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Posts: 17
| Hello there , time to post my first contribution here...
I post this "QUITE" epocal post then for a good overture
:-)
See the story on the blog
http://proreverse.blogspot.it/
So many time I saw people complaining about the low volume of the Ovation Op Pro!
Well............problem solved forever!
;-)
Cheers!
KK
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Location: Thredbo, NSW, Australia | Thanks KK.
This look very interesting. |
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Location: undisclosed | Good job on the homework, one of those "What were they thinking?" things. |
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Location: Keepin' It Weird in Portland, OR | This is why I often switch-out my OP-Pro's for OP30's. 
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Location: Lake Forest, CA | Kewl find. Looks like I'm going to be doing some soldering on my OP-Pros.
Thanks! |
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| Old Man Arthur - 2016-07-21 5:31 AM
This is why I often switch-out my OP-Pro's for OP30's.
I'm new to Ovation world. I was thinking OP30 not "CAN COMPATIBLE"
with OP PRO \ OP PRO STUDIO / OP VIP 5.
7 pins versus 8 pins.
I'm I wrong ?
KK
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Location: Keepin' It Weird in Portland, OR | You are correct that you cannot just swap them out.
You must change the can.
But they all fit in the same hole, and plug in the same.
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| DanSavage - 2016-07-21 6:18 AM
Kewl find. Looks like I'm going to be doing some soldering on my OP-Pros.
Thanks!
Be careful, these are 0805 smd resistor components.
You need proper sight, magnifier glasses and equipment (2 small 10 watt solders) , the job per se is easy..
You may consider to go with 68K and 1.2 Meg to get near full power.
But 220k & 1 Meg are fine as well...
Cheers!
KK
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Posts: 17
| Hello all , the FIX of the OP PRO is now definitive and tested:
Replacing 4 resistors I was able to optimise
the pickup input level and also to increase
the gain of xlr \ jack differential stage.
The overall output of the OP PRO is more than doubled.
Check the last post on the dedicated blog
http://proreverse.blogspot.it/
Cheers
KK
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Posts: 2303
Location: Lake Forest, CA | Thanks for the head's up.
I'm familiar with both soldering and SMD components, but you can never be too careful. :D
Dan
kkprince - 2016-07-21 6:55 AM
Be careful, these are 0805 smd resistor components.
You need proper sight, magnifier glasses and equipment (2 small 10 watt solders) , the job per se is easy..
You may consider to go with 68K and 1.2 Meg to get near full power.
But 220k & 1 Meg are fine as well...
Cheers!
KK
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Posts: 1769
Location: When?? | Very cool. Thank you for being smart and for sharing your findings with the rest of us. |
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Posts: 2303
Location: Lake Forest, CA | After three years I was finally able to try this upgrade to one of my OP-Pros.
As Carlo says, these components are extremely small and therefore tricky to solder. But, I was successful.
Moody gave me an OP-Pro a couple of years ago that had a flaky gain knob. I figured this would be the perfect test subject as I wasn't using it in any guitar.
As Carlo notes, there is a noticeable improvement (increase) in the output without sacrificing the quality of the sound.
It worked so well, in fact, that I decided to apply the same upgrade to my new OP-Pro that I installed in my Black Pearl. I bought this pre-amp from Thomann Music last year when I was gathering parts for the Black Pearl.
When I cracked open the case I was surprised to see that Ovation had revised the internal circuit boards. This one is a Rev.3 instead of the Rev.2. Gone are the wires that connect the main and daughter boards. These have been replaced with ordinary pin connectors. Also perplexing was that the layout of the circuits are completely different. And, the SMDs are about 2/3 the size of the 0805 components in the Rev.2 board.
I figured that Ovation probably didn't redesign the circuit, but just altered the layout. I searched around and soon found the same value resisters as what's on the Rev.2. Not being an electronics guy, I decided to dive jump in with both feet and replace these with the new resistors. The worst case scenario would be I broke a $100 pre-amp and would have to buy a new one.
Since these SMDs are impossibly small it took me a while to get them soldered. I reassembled the pre-amp, plugged in the battery and tested the tuner. Still works. So, I plugged it into the guitar and it works! Yay!
And, it's as loud as the first one. Yay! |
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Location: Lake Forest, CA | Here's a pic that shows the relative size of these SMDs sitting on a Dunlop pick.
The one on the right is out of the Rev.2 board. The one on the left is out of the Rev.3 board.
The Rev.2 SMD is 2mm x 1.5mm. The Rev.3 is 1.5mm x 1mm.
Like I wrote, impossibly small.
Luckily, with careful alignment I was able to use the Rev.2 SMD in the Rev.3 board. 
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Location: Utah | Strange, but I've never pined for more output from any of my O's or A's. I have wanted an XLR sometimes in guitars that didn't have them. |
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Location: Lake Forest, CA | I wanted more output for when I play on the worship team. |
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Location: When?? | >>>when I play on the worship team.<<<
The louder sang on Earth, the louder heard in Heaven. At least that's what our old church choir director used to say. And wow.. that SMD really IS small! Like, ridiculously small. Both are. |
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Location: Cicero, NY | Ok, you had me (lost) at “What were they thinking?”
I wish I knew e-talk that some of you guys are so comfortable with but capacitors, resistors, SMD’s...ugh! I understand the “can” but I get the impression it might not be the same one you’re referring to...??
Carry on because I am positive that there is some seriously valuable detail in there. I just wish I knew Greek... |
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Location: Yokohama, Japan | kkprince - 2016-09-08 11:45 PM
Hello all , the FIX of the OP PRO is now definitive and tested:
Check the last post on the dedicated blog
http://proreverse.blogspot.it/
Cheers
KK
WOW! Thanks for sharing kkprince! Electrical Engineers just amaze me! SWEET! |
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Location: Lake Forest, CA | Weaser P - 2019-11-26 5:29 PM
Ok, you had me (lost) at “What were they thinking?”
I wish I knew e-talk that some of you guys are so comfortable with but capacitors, resistors, SMD’s...ugh! I understand the “can” but I get the impression it might not be the same one you’re referring to...??
Carry on because I am positive that there is some seriously valuable detail in there. I just wish I knew Greek...
Trust me. I can wield a mean soldering iron but that's the end of my E-knowledge.
From what I gather from Carlo's blog, when Ovation built the OP-Pro, they limited (clamped) the input of the saddle piezos down to 54%. Basically, they cut the input strength from the saddle in half. By changing out the resistors, it allows the pre-amp to see, either 88% or 94% of saddle's piezo signal, depending on the resistors used. The resistors I'm using (according to Carlo's blog) allow the pre-amp to see 88% of the piezo input. I've ordered some of the resistors Carlo recommended to allow the pre-amp to see 94% of the piezo input. I'm going to experiment with these resistors on the Rev.2 OP-Pro that Moody gave me.
The can is the receptacle mounted to the side of the guitar body. The preamp is inserted into the can. 
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Posts: 1609
Location: Colorado | Like FlySig - I have never needed more gain....I have used them all...I always come back to a line driver only, or the OP-24...though a few of my instruments have the OP Pro Studio - and it is fine...I never found it lacking...what are you guys plugging into where you need more gain? Most high impedience inputs on amps have enough, if you are in the sanctuary, and running direct, don't you use an active direct box like Countryman, or SansAmp? Asking for real....I have played a lotta shows - never needed more output from an Ovation....sometimes I needed the string tubes - but that is another post. |
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Location: NJ | that looks like a ton of work |
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Location: Utah | elginacres - 2019-11-26 8:15 PM
what are you guys plugging into where you need more gain? Most high impedience inputs on amps have enough, if you are in the sanctuary, and running direct, don't you use an active direct box like Countryman, or SansAmp?
I've either plugged into a DI box provided by the venue or used the line out from my acoustic amp. A few times I've had to use a 1/4" to XLR impedance converter into a very long balanced line to the board, and it still sounded great.
Never has there been a gain problem. Sometimes a crappy sound engineer problem, but that's a different story! |
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| Hello DanSavage!
Heh... after a couple of Year I sold my almost unique Op Pro to an amateur musician for 300Euro...
Now I'm using an Op Pro Studio.
:-)
Definitely The Op Pro was soo deaf.... signal cutted in two... considering all the amplification done
using the TL 064 , a Jfet Operational Amp engineered in 1974..... bit noisy... the mods I did were
pretty good oriented with a reason...
A standard Op Pro signal to noise ratio is a diaster...
I'm very surprised new releases was keeping the same errors....
Tradition... Same old mistakes...
Glad You have applied my mods with success.
Now You have something that is kindof unique :-)
Cheers!
C.
Edited by kkprince 2019-12-26 1:41 PM
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Location: Lake Forest, CA | kkprince - 2019-12-26 11:39 AM
Hello DanSavage!
Heh... after a couple of Year I sold my almost unique Op Pro to an amateur musician for 300Euro...
Now I'm using an Op Pro Studio.
:-)
Definitely The Op Pro was soo deaf.... signal cutted in two... considering all the amplification done
using the TL 064 , a Jfet Operational Amp engineered in 1974..... bit noisy... the mods I did were
pretty good oriented with a reason...
A standard Op Pro signal to noise ratio is a diaster...
I'm very surprised new releases was keeping the same errors....
Tradition... Same old mistakes...
Glad You have applied my mods with success.
Now You have something that is kindof unique :-)
Cheers!
C.
While I was doing this mod I wondered why Ovation would cut the output.
Then, I remembered that the ADII as well as the OFC II guitars have a boost switch that 'increases' output 4 dB.
I'm guessing that the 'boost switch' doesn't really boost anything.
Instead it has a separate daughter board that has different values of resisters, such as those used in this mod, to remove the inhibition built into the circuit that you found. |
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Posts: 110
Location: Moscow, Russia | While I was doing this mod I wondered why Ovation would cut the output. Then, I remembered that the ADII as well as the OFC II guitars have a boost switch that 'increases' output 4 dB. I'm guessing that the 'boost switch' doesn't really boost anything. Instead it has a separate daughter board that has different values of resisters, such as those used in this mod, to remove the inhibition built into the circuit that you found. Seems you got the point, Dan. Supposedly, 1769 ADII has special "modified" can (=housing) + outer "Boost" switch whilst OP-Pro preamp itself is very standard. ;-) Best,
Edited by MatureWolf 2019-12-26 4:15 PM
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FIX THE OP PRO LOW OUTPUT
