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

[diylan]

Hi everyone, I'm re-posting this here because I haven't gotten a response elsewhere and this thread seems to be a bit more active.

It's a little off topic, but...

Does anyone know what's going on with Abe? I ordered a few discrete opamp PCBs from him back in October, but never received anything. He hasn't responded to emails and it looks like his website is down now too.

I'm only out $18, so I'm not furious, but I also figure I can't be the only one. More than anything I just want to know what the story is.

Anyone know what's up?

 

[anvl]

I also wonder what happened to Abe.  I've been writing him for the last months asking him for another PCB kit, but no answer at all.

Diylan, I have some spare DOA PCBs.  I didn`t use them.  If you are interested, write me a PM.

One more thing.  I think a Voltages Map would be very useful.  Let's work on it. 

Regards

 

[berkleystudios]

Adam, in which conditions is your build? Is it working?  Which problems?

Mitsos, which links do you need?  I could upload again.

I am still building op amps.

build is about 95% complete.  redesigning somethings now, and working on my final front panel design. but I should be up and running soon. I  had originally bought edcors  for all my transerformers but I will be replacing the interstages with cinemags and possible jensen on the outputs

really funds are the only thing holding me back haha

 

[mitsos]

Thanks to both!

Adam, so it's definitely 1:1 then?  I've found the CMLI15-15PCA, CMLI15/15B and CMLI15/15C, with max levels of  +18dBu, +20dBu and +27dBu, respectively, so probably C uses a bigger core than B, which uses a bigger core than the PCA.  I think I have some 10K:10K's that might work and might have some "vintage" 15K:15K that might work but definitely won't fit the footprint. 

EDIT: Got the files and it looks like it's the CMLI15/15B.   

Mitsos, which links do you need?  I could upload again.

Thanks for the offer, if you have the build manual and BOM, I'd appreciate it! It would help. 

EDIT: Looks like Abe's site is back up, and the links are working again, I just downloaded the files! But thanks again for the offer, appreciate it! 

I hope this means that Abe is OK.

 

[ding]

Any US builders having issues with the LM337 / LM317 and excessive heat? I am going to put a small order in on mouser and I am rethinking my heatsinks. I had originally bought these...
http://www.mouser.com/Search/ProductDetail.aspx?R=551002B00000Gvirtualkey53210000virtualkey532-551002B00G
But I have a feeling those won't do. Any suggestions from successful US builders on the regulators and heatsinks?

 

[ding]

Hey abe could you share what power trafo you're using for the reference of us American builders?  Under load I'm at 49-50V before the regulator which means I'm dropping 33-34V to get it to 16V.  Most of the regulators are spec'd to drop a max of 35V so I'm right at the top tolerance but not over...I'd prefer to not have to get another toroidal but at 50ish Volts under load it does seem the power supply is nearly tripling the voltage as opposed to doubling it?

Did you get this sorted?

 

[dacapitan]

I also wonder what happened to Abe.  I've been writing him for the last months asking him for another PCB kit, but no answer at all.

Diylan, I have some spare DOA PCBs.  I didn`t use them.  If you are interested, write me a PM.

One more thing.  I think a Voltages Map would be very useful.  Let's work on it. 

Regards

I would also like to know where Abe is or what is going on. I pre-ordered boards from him and paid for them upfront . I'm about $120 out - not too bad but still annoying! More disapointed that I wont be getting these boards :/

The last time I heard from him was on 6th November 2014 - After emailing him twice asking if he received my emails his response was ;

"They are still in transit. Again sorry for the delay.
Thanks
Abe"

(Meaning he was still receiving the order)

I have tried calling but get no answer.

 

[FredW]

Hi guys,

I'd like to go to build this compressor too.
is someone have a rev.4 complete BOM (or near complete) for mouser, farnell, or any other company to share ?

I'm also searching for PCBs since Abe seems not to answer to emails for a long time...

thanks a lot in advance for your help !

 

[dacapitan]

Great news! It seems as though Abe is back online... These are the comments on the AC sound facebook

"Sorry Everyone. We are working through the delays and have been in the middle of solving some personal issues. We will make sure everyone gets taken care of. Again sorry for the lack of communication and non response to emails."

 

[boneindian]

Yes to a voltage map from someone with a working unit! I'm hoping to hear back from Abe now that he's back up and running as I've been trying to get a replacement PSU board.... A couple of you have asked if I ever got mine up and I did not.  I'm on my third power traffo (spec'd one was too hot, the 12V was too cold, hoping the 15V will be just right   at this point I can't get the damn thing to even pass voltage on all the lines (my 100V and the heaters are fine)  the +/- either flickers at super low voltages and then craps out or never even gets going in the first place.... But I've been through so many regulators that I'd just rather start over on the PSU and remove that from my list of problems.  Given that it was almost a year ago that I started giving up on this guy I can't remember if I ever fired it up with ICs before switching to DOAs but if I recall  I did have it up for a few hours at one point before it started frying regulators.  In any event, definitely start out with IC opamps (as per anvls suggestion ) before switching to discreet I guess because that seems to be where I started having problems...to the point where I feel like it shouldn't be suggested as a plug and play option but rather a mod.  Hopefully, if people have more success stories, Abe can update the build guide with better info what power transformer should be used with the DOA option.  This has been the only unsuccessful build I've evere undertaken, but I'm all about optimism for it in the new year! (Also, I  refuse to believe that I wasted $1200 putting it together!).  There seems to still be a gap between successful US builds and non-US  builds so I hope  more successful US builders will share their process,  experience, and results here!

 

[anvl]

Boneindian, this year will be the one to finish your PRR176 compressor succesfully 

Again, it's useful to start using IC opamps to check the rest of your build.  When everything is fine, then change to discrete.

Regarding the PWR transformer, European builders, I've used Don-Audio and it's ok.  That means

Primary: 2 x 115v (230v)

Secondarys:
120v 50mA (red)
18 v 1.2A (blue) -> Ensure to use this one for +18V rail  !!!!!!!!!! 
18v 0.4A (yellow) -> Ensure to use this one for -18V rail

Salud

 

[ding]

I'm going to start with the basic components on the bom and this transformer
http://www.mouser.com/Search/ProductDetail.aspx?R=VPT36-1390virtualkey55310000virtualkey553-VPT36-1390
I will start out with all ICs and no output transformer and then slowly start adding things. First the output transformers, then the output DOA and finally the input DOA. Hopefully I will have some success or at least figure out what mod is causing problems.
If I put 150pf on the ICs that I plan on replacing with the DOAs will that cause problems?

 

[shot]

If I put 150pf on the ICs that I plan on replacing with the DOAs will that cause problems?

Good question!!

 

[anvl]

I'm not sure, I soldered 22pF caps and checked everything with IC op amps.  Later I removed them and changed to 150pF and discrete op amps. 

 

[boneindian]

I'm going to start with the basic components on the bom and this transformer
http://www.mouser.com/Search/ProductDetail.aspx?R=VPT36-1390virtualkey55310000virtualkey553-VPT36-1390
I will start out with all ICs and no output transformer and then slowly start adding things. First the output transformers, then the output DOA and finally the input DOA. Hopefully I will have some success or at least figure out what mod is causing problems.
If I put 150pf on the ICs that I plan on replacing with the DOAs will that cause problems?

FYI ding, that'd the transformer I started out with and it was way more than I needed.... And actually too much for my PSU to handle.

 

[anvl]

http://www.mouser.com/Search/ProductDetail.aspx?R=VPT36-1390virtualkey55310000virtualkey553-VPT36-1390

It will work for +18V and -18V rails (I used at the beginning) ... and it will get quite hot !!!  Nice for US builders with winter cold and snow at the window

 

[ding]

Hopefully someone will weigh in on a good transformer. I haven't even opened the box yet. I wonder if I should try it out or try to return it?

Edit: 30 day return policy from mouser sucks! Oh well.  Abe, any thoughts?

 

[ding]

According to Abe on the original PRR thread that transformer should work.

Any toroid advice?  I thought I had it figured out, but after reading Kingston's post a page back I'm not so sure now.  Are two transformers required for the project or will one work just fine?

You mentioned using a 50VA dual 18V secondary.  That led me to think this guy would work: https://system.netsuite.com/core/media/media.nl?id=12599&c=ACCT126831&h=9bf90c20991f70f0e64c&_xt=.pdf
Assuming it even fits in a 1u case...
Hopefully I can avoid blowing $30 on the wrong tranny.

Depends on what mains you have. If you have 120v Mains you can use a dual primary, hook  one primary to the mains and the second primary to the 100V transformer in on the board.

If you have 120v mains that transformer will work fine.

 

[ding]

also I found this. could help?

2. If you plan to use DOA's and strong modern opamps for sidechain, you can't have 100 ohm droppers in the PSU. They have to be 10-22ohm. There's is something like 60mA used per rail and 100 ohms drop way too much (6volts wasted).

 

[anvl]

Everyone of us (Europe and US) needs AT LEAST a 18v+18V (50VA) PWR transf for +18V, -18V rails.  Later we'll find a different solution for 100V rail.