DOD - FX84 Milkbox Compressor  [schematic]

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DOD - FX84 Milkbox Compressor

Postby Liquids » 03 Jul 2011, 01:10

I'm going to be taking the THAT 2159 chips out of this Milkbox, so figured I'd take some pictures while I was at it.

It's a good circuit, that could probably be tweaked to excellence as well, so hopefully it can be traced.

If more photos are needed, just let me know.
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Re: DOD FX84 Milkbox Compressor

Postby iq01221 » 03 Jul 2011, 04:37

Boss cs-3 needs only one THAT, so, I think is a good idea to clone it, but you can put socket in the DOD board( Well, I would :roll: )...
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Re: DOD FX84 Milkbox Compressor

Postby iq01221 » 03 Jul 2011, 18:40

askwho69 wrote:cs3 has 2 different THAT, the other one on your DOD is the obsolete and the new CS3 has THAT2181l... do have a layout on your cs3? :D im interested too:D

Ok, if you want:
http://img267.imageshack.us/img267/5364/bosscs3.jpg
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Re: DOD FX84 Milkbox Compressor

Postby iq01221 » 03 Jul 2011, 18:41

Sorry for double posting... :oops:
The THAT ic is 1252!! :shock: check it out!
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Re: DOD FX84 Milkbox Compressor

Postby atreidesheir » 04 Jul 2011, 02:03

Probably the best DOD pedal of that line. This is the first look I have ever had under the hood.

I always thought it sounded better than the Boss cs-3.

My very subjective opinion. Thanks for the pics.
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Re: DOD FX84 Milkbox Compressor

Postby jstbrowsin » 04 Jul 2011, 10:08

I really hope someone can trace this as I have been looking around for this circuit for ages to fix my one that has missing parts. I emailed DOD but no reply whatsoever (s hooooooles) :thumbsdown
I would attempt to trace this myself but my pcb tracing fung foo is sadly not up to the task. :slap:
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Re: DOD FX84 Milkbox Compressor

Postby Liquids » 04 Jul 2011, 18:59

jstbrowsin wrote:I really hope someone can trace this as I have been looking around for this circuit for ages to fix my one that has missing parts.


Take a picture or let me know what parts are missing via PM, and I can tell you what's on mine most likely - all the components are numbered.

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Re: DOD FX84 Milkbox Compressor

Postby mr coffee » 19 Jul 2011, 04:51

How about a sound clip of the Milkbox?

I've never heard one and just figured it was another 3080 design. The better VCAs (which appear to be in series) might make it into a much better compressor than I had assumed and has got me interested?

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Re: DOD FX84 Milkbox Compressor

Postby ryanuk » 19 Jul 2011, 15:38

Just wanted to show my support for this thread.

The FX84 is a seriously underrated compressor. I love it.

I have 2. Both have working VCAs but the bypass on one is a little tempremental, the other is fine but the way the dc jack is mounted has cause shorts on the casing in the past. I wanted to clone the circuit utiilise the VCAs from one and then tape it permanently to my board. I been using a demeter clone in the interim (thanks Bajaman!) but the Dod has its own qualities. Kinda silky. A coloured output but in a good way.

Been meaning to reverse one of these for ages. If I can be of any help lemme know chaps.

Ry
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Re: DOD FX84 Milkbox Compressor

Postby ryanuk » 25 Jul 2011, 14:18

Chaps

Just wanted to mentioned that I've opened up my older Milkbox and have begun tracing it. Its one of the ones with the quirky names for the controls e.g. "Pasturisation", as opposed to the later models which had "compression" etc.

It has the THAT2159 chips. However I couldnt find a pinout for them but found details of the SA2159 which appear to share function and form with other that chips (215x series).

Switching is based on FETs and a 4007 IC.

Not used to tracing such complex circuits so bear with me.

I should finished this week hopefully.

RyUK

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Re: DOD FX84 Milkbox Compressor

Postby ryanuk » 13 Sep 2011, 14:12

Hi

Update to this thread. I have a preliminary schematic for this pedal. Its taken me a while longer than I thought but it should be finished very soon.

Its taken me a while cause the traces are soooo thin and there are several connections to the 2 VCAs. Also, my schematic is showing 2 more resistors than is on the board.

Ill iron these out and post the results this week.

Looking forward to putting the pedal back together so I can play with it again. Not only does this pedal compress well. But i find it also adds a "hifi" polish and thickness to the sound.

RyUK

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Re: DOD FX84 Milkbox Compressor

Postby pedalgrinder » 15 Sep 2011, 09:45

sensational iam looking forward to the schematic on this one. I reckon it will sound nice and warm.
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Re: DOD FX84 Milkbox Compressor

Postby ryanuk » 15 Sep 2011, 13:42

pedalgrinder wrote:sensational iam looking forward to the schematic on this one. I reckon it will sound nice and warm.


It does - thats a good way to describe it. Very warm. Its deffo not a transparent compressor. You can tell its on even with very little compression dailled in. However, it just adds thickness that I cant describe.

The schem will be finished soon.

RyUK

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Re: DOD FX84 Milkbox Compressor

Postby ryanuk » 20 Sep 2011, 13:34

Guys - quick update - I am getting there with the Milk Box Schem. I had a couple of extra Res on the schem and had some fun tracking them down.

Is 90% complete but messy and not well presented. Give me a few more days and Ill have it done. Trust me - I'm anxious to get it sorted cause I wanna use my pedal again.

I was looking at the CS-3 schem yesterday. There are similarities - in particular the sustain circuit. This should help.

Just hope we can make a sensible layout out of it so I can build a clone.

RyUK

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Re: DOD FX84 Milkbox Compressor

Postby cuthbertg » 20 Sep 2011, 22:20

ryanuk wrote:Guys - quick update - I am getting there with the Milk Box Schem. I had a couple of extra Res on the schem and had some fun tracking them down.

Is 90% complete but messy and not well presented. Give me a few more days and Ill have it done. Trust me - I'm anxious to get it sorted cause I wanna use my pedal again.

I was looking at the CS-3 schem yesterday. There are similarities - in particular the sustain circuit. This should help.

Just hope we can make a sensible layout out of it so I can build a clone.

RyUK


Looking forward to it - I had one of these when they came out but it got nicked a couple of weeks later :(
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Re: DOD FX84 Milkbox Compressor

Postby pedalgrinder » 21 Sep 2011, 05:43

Iam also keen on this one. Thanks for the effort you've put in on tracing this one much appreciated. I'll be keen on building one
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Re: DOD FX84 Milkbox Compressor

Postby ryanuk » 21 Sep 2011, 13:53

No worries guys. Hopefully I can spend some time on this today - at a push I might be able to finish it.

I spent a few minutes googling the pedal the other day. Its wierd. Whilst they were in production, they got such a bad rap (present company accepted). Now, everyone seems to be after one.

I've also been a fan though. I've got 2.

Compared it to a CS-3 which had for repair the other day. I prefer the DoD. Soooo much fatter sounding.

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Re: DOD FX84 Milkbox Compressor  [schematic]

Postby ryanuk » 28 Sep 2011, 09:25

Hi

Here's my V1 Milk Box Schem (FINALLY!! :P )

There still may be errors. I spent some time cross checking it against the original board but you never know. If anyone pots any errors lemme know and Ill correct it. Ill give it a few days but after that I'm gonna put my pedal back together so if you need me to check anything, speak up now.

You will see similarities in the compress section with the Boss CS3, however clearly there's an extra THAT IC. I hope someone can explain how this is being used.

Switching is the same as other DOD pedals.

I will be drafting a layout for this but not for a while so feel free if you have the time/energy.

RyUK
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Re: DOD FX84 Milkbox Compressor

Postby jstbrowsin » 28 Sep 2011, 12:02

Just had a quick squizz at your schematic and I have the very same board here but there is a bit of difference between my board and the schem.

Just quickly though as I haven't had a chance to study it properly and most probably won't be able for a while. Got lots of tech assignments and an amp to fix etc.


As you might be able to make out from my pic.

Q1 = 2N5088
Q4 = J201 (it was until I attacked the board for fets (please forgive me I didn't know what it was then and now I cry everytime I see it :cry: )
Q5 = J201
Q6 and Q7 = MPS4124

That's just a quick comparison though. If you need to know any more details values etc I'm willing to help as much as I can. If you like I could take a pic of the solder side for you. It a single layout anyhow. I really hope we get this done so I can piece back together my board also.

Anyway here's the pic. . .

Milkbox.JPG
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Re: DOD FX84 Milkbox Compressor

Postby ryanuk » 28 Sep 2011, 13:05

jstbrowsin wrote:Just had a quick squizz at your schematic and I have the very same board here but there is a bit of difference between my board and the schem.

Just quickly though as I haven't had a chance to study it properly and most probably won't be able for a while. Got lots of tech assignments and an amp to fix etc.


As you might be able to make out from my pic.

Q1 = 2N5088
Q4 = J201 (it was until I attacked the board for fets (please forgive me I didn't know what it was then and now I cry everytime I see it :cry: )
Q5 = J201
Q6 and Q7 = MPS4124

That's just a quick comparison though. If you need to know any more details values etc I'm willing to help as much as I can. If you like I could take a pic of the solder side for you. It a single layout anyhow. I really hope we get this done so I can piece back together my board also.

Anyway here's the pic. . .

Milkbox.JPG


Thanks for the pic but I cant see any difference between my board and the board you have. The 4 FETs are J201 (Q2-5), Q6 and Q7 = MPS4124 , and Q1 is a 2n5088.

I've quickly cross checked the values of the Rs between our respective PCBs and cant see any differences.

:hmmm:
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