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gusrus
Copper Member
United Kingdom
3 Posts |
 Posted - 03/12/2009 : 17:28:47
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| While playing with my dad's Boss ME50 multieffects pedal I found that point where I reached a distortion tone that I love and I want to be mine. I was unfortunate to find that the pedal I stumbled across was the Boss OD1 which I can't buy on UK student pocket money. So I decided to see If I could find a schematic of one and have done only downside is that it is a bit vague in the exact components it uses and the values it uses. If it helps I found the schematic on the freeinsociety.com website. Could someone please email me an annotated and correct schematic to gusrus2288atc@yahoo.co.uk. Thanks |
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Laurie
Double Platinum Member
Canada
4854 Posts |
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gusrus
Copper Member
United Kingdom
3 Posts |
Posted - 03/12/2009 : 22:08:27
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| Thanks for your help so far but i now need the component numbers for the diodes and transistors used in the Boss OD 1 in order to source them even if this includes diodes and transistors that are not in the OD1 yet have the same features as their ancestors,also on the diagrams it has given me values for capacitors (some with units) yet it hasn't given any units like micro or peco farads what should this be. I have complied all the resistors so far and have sourced them so this at least is good. |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 03/12/2009 : 23:17:29
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| Original component numbers are in the table on the top left... tell us what you can't find and we can advise you an equivalent. |
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bossarea
Forum Admin
United Kingdom
3652 Posts |
Posted - 03/12/2009 : 23:41:17
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Hi gusrus and welcome to the forum.
Electrolytic capacitors are specified in uF and cn be identified by the existance of polarity or additional voltage. Ceramic capacitors are given in pF and the values are denoted by a p behind the value. All foil caps are specified in nF although this is not mentioned on the schematic.
The OD-1 has 7 transistors which can be very hard to find. There are however equivalents available for all of them.
Here's the equivalents based on Heiniger Schnellvergleichliste 1984 and Semiconductor cross reference book by Sams publishing, 2000.
2SK30ATM Y - BF245, NTE459, SK3112
2SK30ATM GR - BF245, NTE459, SK3112
2SC945 P - BC546, NTE85, SK3124A
2SC1815 Y - BC550, NTE85, SK3124A
Obviously this raises the question, why would Boss use different transistors when the replacements are the same? I don't know the answer to that. The reference books might not always be trustworthy and in some cases the replacements might work perfectly well in the curcuit but sound a little differently. When working with replacements you will often just have to test and see what happens.
I wrote down 3 suggested replacements for each transistor above. In most cases there are a lot more and you should be aware that the replacements often have different leg placements. I just bought some 2N3705 for a project of my own. They will replace original 2SC945 and I chose 2N3705 because the leg configuration is the same and because they were available through rapidonline.com. I'm however not perfectly sure they will work until I've tested them.
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 03/13/2009 : 12:33:02
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quote:
Originally posted by bossarea
Hi gusrus and welcome to the forum.
edited
The OD-1 has 7 transistors which can be very hard to find. There are however equivalents available for all of them.
Here's the equivalents based on Heiniger Schnellvergleichliste 1984 and Semiconductor cross reference book by Sams publishing, 2000.
2SK30ATM Y - BF245, NTE459, SK3112
2SK30ATM GR - BF245, NTE459, SK3112
2SC945 P - BC546, NTE85, SK3124A
2SC1815 Y - BC550, NTE85, SK3124A
edited
Hi gusrus, Bossarea & Guys
The:
2SC945 and the
2SC1815
Can be found secondhand, in a lot of PC power supplies
The 2SC945 being the most common.
The 2SC1815 is a low noise hi-gain NPN commonly used in a lot of Japanese electronics, and can be salvaged from amost anything,
from an answering machine to an old pedal.
We buy the 945 in bulk just for repairs on Switch mode power supplies, in PC's.
At a pinch you can most times substitute the more common BC549 NPN for the 1815, but the pinouts DO differ.
We have a thread in the "Mods & Technical",
that lists free access datasheet sites.
Free Online Chip Data Sites
http://www.bossarea.com/forum/topic.asp?TOPIC_ID=1881&SearchTerms=free
I will make this a sticky, as it was buried too deep to find quickly.
The 2SK30ATM is a FET typically used in the bypass circuits of most Boss pedals.
Laurie sourced a bunch of these on evilbay.
http://www.bossarea.com/forum/topic.asp?TOPIC_ID=4078
Hope this has been of some help. 
Regards Dr. Bob  |
Edited by - Dr. Bob on 03/13/2009 12:53:24 |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 03/13/2009 : 13:07:05
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Hi gusrus
BTW, which Version-Revision of the OD-1 are you building?
As the SS long dash early versions, had a 14 pin RC3403
Quad op-amp.
Regards Dr. bob |
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gusrus
Copper Member
United Kingdom
3 Posts |
Posted - 03/13/2009 : 18:04:39
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| the schematic I have is dated DEC.26 1980 and from the diagram the only amplifier chip in it is the UPC4558C. Thanks for the help on the transistors now I can begin sourcing them aswell and try sourcing the diodes as well |
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bdhact1
Copper Member
USA
3 Posts |
Posted - 11/24/2009 : 23:13:25
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I made an exact copy from that schematic. the only things that matter for the sound is the IC and the capacitors. all the other transistors can be substituted without effecting the sound. Keep in mind that the service manual schematic is for the 12v power adaptor but will still run on the 9v power adaptor. The only draw-back is you can't daisy chain the power with more than 3 or 4 pedals at one time. It likes it's own 9v supply.
BTW, I tried a few different 4558 chips, but So far I like the TL072 for the best sound. |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 11/25/2009 : 13:59:16
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Hi bdhact1
Welcome to the forum from Australia.
Regards Dr. Bob |
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nathanscribe
Silver Member
United Kingdom
376 Posts |
Posted - 11/25/2009 : 18:11:17
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| For info, Farnell here in the UK sell the 2SC1815 transistors, and Nikko sell the 945s. I bought a few hundred a while back and they're fine. As for 2SK30xxx replacements, my own equivalents book lists the BF246 and 2N5458 - among others. I've bought a few of the latter but haven't tried them in-circuit yet. |
Edited by - nathanscribe on 11/25/2009 18:14:31 |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 11/27/2009 : 15:49:48
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quote:
Originally posted by nathanscribe
For info, Farnell here in the UK sell the 2SC1815 transistors, and Nikko sell the 945s. I bought a few hundred a while back and they're fine. As for 2SK30xxx replacements, my own equivalents book lists the BF246 and 2N5458 - among others. I've bought a few of the latter but haven't tried them in-circuit yet.
Hi Guys
Here's a quick heads up, secret tip.
2SC945's can be found in a lot of older around 200Watt IBM & Clone, PC power supplies.
I'm sure we all have a few dead ones lying around in the shed or under our desks, or at our friends places.
And the 2SC1815's, can be found in almost every bit of Japaneese electronics consumer gear.
Old amps, answering machines, old stereo's, cassette recorder/players.
Man! ... Soon I'll no more tips of secrets...  
Regards Dr. Bob |
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Boss OD 1 Schematic Help
