the Poor Man 660 support thread

[Silvas]

My sidechain proto board....waiting to be installed.

 

[Kingston]

Great idea with proto board!

Looks like I need to do something like that as well.

I'm currently fighting with Lundahl LL1676 input and output transformers (sidechain will stay as edcors). The Lundahls sound quite brilliant but I screwed up something while installing a custom PCB I had designed for them. Compression sounds really odd. Probably something quite simple.

 

[Silvas]

Great idea with proto board!

Looks like I need to do something like that as well.

I'm currently fighting with Lundahl LL1676 input and output transformers (sidechain will stay as edcors). The Lundahls sound quite brilliant but I screwed up something while installing a custom PCB I had designed for them. Compression sounds really odd. Probably something quite simple.

Are you going to do MS matrix with them?

 

[Kingston]

Are you going to do MS matrix with them?

I actually already tried that. But failed royally. I had wrong type of transformers for the job, and now I'm too lazy to redraw that part of my custom PCB, and have it etched again.

Maybe later.

For a sensible midside/stereo selection switch with poorman configuration one needs LL1676 for the input (mid side conversion done on secondaries) and reversed LL1674 for the output (mid side conversion done on secondaries again) to preserve the 1:4 step up and 2ct2:1 step down (actually 4ct4:2 looking at the LL1674 datasheet). Perhaps I will post a schemo later as well.

 

[skal1]

hi


did anyone post the voltages of the psu without the amp boards connected.

Thanks

skal1

 

[Freddy G]

The voltages don't change in mine with or without amp boards connected

 

[[silent:arts]]

The voltages don't change in mine with or without amp boards connected

which is like it should be
(except stock heater part of the PSU)

 

[Silvas]

The voltages don't change in mine with or without amp boards connected

which is like it should be
(except stock heater part of the PSU)

The PSU doesn't need a load to provide the right voltages ?

I tested the PSU with some resistors, way before finishing assembly of the PM, just to make sure it was alive...

 

[skal1]

well the reason i ask is that i am getting 287vdc on the 250 tap and 157vdc on the 136 tap , should this be OK..

skal1

 

[skal1]

OK , have made several attempts to get this power supply working to no a vile.


in the process i have faulting the psu, i have found out way the power supply can not hold the rails  Q3 keeps breaking down , so when you apply the load the rails drop off.

can some one please supply me with the  voltages around q1, q2 ,q3 and q4.


my dc voltage at R1 junction of D4 and Q4 pin 2  is 414vdc is this right is it on the high side.

thanks

skal1

 

[skal1]

hi lads



i got the poorman blues , can anyone tell the current drawn from the  amp boards at the 250v and 136 volt taps .

thanks

skal1

 

[skal1]

bump  for above


skal1

 

[Silvas]

my dc voltage at R1 junction of D4 and Q4 pin 2  is 414vdc is this right is it on the high side

It seems way too high to me....cannot measure mine right now, but from memory, it´s around 350v at this point.

 

[skal1]

Hey

thanks Silvas , looks like i have to get new tx .

skal1

 

[envelope]

this is kind of an embarrasing post considering the amazing work by some of the members, but I am still trying to figure out an easy and cheap way to label my home spray painted 'hammered' bronze PM670 panel. I read somewhere about using "letraset" rub on letters and finishing with a aerosol clearcoat. Has anyone tried this, or anything else, to great result?  

EDIT: after several attempts at amateur labelling, I designed and got one engraved by a local guy (pic is below). Local guy made 3 mistakes,   Still, it looks better than home made labels.

 

[mich]

The rub on letters works great for me - i used it on almost all of my projects.

 

[radiance]

I would suggest dymo lettering.
I think it would look very cool on your already good looking unit!

 

[kazper]

Airbrush ? Paint brush and steady hands?

 

[Silvas]

Airbrush ? Paint brush and steady hands?

I´ve always wanted an airbrushed panel...maybe some day i´ll hire an airbrush artist to do me one !

I finally connected my sidechain proto board on my PM...WOW !

I liked this comp on some things, but, with the added flexibility and the super fast time constants, wow, this is one remarkable compressor. Finally, i was able to use it on a drum buss and loved it. I managed to do a better match on my 6bc8´s and i´m quite happy with it. The best part, is, i can change the litle "plug-in" TC modules (the caps and resistors) anytime i want. 

I still have to tidy it up a bit, and take some pics for you guys.

Next mod : Installing better input trafos, and it will be done for good. With this kind of flexibility, i can use another one !

 

[idylldon]

Just wanted to add some time constant data.  I changed my values to 2.2uF/68K, 3.3uF/180K, 4.7uF/470K, and 10uF/no resistor and I'm really pleased with the result.  It's a whole 'nother beast with these values and I find it more usable on just about any source.  I was going to install the SCAB board, but, alas, I really don't have the room in my old PA head for another PCB.  Perhaps if I build another one I'll make that part of it from the start and plan accordingly.  In the meantime, the four selections I currently have will be more than adequate.

Thanks for all the discussion about the time constant network.  I learned a lot from reading it.  Thanks again to silent:arts and analag for such an amazing project.  It will get a lot of use in my studio.

Cheers,
--
Don