dbx 160vu clone

[Echo North]

I should be able to get them as a 3 gang.

Give me a week!

Mike

 

[arska]

NO pcb changes needed for  NEW metering , just any 0,1mA or 1mA scale analog meter will do . I release schematic asab.

 

[haima]

nice job!!  ;D

 

[abechap024]

Arska,
Thanks for testing the meters! That's fantastic news. Even cheapskates like me have no excuse not to use a meter and with Hairball Audio possibly sourcing the 3 gang switch, this could be a lot of fun.
So:
Meter - check
Power supply (thanks to davids schematic i was able to verify) - check
Main circuit - re re check
VCA check
RMS - check

I think were ready to prototype this spaceship.

 

[arska]

Arska,
Thanks for testing the meters! That's fantastic news. Even cheapskates like me have no excuse not to use a meter and with Hairball Audio possibly sourcing the 3 gang switch, this could be a lot of fun.
So:
Meter - check
Power supply (thanks to davids schematic i was able to verify) - check
Main circuit - re re check
VCA check
RMS - check

I think were ready to prototype this spaceship.

Can you make layout for 10turn cermet trimmers, it´s easier to calibrate and setup.

NEW Metering is working..... needs some testing.... and a document for setup.


 

 

[damnyankee]

Arska,
Thanks for testing the meters! That's fantastic news. Even cheapskates like me have no excuse not to use a meter and with Hairball Audio possibly sourcing the 3 gang switch, this could be a lot of fun.
So:
Meter - check
Power supply (thanks to davids schematic i was able to verify) - check
Main circuit - re re check
VCA check
RMS - check

I think were ready to prototype this spaceship.

AC,

Thank you for answering my transformer question.  I'm getting geeked about this project - this should be a relatively inexpensive build.  My main concern still is transistor matching (http://www.national.com/rap/Story/transistors.html).  It's beyond the scope of simple pedal builders like me!

Also, we should augment your parts list to include vendor (Mouser/Digikey/etc), part numbers, part cost.  Is your parts list complete with power supply components?  I can get started on that but I'm probably going to need a little help on the transformer and a few other odds and ends.

Besides the power supply, the meter section components are a question too: Mike/Hairball's gang switch availability, which meter, and are there any other components to the meter section other than the 10-turn trim pot?

Speaking of meters, we'll need to replace the stock label scale with the one used by dbx.  I'll whip up a few ideas...

Thanks EVERYONE for all your efforts!!!

DY

 

[arska]

NEW meter schematic for 100uA standard meter. R4 1k00 for 1mA meter, other current values: varying R4
DC current VU meter response is faster.

 

[abechap024]

Hi Arska,
so that schematic is what needs to be added after the 270 resistor? If so why does it need to be added? is it to drive the meter better? Sorry i'm just curious that the stock circuit doesn't have enough options to drive a 1ma dc meter.
And yes I'm making it possible to put a couple different footprints for miltiturn pots.
Also Mike for Hairball let me know that his 4 gang switches can easily be turned into 3 gang switches. That is good news!

 

[arska]

Hi Arska,
so that schematic is what needs to be added after the 270 resistor? If so why does it need to be added? is it to drive the meter better? Sorry i'm just curious that the stock circuit doesn't have enough options to drive a 1ma dc meter.
And yes I'm making it possible to put a couple different footprints for miltiturn pots.
Also Mike for Hairball let me know that his 4 gang switches can easily be turned into 3 gang switches. That is good news!

The original meter is custom product, it´s mechanical zero(0dB) is at point 66,6% (scale 0....100%). standard meter has mechanical zero at 0% (scale 0...100%)
So original meter has negative current at -40dB point, zero current at 0dB point , positive current at +20dB point.
Implementing standard meter, offset current needs to be setup. Original meter is  2mA device, or near that value.

 

[abechap024]

The original meter is custom product, it´s mechanical zero(0dB) is at point 66,6% (scale 0....100%). standard meter has mechanical zero at 0% (scale 0...100%)
So original meter has negative current at -40dB point, zero current at 0dB point , positive current at +20dB point.
Implementing standard meter, offset current needs to be setup. Original meter is  2mA device, or near that value.

Ok, that makes sense, now that you've written it out. i'll add that to schemo and make changes to PCB. Better now than later! Thanks Arska.
ac

 

[matthias]

here's a scan of the 160 meter scale...

 

[haima]

thanks matthias! very handy 

 

[abechap024]

interesting to read about the 160vu. I've never had the chance to use one. A lot of great reports - someone said one was used to track some high profile vocals....interesting to hear theey get used on vocals with good results...I've always heard them to be kick snr bass buddies...anyway just thinking out loud

As far as the meter goes, am I missing something or can't we just adjust the "zero-meter adj" trim pot to electronically make the meter rest at 0. I am obviously probably missing something here but why add another zero adjust circuit when there is already one? sure we might have to switch the 1.5 meg current limiting resistor to something smaller - but still should be that big of a deal right?

Sending out for prototypes in a couple weeks. if anyone is wondering. then probably a another couple weeks to receive them then another couple weeks till ordering the ones to be made available to everyone

 

[Tekay]

Think I read that the 160VU is Allen Sides favorite compressor and that he sometimes only feeds signal though it with out compressing to catch the flavour

 

[arska]

IT`S NOT THE SAME THING!!!!!!!! built one and wonder then how it behaves when you change component values from original.
Every component in meter amp is critical, change something and the rest goes down..........

 

[damnyankee]

interesting to read about the 160vu. I've never had the chance to use one. A lot of great reports - someone said one was used to track some high profile vocals....interesting to hear theey get used on vocals with good results...I've always heard them to be kick snr bass buddies...anyway just thinking out loud...

If you listen to the Boston albums, Tom Scholz has always used dbx compression & de-ess....even used dbx compression on everything:  http://www.youtube.com/watch?v=rJ0omnL5q0A

He has (4) dbx 160VU, a dbx 166, and a dbx 263x; on the first album tho, he used a dbx 119 & RE-15 mic on the acoustic guitar.

I think one of the inspiring things about Scholz being a home rec'er:  he says you don't need all that expensive gear (neumanns, etc) to make a great sounding record.  EV RE-20s were always used to record Brad Delp and Fran Cosmo's vocals on those albums.  The big part of his sound is his insistence to using analog gear and record on 2" 24 track Scotch tape and mix down to 1/2" tape.

 

[Biasrocks]

I think one of the inspiring things about Scholz being a home rec'er:  he says you don't need all that expensive gear (neumanns, etc) to make a great sounding record.  EV RE-20s were always used to record Brad Delp and Fran Cosmo's vocals on those albums.  The big part of his sound is his insistence to using analog gear and record on 2" 24 track Scotch tape and mix down to 1/2" tape.

I'm not sure how accurate this is,

As I understand it, the first album was done on a 1-inch 12 track Scully in Tom's basement on 3M 226 tape, his favorite tape for squash. The vocals were mostly recorded with AKG 414's. The performances were amazing, but that was Delp.

He did like dbx compressors.  ;D

Mark

 

[damnyankee]

I'm not sure how accurate this is,

As I understand it, the first album was done on a 1-inch 12 track Scully in Tom's basement on 3M 226 tape, his favorite tape for squash. The vocals were mostly recorded with AKG 414's. The performances were amazing, but that was Delp.

He did like dbx compressors.  ;D

Mark

It's accurate.  You're right he used AKG 414's...but those were used on overheads.  And you're right about the Scully however several of the tracks were originally recorded on a homemade multi-track tape deck he made before he bought the Scully.  When he and Delp signed the record deal (there was no band "Boston"), John Boylan backed up a truck with a 3M M79 to his house, ran a snake to the Scully, duped the tapes onto the 3M M79 in the truck, flew the tapes with Scholz out to California where Delp and a couple of their buddies were laying down tracks for Brad's song to complete the album, and the rest is history.

If you look at pics of Scholz's original studio from Boston/Don't Look Back albums, you'll see the dbx 119 to the right of his (4) 160 VUs and his sole UREI 1176.  If you see the pics around the Walk On era, you'll see the dbx 160VUs, 166 and 263x in his rack - the dbx 119 is gone.

And another factoid about Tom Scholz: did you know he invented the wildly popular Polaroid SX-70 Land camera when he worked for Polaroid?  
(Tom Scholz is from my home town; his dad owned Scholz Homes there.  His folks were good people - and his dad was a giant man in his day at 6'9").

 

[abechap024]

Hi,
Great news! The prototype is ready! See other post in the lab if you want to buy one. We need all the input we can get on the build, so don't hold back!

Also, this is kinda off topic, but i was listening to the doobie brothers "listen to the music" and does anyone know if this comp was used on that record? I could be going crazy, but I swear I could pick up some of its vibe on the bass....Just wondering
great record btw.

 

[damnyankee]

Hi,
Great news! The prototype is ready! See other post in the lab if you want to buy one. We need all the input we can get on the build, so don't hold back!

Also, this is kinda off topic, but i was listening to the doobie brothers "listen to the music" and does anyone know if this comp was used on that record? I could be going crazy, but I swear I could pick up some of its vibe on the bass....Just wondering
great record btw.

AWESOME!!!  Thank you, AC!  I'll head over and purchase one.

The answer to your Doobie's question is "no...".  I'm almost positive the Doobie's Toulouse Street album (which featured "Listen") came out in '72.  The dbx 160 came out around '76.