UA 175b/176/177 pcb...

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damnyankee

Well-known member
Joined
May 23, 2009
Messages
326
Location
Motown
Hi All,

It appears Greg/Drip has stopped selling the 175b pcbs.  Is there anyone who still makes/sells them (yes, I used the Search but nothing really turned up).  If noone is making/selling these, does someone have a pcb file I can purchase so I can make a pcb to make my own unit?

Thanks in advance,

DY
 
It's a very simple mono compressor project to build point to point. In fact p2p is ideal solution for it.

You don't really need the blankie.
 
*LOL* You mean....like turret boards???

I wouldn't supposed anyone would know if either of these UA schemos work...?

UA-175 (http://www.waltzingbear.com/Schematics/Urei/UA_175.htm)
UA-176 (http://www.waltzingbear.com/Schematics/Urei/UA_176.htm)

BTW, I've never used either unit.  However I think I would prefer the 176 due to its flexibility of the gain select (2:1, 4:1, 8:1 and 12:1 via multi-tap trafo) vs the 175's fixed ratio of 12:1.  My first question is why didn't Greg do a 176?  Was it a parts issue (that multi-tap trafo)?

DY
 
damnyankee said:
Was it a parts issue (that multi-tap trafo)?

DY

This part is not available.  I spoke to Cinemag who I believe make the part used in the current commercial reissue but they were not for selling it.  Without that specific transformer this project is not possible,  There's good info here on the board about the 176 with some speculation on how that transformer might be put together.

Cheers,
Ruairi
 
damnyankee said:
*LOL* You mean....like turret boards???

I was not joking. Look at the parts count. This is a simple p2p project. The original only had a pseudo PCB as well, built like a turret board and split into two.

Fairchild 670 is a p2p project, and that is double or triple the complexity.

Time to graduate from the paint by numbers school.
 
But...but..but...I like paint by numbers...!  Seriously tho, I'll take a look at the schemo and read up on the trafo options posted on this board.  I'm still a beginner and don't know much about multi-tap trafos. 

Would it be possible to run the signal thru to the inputs of 4 different single-tap trafos (each doing 2:1, 4:1, 8:1 or 12:1 gain selection) and attach the outputs from the trafos to a 4 position rotary switch and feed the output back in to the circuit? 

Or, could I build the 175 and hook a potentiometer at the trafo and dial down from 12:1 ratio?

I'm learning here...so be gentle!

Thanks!!!

DY
 
HI,


  I used to own an original 175. It sounded great. I also used a 176. It also sounded great. More flexible, but . . . .


  If you are a newcomer, I would strongly advise keeping it simple. Build a 175. Transformer is available. You will quite quickly have a fantastic compressor to use. THEN think about trying to sort out a 176. I pretty much always used the 176 at higher ratios anyway. FWIW, there is no ratio control on a 660 . . . .


  Good luck, I seriously regret selling my 175



    AndyP
 
Thanks, All!

I emailed Greg to see if he has any more 175b pcb (paint-by-number!) or if he plans on doing another run. 

DY
 
> You don't really need the blankie.
> Time to graduate from the paint by numbers school.

Could you get more condescending?  :p
 
damnyankee said:
Would it be possible to run the signal thru to the inputs of 4 different single-tap trafos (each doing 2:1, 4:1, 8:1 or 12:1 gain selection) and attach the outputs from the trafos to a 4 position rotary switch and feed the output back in to the circuit?   

Or, could I build the 175 and hook a potentiometer at the trafo and dial down from 12:1 ratio?

There's a discussion regarding using a switch to simulate the taps here :)
 
alexc said:
Could you get more condescending?   :p

Probably.

I don't hide the fact I dislike the paint by the numbers disposition of this forum. It makes finding actual content difficult, curbs discussion of more advanced topics and is the cause of major exodus of some of the most interesting contributors of this forum in the past.
 
Kingston said:
Probably.

I don't hide the fact I dislike the paint by the numbers disposition of this forum. It makes finding actual content difficult, curbs discussion of more advanced topics and is the cause of major exodus of some of the most interesting contributors of this forum in the past.

I know you're better than posting a selfish, elitist response like that.  Lord knows many people helped you out in your life and if you don't want to give back and share, then fine.  Just keep those kind of comments like that to yourself.  There's no place for them here or anywhere.

Thank you.

DY
 
If it makes the difference between getting it done or not
there is NOTHING wrong with paint by numbers
When is the right right time to graduate ? not your call

It's different if someone wants it done for them , or has
no intention of becoming self sufficient or profit off of others
Is it laziness or insecurity , hard to know , maybe they just want
to use a classic device that doesn't cost a fortune , then again
there always the guy who wants something built here & sold to him cheaply

If someone is willing to pay the drip price , that says something about them

point to point would also teach someone about layout , not a bad place
to start
 
The ONLY reason many of us around here ever move onto P2P is because of the generous information sharing, and willingness to help people who have less knowledge than themselves.

I for one hope that this culture NEVER changes here.

I would be keen for a 175 PCB, but I enjoy etching my own. This could be laid out as a single side self etch?
Mac
 
I purchased Eagle, a nice laser printer, and am investigating a decent bench drill press so I can etch/drill my own boards.  At some point, I'd like to be able to make my own chassis/front panels too.  In my mind, that's truly DIY.  However, I'll continue to purchase pcbs to support others and their efforts in here too.

I'm sure the 175 can be laid out in a single side pcb.  Same with the 176 (which is the one I want to do).  I used Photoshop to clean up the 176 output trafo schemo but I can't get Photoshop to decipher that 1st letter/number: ?WG. C-10477; I went thru all the trafo catalogs I could find (including electronic books in GoogleBooks) from the '50s/'60s and that part number (or similar) is not a UTC, Freed, Triad, Chicago, Hammond number.  Maybe it's a Universal Audio part number...I don't know.
 
damnyankee said:
I used Photoshop to clean up the 176 output trafo schemo but I can't get Photoshop to decipher that 1st letter/number: ?WG. C-10477

DWG. = Drawing

The full text reads:

Reference DWG. NO C-10477 for circuit.

The transformer is the PA-5946 Output (UA1008,UA175) with extra taps for the different ratios. I would imagine you could simulate this with a series of resistors, albeit with less than 100% accurate results.

The turns for the 5946 output are:

Pri: 30K/7.5K split
Sec: 600/150 split
Tert: 600

Min L with 10mA DC = 55Hy.

The 176 dispenses with the Tertiary winding.

Somewhat similar, but not exactly like the UTC H-22, H-23, A-26 transformers.

Mark
 

Attachments

  • 177Schemo1.JPG
    177Schemo1.JPG
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Mark,

You're my hero!

Here's the cleaned up 176 output trafo hopefully someone will be interested in:
UA176-177-OutputXfmr.jpg



This is the modded UA-175b with the 6386 mod I'd drool over if it were in my rack:
UA175B6386mod.jpg



Finally, here's to ya, Mark!  (my homebrew Hefeweizen; and yes, it's as good as it looks...I wish I was as good at electronics as I am at making great brew!)

http://i1121.photobucket.com/albums/l516/damnyankee20/Hefeweizen.jpg
 
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