Author |
Message |
LektroiD
Joined: Aug 23, 2008 Posts: 1018 Location: Scottish Borders
Audio files: 2
G2 patch files: 2
|
|
Back to top
|
|
|
LektroiD
Joined: Aug 23, 2008 Posts: 1018 Location: Scottish Borders
Audio files: 2
G2 patch files: 2
|
Posted: Mon Jul 13, 2009 5:37 pm Post subject:
|
|
|
If I'm reading my international transistor equivalents guide correctly, the following should be:
2SA564 = BC258
2SC644 = BC182
2SC828 = BC167
DOUBLE CHECK THE ABOVE!
I still have no idea what the transistor next to the bold '65Hz' text is though. it could either be 2SA564 (going by the two surrounding rings) or 2SC644 (going by the polarity).
Help would be a virtue right now _________________ LektroiD |
|
Back to top
|
|
|
esnabez
Joined: May 01, 2009 Posts: 13 Location: Brooklyn, NY
|
|
Back to top
|
|
|
beszedes
Joined: Jul 20, 2009 Posts: 3 Location: Hungary
|
Posted: Mon Jul 20, 2009 6:20 am Post subject:
|
|
|
I also got that sch for MP7 but unfortunately it seems to be incomplete: a part is missing from the central region (rhythm section).
@esnabez: could you please send (or post) the entire schematics of the univox? thanks,
Btw, I think replacements BC183B and BC237B are OK. |
|
Back to top
|
|
|
esnabez
Joined: May 01, 2009 Posts: 13 Location: Brooklyn, NY
|
|
Back to top
|
|
|
beszedes
Joined: Jul 20, 2009 Posts: 3 Location: Hungary
|
Posted: Mon Jul 20, 2009 1:45 pm Post subject:
|
|
|
Thanks for that! Know, what I don't understand in this schematic is that where do some of the instrument's triggers come from, for instance TAM, QUI, GUI?? |
|
Back to top
|
|
|
esnabez
Joined: May 01, 2009 Posts: 13 Location: Brooklyn, NY
|
Posted: Mon Jul 20, 2009 2:19 pm Post subject:
|
|
|
Yes, I see what you're saying... I never noticed that before!
I checked the entire service manual, and it makes no reference to where the TAM, GUI, and QUI get their triggers. Being that they are always on (output controlled only by their volume pots), they must be hardwired to the rhythm generator SOMEWHERE!
I guess the only thing I can do is pop open my Univox and see what I find. Be patient, though; I'm super busy these days. I'll try to get to it by Wednesday... |
|
Back to top
|
|
|
LektroiD
Joined: Aug 23, 2008 Posts: 1018 Location: Scottish Borders
Audio files: 2
G2 patch files: 2
|
Posted: Mon Jul 20, 2009 6:15 pm Post subject:
|
|
|
I would imagine the Guira uses Gate rather than Trigger, since the inbuilt sequences have different length notes (almost like a synthesizer sound). The Quidjada & Tambourine would work triggered (one-shot).
Correct me if I'm wrong, but if you look at the Korg diagram that I posted in the initial thread (you'll need to cross reference between the korg & univox diagrams for component numbers). It appears it is in fact a Gate signal input which goes to the collector of Q21 base of Q20. This also is also depicted with a square 'pulse' wave (on/off) symbol just underneath where it says (GUI).
It would be great to have an up to date 'clone' of the gui/qui/tamb, with the hard to find inductors substituted. Anyone know what would work as good substitutes? _________________ LektroiD |
|
Back to top
|
|
|
tonewill
Joined: Aug 21, 2009 Posts: 135 Location: England
|
Posted: Mon Sep 21, 2009 8:55 am Post subject:
|
|
|
Did you get any further with this project? |
|
Back to top
|
|
|
LektroiD
Joined: Aug 23, 2008 Posts: 1018 Location: Scottish Borders
Audio files: 2
G2 patch files: 2
|
Posted: Mon Sep 21, 2009 9:33 am Post subject:
|
|
|
Unfortunately not, without knowledge of what I could substitute for the inductors. _________________ LektroiD |
|
Back to top
|
|
|
tonewill
Joined: Aug 21, 2009 Posts: 135 Location: England
|
Posted: Mon Sep 21, 2009 5:07 pm Post subject:
|
|
|
That's a shame. If we knew what other old gear they were used in maybe something cheap could be picked up on eBay.
I did a search for inductors. What is it about the new ones that makes them unsuitable as a replacement? |
|
Back to top
|
|
|
andrewF
Joined: Dec 29, 2006 Posts: 1176 Location: australia
Audio files: 4
|
|
Back to top
|
|
|
tonewill
Joined: Aug 21, 2009 Posts: 135 Location: England
|
Posted: Tue Sep 22, 2009 4:10 am Post subject:
|
|
|
andrewF wrote: | unusual to find inductors with values over 50mH these days |
I see.
Interesting, thanks. I'll read through that, though somehow I think it's going to be beyond me, but maybe not LektroiD perhaps.
I had an additional reason for being interested in this. I just bought the Univox SR-95. Everywhere says this is a 're-badged' Korg Minipops but I didn't see anyone mention that the rimshot sound is missing and the cowbell substituted: ta ta ta CLONK ta ta, ta ta ta CLONK ta ta... . However, looking at the sound generator board you can see near the bottom centre a missing inductor (4H ) with several other components around it missing. The pulse trigger wire below it is marked RS (rimshot) and when you put 5 volts across it it plays the cowbell sound. There is a CB pulse connector at the top of the board that you can see here (yellow wire) which plays the same sound. So, I reckon that adding the missing components and disconnecting the rimshot trigger to the cowbell, then the rimshot sound could be added.
Thought I'd share that, hope it isn't too off topic.
Description: |
SR-95 voice generator board |
|
Filesize: |
189.62 KB |
Viewed: |
749 Time(s) |
This image has been reduced to fit the page. Click on it to enlarge. |
|
Last edited by tonewill on Fri Mar 11, 2011 4:44 am; edited 1 time in total |
|
Back to top
|
|
|
ickystay
Joined: Nov 15, 2006 Posts: 142 Location: Oregon
|
|
Back to top
|
|
|
tonewill
Joined: Aug 21, 2009 Posts: 135 Location: England
|
Posted: Wed Sep 23, 2009 5:03 am Post subject:
|
|
|
That's great news ickystay, I'll definitely PM you!
I've checked the RS components on that circuit diagram and they match the missing components on the Univox board, so that's even more encouraging. |
|
Back to top
|
|
|
tonewill
Joined: Aug 21, 2009 Posts: 135 Location: England
|
Posted: Wed Oct 07, 2009 9:35 am Post subject:
|
|
|
Received the inductor from ickystay today .
There's a diode in the rimshot circuit. The service manual lists only one type of diode for the sound generator board which is: WG. 713. Anyone know what that is?
Many thanks.
EDIT: this site says BAY 74, BAY 95, 1N4154, 1N4148...49 are replacements.
Found a 1N4148 here. If anyone knows whether this is okay or not, please let me know.
By the way, I feel I've hijacked this thread (sorry), I'll start another to show progress in case anyone is following. |
|
Back to top
|
|
|
esnabez
Joined: May 01, 2009 Posts: 13 Location: Brooklyn, NY
|
Posted: Thu Oct 08, 2009 4:31 pm Post subject:
|
|
|
I think your info is right. According to a semiconductor cross-reference book I have, a WG713 can be replaced by Radio Shack part # 276-1122, which are 1N914/1N4148 diodes.
Don't know what others think, but I don't feel you've hijacked the thread. For me it's nice to have all this MP7/SR95 info in one place... |
|
Back to top
|
|
|
tonewill
Joined: Aug 21, 2009 Posts: 135 Location: England
|
Posted: Fri Oct 09, 2009 7:39 am Post subject:
|
|
|
Thanks esnabez! I appreciate you looking that up. I just need to sort out a few other components I need for something else I'm doing then I'll place an order. I'll post my progress here then if no-one objects.
Thanks again. |
|
Back to top
|
|
|
LektroiD
Joined: Aug 23, 2008 Posts: 1018 Location: Scottish Borders
Audio files: 2
G2 patch files: 2
|
Posted: Wed Oct 14, 2009 10:20 pm Post subject:
|
|
|
esnabez wrote: | Don't know what others think, but I don't feel you've hijacked the thread. For me it's nice to have all this MP7/SR95 info in one place... |
I have absolutely no qualms either, It's good to amalgamate as much info on the same topic into one thread, it's all relative.
That said, I was keen to get this project off the ground, but I have recently got major commitments in the music industry with a new recording contract, which has lead to another, and another. So, if someone else wants to pick this up where I left off, please feel free to do so, it will be a great little project. _________________ LektroiD |
|
Back to top
|
|
|
tonewill
Joined: Aug 21, 2009 Posts: 135 Location: England
|
Posted: Fri Oct 16, 2009 3:59 am Post subject:
|
|
|
Thanks LektroiD, good luck with the recording.
I'm expecting the components I need to arrive next week so I can try the 'rimshot' mod. Meanwhile, if anyone has the SR7 service manual pdf and would like to swap it for the SR95 service manual, please send me a PM. I need to compare the two to determine where the cowbell and rimshot triggers are linked. I'm hoping it's not under the rhythm selector switches. Also want to compare the circuit for the rhythms that are different.
Will keep you updated. |
|
Back to top
|
|
|
tonewill
Joined: Aug 21, 2009 Posts: 135 Location: England
|
Posted: Wed Oct 21, 2009 6:14 am Post subject:
|
|
|
For those reading this who missed my previous posts, I'm adding the missing rimshot sound to the Univox SR95 that the Korg MP7 has. On the SR95 it is substituted by the cowbell sound. However, the tone generator circuit board is the same with some components missing.
'ickystay' very kindly sent me the required inductor that are hard to find. I've now soldered all the components in place. I also replaced all electrolytic capacitors, thought it was probably not necessary.
As you can see the inductor is the same as the originals.
I wasn't sure whether it had worked at first but that's because the rimshot is drowned out by the cowbell, as expected, but it is there .
I now need to find out where they are coupled and I'm sure this is on the pulse generator board. I really need the layout of the MP7 board to look at now in order to determine where it differs from mine. I expect there's a jumper somewhere. I can't find the MP7 schematic at musicparts.com only the SR95 which I've already bought. Can anyone help with this?
Many thanks.
Description: |
Standard SR-95 without rimshot components |
|
Filesize: |
42.97 KB |
Viewed: |
36631 Time(s) |
|
Description: |
With added rimshot components |
|
Filesize: |
50.37 KB |
Viewed: |
36630 Time(s) |
|
Last edited by tonewill on Fri Mar 11, 2011 5:04 am; edited 6 times in total |
|
Back to top
|
|
|
tonewill
Joined: Aug 21, 2009 Posts: 135 Location: England
|
Posted: Sat Oct 24, 2009 6:32 am Post subject:
|
|
|
Alright, looks like no-one can help with the circuit layout. Anyone know how to remove the rhythm selector buttons and metal cage in a non-destructive way? |
|
Back to top
|
|
|
tonewill
Joined: Aug 21, 2009 Posts: 135 Location: England
|
Posted: Wed Oct 28, 2009 6:19 am Post subject:
|
|
|
I'll update this just in case someone finds this thread one day while searching for info on adding the 'missing' rimshot sound to their SR95.
There are 2 through-board jumpers on the pulse generator board that connect the cowbell and rimshot together, one of these needs removing. If you're careful you should be able to pull one of them out with tweezers while melting the solder. I, on the other hand, pushed both of them into the board causing problems. I thought they were connected with a wire jumper.
The only way to fix this was to buy myself a solder sucker and remove the rhythm selection button 'cage' completely to get to the other side of the board.
It now works fine. I can post a recording if anyone wants to hear.
The next task then is to change the patterns to match the MP7 (in the name of something interesting to do). The schematic esnabez posted earlier showing CY1 (cymbal 1) and CL (clave) give a clue to what needs to be done I think.
Description: |
|
Filesize: |
26.2 KB |
Viewed: |
36627 Time(s) |
|
Description: |
Where the cowbell and rimshot are connected |
|
Filesize: |
60.3 KB |
Viewed: |
36627 Time(s) |
|
Description: |
Better to pull the link out from one of these two points on the other side of the board |
|
Filesize: |
48.64 KB |
Viewed: |
36627 Time(s) |
|
Last edited by tonewill on Fri Mar 11, 2011 5:15 am; edited 5 times in total |
|
Back to top
|
|
|
esnabez
Joined: May 01, 2009 Posts: 13 Location: Brooklyn, NY
|
Posted: Wed Oct 28, 2009 10:18 am Post subject:
|
|
|
Congratulations on your success!!
Until this thread, I didn't even know there were differences between the Korg and the Univox. Thank you for sharing your hard work! And, I'd love to hear a recording if you get a chance... |
|
Back to top
|
|
|
ickystay
Joined: Nov 15, 2006 Posts: 142 Location: Oregon
|
Posted: Wed Oct 28, 2009 12:14 pm Post subject:
|
|
|
Looks like you are the pioneer in SR-95 to MP7 conversion. Congrads on your success so far! |
|
Back to top
|
|
|
|