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Forums - Synths & synthesis
Subject: Transposing Problem
Viewing all 32 messages - View by pages of 10: 1 2 3 4
Original Message 1/32 01-Apr-00 @ 08:38 PM - Transposing Problem
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problem...when I make a pattern and play it back, it sometimes plays the pattern but transposed a few notes from what I originally made it.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
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
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
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
Message 6/32 03-Apr-00 @ 04:35 AM - RE: Transposing Problem
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
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
Message 9/32 03-Apr-00 @ 01:10 PM - RE: Transposing Problem
Message 10/32 03-Apr-00 @ 04:33 PM - RE: Transposing Problem
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??
Message 11/32 03-Apr-00 @ 09:09 PM - RE: Transposing Problem
Message 12/32 04-Apr-00 @ 08:07 AM - RE: Transposing Problem
There are many people around who would be able to service your TB303. Either R@F or I would probably be able to sort it out. I'd be happy to take a look at it, if you shipped it to me and covered the cost for return postage. I doubt I'd charge much if it is something simple.
It is well worth you getting your TB303 serviced by someone who is very familiar with the machine, rather than someone who has a bit of general knowledge.
Oh yes - I ordered a new, original memory IC (444) from Roland today, and I've got a new modeswitch to solder in tonight. Hopefully by tomorrow that will be all the repairs completed :-)
Message 13/32 04-Apr-00 @ 09:56 AM - RE: Transposing Problem
Message 14/32 05-Apr-00 @ 06:19 AM - RE: Transposing Problem
Trev
Message 15/32 05-Apr-00 @ 02:31 PM - RE: Transposing Problem
I wish I'd just paid 200UKP for my 303 one year ago...
have fun!
Message 16/32 07-Apr-00 @ 06:06 AM - RE: Transposing Problem
What do you think is the sort of price they go for now? I've heard of one going for 400 UKP, but that was being sold to a shop for resale (they never do give you that much). OTOH, I see them being advertised for 800UKP still.
Trev
Message 17/32 07-Apr-00 @ 05:56 PM - RE: Transposing Problem
Since buying it I have resoldered the sync socket, done a few mild mods and replaced the LEDs with Kingbright Blue ones which look stunning.
Message 18/32 08-Apr-00 @ 04:29 AM - RE: Transposing Problem
Trev (who is 21... and probably missed out on shitloads)
Message 19/32 08-Apr-00 @ 04:06 PM - RE: Transposing Problem
BTW I'm 30 (old bastard!)
Message 20/32 08-Apr-00 @ 09:04 PM - RE: Transposing Problem
Message 21/32 10-Apr-00 @ 09:51 AM - RE: Transposing Problem
for it and won't sell it , even over my dead body! See , price doesn't matter that much no more if you're determined to have THAT real sound,and knowing that chances are you keep it for the rest of your life.Anyone want to purchase a $5000 car (1995) which probably has a life-span to 2003?
Heads-up.
-M-
Message 22/32 11-Apr-00 @ 04:55 AM - RE: Transposing Problem
Message 24/32 11-Apr-00 @ 02:23 PM - RE: Transposing Problem
Message 25/32 11-Apr-00 @ 03:04 PM - RE: Transposing Problem
And there were just about 10000 TR-909's made!!! So people hurry up and get one of the last ones till they're gone. LOL
Message 26/32 11-Apr-00 @ 03:06 PM - RE: Transposing Problem
Message 27/32 16-Apr-00 @ 06:03 AM - RE: Transposing Problem
Here's the website of someone else who has already completed a combined 808 and 909 clone. He's helped me by giving me the original ROM images for the cymbal / hihat sounds for the 909 circuits.
Actually I think it was on a different thread that we were talking about this, but never mind... ;-)
http://www.octavo.demon.co.uk/colinf/home.htm
Cheers, Trev
Message 28/32 16-Apr-00 @ 06:31 PM - RE: Transposing Problem
Did you see his nice small Midi2DinSync converter? Looks very interesting! I'm currently searching for someone who has a PIC-programmer.
CYa
R@F
Message 29/32 17-Apr-00 @ 07:35 AM - RE: Transposing Problem
Yeah we did discuss the 1469's. I think that, just like yourself, he's experimenting with equivalents.
Cheers,
Trev
Message 30/32 19-Apr-00 @ 04:47 PM - RE: Transposing Problem
My skills are limited to pure analog stuff. I thought of getting into microcontrollers but then I always prefer to use my spare time for producing, hehe. So what's your price for a programmed 12C508?
Message 31/32 20-Apr-00 @ 04:41 PM - RE: Transposing Problem
In fact, Colin himself would also supply you with one. But if he is too busy, I would do it for you.
Cheers,
Trev
Message 32/32 24-Apr-00 @ 01:35 PM - RE: Transposing Problem
I'd like to build 3 of these Midi2Sync converters. Would it be okay to send you three PIC's ?? Which PIC-programmer are you using?? I thought of building one of these programmers which can be found in the net. Anyways just give me your address and tell me how much money you need for sending it back. I gonna order the PIC's next days.
thanks
R@F
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