EH Deluxe Phaser/Polyphase parts subs and IC ident help.

[nelson]

Ok those that have been reading my posts know I have a thing for anything EH with deluxe or poly in the name. I am putting together plans for a clone of the Polyphase/ Deluxe Phaser, without further ado here are the questions.

I have been Looking for a replacement for the CLM8200/2 which is now obsolete. Comparing the datasheet that was given to me by Stephen Giles for the CLM8200/2 (Thanks Stephen) I have found the nearest matching vactrol which happens to be the VTL5C3/2. Datasheet here http://old555.com/LPE/PDF/Vactec/VTL5C2X2-3X2.PDF

Now is this a good replacement? Or is there something I have overlooked?

Secondly, the pesky thermistor in the circuit I am going to have to replace with a resistor as I cant find any info ANYWHERE on it, does anyone know what value I should replace it with?

Thirdly there is an IC which is illegible on both the dlx phaser schematic and polyphase schematic I have. It is to the right and just below the 4013. Does anyone know which IC this is?


These are the final pieces I need to put together to clone this unit. The other components are easy to sub/find and a PCB wouldnt be too difficult to design (although If anyone has a unit and would like to take pictures of it I wouldnt say no). :wink:

Thanks for reading my inane ramblings and questions.
Paul Nelson  

[StephenGiles]

That is a WO2M which is nothing more than a bridge rectifier often used in power supplies.
Stephen

[puretube]

huh?

[nelson]

That is a WO2M which is nothing more than a bridge rectifier often used in power supplies.
Stephen

Wha!?

nope, its def an IC not a bridge rectifier. pin 7 connected to 15v.

[StephenGiles]

...........close.......if you were referring to a deluxe Octave Multiplexer!

This one is a CA3140 - read all about it!
http://www.intersil.com/data/fn/fn957.pdf
Stephen

[nelson]

Thanks Stephen!


Now for the other 2 questions.

[nelson]

Stephen, you have one of these thermistors dont you? Could you measure the resistance of it at room temp?


I am going to try the VTL5C3/2. Before I go and order them, is everyone sure they will work? at $6 each I want to be doubly sure.

[hank reynolds 3rd]

Nelson,
have you thought of diy led/ldr combo instead??
its far cheaper, and i'm guessing that the resistance is set similar to the mutron biphase (where the 220k resistors set the highest point), so just get some ldr's from somewhere (rapid electronics if you're in the uk are cheap and..err...rapid!!) and try that method...

oh yeah, the vactec is 1led and 2 ldr's that share a middle pin/leg (to gnd i'm guessing??)

That's my ten bob's worth

Cheers
Sam

[Mark Hammer]

Although it obviously makes life a whole lot easier to have a perfect replacement for the Clairex part (if not the Clairex part itself), keep in mind that all you really *need* is something that exhibits the approximate resistance characteristics, and speed characteristics (it should be able to change resistance fast enough that a full sweep in the range of 10hz is noticeable), and you can easily compensate for the rest of it.  

For instance, for all the brouhaha one sees about FETs in phasers, you will note that they are almost accompanied by a parallel resistor to ground.  In other words, the resistance that is actually being modulated is the combined parallel resistance of the FET and fixed resistor.  So why couldn't you do this for an LDR that just happens to be a bit bigger/higher than you need?  Maybe you NEED something that doesn't go higher than 500k and what you have goes up to 2meg.  So, stick a resistor in parallel with the LDR so that their combination maxes out at 500k.

By the same token, where the phase shift starts/maximises in the frequency spectrum, in this particular allpass topology, is a function of both the cap value and resistance to ground. So, if your LDR turns out to be a little too high in resistance (or low), why couldn't you compensate by shifting the cap values over a bit in the appropriate direction?

[nelson]

The light is 5K the dark is 10m, I would "roll my own" but I want to avoid the hassle of finding the perfect combo of Led/LDR, and 6 bucks isnt that bad given the exchange rate just now it would be almost just as costly to get 2 LDRs and an LED. The VTL5C3/2 is used in the MXR Phase 100 and the specs are almost identical, so It stands to reason it will work in this. I may email smallbear and see if he can source me some CLM8200/2.

The other thing thats really bugging me is the thermistor, I think stephen giles has one? I know next nothing about thermistors except that thier resistance changes by temp, so what resistance is it at room temp?

Thanks for your help guys, If it works out cheaper to "roll my own" I will try it out on the second unit I build. Yes, I plan to build More than 1  

[Mark Hammer]

1) Is the thermistor cross-referenced in the E-H house numbers listing?
2) Is there an ECG/NTE replacement for that part?

[nelson]

Nope the EH number isnt cross referenced. I have no way of knowing if there is an NTE replacement. It should be fine just replacing it with a resistor(I think?).

[StephenGiles]

Stephen, you have one of these thermistors dont you? Could you measure the resistance of it at room temp?

Yes if I can find it!
Stephen

[nelson]

Stephen, you have one of these thermistors dont you? Could you measure the resistance of it at room temp?

Yes if I can find it!
Stephen

Thanks Stephen!    also if you have any xerox copies of this PCB  :wink:

I cant thank you enough for your EH info.

Did you check the echoflanger PCB thread?

[hank reynolds 3rd]

Nelson...
I'm with you on the eh cloning mission...waiting to see if the a 1048 can be subbed for the deluxe octave multiplexer...then game on (i redrew the schem as it the grounds etc on the orig looked a mess!!)...doesn't look that complex... :?
I'll try and add something to the flanger pcb aswell ,when i've got time (I'm gonna be working for a week straight from sunday in the middle of fairford ...\Rocksteady security rules!!! honest)...hopefully on saturday...

[nelson]

Dude, I have a friend who owns a dlx octave multiplexer, I am waiting on him to scan the traces and photograph the component side. You can buy the CA3094 from smallbear (I think). No need to replace it, that way we can have an exact clone.....Also if you must sub it it should be that hard to modify the existing PCB to accomodate it. I will post the pics when I get them. I have almost finished the EH echoflanger trace side in vector graphics it looks really good.