Polyphase Precautions - Assistance from other poly builders ?

Started by Rectangular, January 23, 2007, 02:06:36 PM

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Rectangular

Hey guys,  I've been putting together a polyphase clone from Nelson's project file. as you all know there are a few inconsistencies, and I just wanted to double check a some things before soldering them on board.

quite a few resistors shown on the board layout fail to appear in the parts list,  they are: 10R x3, 22R x2, 4R7 x2. so I assume those are all in ohms, not kilo ohms. in the parts list there's a 47ohm resistor, but it doesn't show up anywhere in the board layout. so which is it, 4.7ohms, or 47ohms ?

also, there were some extra capacitors not present in the parts list: 1000uf x1, some additional 220uf's, and a 1uf if I'm not mistaken. again, just double checking those values.

lastly,  how would I go about making my own optocouplers for this project ? I know the CLM8000/2s no longer exist, and the VTL5-somethings are what most used, but how can I make a few of these using some LEDs and LDRs ? it be nice to save the money.

thanks as always for your time
-Rec

lowstar

banzai has the clm8000/2, since this is a big and complicated build, i would not add to the debugging woes by building my own opto´s, compared to the fact that you will own a real polyphase afterwards (and, having thoroughly tried the reissue, i can confirm you it is nowhere near soundwise), i happily dished out the few bucks for the clm´s (plus, don´t forget the mojo factor  ;D).
as for your other questions, i have to go and check all my printouts and scribblings and stuff, it´s been such a long time that i can´t remember. but if you search for the old polyphase threads here (there aren´t that many), you will find a lot of my posts while i was debugging (which took quite some time  ::)) where i asked nelson similar questions about some of the resistors, and he may have answered your questions already in my earlier posts.

cheers,
lowstar
effects built counter: stopped counting at 100

Rectangular

Hey lowstar, thanks for the info.  I actually already have a polyphase, but its in good condition (the paint job especially) and I need something expendable that I can gig with, so this project seemed to be the easiest route (short of encasing my original polyphase in kevlar). as for the CLM8200/2s,  I figure the ones being manufactured in the late 70s weren't exactly precision stuff, and I'm sure a lot of the original CLM's have only degraded over the years...  this is meant to be a budget build, so shaving 20+ dollars off the optocoupler costs would be preferred.

-rec

Dave_B

I just found this thread while looking for something else. 

If there's still interest, I can add my 2 cents on the extra parts.  Paul revised the PCB and added several small resistors for power supply decoupling, but the parts list obviously didn't get updated.  The 1000µf cap is there for the same reason, and probably the rest of the caps you noticed.  I used Vactrols in place of the CLM's and they worked fine if the CLM's are too pricey.  Also, the 15µf's don't seem to be available anymore.  I modified my board to allow for a 10µf and 4.7µf in parallel, but Paul mentioned that other schematics had 10µf's, so you might try them instead.
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