the Poor Man 660 support thread

[elektrovolt]

thanks, that's just what I thought, but only to be sure...

just started matching resistors and soldering them to the elma switches... this is actually less difficult than it seems.

 

[stereokillah]

i know i did it one week ago for 4 switch but not elma it's very long.
but i don't how to link it i've checked the wiring guide but i've only two point on my swicth.
http://cgi.ebay.fr/New-24-step-DIY-Selector-switch-2-pole-Attenuator-Pot_W0QQitemZ110391296000QQcmdZViewItemQQptZBI_Connectors_Switches_Wire?hash=item19b3d58000&_trksid=p3911.c0.m14&_trkparms=72%3A1526|66%3A2|65%3A12|39%3A1|240%3A1318|301%3A0|293%3A2|294%3A50

 

[stereokillah]

i think the point are the first, the return and the end

 

[elektrovolt]

now I am looking at the pot resistor spreadsheet,it seems to be in reverse order, or isn't it ?
it seems logical to me that the most counter-clockwise position #one (or zero, whatever your switch says) is the position with the lowest gain and more resistance.

please, someone ?

 

[[silent:arts]]

na, there is nothing reversed 
think of potentiometers.
in CCW position the wiper is 0Ω to pin one, and 15KΩ to pin three, pin one to three is 15KΩ.
in CW position the wiper is 15KΩ to pin one, and 0Ω to pin three, pin one to three is still 15KΩ.
now in the poorman, position one (CCW) on the switch gives you a 2x15KΩ resistance in between the tubes and the input transformer.
and since the positive and the negative side of the symmetrical signal are shorted there won't be any signal left.
full on (CW) you have 0Ω between the transformer and the tubes, but 2x15KΩ between "hot" and "cold".
this will be louder ;D ;D ;D

 

[elektrovolt]

tricky !

now I know why there is this wire between the two decks. it took me 15 minutes to get it  ;D

 

[stereokillah]

ok it's always 2x15ohm between the cold and hot and the variable between tube and transformer.

It's very good explain thank you

 

[W DeMarco]

Sup fellas!

Got the PM fired up and the voltages under load are stable.  Right channel sounds awesome!

Left channel... not so good. 

The gain seems to work fine as I can match the input signal on the output well.  however the threshold is acting strange.  If in the first position with no attenuation meter pegs right.  as I lower the threshold nothing happens until maybe the 6th position when the signal gets smacked extremely hard with compression.  the meter reads -15dB.  from there as I lower the threshold it continues to compress more.  Also the attack switch pins the needle right in any position other than the 3rd.  The only dif I can find is that the attack switch was wired lugs 7-12 and the C lug rather than 1-6 and the A lug.  Its a 2*6 lorlin.  Should I have programed this switch starting on the 7th poistion and locking it at the 1st and using the A lug or should I pull it out and go 1-6 with A?

Any thoughts?  This Babys gonna rock real soon!

 

[W DeMarco]

Now I have noticed that the frontmost 5687 on the bad channel has no silvered surface area in the top of the tube.  I looks like it burnt out or something..  All thats there is a small white stain.  Any thoughts on how this could have happened?  Im figure this is what my problem is but am hoping that the tube was bad from the go and will not happen again!

 

[emrr]

Small white stain where the silver getter material was sounds like you've lost vacuum in that tube.  Air leak around a pin when stressed on insertion, possibly. 

 

[W DeMarco]

Grrrr... I hope I can still get a match for this damn nos tube!  Thanks for the reply!

 

[W DeMarco]

Replaced bad tube and checked out all of the interconnects and soldering to no avail.  Still getting a major crush at 5th position of threshold switch.  Any ideas?

 

[Knarleybass]

I have mine wired up, and it passes audio in bypass, but I am getting nothing when it's engaged. and the needle remains pegged as high as it will go. I am stumped

 

[giltmastering]

Replaced bad tube and checked out all of the interconnects and soldering to no avail.  Still getting a major crush at 5th position of threshold switch.  Any ideas?

have you tried swapping the rotary switches with the working side just make sure your issue is not in the switch?

 

[[silent:arts]]

I have mine wired up, and it passes audio in bypass, but I am getting nothing when it's engaged. and the needle remains pegged as high as it will go. I am stumped

- check all voltages
- check if you wired the bypass PCB correctly (or try it without the bypass PCB)

 

[W DeMarco]

Replaced bad tube and checked out all of the interconnects and soldering to no avail.  Still getting a major crush at 5th position of threshold switch.  Any ideas?

have you tried swapping the rotary switches with the working side just make sure your issue is not in the switch?

I was gonna try that today figuring I could at least figure out if the problems in the board or the switches. 
Thanks, will report back!

 

[elektrovolt]

Hm, now I have the input switches ready, but what about the treshold switches ? Should they be just the same as the input switches ?

 

[[silent:arts]]

Hm, now I have the input switches ready, but what about the treshold switches ? Should they be just the same as the input switches ?

if you made normal rev log input switches the answer is yes

 

[lolo-m]

Hm, now I have the input switches ready, but what about the treshold switches ? Should they be just the same as the input switches ?

If your input switches are filled as pots (-inf to 0dB), yes they are the same... If you filled your input switches as -20dB to 0dB, you should fill the threshold switches as pots to have the possibility not to compress in comp on mode.

 

[radiance]

If your input switches are filled as pots (-inf to 0dB), yes they are the same... If you filled your input switches as -20dB to 0dB, you should fill the threshold switches as pots to have the possibility not to compress in comp on mode.

Nice one! 
So what would work best as threshold pot? Log or lin? Anyone experiemented with both yet?