Octavia

[Dirk_Hendrik]

In the past few months I've built a RM as well as a Tycho as well as a Foxx. Although I don't have a Univox I do own a Rands which is by my best knowledge the same but targetted on the German market. Both the tycho and the Foxx have not made it to the final "boxed up" stage. Too much fuzz and too little octave. Same goes for the Rands. On the contrary the RM is an absolute stayer in my setup. Never fallen more in love with an effect in a very long time.

One thing should be added. I'm not at all a fuzz fan. The RM is the only which gave me the octave at such low gain levels that it could be regarded kinda clean and have other OD stuff (usually my trusted ST-9 supertube) or Amp OD after it.

[octafish]

Well I stand corrected. I built my RM with BC459C's rather that the commonly available darlingtons here, MPSA14's. I quickly scrapped the fuzz section cos I hated the sound and added a fuzz face instead. IIRC without looking at the schem the octave section is basically a phase splitter using diodes, and a gain recovery stage. There are some slight differences between this and the green ringer but I prefer the sound of the RM with the inbuilt fuzz. Of course I mostly use a Superfuzz for octave sounds now because I love that scoop, plus having 10uF coupling caps its a very versatile fuzz for guitar or bass.

[spudulike]

PCB layout for the RM Octavia anywhere ?

[Fret Wire]

http://bryant02.home.att.net/schematics/mayeroctaviaschem.gif

http://bryant02.home.att.net/pcbs/mayeroctavialayout.gif

http://bryant02.home.att.net/pcbs/mayeroctaviapcb.gif

[spudulike]

:shock:  Wow, thanks.  

[SmokinStrat]

Hey Fellows,

I am a new guy here, and would like to make the RM octavio my first build.  I am currently majoring in electrical engineering technology, but I'm only in my first year and have a lot to learn.  I figured that building some effects pedals could help me further understand how electrical components work together.  With that said I have a couple basic questions about this build.  Hopefully those of you that already built the octavio can help me.  My first questions is where can I purchase a PCB like in the previous post for this project?  My second questions what value pots should I use for the Volume and Drive controls?  Also, I am assuming that this would have a stereo input jack and a mono output jack?  Last question I have for now is where can I purchase a wedged-shape enclosure that looks the original octavio prototype, like the one in this picture:  (http://www.emplive.org/create/pedals/octavio.asp)?  Sorry for the all the questions, and I appreciate all the help.

Brandon

[aron]

I like the Tyco. Great octave up even at low volumes for me. I also like the Green Ringer and the lowly Dano French Toast.

[leonhendrix]

hi smokinstrat

i dont think you can buy the pcb for the RM octavia, but majoring in electrical engineering technology you might know someone who can use the pcb layout (using the link above) to make it (i used to get my college lecturer to make mine).

http://www.generalguitargadgets.com/  sells the tycobrahe octavia PCB, if you ask him might etch the RM octavia board for you.

Drive= 10k reverse log
Volume 1meg log

reverse log pots a harder to find, i got mine from http://wah-wah.co.uk/
but you could try out log or linear to see if they work well with the circuit

leon

[SmokinStrat]

Leon,

Thanks for the reply.  I didn’t realize how hard it is to track down a reverse log pot.  It looks like I found a supplier over here in the US, thanks for the link though.  Unfortunately I’m on summer vacation so I cant ask my electronics professor if he could fab me up a PCB, so Ill see if GGG can make me one like you suggested.  I do have all the other electronic components I need to do the project except the pots and input/output jacks.  Id like to make this Octavia a true bypass, but can’t tell from the schematic if its set up like that.  Either way, Ill get the project working one way or another.  Thanks again for the help Leon.

Brandon

[leonhendrix]

check this link on how to wire up the footswitch

http://generalguitargadgets.com/index.php?option=content&task=view&id=173&Itemid=200

leon

[petemoore]

Soo...
 Just take the RM Octavia from the last two darlintons and throw a Fuzz in front?...
 Hafta try that///

[dadude]

I built the Tyco one and modded it with a switch to cut the octave and use as a fuzz. I found that the fuzz sounded a lot like Jimi's fuzz tone with Band of Gypsy's. To me anyway. His sound seems like a modded type of fuzz face. I wondered if his fuzz face was this circuit as well.

The octave I didn't think sounded that great, cool but did not nail that 'Who Knows' tone like Redhouse is describing. I always wondered if RM may have forgotten the exact build of those pedals he did for Hendrix. Maybe those guys who "got a hold" of the "broken" Hendrix pedal did really get a hold of it and reversed engineered it but made changes to it based on parts they had on hand or thinking they would get sued. It's all speculation of course but damn, that fuzz alone sounds like the 'Band of' period.

Man I wonder if you put the Tyco fuzz part in front of the octave part of the RM = some Jimi magic.

[RicF]

I just breadboarded a Tyco last night and i'm now in the stage of trying to decide if it's worth drilling a box for it. The octave effect seems to have definate "sweet spots" where it's really noticable on some notes, not so much on others, and downright discordant on some note combinations.

I just grabbed a pair of diodes and stuck them in, should I (and how do I) try to use matched diodes? I think I'll get the parts to make a RM and see how it compares.

[SmokinStrat]

Well,

I was actually thinking of e-mailing EMP to see if they have any pictures of the guts to that octavio pedal they have in their possession.  I also want to ask them if that pedal has a power jack, and how many batteries it takes.  I hope there not sworn to secrecy, because there is very little known about that pedal other than Hendrix owned it.  I'm trying like hell to nail down that "Who Knows" tone.  For all of you out there who has Hendrix’s "Live at the Fillmore East", look at the CD insert.  You can see several pictures of that octavio, but it doesn’t appear to have a power cord.  But, RM could have run two 9V's in series to get the 18V he needed.  Anyway, the thing is still a big mystery to me.  I hope EMP can help solve the mystery.  I'll post any info I get from them.

Brandon

[johnabraham]

Makes one wonder if they will do this.

[bluesdevil]

I just grabbed a pair of diodes and stuck them in, should I (and how do I) try to use matched diodes? I think I'll get the parts to make a RM and see how it compares.

How do you measure diodes with a DMM and what would you look for to match? I was wondering about it, I just made a pcb for the tyco and read somewhere that the matched diodes are supposed to give a more pronounced octave.... was going to post this question as a seperate thread later until I read your post.

[petemoore]

Measuring the foreward voltage threshold [for clipping] is fairly easy, if the DMM has a 'diode tester' mode...the continuity checker.
 Set the DMM for ' -->l ", put the diode across it, write down the number shown, the threshold. [if no number shows turn the diode around and try it again].
 IIRC It's the line side of the diode that goes to the + lead of the DMM.

[bluesdevil]

Measuring the foreward voltage threshold [for clipping] is fairly easy, if the DMM has a 'diode tester' mode...the continuity checker.
 Set the DMM for ' -->l ", put the diode across it, write down the number shown, the threshold. [if no number shows turn the diode around and try it again].
 IIRC It's the line side of the diode that goes to the + lead of the DMM.

Many thanks, Pete. Looks like my DMM has a diode setting in the continuity mode..... I'm good to go with my handfull of 1N34A's.

   Just to mention again what Pete said earlier in this thread: the Gus Smalley octave circuits are great!! I just built a Scrambler and the "Octave Up Sick Box" I put together a while back blows it away. Would be even better if it had a mix control like the Scramble.... something I need to figure out how to do one day.  Also the "Simple Octave Up" has to be tried if you just want to take on something with a small parts count.
   
        Keep on picking!!!!!!!!!

[petemoore]

Sometimes there are 'mirror' resistors, or resistors around the diodes that will *bias them [*?]. Matching closely or allowing for adjustment of these resistors may influence the amount and type of harmonics produced including octave.
 I think the idea is that the diodes conduct at the same foreward voltage points on either side of the incoming waveform...[or something like that]...maybe someone who understands the language and funtion better than I can jump in, at any rate the FWR section, if tuned differently exhibits different amounts of certain harmonics, intermodulation [3rd note] Ring moddyness, Octave etc.