Difference between revisions of "OC-2"

From Thermionic Studios
Jump to: navigation, search
m
m
 
(40 intermediate revisions by the same user not shown)
Line 2: Line 2:
 
  | __TOC__
 
  | __TOC__
 
  |}
 
  |}
−
[[Boss]] OC-2 Octave
+
The [[Boss]] OC-2 Octave pedal uses the existing note going through it to generate 2 more notes: one octave, and two octaves down, respectively. The first version, released in 1982 was titled "Octaver" and was enameled in a reddish-brown color. As the circuit was updated, note tracking improved, and parts substitutions were made, the OC-2 was renamed the "Octave", and the paint scheme was changed the more familiar metal-flake brown.
  
−
Subsequent Boss Octave models include:
+
The Boss OC-2 Octave is no longer being made.
−
* OC-3
+
 
 +
 
 +
; Thermionic Studios has two (2) OC-2s available for rental.
  
 
==Controls==
 
==Controls==
−
[[File:Boss_OC2_front.png|right|frame]]
+
[[File:Boss_OC2_front.png|right|frame|<div style="text-align:right">Image from [https://www.boss.info/us/products/oc-2/ Boss' website]</div>]]
 +
 
 +
* Knob 1 - '''"Oct2"''': Sets the volume level for the signal two octaves lower than the dry signal. Turning the knob clockwise increases the volume.
 +
* Knob 2 - '''"Direct Level"''': Sets the volume level for the dry signal. Turning the knob clockwise increases the volume.
 +
* Knob 3 - '''"Oct1"''': Sets the volume level for the signal one octave lower than the dry signal. Turning the knob clockwise increases the volume.
 +
* Footswitch 1 - '''"On/Off"''': Toggles the pedal between active ("on"), or bypassed ("off").
 +
 
 +
==Bypass:Buffered==
 +
Like all Boss pedals, the OC-2 has a buffered bypass.
  
 
==General Information==
 
==General Information==
−
http://www.bossarea.com/boss-oc-2-octave/
+
This Boss pedal, is like most other octave pedals that came out in the 1980s and is best played one note at a time. It's typically used either to thicken melody runs, or on solos. Because the OC-2 was not created as a polyphonic pedal, if more than one note is played, the note tracking circuitry will not be able to keep up. This tends to create sounds that are more like a cacophony than multi-octave chords being played; of course, this may be the sound you're looking for.
  
−
==Phase Inversion==
+
[[Eddie Van Halen]] used a rackmount Eventide Harmonizer for the outro to Fair Warning's "Unchained" (1981). The OC-2 makes a good (and far more portable) substitute for the Eventide.
  
 +
Subsequent Boss Octave pedals include:
 +
* OC-3 Super Octave
  
 
==Pedal Manual==
 
==Pedal Manual==
 +
* [[Media:Boss_OC-2_OwnersManual.pdf|Boss OC-2 Octave Owner's Manual]]
  
 +
==Phase Inversion: No==
 +
From our examination of the schematic below, the OC-2 does not appear to invert phase on the output as compared with the signal that goes into the pedal.
 +
 +
If you look at the schematic, you can see that there are a number of amplification stages after Q1 that are taken up by 3 IR9022 opamps. However, you'll also see that the output at pins 1, and 7 for all of J, I , H, G, F, and E are connected and feed back into pins 2 and 5, respectively. This appears to us to be negative feedback, lowering the total amplification, but adding signal stability. If anyone is more knowledgeable about this, we'd love to be updated for the most accurate explanation possible.
 +
 +
The other thing to note is that the 4013 output gets split, with part of the one-octave down signal directed into the 4027 chip. Afterwards, it should be fairly easy to track the Octave1 and Octave2 signals running parallel through similar circuit architecture.
 +
 +
{| class="wikitable" style="left; margin-right:20px; background-color:#eeffee;" cellpadding="10"
 +
|-
 +
! Schematic ID || Electronic Part || Action || Phase State
 +
|-
 +
| Q1 || 2SK30A || Does Not Invert || Not Inverted
 +
|-
 +
| IC-J || IR9022 || Does Not Invert || Not Inverted
 +
|-
 +
| IC-I || IR9022 || Does Not Invert || Not Inverted
 +
|-
 +
| IC-H || IR9022 || Does Not Invert || Not Inverted
 +
|-
 +
| IC-G || IR9022 || Does Not Invert || Not Inverted
 +
|-
 +
| IC-F || IR9022 || Does Not Invert || Not Inverted
 +
|-
 +
| IC-E || IR9022 || Does Not Invert || Not Inverted
 +
|-
 +
| Q2 || 2SK30A || Does Not Invert || Not Inverted
 +
|-
 +
| IC-B || IR9022 || Does Not Invert || Not Inverted
 +
|-
 +
| IC-C || IR9022 || Does Not Invert || Not Inverted
 +
|-
 +
| Q3 || 2SK30A || Does Not Invert || Not Inverted
 +
|-
 +
| IC-A || IR9022 || Does Not Invert|| Not Inverted
 +
|-
 +
| IC-D || IR9022 || Does Not Invert || Not Inverted
 +
|-
 +
| Q4 || ''"NPN"'' || Does Not Invert || Not Inverted
 +
|-
 +
|}
  
 
==Schematic==
 
==Schematic==
 +
 +
[[File:Boss_OC-2Schematic.png|center|frame|<div style="text-align:right">Assumed Public Domain, unaware of any Copyright claims by Lehrberg.</div>]]
 +
 +
==Artists==
 +
<div style="column-count:3;-moz-column-count:3;-webkit-column-count:3">
 +
* [[Melissa Auf der Maur]]
 +
* [[Nuno Bettencourt]]
 +
* [[Yngwie Malmsteen]]
 +
* [[Gary Holt]]
 +
* [[George Lynch]]
 +
* [[John Petrucci]]
 +
* [[Joe Satriani]]
 +
</div>
  
  
 
----
 
----
 
;Additional Sources
 
;Additional Sources
 +
# http://equipboard.com/items/boss-oc-2-octave-pedal
 +
# http://www.freeinfosociety.com/electronics/schemview.php?id=135
 +
# http://www.bossarea.com/boss-oc-2-octave/
  
  
 
[[Category:Pedals]]
 
[[Category:Pedals]]
−
[[Category:Octave Pedals]]
 
 
[[Category:Pitch Pedals]]
 
[[Category:Pitch Pedals]]
 
[[Category:Boss Pedals]]
 
[[Category:Boss Pedals]]
 
[[Category:Thermionic Pedals]]
 
[[Category:Thermionic Pedals]]

Latest revision as of 08:58, 19 November 2020

The Boss OC-2 Octave pedal uses the existing note going through it to generate 2 more notes: one octave, and two octaves down, respectively. The first version, released in 1982 was titled "Octaver" and was enameled in a reddish-brown color. As the circuit was updated, note tracking improved, and parts substitutions were made, the OC-2 was renamed the "Octave", and the paint scheme was changed the more familiar metal-flake brown.

The Boss OC-2 Octave is no longer being made.


Thermionic Studios has two (2) OC-2s available for rental.

Controls

Image from Boss' website
  • Knob 1 - "Oct2": Sets the volume level for the signal two octaves lower than the dry signal. Turning the knob clockwise increases the volume.
  • Knob 2 - "Direct Level": Sets the volume level for the dry signal. Turning the knob clockwise increases the volume.
  • Knob 3 - "Oct1": Sets the volume level for the signal one octave lower than the dry signal. Turning the knob clockwise increases the volume.
  • Footswitch 1 - "On/Off": Toggles the pedal between active ("on"), or bypassed ("off").

Bypass:Buffered

Like all Boss pedals, the OC-2 has a buffered bypass.

General Information

This Boss pedal, is like most other octave pedals that came out in the 1980s and is best played one note at a time. It's typically used either to thicken melody runs, or on solos. Because the OC-2 was not created as a polyphonic pedal, if more than one note is played, the note tracking circuitry will not be able to keep up. This tends to create sounds that are more like a cacophony than multi-octave chords being played; of course, this may be the sound you're looking for.

Eddie Van Halen used a rackmount Eventide Harmonizer for the outro to Fair Warning's "Unchained" (1981). The OC-2 makes a good (and far more portable) substitute for the Eventide.

Subsequent Boss Octave pedals include:

  • OC-3 Super Octave

Pedal Manual

Phase Inversion: No

From our examination of the schematic below, the OC-2 does not appear to invert phase on the output as compared with the signal that goes into the pedal.

If you look at the schematic, you can see that there are a number of amplification stages after Q1 that are taken up by 3 IR9022 opamps. However, you'll also see that the output at pins 1, and 7 for all of J, I , H, G, F, and E are connected and feed back into pins 2 and 5, respectively. This appears to us to be negative feedback, lowering the total amplification, but adding signal stability. If anyone is more knowledgeable about this, we'd love to be updated for the most accurate explanation possible.

The other thing to note is that the 4013 output gets split, with part of the one-octave down signal directed into the 4027 chip. Afterwards, it should be fairly easy to track the Octave1 and Octave2 signals running parallel through similar circuit architecture.

Schematic ID Electronic Part Action Phase State
Q1 2SK30A Does Not Invert Not Inverted
IC-J IR9022 Does Not Invert Not Inverted
IC-I IR9022 Does Not Invert Not Inverted
IC-H IR9022 Does Not Invert Not Inverted
IC-G IR9022 Does Not Invert Not Inverted
IC-F IR9022 Does Not Invert Not Inverted
IC-E IR9022 Does Not Invert Not Inverted
Q2 2SK30A Does Not Invert Not Inverted
IC-B IR9022 Does Not Invert Not Inverted
IC-C IR9022 Does Not Invert Not Inverted
Q3 2SK30A Does Not Invert Not Inverted
IC-A IR9022 Does Not Invert Not Inverted
IC-D IR9022 Does Not Invert Not Inverted
Q4 "NPN" Does Not Invert Not Inverted

Schematic

Assumed Public Domain, unaware of any Copyright claims by Lehrberg.

Artists


Additional Sources
  1. http://equipboard.com/items/boss-oc-2-octave-pedal
  2. http://www.freeinfosociety.com/electronics/schemview.php?id=135
  3. http://www.bossarea.com/boss-oc-2-octave/
Retrieved from "https://thermionic-studios.com/wiki/index.php?title=OC-2&oldid=4736"