Pitch to Voltage PV-1 trouble shooting help

[lulu_joe13]

Hello, I am working on getting a PV-1 up and going.

The PV-1 is a pitch to voltage converter designed by Harry Bissel and I know of one person that uses it.
Needless to say mine doesn't work and I'm stuck. I have added a link for the original project pdf that has the schematic. There is a link to a pdf of my project with voltages listed for ICs, transistors and diodes. There are links to a photo of the top and bottom of the board I made and populated, Any help would be much appreciated.

http://www.radioles.com/works/pv1_611-1.pdf

http://www.radioles.com/works/PV-1%20trouble%20shooting.pdf

[Mark Hammer]

Harry posted here sometime within the last 3 years or so, expressing some shortcomings and dissatisfaction with the PV-1.  I have a board etched and stuffed sitting around, but have never bothered to wire it up because of his post.  Wish I could help but I don't have anything to offer.

An excellent place to start, though, would likely be here: http://www.electro-music.com/forum/

If I can find his e-mail address, I'll PM you with it.  He's a helluva nice guy and I'm sure he'll provide some tips.

[Lurco]

Joe, are your copper-traces all trustworthy? (can`t tell from the picture).

[lulu_joe13]

Dude, nothing I say or do is trustworthy!!!!!!! Seems so in this case, though. I'll check continuity thoroughly though.

[lulu_joe13]

The copper traces are ok. I have systematically checked continuity under the board.

[Strategy]

Quick comment here, haven't looked over the circuit, but if this is a modular synth circuit and you're feeding it guitar - does it need a boost up to a hotter level? even above line level, 10vpp.
this may already be accounted for in the circuit but just in case

Strategy

[lulu_joe13]

Hello and thanks for the suggestions. It turned out I had a short. It's working!

[Mark Hammer]

One of the reasons why I like to go over more complicated boards with a toothbrush and methyl hydrate is to make it easier to find such annoying shorts.  When boards are dense, the leftover flux makes it hard to see shorts, so getting rid of the excess flux makes "naked eye" work easier.

Of course that doesn't necessarily address those instances where one inadvertently makes a solder bridge during component installation that ends up looking like it is supposed to be there.  

But, since you have it up and running, how do you find its performance?

[Johan]

Not a Helpful reply, but...   Why not just use a lm2907?
a little gain, a schmittrigger and an lm2907?...or is the output nonlinear in a funny way in responce to frequency?
j

[Mark Hammer]

Not a Helpful reply, but...   Why not just use a lm2907?
a little gain, a schmittrigger and an lm2907?...or is the output nonlinear in a funny way in responce to frequency?
j

I would imagine probably because P-2-V with a guitar requires doing a number of other things, such as extracting an envelope, a gate, and pre-conditioning the signal.

[StephenGiles]

Not a Helpful reply, but...   Why not just use a lm2907?
a little gain, a schmittrigger and an lm2907?...or is the output nonlinear in a funny way in responce to frequency?
j

I would imagine probably because P-2-V with a guitar requires doing a number of other things, such as extracting an envelope, a gate, and pre-conditioning the signal.

.....to say nothing of decent fundamental extraction. Without that, the LM 2907 is useless.

[PeterPan]

Also likely not a helpful reply, but I have had the need for a few frequency -> voltage converters (and voltage -> frequency converters) in my past, and though its been too long in the past to recall all the details, i do remember being pleasantly surprised at the relatively easy time I had of it, starting with a single IC solution like the LM2917 http://www.ti.com.cn/general/cn/docs/lit/getliterature.tsp?genericPartNumber=lm2907-n&fileType=pdf. At least the critical function was done for me with just a few parts, and I mainly had to concentrate custom circuity to conditioning the input signal. I know and understand you don't want to abandon the existing work, but if nothing else it might be a solution to tuck away for a future endeavor.

[lulu_joe13]

Thanks for the info on the chips. I searched the web for P2V a while back and found the one I am building which is essentially the circuit out of an etherwave plus theremin by Bob Moog. I am going to use it with bowed instruments to modulate something like the bias of my Gristleizer. There is a discussion in the project pdf why Harry Bissel felt tachs were not the way to go. Thanks. Joe

P.S. I found 2 resistors I used that were only 10% of the value they should be. Dang my old eyes... Hopefully, that'll be it and I can calibrate it and move on to making it useful for music(or some semblance there of).

And, By the way. Where can I find methanol in a store? I tried several hardware stores with no luck.

[Mark Hammer]

And, By the way. Where can I find methanol in a store? I tried several hardware stores with no luck.

Is there a Fisher Scientific, or similar lab-supply distributor, in your area?  They would probably have it.  Also possible that pharmacies might carry it behind the counter.

[lulu_joe13]

Thanks. Called Grainger and they have it.

[lulu_joe13]

I found I had the wrong value resistors in 2 places (4.9K, when it should have been 49.9k) and there is an error in the parts list as well, but not on the schematic. The parts list calls for a 22.1K resistor at R17 and the schematic calls for 221K at R17. I put in the 221K and the machine calibrated right up. Joe.