the Poor Man 660 support thread

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[quote author="Purusha"]OK, I know this but I thought you maybe used something different than linear the end... anyway :?[/quote]
I'm totally happy with analags original design, and still don't understand why people want to mod it before they have build and heard it.
mine is an original poor man :thumb:
never mind, I'm only surprised how many people want to mod before they build it.
 
Hi there,
some people asked for a picture of how to set up a rotary switch for the PM670. I used the Uraltone switches 2 decks 24 positions. In order to limit to 21 positions, you have to open the screws of the switches and make your own stopper with a piece of plastic (attention: hold together the blue rings with the contacts, otherwise the switch will fall apart) Use Volkers Excel calculator to find the resistor values for a 15k log pot. Here is a picture of how I soldered the resistors (not nice but not too bad for the first try)


Uraltone_switches_004.jpg



regards
Bernd
 
[quote author="[silent:arts]"]
never mind, I'm only surprised how many people want to mod before they build it.[/quote]

well, I can't speak for others, but I just wanted to place orders for stuff with future possibilities in mind. I have always been going to have the basic pot-based design in there, but was already thinking of adding switched settings alongside that... and therefore looking to pre-order any bits for that if they looked like they might be problematic to find easily... because to me, the switched circuit looks like it adds in a bunch of different kinds of responses that won't be gettable with the basic variable R and fixed C.

anyway - wimas and electros from laura at taw (she is great!) should arrive soon.. then I can get building this thing and see for myself!!
:)
 
[quote author="khstudio"]EDCORE XPWR063 - Power for PM670 ***WRONG*** ???

Look Here:
http://www.groupdiy.com/index.php?topic=353395[/quote]

Sounds wrong for sure. I haven't looked back at the Edcor spec as originally described to see what was stated.

We haven't heard any test results on the USA GB toroid either; curious to hear.
 
[quote author="emrr"][quote author="khstudio"]EDCORE XPWR063 - Power for PM670 ***WRONG*** ???

Look Here:
http://www.groupdiy.com/index.php?topic=353395[/quote]

Sounds wrong for sure. I haven't looked back at the Edcor spec as originally described to see what was stated.

[/quote]

I just tested it & it is definitely WRONG :!: :mad:

I measured aprox = 17v full across
& aprox = 8.5v from each end to the Center Tap!!!

Damn... not only did I miss out on the Toroidal Group Buy, but I'm left with no PT for this project.
It's not like WE picked the wrong one... Brian saw the thread about the PM670 PT (& the required specks) & HE offered this one, saying it had ALL the right specks. Now I have to pay to ship it back & wait some more.
It's now the only part I'm missing to complete this project.

:sad:

Did anyone else order the EDCORE XPWR063 :?:
 
looks like the Edcor power xfrmr order was described and taken correctly:

http://www.groupdiy.com/index.php?topic=27678&postdays=0&postorder=asc&highlight=edcor+xpwr063&start=60
 
fazeka wrote:
Hi Analag (or anyone else who may have an answer),

I read somewhere that Fairchild when building the originals removed the diode bridge from the Simpson VU meters, essentially making them DC milliammeters:

Fairchild 670 meter thread

My question: can I use my pair of Simpson model 127 1 mA DC milliammeters instead of VU meters for the PM670?
emrr wrote:
Placement of 5K meter trim; in series to meter?

depends on your meter I think.
for my standard VU I used it in parallel and had no problems to zero it, tracking was fine.
Click to expand...
I see that people asked about "Vu" but can't see right answer about. To me PM's "VU" looks like ma meter with Vu scale :? So, since nobody mentioned that I must ask. Am I correct? I think that regular VU can't pass DC in series and in this PM topology it seems the way it is. So, final question is, is this the simple 1ma meter ? or something else... :?: Or, let me ask from different view. Can PM work without "VU" placed across 22k resistor? I think it can't . Please let's clear this out :grin:
 
Hi,
with a VU meter you are on the save side. In my prototype I used ordinary 250mA ampermeters with a 100R resistor parallel. I compared the tracking to a Beede VU meter and there is not really a big difference. My suggestion: Build it an try various meters, in the end it´s your choice.
regards
Bernd
 

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