Pul-Al-Tec

[rafafredd]

The compressor part looks very interesting. It´s like an upgraded 436 compressor. I´m sure this works much better than the 436. More like an UA-175 compressor.

The schem is not very readable, so can someone help me identifying the tube after the interstage transformer? Is it an ECC83 or ECC88?

Also, any info about the interstage would be nice. I guess something like 1:2, 20k/80k, but who knows? I´ve heard about step-down transformers at vari-mu interstage sounding better than step-up...??? Some people here likes 4:1.

 

[Bryson]

[quote author="rafafredd"]The compressor part looks very interesting. It´s like an upgraded 436 compressor. I´m sure this works much better than the 436. More like an UA-175 compressor.

The schem is not very readable, so can someone help me identifying the tube after the interstage transformer? Is it an ECC83 or ECC88?

Also, any info about the interstage would be nice. I guess something like 1:2, 20k/80k, but who knows? I´ve heard about step-down transformers at vari-mu interstage sounding better than step-up...??? Some people here likes 4:1.[/quote]

Yeah, a 436C with an extra triode stage, and interstage xfrmr. Plus, the P.S. does not use a voltage doubler for B+ (like Altec), and the B+ for V1 is regulated. The reg voltage also goes to the detector tube via the ratio switch (up to 12:1 ratio!!). It looks like it started as an Altec schematic, as much of the print, Peerless xfrmr id, etc. matches.

V2 looks like ECC83 to me (zoomed in with Acrobat).

 

[Bryson]

I can't see Rob's EQ. I get a 404.

 

[Tekay]

Nice one John! Thanx!
Rob! did you kill the link?

 

[Guest]

I can't really make out the coil/cap nomenclature on the input High Boost section. Is there any detail for this that can help clear up my muddled mind?

Thanks for this posting. I like this type of compressor topology and EQ front end makes it even more interesting.

 

[Rob Flinn]

Sorry guys I ran out of space & had to delete the diagram down. Not only that but I`m losing this space, because I had that phone line disconnected the other day in an overhead reduction drive, so I need to find some space somewhere.

If you PM me your address I`ll email it to you when I get home later. I`m over a friends at the moment.

 

[NewYorkDave]

I've given the BBC EQ diagram a temporary new home here:
760kB JPEG

Grab it now. I might have to remove it before too long due to space restrictions.

EDIT: There was a problem with the link, but I've fixed it. Apparently, my server doesn't like filenames with blank spaces (%), so I had to rename the file.

 

[soundguy]

a friend of mine has one of these EQ's which he is claiming to have taken out of columbia in NYC. I have looked through it several times, but got to hear it for the first time a little while ago, for all the similarities between a 436, it really doesnt sound like one. Its a very cool box. If anyone built one Im sure yours wouldnt sound much like a 436 either just based on the different transformers youd likely wind up using. 436's are wierd and very one trick pony ish, that wasnt the vibe I got off of my friends limiter which matches that schematic dead on.

this might be a cool one for someone to try. I'll see if I can get photos of the thing when I get back this spring.

dave

 

[toby]

great schematics guys.


the pultec comp reminds me of the ua 177, but without the silly output transformer. will definatly borrow some ideas in varimu project i'm working on.


Toby

 

[kpeek]

http://www.unityaudio.co.uk/thermionic_culture_site/mr_thermionic.htm

Check out this link.

Underneath the picture of the console, it has this:

"He basically gave them the design for an Altec compressor, which they copied for him, and also an equaliser, which was based around a Pultec but with extra flexibility. Only one of these EQ's were ever made and we have it here - it's an excellent and quite unique piece of gear. It introduced a little bit of phase shift and second harmonic distortion, but this is one of the things that give it a very characteristic sound which is especially good on vocals. I know that Joe regularly used it to lift vocals rather than turning up the level - he would boost at 3kHz which pushes the voice right up front in the track."

This must be the PUL-AL-TEC

 

[Winston OBoogie]

...

 

[zmix]

[quote author="Winston O'Boogie"]About 10 years ago I owned the unit that I posted the schematic for. [/quote]

Did the 'Pul-Al-Tec' have anything to do with Joe Meek??

It fascinates me that Vic Keary has one of Joe's original boxes....