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Goran
Double Platinum Member
Sweden
2203 Posts |
 Posted - 06/07/2005 : 07:24:13
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How can one see the evolution of OD-1?
The metal screw is obvious, the bottomplate-sticker too.
Anything more on the outside?
How about the inside? OP-amps, pc-board, the proteting sheet...
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stinkfoot
Silver Member
Sweden
181 Posts |
Posted - 06/07/2005 : 18:24:15
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Of course, the OD-1 evolved and changed slightly over the years - often due to which component supplier happened to be the cheapest at the time. But there were also two (and a half) distinct versions that appeared.
The very first pedals used a quadruple op-amp (Raytheon's RC3403 and sometimes a similar unit from NEC), which is easily recogniceable from its size - rather than having the more usual 8 pins, it had 14 pins. 2 quarters was used as clipping and tone stage, respectively, while the other two quarters served as input and output buffer stages. If you find an OD-1 with the momentary LED (the one that only lights up while you step on the pedal to turn it on/off), it is most likely this version. Here are two different pedals with different op-amps (same circuit, though):
http://eu11.stripper.jp/pulcino/blog/images/6600_in1.jpg
http://eu11.stripper.jp/pulcino/blog/images/8700_1.jpg
The "half" version is a transitionary model that used two dual (8 pin) op-amps instead of the quadruple. One of them did the clipping/tone control job, while the other handled the input/output stages. I've only seen a few of these, and never in person. Or maybe it was just a dream...? 
Anyway, a bit later Boss dropped one of the dual op-amps in favour of regular transistor based input and output stages, and this version is by far the most common. A standard 4558 dual op-amp was used for the clipping and tone stages, as before. This circuit had lots of other changes too, and is even called "second edition" in the official Boss service notes. The circuit board is also marked "ET-23D" on the component side, as you can see in these pics:
http://eu11.stripper.jp/pulcino/blog/images/9900_1.jpg (JRC op-amp)
http://eu11.stripper.jp/pulcino/blog/images/9300_1.jpg (NEC op-amp)
Soundwise, the earlier version sounds quite different from the later version - Boss redesigned the second edition OD-1 to be a little more like a treblebooster, rolling off quite a lot of bass. However, the first edition has a much fuller sound, with very little bass roll-off. Where the transitional pedals fit into this scheme - wether they have the second edition's bass roll-off or not - I don't know...
/Andreas |
Edited by - stinkfoot on 06/07/2005 18:25:42 |
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bossarea
Forum Admin
United Kingdom
3652 Posts |
Posted - 06/07/2005 : 21:09:08
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That's great info, Stinkfoot. Thanks.
In addition we have the more known differences like the metal or plastic thumb screw, the short or long hyphen in OD-1 and 4 or 6 digit serial number.
After the ET-23D PCB, the next version was ET-23E. These pedals also had the Nec opamp.
http://www.bossarea.com/test/od1.jpg
The Boss book also says that the last OD-1 pedals made had Made in Taiwan printed on the PCB. All OD-1 pedals ever made have black Made in Japan labels.
I have one of the 9900 pedals with the JRC opamp and the ET-23E pedal mentioned above (serial 124000). They sound very similar. There's a little more mid on the 124000 but they definitely appear to have the same bass roll-off characteristics. Another notable difference between these two pedals are that the 9900 is a little bit wider. It is actually so wide it doesn't fit properly on my BCB-6 pedal board. |
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Goran
Double Platinum Member
Sweden
2203 Posts |
Posted - 06/08/2005 : 07:10:53
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Thanks for all of the information Stikfoot & Bossarea!
I�m now pretty sure I own one of the earliest, it really sound full and creamy, great on strats. |
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bossarea
Forum Admin
United Kingdom
3652 Posts |
Posted - 06/08/2005 : 09:15:24
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The web page that stinkfoot linked to http://eu11.stripper.jp/pulcino/blog/ is really good. It looks like the serial number is anumber of batches and you can probably figure out which model you have from the 4 digit number.
I dug through my Boss docs yesterday and realised I had the orginal schematics for both the 23B (RC3403) and 23D (4558) versions. These two versions are very different.
Two more differences that we didn't mention. The first models had a transparent switch that was later exchanged for a black switch. The first models also had the brown cardboard insulation between the PCB and bottom plate. This was later replaced with a yellow transparent plastic sheet. |
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Goran
Double Platinum Member
Sweden
2203 Posts |
Posted - 06/08/2005 : 10:07:31
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| Now I KNOW I have the first version! |
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bossarea
Forum Admin
United Kingdom
3652 Posts |
Posted - 06/08/2005 : 11:45:08
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| Cool, what's the serial? Does it start with a 6? |
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Goran
Double Platinum Member
Sweden
2203 Posts |
Posted - 06/09/2005 : 11:35:36
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| I think it starts with an 8, but I�ll check tonight. |
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Goran
Double Platinum Member
Sweden
2203 Posts |
Posted - 06/10/2005 : 07:36:04
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Mine have serial 8800 and have the black switch, my memory missed that..
But everything else is indicating an early version. |
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boss freak
Gold Member
USA
663 Posts |
Posted - 06/10/2005 : 07:42:54
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As far as I know, the true original version from 1979 has the clear switch and LED which only flashes one time when the pedal is stepped on. The second generation is apparently starting with models produced beginning some time in 1980, according to the technical service manual.
I have a few ink-stamped serial OD1s, but only one is the true original (with quad op-amp). Even though by the serial stamp, I thought I was getting the original, some turned out to be the second version. |
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bossarea
Forum Admin
United Kingdom
3652 Posts |
Posted - 06/10/2005 : 11:31:58
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Let me summarise the info from the Japanese web site that stinkfoot found. I've also added the information from my own OD-1E.
OD-1A
Serial: 6400 - 6500
Marking of PCB: 052-281a
Switch: Transparent
Silver screw
OP-AMP: RC3403ADB
OD-1B
Serial 6600-8800
Marking of PCB: 052-281b
Switch: Up to 8400 transparency, from 8600 black (don't know for 8500)
Silver screw
OP-AMP: Up to 8400 RC3403ADB, from 8600 uPC4741C
OD-1D
Serial 8900-
Marking of PCB: 052-281d
Switch: Black
Screw: 8900-0300, silver screw, 0500- black screw
OP-AMP: 9900 - NJM4558D (JRC)
9300,0300 - uPC4558C (NEC)
0000 TL4558P (Texas Instruments)
OD-1E
Serial: 6 digit sticker
Marking of PCB: 052-281e
Switch: Black
black screw
OP-AMP: uPC4558C (NEC) |
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boss freak
Gold Member
USA
663 Posts |
Posted - 06/10/2005 : 12:04:43
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| Wow! Thanks for posting that. It's great information to have. |
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Sunburst
Silver Member
427 Posts |
Posted - 10/28/2005 : 12:09:50
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My OD-1 "version D" with the NEC opamp and marking of PCB 052-281D. Interesting though is that it has the six digit sticker serial, starting with a 0xxxxx, so Im guessing the pedal is from 1980 and most likely a transition model. My OD-1 also has the old type logo.
Perhaps the OD-1E version took over from 1980 when the sticker type serial saw daylight... |
Edited by - Sunburst on 10/28/2005 12:22:37 |
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bossarea
Forum Admin
United Kingdom
3652 Posts |
Posted - 10/28/2005 : 12:46:09
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Thanks for the info, Sunburst.
I wasn't sure what came first; The E model or the 6 digit serial but now we know.  |
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lightburst
Silver Member
Germany
158 Posts |
Posted - 10/28/2005 : 18:42:15
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My OD-1 is exactly like the one of Sunburst. Maybe it�s because of the 'burst' in our nicknames 
Serial on sticker is 080300. And although it has a black thumbscrew the bottom plate says 'Use a coin to open battery compartment...' So I think it�s really a transistional version.
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Edited by - lightburst on 10/29/2005 18:24:52 |
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Sunburst
Silver Member
427 Posts |
Posted - 10/29/2005 : 13:28:10
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Thats interesting to know. I actually didnt think about that when I wrote about my pedal.
I went and checked it and the same "Use a coin to open battery compartment" text is on my pedal too, and mine has a black thumbscrew aswell.
I just got a mental pic of the original buyer scratching his/her head...
quote:
Originally posted by lightburst
My OD-1 is exactly like the one of Sunburst. Maybe it�s because of the 'burst' in or nicknames
Serial on sticker is 080300. And although it has a black thumbscrew the bottom plate says 'Use a coin to open battery compartment...' So I think it�s really a transistional version.
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Edited by - Sunburst on 10/29/2005 13:29:55 |
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Topic |
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OD-1 evolutions
