PYE Compressor/Limiter Thread *boards shipping* BOM up!

[aladan]

my pcbs have arrived!! time to get building!!!

Dan or Abe?  Hoping for Abe, since that means mine might be close behind

/edit/ Damn, just saw your comments about Dan having all the stock now.  Off to my credit card company I go for a refund, then

 

[orangechili]

Ok,

I had thought I had the switchboard wired header assembly right but it was indeed off by one side. Doh!

Here's my measurements on those diodes now
1:1 =0v
2:1 =-8.33v
3:1 =-8.14v
4:1 =-7.71v
Limit = -6.14v

So the channel I was working on was thumping/oscilatting on its own after I reset the trimmers to where the manual recommends. Turn it on hours later and thumping is gone and the channel acts normal as it should. Whatever... I'll take it

Meanwhile the other channel gets no compression at all now. On to some more fun debugging there.

Thank you guys for your help and ideas. If I hadn't traced the emitter of TR18 I wouldn't have discovered that header error so great suggestion!

 

[Ilya]

Ok,

I had thought I had the switchboard wired header assembly right but it was indeed off by one side. Doh!

Here's my measurements on those diodes now
1:1 =0v
2:1 =-8.33v
3:1 =-8.14v
4:1 =-7.71v
Limit = -6.14v

That sounds about right. Glad you figured the issue. Now that you have one channel working you can compare it to the faulty one and find where they differ.

 

[Spencerleehorton]

following the 1.1 BOM and v1 schematic, is there other information i need, or do i have do go through the whole thread?

 

[marcn]

following the 1.1 BOM and v1 schematic, is there other information i need, or do i have do go through the whole thread?

Your pcbs are marked v3.14 no?
That schematic has some corrections compared to v1 posted somewhere on the first pages.
Also someone posted a longer BoM + build guide for v3.14.
I can reupload them unless you're a search wizard. Never hurts though to read through it all at least once.

 

[Spencerleehorton]

If your able to email to

[email protected]


That would be great, otherwise I'll see if I can find.

 

[marcn]

The schematic: (note theres a missing connection from pin6 of the switchboard connection to the B- of the sidechain but that should be there on the pcbs)

 

[marcn]

And the BoM with a few instructions, cant remember who made that one but thanks anyways.

 

[Spencerleehorton]

do any of the transistors have to be hfe matched?

 

[Spencerleehorton]

Also the silk screen for the 470uf are a bit confusing?
Anyone know the correct orientation please ?

 

[shot]

Also the silk screen for the 470uf are a bit confusing?
Anyone know the correct orientation please ?

Use the Build Butler!
https://buildbutler.org/build/pi-3141-rev3-chip-version#_470uF_25v

 

[Spencerleehorton]

thanks shot, i thought it was to the right, as this would then line up with pretty much everything else.

Im going to try and wind myself the input transformer, its a 1:1 but no other info which helps me wind it:

http://cinemag.biz/line_input/PDF/CMLI-15-15B.pdf

it doesn't give DC resistance or inductance so im a bit of a loss at how to interpret this info, could anyone pitch in please?

regards

Spence.

 

[Ilya]

Im going to try and wind myself the input transformer, its a 1:1 but no other info which helps me wind it:

http://cinemag.biz/line_input/PDF/CMLI-15-15B.pdf

it doesn't give DC resistance or inductance so im a bit of a loss at how to interpret this info, could anyone pitch in please?

Well, at roughly 50$ CMLI is a very good value. You'll spend a lot more (both in time and parts) trying to produce your own. Do you stock the lams, wire and mu-metal cases? If yes, this might work. If not, I'd say don't bother.

 

[Spencerleehorton]

yes i have access to all the parts as i have friends in the industry, just down the road actually, Brian Sowter and Best Windings are my local transformer people, just trying to not hassle them as i have winding machine and can go and pick up the bits.
Also the whole point of being on here is to DIY, the first thing i would do if i couldn't be bothered to build something is go and buy the right thing, its all about learning, i don't mind messing stuff up as long as i learn a bit about it.
Ive ended up winding a couple of 1:1 with some M6 which should do the job nicely, just would be nice to have some better info about the cinemag's or similar TXF.
And anyways what everyone forgets is it maybe $50 but i would have to pay at least that again for shipping then i would get stung with a customs charge for the same again, so i'd be looking at $200, not so cheap now!!

regards

Spence.

 

[Spencerleehorton]

right, well i've completed the build and fired it up today, and no smoke so far!!
Ive set the DC voltage to -20v but no signal on output yet, haven't had time really today and its really hot here today, so going to leave until i've read up on setup procedure , if there is one!!!
getting good signal at T4, and getting something at the output pot but doesn't look very nice!!!
Ive linked the units but i'm going to just try and setup one first of all, then i'll pop the other in, one i know i've got them both going.
Need to have some ideas for bypassing it?

regards

Spence.

 

[Spencerleehorton]

Ok I have a few questions now.
The schematic doesn't show output txf connection?

Is it in series with the output xlr connection?

Could someone explain to me the side chain please, I thought a side chain was taking the signal and being able to adjust frequency wise what part of it is effected?

Regards

Spence

 

[Spencerleehorton]

will wait until someone replies about these problems, but i'll try and explain what i've done so it makes it clearer:

I've had to use leads for the decay, limit and rated switches, only lengthened them about 10mm, so this could potentially have wrong wiring so will double check this, although there is some movement on the meter when switching in out etc, and the waveform does seem to respond.

Im using OEP transformers for Input and side chain set to 4:1 ratio, output TXF is about 1:1

I've used 2N3906 and 2N4124 and have reversed them.

On the OUT XLR pins i have run these to the output TXF and then from the TXF to the XLR output sockets.

Is the schematic laid out so that if you use the transistors not in the brackets you use the resistors not in the brackets?

My B- rail is -15.44V and on the other rail it is -11.41V

I am getting good signal up until TR5 middle leg, but nothing on TR6 middle leg?

regards

Spence.

 

[marcn]

Check R23 Trimmer, I get good sound with it being set around 68R, if you didn't pre set the trimmer it might be way off and can cut out the signal. Also as far as meter behaviour and overall responsiveness I found that R52 makes quite a difference so play with that as well once you get signal going through.
Output transformer hookup is straightforward, fromt the connection marked 'output xlr' on the schem to the primary leads of the XF and secondary to the respective + and - of the XLR connector, might have to swap leads for phase on the secondary (at least my Edcor seems to be labelled wrong in that regard)
As for schematic I stuck with all the values as indicated not using any of the values in brackets, the notes in the upper left corner of the schem state also what these values represent. I used 2n2222 in TR12 as well which works fine (my supplier had no 4124 and i wasnt gonna order just from somewhere else for a couple of transistors).

 

[Spencerleehorton]

ok thanks, i will set trimmers as you have said, and yes i have all resistor values not in brackets.
I will report back once done,.

 

[Spencerleehorton]

i took the R23 trimmer as 22R or 100R trimmer, so ive put in a 200R trimmer and i get signal through the unit now!!

could you help suggest where the controls need to be for setup please, as all the documentation seems vague.

I have had a play around and limit seems to work but general Vu metering doesnt seem to be right.