the Poor Man 660 support thread

[weiss]

WIP (thanks to frank for the front panel)

 

[MicDaddy]

weiss, sexy front panel.  Output shorted wide open?  <----(edit)  wrong project... reading too much D-AOC  :

Getting ready to finish this rework monster... lots and lots of rework ugh  :

Speaks to how robust [Silent:Arts] pcbs are, not a single pad lifted. 

For those who need to ever remove those big heat-sink *******s:

Turn you iron up to 11 (actually I think mine was ~700f) dial on the 936.

Remove any hardware (nut/screw) tying TO-220 etc to heat-sink

Hold the heat-sink with non soldering hand, put some tugging force on one end and apply heat to the pad on the underside on the same end.  It will give just a tad.  Let cool.  Do the same on the opposite side.  Rinse repeat. 

I was able to remove these in a matter of seconds with no damage.

Did the same for the big 10uF caps.  They actually came out with minimal effort (turn the iron down for this one).

 

[duantro]

That is a beauty Weiss! How does it sound?
Micdaddy- looks like you have it all laid out and ready! Is that the m670 schematic on the bench?

 

[MicDaddy]

duantro Ya I'm going to try the M670 beings I'm this deep into rework already.

All transistors were thermal pasted directly to heat-sinks, some few mis-designated bits, all sockets were plastic, the PSU has basically become a boneyard as I'll try the other PSU.  This project was from a trade and it came like this.  Good thing I read the thread prior to trying to power up 

Been hanging on to this a few years now and your guys' recent posts on getting it going have inspired me to try learning wth I'm even doing and make it happen.  Getting there slowly.

Did you go T-pad + pots for threshold/output?  I'm thinking T-pad + stepped switches for threshold & output but not set in stone. 

(edit) again with the "output"... can you tell I've read the D-AOC thread a bit much lately

 

[duantro]

Nice! Good luck getting it going.  I originally had switches  all around but now I'm using tpad at inputs and switches at thresholds.  Been working good so far.

 

[MicDaddy]

duantro, how did you build/buy your switches?  Is there a sweet spot for the threshold or is 15-25k log sufficient?

 

[duantro]

duantro, how did you build/buy your switches?  Is there a sweet spot for the threshold or is 15-25k log sufficient?

I used silent arts excel sheet for 15k stepped switch  calculator at the first page meta post. Works good. Kingston's post there also describes a good method. I haven't disliked mine enough to change them!

 

[weiss]

weiss, sexy front panel.  Output shorted wide open?  <----(edit)  wrong project... reading too much D-AOC  :

That is a beauty Weiss! How does it sound?

thanks guys, still in work though. Need to wire and calibrate this thing first, then i can tell

duantro, how did you build/buy your switches?  Is there a sweet spot for the threshold or is 15-25k log sufficient?

i used 25k stepped attenuators for threshold and input gain

 

[weiss]

can anyone help me wire my attenuators? i can't find the corresponding terminals..

this is how it looks:

and now this is what the wiring guide says:

which relays did you use for the bypass boards?

 

[duantro]

can anyone help me wire my attenuators? i can't find the corresponding terminals..

and now this is what the wiring guide says:

which relays did you use for the bypass boards?

Looking back to post 3156 by Mitsos....

I think the actual resistor value for each step is the last value in each line.  Kingston says the total R is 15K.  It's like a pot/ voltage divider like a volume pot.  Signal goes in on top and out the wiper, other side (in the volume pot example) goes to ground, but here the two "pots" connect together and is where the control voltage goes. 

Anyway, between the CCW position 1 and position 2, is where the 1191R resistor goes.  Between pin 2 and 3 should be a 309R, pins 3 and 4 a 183R, and so on til you get to the end of the each section. Signal would go from the trafo to last pin (CW) of the respective switch sections, the first positions (CCW) would connect together and go to CV and the poles of each switch go to the grids of the valves.

I'll include a diagram that someone else posted somewhere in the thread. Their values are slightly different than Mitsos is explaining, but it should help some to visualize the layout.
I used Igor's old bypass relay boards with DS2E-M-DC12V relays. There isn't much too them. PM me if you'd like the schematic to breadboard your own.

 

[weiss]

thanks duantro!

 

[cptpfeffer]

I changed the circuitry of the Time Constant pot to a six pos Switch with a much bigger (faster) timing range possible. I completely took the 10k Pot and the 10uF cap out and replaced it with the 6 pos switch. One end goes directly to the out of the two diodes from the controlvoltage rectifier. The other one goes to the middle pin of the attack socket (wher the pot normaly is connected)
Pictures attached. the timing range goes from 10 msec to 0,5 seconds. I was smashed away by the achievable soundresults!

 

[cptpfeffer]

here is the schematic without the 10k Pot and the 10uF cap. the upper wire goes to one end of the 6 pos switch, the lower wire to the other end ;-)

 

[cptpfeffer]

and here it is:

 

[cptpfeffer]

here we go

 

[djfatum]

I changed the circuitry of the Time Constant pot to a six pos Switch with a much bigger (faster) timing range possible. I completely took the 10k Pot and the 10uF cap out and replaced it with the 6 pos switch. One end goes directly to the out of the two diodes from the controlvoltage rectifier. The other one goes to the middle pin of the attack socket (wher the pot normaly is connected)
Pictures attached. the timing range goes from 10 msec to 0,5 seconds. I was smashed away by the achievable soundresults!

This modification is amazing
I would recommend to anyone

: 8) ;D

 

[djfatum]

Construction completed a great project  8)

 

[[silent:arts]]

Congrats! Nice and clean work  8)

 

[weiss]

i still can't make it work correctly. there are four standoffs available. they seem to be different to the ones in the wiring guide. which of the four leads go where? and what decks do i need to use? maybe someone has used similar switches and can post an image

thanks
weiss

 

[bernbrue]

Hi,
Your resistor are solder wrong. You have to go from one position to the next, not from one deck to the other. Have a look at the pictures of my unit, you'll see what I mean. You have got a switch with four decks, but you need only two. Go to first thread and you will find a link to my unit with pictures.
Regards
Bernd