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Forums - Synths & synthesis
Subject: Transposing Problem
Original Message 1/32 01-Apr-00 @ 08:38 PM - Transposing Problem
After four freaking years, I finally got my TB-303...mint condition and all. Anyways...
I've got a little problem...when I make a pattern and play it back, it sometimes plays the pattern but transposed a few notes from what I originally made it. Can anyone explain this?
I've got a little problem...when I make a pattern and play it back, it sometimes plays the pattern but transposed a few notes from what I originally made it. Can anyone explain this?
Message 2/32 02-Apr-00 @ 07:39 AM - RE: Transposing Problem
Oh oh!!
Does this transposing always affect all patterns or just some of them??
When does it appear exactly? After powering up the machine? During play? Would you say it's real transposing or detuning?
Looks like a fault on the pitch-DA. Or the transopose function is activated by itself. Hhmmm...
Does this transposing always affect all patterns or just some of them??
When does it appear exactly? After powering up the machine? During play? Would you say it's real transposing or detuning?
Looks like a fault on the pitch-DA. Or the transopose function is activated by itself. Hhmmm...
Message 3/32 02-Apr-00 @ 08:02 AM - RE: Transposing Problem
Hi,
I just got a tb303 too! Nice on the outside, but a bit mangled on the inside. Anyway, I have spend the last three days bringing it back to life. As well as other things, one of the memory chips was on the way out. Two of the four data lines were playing up, and often remained asserted constantly. During use, this caused the pattern pitch to shift about all over the place.....
Anyway I hope - and expect that yours won't have such a problem. It could be something simple, even psu problem. I can thing of many things that might cause this, without playing with it myself I can't be sure. As R@F suggests quite rightly, a problem with the DA is also a possibility.
Does it shift the pattern about erraticly during playback - or does it *stay* transposed at that pitch all the time?
Trev
I just got a tb303 too! Nice on the outside, but a bit mangled on the inside. Anyway, I have spend the last three days bringing it back to life. As well as other things, one of the memory chips was on the way out. Two of the four data lines were playing up, and often remained asserted constantly. During use, this caused the pattern pitch to shift about all over the place.....
Anyway I hope - and expect that yours won't have such a problem. It could be something simple, even psu problem. I can thing of many things that might cause this, without playing with it myself I can't be sure. As R@F suggests quite rightly, a problem with the DA is also a possibility.
Does it shift the pattern about erraticly during playback - or does it *stay* transposed at that pitch all the time?
Trev
Message 4/32 02-Apr-00 @ 09:22 AM - RE: Transposing Problem
hey Trev! Nice chance to ask...
Did you replace the RAM with an original µPD444? I've asked Roland Germany for some parts last time. Damn the RAMs go for 39DM (20$US). According to my comparsion table they can be substituted with 2114 SRAMs, which are easy to find and quite cheap. Any experiences?? I don't know if they're pin-compatible, since I cannot find a datasheet for the 444's.
BTW: How much did you pay for the 303?
Did you replace the RAM with an original µPD444? I've asked Roland Germany for some parts last time. Damn the RAMs go for 39DM (20$US). According to my comparsion table they can be substituted with 2114 SRAMs, which are easy to find and quite cheap. Any experiences?? I don't know if they're pin-compatible, since I cannot find a datasheet for the 444's.
BTW: How much did you pay for the 303?
Message 5/32 02-Apr-00 @ 05:38 PM - RE: Transposing Problem
It happens during play with stop and start...I would sequence a pattern, play it, stop, then restart it and it would sound transposed...
Message 6/32 03-Apr-00 @ 04:35 AM - RE: Transposing Problem
Yes! I replaced mine with a 2114 RAM.
Take a look at the TB303 schematics. You can see the pinouts there for the '444. I obtained the pinouts for the 2114 from the Chip Directory (can't remember the url offhand). They ARE 100% pin compatable. I simply shoved a 2114 into the existing pads on the PCB.
And the problem? Well, I woke up in the next morning, turned on my 303 and... shit! The batteries were run down! Why? Because, unlike the '444 which draws microamps in standby (i.e. when the chip select line is high) the 2114 I used draws several 10's of mA! During use, the 303 will draw up to double the current. So with the TB303 switched off, the batteries had to supply a lot of current to keep this one 2114 in standby.
The 2114's I had were pulled out of the back of a teletext TV board, believe it or not. I don't know what exact type the are. Anyway, they are not CMOS if they draw this much current.
So you CAN replace them with 2114's - BUT make sure you use low power versions. If it is still possible to find a cheaper source for these 2114's then they are a perfect substitute. It seems as if these IC's use a standard pinout, which many other 1024 x 4 memory IC's will use. There may therefore be other compatible types.
My TB303 is still sitting there waiting for a new memory IC, since I have removed the 2114 I used. I was going to phone Roland for a new 444 today actually, but if they are that expensive, I might not bother! I am actually planning to design a small daughterboard that plugs into an 18pin socket in place of one of the IC's. It would contain a single memory IC that replaces the whole lot, and have a small backup battery too, to retain the memory even without the C cells in place. I think it is a good idea to hack in a newer, cheaper part rather than fork out for an old obsolete part.
Oh - I paid 200UKP for my TB303, which is about $320 I think. Yeah cheap I know, but it needed some pretty major repairs which took me a few days.
Trev
Take a look at the TB303 schematics. You can see the pinouts there for the '444. I obtained the pinouts for the 2114 from the Chip Directory (can't remember the url offhand). They ARE 100% pin compatable. I simply shoved a 2114 into the existing pads on the PCB.
And the problem? Well, I woke up in the next morning, turned on my 303 and... shit! The batteries were run down! Why? Because, unlike the '444 which draws microamps in standby (i.e. when the chip select line is high) the 2114 I used draws several 10's of mA! During use, the 303 will draw up to double the current. So with the TB303 switched off, the batteries had to supply a lot of current to keep this one 2114 in standby.
The 2114's I had were pulled out of the back of a teletext TV board, believe it or not. I don't know what exact type the are. Anyway, they are not CMOS if they draw this much current.
So you CAN replace them with 2114's - BUT make sure you use low power versions. If it is still possible to find a cheaper source for these 2114's then they are a perfect substitute. It seems as if these IC's use a standard pinout, which many other 1024 x 4 memory IC's will use. There may therefore be other compatible types.
My TB303 is still sitting there waiting for a new memory IC, since I have removed the 2114 I used. I was going to phone Roland for a new 444 today actually, but if they are that expensive, I might not bother! I am actually planning to design a small daughterboard that plugs into an 18pin socket in place of one of the IC's. It would contain a single memory IC that replaces the whole lot, and have a small backup battery too, to retain the memory even without the C cells in place. I think it is a good idea to hack in a newer, cheaper part rather than fork out for an old obsolete part.
Oh - I paid 200UKP for my TB303, which is about $320 I think. Yeah cheap I know, but it needed some pretty major repairs which took me a few days.
Trev
Message 7/32 03-Apr-00 @ 04:46 AM - RE: Transposing Problem
Yes! I replaced mine with a 2114 RAM.
Take a look at the TB303 schematics. You can see the pinouts there for the '444. I obtained the pinouts for the 2114 from the Chip Directory (can't remember the url offhand). They ARE 100% pin compatable. I simply shoved a 2114 into the existing pads on the PCB.
And the problem? Well, I woke up in the next morning, turned on my 303 and... shit! The batteries were run down! Why? Because, unlike the '444 which draws microamps in standby (i.e. when the chip select line is high) the 2114 I used draws several 10's of mA! During use, the 303 will draw up to double the current. So with the TB303 switched off, the batteries had to supply a lot of current to keep this one 2114 in standby.
The 2114's I had were pulled out of the back of a teletext TV board, believe it or not. I don't know what exact type the are. Anyway, they are not CMOS if they draw this much current.
So you CAN replace them with 2114's - BUT make sure you use low power versions. If it is still possible to find a cheaper source for these 2114's then they are a perfect substitute. It seems as if these IC's use a standard pinout, which many other 1024 x 4 memory IC's will use. There may therefore be other compatible types.
My TB303 is still sitting there waiting for a new memory IC, since I have removed the 2114 I used. I was going to phone Roland for a new 444 today actually, but if they are that expensive, I might not bother! I am actually planning to design a small daughterboard that plugs into an 18pin socket in place of one of the IC's. It would contain a single memory IC that replaces the whole lot, and have a small backup battery too, to retain the memory even without the C cells in place. I think it is a good idea to hack in a newer, cheaper part rather than fork out for an old obsolete part.
Oh - I paid 200UKP for my TB303, which is about $320 I think. Yeah cheap I know, but it needed some pretty major repairs which took me a few days.
Trev
Take a look at the TB303 schematics. You can see the pinouts there for the '444. I obtained the pinouts for the 2114 from the Chip Directory (can't remember the url offhand). They ARE 100% pin compatable. I simply shoved a 2114 into the existing pads on the PCB.
And the problem? Well, I woke up in the next morning, turned on my 303 and... shit! The batteries were run down! Why? Because, unlike the '444 which draws microamps in standby (i.e. when the chip select line is high) the 2114 I used draws several 10's of mA! During use, the 303 will draw up to double the current. So with the TB303 switched off, the batteries had to supply a lot of current to keep this one 2114 in standby.
The 2114's I had were pulled out of the back of a teletext TV board, believe it or not. I don't know what exact type the are. Anyway, they are not CMOS if they draw this much current.
So you CAN replace them with 2114's - BUT make sure you use low power versions. If it is still possible to find a cheaper source for these 2114's then they are a perfect substitute. It seems as if these IC's use a standard pinout, which many other 1024 x 4 memory IC's will use. There may therefore be other compatible types.
My TB303 is still sitting there waiting for a new memory IC, since I have removed the 2114 I used. I was going to phone Roland for a new 444 today actually, but if they are that expensive, I might not bother! I am actually planning to design a small daughterboard that plugs into an 18pin socket in place of one of the IC's. It would contain a single memory IC that replaces the whole lot, and have a small backup battery too, to retain the memory even without the C cells in place. I think it is a good idea to hack in a newer, cheaper part rather than fork out for an old obsolete part.
Oh - I paid 200UKP for my TB303, which is about $320 I think. Yeah cheap I know, but it needed some pretty major repairs which took me a few days.
Trev
Message 8/32 03-Apr-00 @ 04:57 AM - RE: Transposing Problem
Intrestingly, I just nosed around the DevilFish site. He actually advises against using 2114's in the TB303 maintenance pages - because you must use low power devices. Maybe 2114s aren't available in a suitable low power version..?
Message 9/32 03-Apr-00 @ 01:10 PM - RE: Transposing Problem
Yo Pedicelli! I thought 303's were "overpriced 20 years old unreliable sythesizers" ha ha! Welcome to the real world my friend! Peace 
Message 10/32 03-Apr-00 @ 04:33 PM - RE: Transposing Problem
Yeah, that`s the question: Is there a CMOS version of the 2114 available?? I don't own the datasheet. I found one from NEC (µPD 2114) which is NMOS. I guess that's the point here : There seems to be no low power version of the 2114 
NMOS has always a higher current drain than CMOS.
The store where I usually get my compononts (they offer a wide range of japanese parts including 2SC1583, M5218L, 4558, BA6110 etc.) sell 2114's called "2114LC-3". Low current? Don't know. I would try a new 2114 first, before concerning about a original 444. According to the 808 service docs there's another compatible part called HM4334P-4. But I don't know where to get this RAM.
You've found it in a teletext TV board?? Absolutely possible. The 2114 is used in a C-64 too (Color RAM, 4Bits=16 colors).
According to Pediccelli's transposing problem: You stop a pattern, restart it and it's suddenly transposed?? Oh oh, this looks like a problem very similar to Trevor's 303. RAM or even CPU (i hope not cause it's no longer available).
Anyways, it seems to be real hardware problem. It needs some test equipment and some skills in electronics to locate the fault part. Especially when it comes up to digital stuff (I remember when I've repaired the 202 of a friend which had a damaged RAM too).
Don't you know any guys which are skilled in electronics to repair it for you??
NMOS has always a higher current drain than CMOS. The store where I usually get my compononts (they offer a wide range of japanese parts including 2SC1583, M5218L, 4558, BA6110 etc.) sell 2114's called "2114LC-3". Low current? Don't know. I would try a new 2114 first, before concerning about a original 444. According to the 808 service docs there's another compatible part called HM4334P-4. But I don't know where to get this RAM.
You've found it in a teletext TV board?? Absolutely possible. The 2114 is used in a C-64 too (Color RAM, 4Bits=16 colors).
According to Pediccelli's transposing problem: You stop a pattern, restart it and it's suddenly transposed?? Oh oh, this looks like a problem very similar to Trevor's 303. RAM or even CPU (i hope not cause it's no longer available).
Anyways, it seems to be real hardware problem. It needs some test equipment and some skills in electronics to locate the fault part. Especially when it comes up to digital stuff (I remember when I've repaired the 202 of a friend which had a damaged RAM too).
Don't you know any guys which are skilled in electronics to repair it for you??
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