at my track speeds. In the absence of a wheel trigger as used on some decoders it boils down to the skill of the sound file guy matching a particular chuff rate versus wheel revs at slower speed where the eye can spot any mismatch.

 

Rob

 

Thanks for the explanation. What I don't understand is why then at slow speed when its most obvious Hornby have made such a poor fist of matching chuffs to the particular loco the decoder is supposed to be for( S15 excepted)? Its by far the biggest deterrent to buying the product

[JSpencer]

The only solution I suppose will be to put a resister between chip and motor. I doubt few of us will run the model at fall whack. Even then some chuffs are so out of sync (castle class about 1 chuff every 3 wheel turns) that it might still be impossible.

[Merlin242]

Its sad as it is a great missed opportunity by Hornby. I wont be buying any more TTS decoders but will save up for decoders which actually represent what a steam loco sounds like. 

[DonnyRailMan]

Its sad as it is a great missed opportunity by Hornby. I wont be buying any more TTS decoders but will save up for decoders which actually represent what a steam loco sounds like.

 

I totally agree with you. My dad had a saying when doing any job at home , why spoil a good job for a Pen-arth of tar. The Hornby TTS decoders will do for me as I am not to bother if they are not in synik . The thing is as well you can buy about three TTS Decoders for the price of a good quality decoder. Surely Hornby could have made better TTS for a few £ bob more.

[Pete the Elaner]

Its sad as it is a great missed opportunity by Hornby. I wont be buying any more TTS decoders but will save up for decoders which actually represent what a steam loco sounds like. 

That depends on how much work there was involved with designing & producing TTS decoders.

Re-designing the chip to include chuff rate adjustment may well have pushed the price towards that of a Zimo MX645 or Loksound v4. Only the chip developers will know this.

 

TTS is a cheaper alternative for a reason.

If you can live with its limitations, TTS becomes an alternative, offering you a choice which was not previously available.

You are still welcome to choose a 'full-fat' chip. Justifying the extra cost is a personal decision.

[JSpencer]

On the new versions, you have a coast function which switches the chuff off. I set out an ambitious program of some 40 DCC sound conversions. TTS allows me to add sound for not much more than a plain DCC chip in locos that are generally visitors on my SR layout.

[Pete the Elaner]

I set out an ambitious program of some 40 DCC sound conversions. TTS allows me to add sound for not much more than a plain DCC chip in locos that are generally visitors on my SR layout.

TTS has provided you this choice. Surely this is good?

For anyone wanting more features (more concurrent sounds, adjustable chuff rate, automatic coasting), the full-feature decoders are still an option.

[DonnyRailMan]

I think the TTS Decoders are fine for what I want . The locomotives I have with TTS I do not always have them running switched on. But i plan on buying 3 or 4 TTS decoders for my A3s A4s.

[JSpencer]

TTS has provided you this choice. Surely this is good?

For anyone wanting more features (more concurrent sounds, adjustable chuff rate, automatic coasting), the full-feature decoders are still an option.

 

Yes they have provided a choice, the chuff is in steps so a CV just to make it chuff faster or slower so we are closer to wheel revolutions than the default rate would be the icing on the cake.

 

On my everyday locos, I've gone for more expensive full fat options. However conversion rates are about 3 or 4 a year. As I take time to choose over the package and also budget. Last year there were no full fat conversions due to the huge number of SR items coming out. This year, there will be just 2 full fat as I still have 15 locos appearing this year. Next year I will do 4 full fat conversions, maybe 6 if no one announces anything that pleases me (which I doubt).

 

Currently I have full fat:

black 5 with smoke working lamps and firebox glow

C class with lamps and firebox glow

E4 with lamps and firebox glow

DJM Austerity

C class SECR (no other features)

Adams Radial

Hornby Class 08

TWO Bachmann class 20

Class 23

Class 33

Class 35

Bachmann Class 37

Bachmann Class 40

Class 50

Dapol Class 52

Class 56

Canadian LRC

APT-E

2-EPB

MLV

4-CEP

 

TTS:

Cock O the North

Bachmann 9F

Bachmann A1

Sir William Stanier

King Class

Castle Class

Merchant Navy

S15

Class 31

 

As you can see TTS option has saved a lot of money and avoided just doing plain DCC (£360 max instead £900+ if it was full fat).

[RAF96]

Quote post #85 “...the chuff is in steps so a CV to ...”

 

Not so, as already explained somewhere on here the TTS steam chuff is recorded in 18 lumps and transitioned in coarse steps by throttle amount as modified by BEMF. 128 speed steps / 18 noises equals a noise change approx every 7 speed steps, not every wheel rev.

 

Hence for the first few speed steps you get lump 1 (chuff on if accellerating, chuff off if decellerating as prompted by BEMF). As the throttle hits the transition point then sound lump 2 kicks in, etc towards flat out.

 

You can see that the chuff rate of each lump is fixed across a varying speed range per transiton. No amount of CV fiddling can vary a fixed noise unless that noise is but a single chuff triggered by something else such as a wheel sensor or decoder commanded repeat rate. TTS cannot do that for the money.

 

BTW you have always been able to chuff / coast manually in TTS by way of F17, its nothing new.

Rob

[JSpencer]

Quote post #85 “...the chuff is in steps so a CV to ...”

Not so, as already explained somewhere on here the TTS steam chuff is recorded in 18 lumps and transitioned in coarse steps by throttle amount as modified by BEMF. 128 speed steps / 18 noises equals a noise change approx every 7 speed steps, not every wheel rev.

Hence for the first few speed steps you get lump 1 (chuff on if accellerating, chuff off if decellerating as prompted by BEMF). As the throttle hits the transition point then sound lump 2 kicks in, etc towards flat out.

You can see that the chuff rate of each lump is fixed across a varying speed range per transiton. No amount of CV fiddling can vary a fixed noise unless that noise is but a single chuff triggered by something else such as a wheel sensor or decoder commanded repeat rate. TTS cannot do that for the money.

BTW you have always been able to chuff / coast manually in TTS by way of F17, its nothing new.

Rob

I know that matching g chuffs to wheel revolutions is practically impossible unless unless you had some input (a real scaled down working speedo) actually linked to the wheel revolutions. Any chuff linked to motor power steps alone needs to be aligned with some mean value since a loco with no load requires less power to reach speed X than a loco with 12 bogies in tow. Likewise no two models from the same production line perform exactly alike. I had a discussion over a loco of mine that had no trouble moving off on less than 0.6 volts as the chip makers sound did not kick in until the equivalent speed step kicked in and they left it purposely silent below that.

 

While the chuffs are broken into 18 chunks evenly spaced across 128 speed steps, what I would like is a set of CVs so that I can adjust which chuff triggers at what speed steps. If I find the loco going too faster for a chuff, I can limit it to fewer lower speed steps and have the next chuff rate kick in sooner. While not in sync it will still be better than we what we have now which is on some looks roughly right and on others is totally outclassed by miles by the old fashioned Triang B12 plastic sound box with a bit of steel rubbing against a copper stripe covered in sand.

[DonnyRailMan]

If there was only the Hornby TTS decoders available i think everyone would be chuffed to bit with what they had. You get what you pay for . When Joe Blogs bought Joe Blogs Jr a TTS set for Christmas I bet they both thought it can not get better than this. Mr Blogs said Gordon bennett we never had this when I was a lad .

[RAF96]

Quote “...While the chuffs are broken into 18 chunks evenly spaced across 128 speed steps, what I would like is a set of CVs so that I can adjust which chuff triggers at what speed steps. If I find the loco going too faster for a chuff, I can limit it to fewer lower speed steps and have the next chuff rate kick in sooner. While not in sync it will still be better than we what we have now which is on some looks roughly right and on others is totally outclassed by miles by the old fashioned Triang B12 plastic sound box with a bit of steel rubbing against a copper stripe covered in sand...”

 

This speed step variable triggering is exactly what can be done on Diesel TTS. The notching is controlled by what is know as TTW, CVs that can be changed to alter when notching takes place, both up and down the speed range. However there are usually only three, four or maybe five notches so this doesn’t consume so much decoder memory as would say several more steam ‘notches’. This notching doesn’t utilise BEMF as the noise of a diesel is not load dependant as such. The CV settings determine if during any acceleration the engine speed rises initially then settles back to the previous rate or sustains at that new rate. This happens at the next notch gate and so on. A bit like selecting sport, normal or ice on your posh car.

 

Memory management is a fixed limit with all sound decoders, as can be seen if you have ever used a LokProgrammer to assemble an ESU sound file. Each sound ‘lump’ may need a start phrase, a repeating mid phrase with or without random elements and an end phrase, depending upon what that sound is presenting to the ear. As the memory is filled, it may be that a choice has to be between this or that sound on the decoder build wish list.

 

The Pro sound guys on here can expand on that as I have only dabbled with the ESU sample files from their website as part of the blow-your-own learning curve.

 

Rob

Edited August 22, 2018 by RAFHAAA96

[JSpencer]

Quote “...While the chuffs are broken into 18 chunks evenly spaced across 128 speed steps, what I would like is a set of CVs so that I can adjust which chuff triggers at what speed steps. If I find the loco going too faster for a chuff, I can limit it to fewer lower speed steps and have the next chuff rate kick in sooner. While not in sync it will still be better than we what we have now which is on some looks roughly right and on others is totally outclassed by miles by the old fashioned Triang B12 plastic sound box with a bit of steel rubbing against a copper stripe covered in sand...”

 

This speed step variable triggering is exactly what can be done on Diesel TTS. The notching is controlled by what is know as TTW, CVs that can be changed to alter when notching takes place, both up and down the speed range. However there are usually only three, four or maybe five notches so this doesn’t consume so much decoder memory as would say several more steam ‘notches’. This notching doesn’t utilise BEMF as the noise of a diesel is not load dependant as such. The CV settings determine if during any acceleration the engine speed rises initially then settles back to the previous rate or sustains at that new rate. This happens at the next notch gate and so on. A bit like selecting sport, normal or ice on your posh car.

 

Memory management is a fixed limit with all sound decoders, as can be seen if you have ever used a LokProgrammer to assemble an ESU sound file. Each sound ‘lump’ may need a start phrase, a repeating mid phrase with or without random elements and an end phrase, depending upon what that sound is presenting to the ear. As the memory is filled, it may be that a choice has to be between this or that sound on the decoder build wish list.

 

The Pro sound guys on here can expand on that as I have only dabbled with the ESU sample files from their website as part of the blow-your-own learning curve.

 

Rob

 

That is exactly what I would like to know. Do you or anyone have details on how they do this on the diesel CVs (which ones? what sort of values should I be moving etc)? Its a safe bet the TTS steam is the exact same concept and can be adjusted the same way.

 

I know memory is limited but on a fall fat Zimo we managed to put a whole host of Star Wars noises (R2D2 talking) on top of all the class 37 ones, so maybe there is little extra room for a few digits in the CVs.

[RAF96]

JS

I attach an extract from a TTS Class 67 user ‘manual’ talking about diesel driving, TTW adjustment, etc.

 

...however I can assure you no amount of fiddling with the TTS steamer will recreate TTW as the sound files are assembled completely differently at root functionality.

 

 

Rob

Edited August 22, 2018 by RAFHAAA96

[DonnyRailMan]

Did Hornby stop altogether producing the DCC Sound chip decoders that they where putting in loco's Back in say 2011 / 2013 ish . And now just sell TTS System I know the Hornby DCC Sound would be in the high end price range if they did. If Hornby had spent a lot of money developing

DCC Sound if they where to sell the decoders ariund £100 they could recoup some of the developing cost.

[JSpencer]

If there was only the Hornby TTS decoders available i think everyone would be chuffed to bit with what they had. You get what you pay for . When Joe Blogs bought Joe Blogs Jr a TTS set for Christmas I bet they both thought it can not get better than this. Mr Blogs said Gordon bennett we never had this when I was a lad .

 

I'm not complaining per-se. Just making a minor suggestion that is technically feasible and exists on Diesel versions. My Castle class does 3 entire wheel revolutions for 1 chuff! Instead of 12. Just to move the steps to roughly right is fine for the price. Exactly right obviously needs something more expensive. The other 20 or sounds they supply on the chip today, I have no issues with for the price.

 

BTW Strangely when fitted in Bachmann, they are roughly right.

[JSpencer]

Did Hornby stop altogether producing the DCC Sound chip decoders that they where putting in loco's Back in say 2011 / 2013 ish . And now just sell TTS System I know the Hornby DCC Sound would be in the high end price range if they did. If Hornby had spent a lot of money developing

DCC Sound if they where to sell the decoders ariund £100 they could recoup some of the developing cost.

 

At the time when they first did TTS, they did say that they were going to continue with full fat ESU sound. But it seems to have quietly disappeared probably due to cost. It no longer adds £100 but more like £120 or £130 to the price tag and I guess few will buy a cir £300 sound fitted model and those who do will often have their own preferred DCC sound supplier.

[Fireline]

Just to move the steps to roughly right is fine for the price. 

 

But isn't that the point? They're already doing what they can for the price. More work means more expense, which means a higher price! Then people start complaining that the chip is too expensive, and the chip misses the market it was aimed at. 

[MikeParkin65]

If there was only the Hornby TTS decoders available i think everyone would be chuffed to bit with what they had. You get what you pay for . When Joe Blogs bought Joe Blogs Jr a TTS set for Christmas I bet they both thought it can not get better than this. Mr Blogs said Gordon bennett we never had this when I was a lad .

If there were only Hornby TTS for sound available it would rapidly be seen as a gimmick by most of us and quickly be confined to the history books like Zero One and Live Steam before it. 

[JSpencer]

But isn't that the point? They're already doing what they can for the price. More work means more expense, which means a higher price! Then people start complaining that the chip is too expensive, and the chip misses the market it was aimed at. 

 

They already do it for TTS Diesels (which are the same price), just asking for same adjustable notching concept in steam (maybe it already exists, and I just need to explore the CVs). Its not like I'm asking them to invent something new. They went and added several new sound functions on the latest chips without increasing the price which must be heavier to implement (record, process, compact, load etc...).

Edited August 23, 2018 by JSpencer

[Pete the Elaner]

If there were only Hornby TTS for sound available it would rapidly be seen as a gimmick by most of us and quickly be confined to the history books like Zero One and Live Steam before it. 

But before TTS, many saw Loksound & Zimo options as too expensive.

Now we have a choice.

[RAF96]

They already do it for TTS Diesels (which are the same price), just asking for same adjustable notching concept in steam (maybe it already exists, and I just need to explore the CVs). Its not like I'm asking them to invent something new. They went and added several new sound functions on the latest chips without increasing the price which must be heavier to implement (record, process, compact, load etc...).

You can search the steam CVs all you like, it won’t alter a thing. All you can do is alter the motor agorithm (1 or 2) or associated PI values or BEMF cut in/out point.

See post #91 again.

Rob

[Black 5 Bear]

Does any kind soul out there, have video footage of the Hornby S15 with the new TTS chip fitted ?

Additionally, how difficult is retro fitting on the high sided Maunsell tender ?

I'm torn between buying one of these and waiting for the factory fitted option due next year.

Edited August 23, 2018 by Black 5 Bear