dbx 160vu clone

[Echo North]

Hi Mike,
Glad to see you feeling better. I know there has be talk about using the 4th switch as the power button. Is it pretty easy to unlatch the 4th switch from the others? Sorry I don't have experience with your switches, as of yet. but have to say they do look very NICE!

Thanks
AC

This will not work.  The switches on their own are non-latching.  So if you remove the switch and then disconnect it from the interlocking mechanism it will act as a momentary switch.  Meaning for power to be on you'd have to hold it down.

Mike

 

[abechap024]

ok, well I was thinking last night, weird eh? why don't we just implement the switch like in the 1176? instead of an on button, have an off button? That seems like the most obvious solution, I don't know how or why it eluded me for so long! lol  

so:

In
Out
GR
OFF

anyone see anything that I'm probably overlooking?
Thanks Mike for looking into that, and for having great prices in your store!

AC

 

[Echo North]

That is a good idea.  I should have thought of that too!

Mike

 

[obiwandb]

Hi Mark,

Thank you kindly for your generous offer to forward the vca, etc docs.  May I have a copy?  sevenfoldguitar at yahoo dot com.

As for meters, musicianservice dot com may still have some NOS meters in stock.

anyone have contact info for musicianservice? The site looks dead, no content anywhere, no contact info!

Also, anyone have a schematic for the 903 style rms detector board? I thought i had it off the Gyraf board but now I cannot find it!

Thanks,

David

 

[Biasrocks]

anyone have contact info for musicianservice? The site looks dead, no content anywhere, no contact info!

Also, anyone have a schematic for the 903 style rms detector board? I thought i had it off the Gyraf board but now I cannot find it!

Thanks,

David

Wow, DB "utler".... Been a while.

Mark

 

[abechap024]

Hi Mark,

Thank you kindly for your generous offer to forward the vca, etc docs.  May I have a copy?  sevenfoldguitar at yahoo dot com.

As for meters, musicianservice dot com may still have some NOS meters in stock.

anyone have contact info for musicianservice? The site looks dead, no content anywhere, no contact info!

Also, anyone have a schematic for the 903 style rms detector board? I thought i had it off the Gyraf board but now I cannot find it!

Thanks,

David

Sorry David I'm not familiar with the 903 RMS detector unit. But here is the manual if that helps maybe?

http://www.dbxpro.com/product_downloads/Owner_Manuals/903%20Owners%20Manual.pdf



Edit: Also on the 160vu, I might of been a little too optimistic on the building of the VCA right on the board. It is definitely possible, but be warned it is going to take a lot of time and patience to match al the transistors and trim out all the distortion. If I find an easy way to do it, I will share and I ask the same of anyone else attempting this!

 

[damnyankee]

AC,

I think your PM box is full.  I noticed some components (LM301's, CA3083, etc) are missing from the Mouser parts list.  Do you have the entire parts list for this project?

Thanks in advance,

DY

 

[abechap024]

Hi DY,
The op amps are the only things that should be omitted from the Mouser Cart list. the CA3083 is = NTE929 which is in the cart.
the mouser cart:
https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=0cdcdc43b5
is only a starting point, and some things you should keep in mind if you are going to use it:

1) The Current Cart I uploaded is for the Full Build: Onboard original Powersupply, Discrete VCA, RMS, and mainboard parts. If you want to use the THAT chip your are going to have to look at the BOM below and add/subtract the parts. I'm sorry it seems confusing, but once you jump in it should make sense. Also If I get time, I'll try to upload other mouser carts...

2)There are no op amps in the cart...in retrospect probably a little stupid on my part. But hey who doesn't have a bunch of lm301s and tlo82s laying around?;-)

3) you might have to update some parts, as they will be sold out (I have no control over this

4)also I only put the EXACT amount of bc550c/bc560c you will need when building the VCA...that is assuming that 4 of those are exactly matched....they probably won't happen so I would add 50+ at least to each so you have a chance of matching a few.

BOM for respective sections:

;D ;D ;D:
FULL Build

Section BOMs:
Main Board for Build
Original 160vu Power supply
RMS detector
Discrete / that VCA


updated schematic and PCB overlay (hopefully easier to read)

Just Main Board Schematic - includes panel wiring guide
Full Schematic
Reference PCB Layout


btw sorry the schematics are so funky - I've been fighting this program ever since I converted it from eagle...So bear with me...
Cheers!
AC

 

[abechap024]

Also wanted to add:

I was watching a documentary

http://www.youtube.com/watch?v=VOYvTXUqlrI

Got love the 4 DBX 160VUs behind Butch Vig @ Sound City

Interesting video

 

[damnyankee]

Hi AC,

Thanks for the Full Build list.  It helps.  I started to make a list from the pcb but as we've PM'ed, it's a little challenging.  If you don't mind, I'd like to color-code the components for the VCA & RMS in case folks already have the dbx cans and want to remove those from your Mouser List.

It's easy to augment the Mouser list to add the ICs.  ;D

DY

 

[abechap024]

Lame Mouser is out of NTE929 for 10 days....


(CA8083) they have some on ebay.

Bummer,
AC

 

[envelope]

Looking at the power supply  schematic, they used electrolytics with voltage ratings a little too close to the working voltage of the circuits.

It is advisable to use if possible,
roughly speaking;

+/- 24 rails try to use  50V or 63V caps.

+/- 15 rails try to use 35V or 50V caps.  

general rule o 'tumb.... open, of course, to interpretation......opinions.....but it is a good practice in any case, dictated by available voltages i.e. 10V 25V 35V 50V 63V 80V 100V etc.

 

[abechap024]

Yes I agree.
For this revision you might be stuck finding tall and skinny caps, but for the next revision the ripple caps will have a bigger footprint to accommodate people wanting to use bigger/higher rated caps.\

AC

 

[Nora]

Pcb arrived, looking great.

Can't wait to stuff it!

thanks!

 

[abechap024]

Great! If you got it, it should mean that most everyone should have theirs or getting it very soon...

Good luck and all let us know how it goes/questions!

AC

 

[damnyankee]

I harvested the 200 VCA & RMS off my dbx 119 and soldered them on the board.  ;D

I'm awaiting the transformer & components and will build the power supply section first then test it.  Wish me luck...it's my first non guitar pedal project!

DY

 

[abechap024]

Your very brave to make a prototype your first project that isn't pedal related!! My hats off to you!

And congrats on the fitting of the RMS/VCA units....did you manage to get them into the holes ok??

AC

 

[Biasrocks]

Your very brave to make a prototype your first project that isn't pedal related!! My hats off to you!

And congrats on the fitting of the RMS/VCA units....did you manage to get them into the holes ok??

AC

The 200VCA module from my 119 fit the board, albeit with a bit of stretching of the pins, definitely not a comfortable fit but doable.

The 208RMS module on the other hand didn't fit at all, in fact it appears that the pinout is slightly different between the 208 and 209 modules.

How the hell did you manage to fit it into the current footprint, do you have a 209 or a 208?

208RMS Mod measurements:

Module Width: 3.7cm
Module Length: 4.8cm

Pin spread width (Pin 1 to Pin 9 / Pin 4 to Pin 5): 2.5cm

Pin seperations

Pins

1 to 2: 2.5cm Actually this is 2.55cm, verified on the board
2 to 3: .5cm
3 to 4: .7cm
5 to 6: .7cm
6 to NC: .5cm (*Sits over R44 on PCB)
NC to 7: .7cm (*Sits over Q2)
7 to 8: 1cm
9 to 10: .7cm

Mark

 

[abechap024]

EDIT: NICE! WITH A QUICKNESS! MUCH THANKS


Mark,
Measurements would be great! I don't know whats most convenient for you, but MM would probably work best for me. (Fractions give my calculator a headache ). Wait what am I saying the US is the only country that still uses imperial measurement!

Cheers
AC

 

[abechap024]

Mark,
if you still have the board and VCA on your bench could I get some measurements on the VCA to tighten up the pin spacings?
Thanks
AC