PRR-176 REV 4 Build Thread ***Manual up!***1/16/14 - (chk 1st post)

[ding]

Abe was saying to just use the dip-8 footprint instead of the discrete footprint. I was just curious if anyone has gone that route and would share some pics.

You solder the pins on the bottom of the pcb...so you don't need to clear any parts..I know you probably realize that but just wanted to throw that out there...

There are just some component holes that are so close to each other. They don't seem to clear the plastic housing. I still haven't bought the components for the DOAs. If someone can post a pic of how they soldered the pins I can get a clearer understanding. Maybe I am just overthinking it but I keep going back and forth between buying the 2520 pins or the dip-8 pins. I am trying to order the parts for the DOAs by tomorow so I am trying to make up my mind.

 

[abechap024]

Abe was saying to just use the dip-8 footprint instead of the discrete footprint. I was just curious if anyone has gone that route and would share some pics.

You solder the pins on the bottom of the pcb...so you don't need to clear any parts..I know you probably realize that but just wanted to throw that out there...

There are just some component holes that are so close to each other. They don't seem to clear the plastic housing. I still haven't bought the components for the DOAs. If someone can post a pic of how they soldered the pins I can get a clearer understanding. Maybe I am just overthinking it but I keep going back and forth between buying the 2520 pins or the dip-8 pins. I am trying to order the parts for the DOAs by tomorow so I am trying to make up my mind.

I'll take some pictures tomorrow

 

[ilfungo]

Hi I need help
how wire lundahl 1539 for 1:1 ratio
I've seen the data but I don't understand



Hi Abe
can you help with stereo interconnection ( there is something strange) as it is now all controls are interconnected...
is there a way to disconnect the threshold trimmer?
Last problem
a vu meter reading is out of about 1.5dB
the other is perfect.
I tried trimmer in series and in parallel but without success ..
Tips?
It may make sense to insert a buffer for Vu meter?
Thanks

 

[abechap024]

Hi I need help
how wire lundahl 1539 for 1:1 ratio
I've seen the data but I don't understand



Hi Abe
can you help with stereo interconnection ( there is something strange) as it is now all controls are interconnected...

that is correct, that is how the 1176 is if you stereo link them. Just use the same attack and release for both channels. I'll update a picture if you want to do it the old way and have left channel as "master". it will be in the build manual almost finished.

is there a way to disconnect the threshold trimmer?

Yes just jumper were the 5k trimmer would be.

Last problem
a vu meter reading is out of about 1.5dB
the other is perfect.

So after you adjust the VU meter trimmer it can't zero? Does the meter move at all?
no you shouldn't need a buffer...

 

[ilfungo]

Thanks Abe
the meter goes well
but
Left channel  the meter reads a value of 1.5 db off
Right channel read compression correctly...

"is there a way to disconnect the threshold trimmer?

Yes just jumper were the 5k trimmer would be."

I want in stereo mode to have a threshold trimmers independently...

 

[mrdarwin]

Thanks Abe
the meter goes well
but
Left channel  the meter reads a value of 1.5 db off
Right channel read compression correctly...

"is there a way to disconnect the threshold trimmer?

Yes just jumper were the 5k trimmer would be."

I want in stereo mode to have a threshold trimmers independently...

perhaps its your vus...
mine are matched and show correct gain reduction... for 5db vu, 4.3db compression...

 

[ilfungo]

I don't know but I've tried 4 different VU's with same result :-\

 

[ilfungo]

I've a big problem
my +18v rail is out ( now I have 60v ???)
I've tried to change 2 LM317 and both burned
-18v and 1.5v are ok
What can I check?
Thanks

 

[e.oelberg]

Ilfungo


did you pre set your 18V trimmer to around 1.3K  before testing ? if your lm317 is set to 5k it will put out 64 V
and wast 1.6 Watt in termal energy.
It is anyway wise to use 2k trimmers at that place

 

[ilfungo]

Yes I've  pre set  the trimmer at 1k3....
Now I will try with 2k trimmer...
any other suggestions?
Thanks

 

[e.oelberg]

no, circuit is simple, I had a fawlty LM317, voltage was fixed at maxiumum, so I changed it for a new one.

 

[ilfungo]

R113 is burned...

 

[e.oelberg]

could someone with a working unit do a voltage map? especially around the sidechain. My unit is sort of working
and sounds nice. nevertheless VU is not adjustable to read 0, it will all ways stay in the red and the compression is kind of odd.

 

[ilfungo]

Ilfungo


did you pre set your 18V trimmer to around 1.3K  before testing ? if your lm317 is set to 5k it will put out 64 V
and wast 1.6 Watt in termal energy.
It is anyway wise to use 2k trimmers at that place

Sorry e.oelberg
the LM317 in out max is 40V

64v-18v=48v...
How?
5 x LM317 + 2 100R resistor burned
Thanks

 

[e.oelberg]

Ilfungo


did you pre set your 18V trimmer to around 1.3K  before testing ? if your lm317 is set to 5k it will put out 64 V
and wast 1.6 Watt in termal energy.
It is anyway wise to use 2k trimmers at that place

Sorry e.oelberg
the LM317 in out max is 40V

64v-18v=48v...
How?
5 x LM317 + 2 100R resistor burned
Thanks

well I had 60v when I set the trimmers wrong and blew a fuse

 

[mrdarwin]

could someone with a working unit do a voltage map? especially around the sidechain. My unit is sort of working
and sounds nice. nevertheless VU is not adjustable to read 0, it will all ways stay in the red and the compression is kind of odd.

my unit seems to work.
make a list of test point , I will check and tell you.
Anyway, Ive got 4 abe's doas, they are working on input but not on output and sidechain... mystic!
perhaps they need more current than psu or toroidal transfo can give...Abe?

 

[prh]

well I had 60v when I set the trimmers wrong and blew a fuse

I don't understand how you could possibly get 60V from the 18V rail.  What are the voltages of the power transformer secondaries, and what is the voltage of the rails before the regulator?

 

[e.oelberg]

Just turn your 5k trimmer to maximum and checkout yourself

 

[prh]

Well, I am pretty certain that the LM317/337 devices can not provide an output voltage higher than the input voltage, and the voltage regulator circuit looks pretty much like the data-sheet implementation.

This is why I was curious about the voltages being applied to the regulator.

Otherwise, I would double-check which points are being used to check voltages, and if the volt meter has good batteries  8)

Naturally, I can't question your observations but I would like to make sense of them 

 

[ilfungo]

Prolem Solved with LM317 HV
Thanks!!!