the Poor Man 660 support thread

[kafka]

[quote author="[silent:arts]"]the rotary switches
you would better want it exponential (or log in potentiometer language).
it took some time to figure this out, but with some help I was able to do an Excell sheet to calculate the resistors for emulating a real log potentiometer.
fill in the desired steps you want: Log Pot to Switch Excell Sheet
[/quote]

Hey, Volker. Any chance you could unprotect this, or increase the max # of steps to something like 100? I'm doing a coarse/fine control adaptation, and it would simplify things if I could use your spreadsheet. Thanks.

 

[[silent:arts]]

send you an email

 

[kafka]

[quote author="[silent:arts]"]send you an email[/quote]

Excellent! Thanks!

 

[mrclunk]

The logToPot is bloody marvelous!!
tried to make one a while ago and failed miserably
thanks :thumb:

 

[analag]

Here is is a look see at the signal flow of the PM660.
http://groupdiy.silentarts.net/pm660/PM660-BlockDiagram.pdf


analag

 

[seavote]

Volker, sorry to ask again about the molex connectors but which 2 pin connector does the poor man use? the smaller 2.5mm spacing or the larger 5mm spacing like the one use to connect the ac to the d-aoc?

 

[[silent:arts]]

[quote author="seavote"]Volker, sorry to ask again about the molex connectors but which 2 pin connector does the poor man use? the smaller 2.5mm spacing or the larger 5mm spacing like the one use to connect the ac to the d-aoc?[/quote]
the small white ones, 2.54mm spacing.
and one 6pole 5.08mm screw terminal.

 

[[silent:arts]]

Block Diagram and Component Placements for the PCBs (incl. dimensions) added to the first post in this thread.

PM660 Block Diagram
PM660 Component Placement and Dimensions
PSU660 Component Placement and Dimensions

 

[Moby]

Volker, I never saw a schematic of your PM PSU but it seems that diode bridge has no capacitors across diodes. Usually 0.1uF film bypass capacitors...

 

[[silent:arts]]

[quote author="Moby"]Volker, I never saw a schematic of your PM PSU but it seems that diode bridge has no capacitors across diodes. Usually 0.1uF film bypass capacitors...[/quote]
you are right, there are no diode bridge bypass caps.
I know some manufactures do it, but I still can't see the reason why.

 

[Moby]

Simply, capacitors are helpful :wink:
here's the pic with just full diode bridge
http://really.slacking.net/~modat7/howto/circuits/Scope_DiodeBridge-Full-2.jpg
and bridge with caps across :wink:
http://really.slacking.net/~modat7/howto/circuits/Scope_DiodeBridge_0.1uFBypassCaps-2.jpg
But no probs it's possible to add caps on the down side of PCB ...

 

[kafka]

I think I have the correct Mouser part numbers for the heat sinks here. Would someone care to take a look to verify? They're all found on page 1880.

PM660 Q1 707-411320B25 12.7x34.9x50.8

PSU670 IC1,IC2 707-411910B25 12.7x35.0x25.4

PSU670 Q1,Q2 707-411621B25 25x41.6x50.8

Only PSU670 IC1&2 are spec'd exactly, because that was the only one I had exact measurements on. The others were put at 50.8mm high because that was the most efficient heatsink in that series. If a smaller one works go for it. Similarly, IC1&2 could also use the same one I've identified for PM660 Q1.

 

[[silent:arts]]

from your description I would swap the heatsinks from the PM660 Q1 with the PSU670 IC1,IC2.
the PM660 Q1 doesn't get that hot, the smaller one (25.4) is fine.
the PSU670 IC1,IC2 will depend on how many Lamps or Relays you want to use (and at which voltage) from the "+17V"

 

[delaymix]

One question, about the resistance heaters, do for a stereo unit is correct to use an R = 1R5 and 50-w?, What specific situation should be considered other values of resistance and power?

Thanks.

 

[codered]

anybody know where I can find small indicator lamps like the original

TIA

 

[[silent:arts]]

[quote author="delaymix"]One question, about the resistance heaters, do for a stereo unit is correct to use an R = 1R5 and 50-w?, What specific situation should be considered other values of resistance and power?[/quote]

In theory it is 2R for Mono (4 tubes), and 1R for Stereo (8 tubes)
in theory 10W for Mono, but the 11W resistor I used just went too hot.

BUT it seams to vary with the tubes, the Power Transformer and of course the mains power voltage.
I have ordered some 25W and 50W resistors, will post some pics and tests when I'm back from vacation.

 

[syn]

Hi there
I have those Stancor 4:1 transformers used as line inputs in MCI jh series desks. Can i use them in the 10k:600r position(s)?

pri dc resistance:~950ohm
sec dc resistance:~58ohm
pri ~ 14H
sec ~0.9H

Thank you

 

[analag]

What is the current carrying capacity of the windings or the wattage of the transformer. This is the reason I chose Edcor's XSM line in this app. While we can experiment with the input transformers I recommend the XSM for all outputs

analag

 

[syn]

[quote author="analag"]What is the current carrying capacity of the windings or the wattage of the transformer. analag[/quote]

I'm not sure. Any ideas how to measure this? I was thinking of using them in the side chain...I'll get edcore for the outputs for sure.... or equivalents...

Thanks

 

[rrs]

[quote author="kazper"]Found some more part numbers that I wanted to pass on as possibilities.

12 pos switch for Attack

www.alliedelec.com
Mfr Part#: 71BD30-01-1-AJN
Allied Stock#: 948-7247
$13.65

Inexpensive 12 pos 2 deck for Gain and Threshold for those trying to save a few$

Mfr Part#: 71BD30-02-1-AJN
Allied Stock#: 948-7249
$17.52[/quote]

I have purchased these for Attack, Gain and Threshold, should arrive this week. What would be a option for the bypass ?

Also looks like I need to solder some resistors to these suckers. Is anyone able to help regarding values and working out where the go??

Hope I havent made this too hard for myself.