Is that the End of the x0xb0x ???
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Re: Is that the End of the x0xb0x ???

by synthplayer on Tue Jan 08, 2013 8:53 am

antto wrote:it's basically Mr. Cy from technology transplant afaik
Robin W. is supporting it because he has business with Cy/TT from before, and will be making devilfish mod for this thing too
[/methinks]


WTF,
Robin W. is in with this!!!??? Sold out to the devil? Oh well, money talks I guess..... :roll:
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Re: Is that the End of the x0xb0x ???

by roxxx303 on Tue Jan 08, 2013 12:02 pm

Two more Comments to TT-303:
(http://www.discogs.com/groups/topic/353794)

doobydoo
3 days ago
Just got my Bass Bot TT-303 from Superior Sounds banned
I've been playing around with the TT-303 for an hour or so and comparing it to my TB-303 and the sound is so close to the original it's remarkable !
The internal sequencer plays just like the TB-303's one - which is so important to get the real 303 sound.
Slides and accents sound convincing and squelchy - the accent may go up slightly higher though.
Mutate is great for getting quick variations on patterns.
Having a whole extra set of generatable random presets to go through and to be able to copy/paste and edit into a pattern is excellent.
The scratchpad is also a handy feature.
Build quality is good.


And from Robin Whittle:
(http://analogue-heaven.1065350.n5.nabble.com/Cyclone-Analogic-TT-303-Bass-Bot-td104517i40.html)

Hi Filip,

I just measured the four capacitors in the TT-303 filter. The first one
is 0.018uF (micro Farads) and the other three are 0.033uF. These are
the same values as in the TB-303.

The TT-303 uses transistors for the diode functions - an exact copy of
the TB-303 arrangement. It doesn't matter what the transistors or
diodes are, since they all have the same (or similar enough) voltage to
current curve at any given temperature. Diodes would have been
marginally less expensive and would have worked just as well. Maybe the
choice of transistors over diodes in the TB-303 was to get around some
patents involving actual diodes in the filter.

I haven't traced out the circuit of the TT-303 filter, but these crucial
components look the same as in the TB-303. There are dual transistors
at the driving and receiving ends too, as in the TB-303 circuit.

As far as I know the filter and the rest of the audio circuitry is the
same as the TB-303. Other people with more patience then me will
probably do A/B sound comparisons.

Whether or not this is exactly a 24dB per octave filter is something
which could be debated. The filter probably wouldn't be 24dB per octave
even if all the four capacitors were the same, since these stages, with
their resistor equivalents in the small signal transfer function of the
diodes, are coupled together in a way which means their input and output
impedances are not quite what would be required for them to operate at
6dB per octave.

David Bulog pointed to David Stinchcombe's treatise on diode ladder filters:

http://www.timstinchcombe.co.uk/index.php?pge=diode

which links to another page with this new URL:

http://fa.utfs.org/diy/roland_filters/

You can see the x0xb0x version of the filter at the "snapshot" image from:

http://www.ladyada.net/make/x0xb0x/download.html

There are three dual transistors - Q12 to drive the ladder, Q22 to
terminate it and Q21 as a differential amplifier receiving the signal
from the top. This follows exactly the TB-303 arrangement:


http://machines.hyperreal.org/manufactu ... chem-5.gif

You can think of the capacitors as reasonably heavy wooden rungs on a
rope ladder. I am up in a tree holding the two ropes at the top, only
interested in the difference in tension between the two ropes, not
caring about the total or average tension. You are on the ground
differentially wiggling the two ropes at the end with your "VCO" signal,
which contains a bunch of harmonics. If the VCO signal is positive, you
pull more on the left rope and less on the right. When it is negative,
you do the opposite.

If you don't place general overall average tension on the ropes, they
are hanging loose and each pair of ropes between one rung and the other
is quite stretchy. This means they have a "high impedance". In
electrical terms their resistance or impedance to small AC signals (your
wiggling) is high, meaning not much of the wiggling from one rung can
affect the next rung above. Since the rungs are made of heavy wood,
they have a fixed inertia. All that matters to my perception is their
inertia in terms of one end being raised while the other is pulled down
- which is what you are attempting to do with your wiggling. The wooden
rungs are the exact equivalents of the fixed capacitors in the diode
ladder filter. After a few sets of slack rope and heavy rungs, with
each stage forming a low-pass filter with a low cut-off frequency, I
either feel none of your "VCO" wiggling, or at most just the very lowest
harmonics.

If you pull down tight on both ropes, while maintaining your wiggling,
this tightens up each section of rope and reduces its impedance to small
changes in tension. The rope behaves much like a diode or a transistor
with its base and collector connected, as is done in these filters.
(Using chain, steel cable or thick solid nylon would not behave this
way, because their impedance for small changes is much the same, quite
low, no matter how much tension is on them - assuming the chain has at
least some tension.)

Now each stage of the filter has a higher cut-off frequency, since there
is less impedance in the ropes, and so a stronger drive to move each
rung above with your wiggling signal. I will feel more of your wiggling
signal in general. In particular I will feel much more of the higher
frequencies, since each stage of the filter now has a higher cut-off
frequency and is not attenuating these higher frequencies as much as
when the rope had little tension on it.

Tim Stinchcombe has some daunting maths concerning this.

Returning to the TB-303, the important thing for me is not so much
precisely what the frequency response of the filter is, but how the
whole circuit behaves at higher resonances, and in the Devil Fish, how
it behaves with very low currents (very low tension on both ropes)
and/or with very high drive signals. In the Devil Fish I drive the
filter, in theory, 66.6 times harder than usual, if the Overdrive pot is
fully clockwise. This would be hard to measure, but it is the
theoretical ratio between the drive resistances of the unmodified TB-303
and the Devil Fish with Overdrive fully clockwise.

These "slack tension" (very low cut-off frequencies) and/or heavy
overdrive characteristics of the diode ladder filter are musically
really fruitful, and are not as accurate or mathematically perfect as a
"properly designed" 4 pole LPF, in which each resistor-capacitor stage
is used in a manner which is unaffected by the frequency varying
impedances of the other stages, by way of op-amps or transistors:

http://fa.utfs.org/diy/roland_filters/SH1.jpg
http://fa.utfs.org/diy/roland_filters/JP8.jpg

I would be surprised if the choice of 0.018uF instead of 0.033uF for the
first ring in the TB-303 made a clearly audible difference and I don't
know why this choice was made. It is equivalent to using a lighter
piece of wood for the first rung of your ladder, which means that in
theory the first stage has a cut-off frequency 0.033 / 0.018 = 1.833
times that of the other stage.

- Robin http://www.firstpr.com.au/rwi/dfish/TT-303/


This sounds really not bad - shall I exchange my TB with TT and save the extra money for another funky gear? :?
- roxxx303
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Re: Is that the End of the x0xb0x ???

by Luap on Tue Jan 08, 2013 12:13 pm

roxxx303: Are you even bothering to read the replies you are getting here?
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Re: Is that the End of the x0xb0x ???

by roxxx303 on Wed Jan 09, 2013 4:14 am

Luap wrote:roxxx303: Are you even bothering to read the replies you are getting here?

Hi Luap,

I read all comments, but I am also very interested in this machine because it seems to be a serious project.
When I read about the features it sounds really impressive and Robin is a TB-Guru for years. Why should he modify it, if he thinks it is banned?

I only wonder why nobody has done an A/B-comparision to a real TB yet. The Youtube videos are really weak and say nothing about the sound-quality of the machine.

And why is everybody on this forum talking bad about the TT though no one has ever owned or seen one in real?

I love the TB-Sound for years and own a TB and a x0xb0x and would like to compare them to the TT...

-roxxx303
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Re: Is that the End of the x0xb0x ???

by synthplayer on Wed Jan 09, 2013 5:33 am

roxxx303 wrote:Hi Luap,
I read all comments, but I am also very interested in this machine because it seems to be a serious project.
When I read about the features it sounds really impressive and Robin is a TB-Guru for years. Why should he modify it, if he thinks it is banned?


Why do people work? Eventhough that's a different question but I think it will get you a similar if not the same answer.

And why is everybody on this forum talking bad about the TT though no one has ever owned or seen one in real?


Personally, I think a faithful clone with well built quality is a great gift to people like us who admires the original TB. However, the speculation about the production of this tb303-clone from HongKong "Cyclone Analogic TT-303" just doesn't sit right with me. If I remeber correctly, this is the guy that attempted to profit from the x0x open source project by mass commercial production and came to the forum openly challenged adafruit for a lawsuit to be stopped?? (correct me if I am wrong, as I could be very mistaken here)

If indeed he is the very same guy, I do not condone his action and would not like to support his business. Not because he violated the Open Source license agreement and its unethical to do so or what not, but simply because I do not want to endorse and financially support a character whom prey and looking to PROFIT from someone else's hard work and good intention to share their ideas/project. To me, this is a disease to openly sharing ideas and inspire creativity. Can you imagine characters like this suck the life out of open source projects till no one is willing to openly share ideas anymore??

That would be really sad. :(
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Re: Is that the End of the x0xb0x ???

by rarara on Wed Jan 09, 2013 5:55 am

I am fairly unconcerned about this new machine - if it nails the sound they I say well done to whoever has managed it. By rights it should be better than a x0xb0x since its several hundred pounds more :? . I am fairly happy that I built my little unit myself, so its good enough for me - if anything it may make me strive to get the sound of mine better by checking out a few components etc

What I am surprised by is the fact that if this new machine as some independent ( :roll: ) reviewers claim, is 99% towards a real 303, it seems to have appeared from nowhere as a fully fledged item. There are threads on here going back years with people trying to get their x0xb0x more 303-like by swapping out components and there is still no concensus. maybe these boards have been used sneakily by the builders to improve their product?
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Re: Is that the End of the x0xb0x ???

by roxxx303 on Wed Jan 09, 2013 7:51 am

synthplayer wrote:Why do people work? Eventhough that's a different question but I think it will get you a similar if not the same answer.


Not everyone hates his job! If you are skilled (and I believe Robin W. is!) you can choose the job you love most.
And who wants to ruin his good reputation, if he could work for someone else?

I think it's not proved that the TT-303 is produced by the same bad people which got in trouble with adafruit.
And it's not a small one-man-project only to make fast money. It's not soldered by hand in a small workshop.
It's surface-mount-technology for which you need a modern factory! And they tried to make the TB-clone even better
with a clever modern sequencer.

For me I want to know if I should get one before Roland will stop this project.
But who knows about the future. Perhaps Roland does not do anything and thousands of TTs
will be produced and you will get one for 100 Euros in 2 years... (like the TB in the 80ties :wink: )
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Re: Is that the End of the x0xb0x ???

by antto on Wed Jan 09, 2013 8:05 am

the TT-303 is produced by Cy
and i don't think you have to own the machines in order to make surface-mount stuff, afaik there are companies which offer such things, you just supply schematics and stuff and they build the things
but that's not important

even if these things become really cheap as you say, you can't compare it to a 303 because while the 303 has schematics in the manual, the TT-303 doesn't
and i doubt whether the components are even labeled on the PCB
this all means that if something goes wrong with it - it won't be very simple to repair

now if you had problems with a TB-303 - you can always ask someone familiar with x0xb0xes because 99% of the things are the same, and vice-versa
you can send it to repair, schematic is available.. etc..
or you can repair it yourself

this aspect IMO is important :wink:
We are here too: irc.freenode.net >>> #x0xb0x
..:: c0nb0x v1.00 ::.. http://forums.adafruit.com/viewtopic.php?f=7&t=29282 (new control app - win/osx)
VCO Tuning: http://forums.adafruit.com/viewtopic.php?f=12&t=24759 (do it the EASY way)
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Re: Is that the End of the x0xb0x ???

by roxxx303 on Thu Jan 10, 2013 7:00 am

antto wrote:even if these things become really cheap as you say, you can't compare it to a 303 because while the 303 has schematics in the manual, the TT-303 doesn't
and i doubt whether the components are even labeled on the PCB
this all means that if something goes wrong with it - it won't be very simple to repair

now if you had problems with a TB-303 - you can always ask someone familiar with x0xb0xes because 99% of the things are the same, and vice-versa
you can send it to repair, schematic is available.. etc..
or you can repair it yourself

this aspect IMO is important :wink:


This is an aspect I'm also aware of. A machine for nearly 700 Euros (including shipping and taxes) from china. What to do if it's broken?
An expensive fun...
I think I will wait if they will be available at local music-stores like the mode machine x0xb0x. If you have a problem the music-store has to fulfill the warranty...
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