Boss - DM-2 Delay  [schematic]

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.
analogguru
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Post by analogguru »

People like guts? ok, here are some others from our japanese hackerfriends (click on the pictures for high resolution):

Boss DM-2 guts

enjoy,
analogguru
Last edited by analogguru on 29 Jun 2007, 22:39, edited 1 time in total.
There´s a sucker born every minute - and too many of them end up in the bootweak pedal biz.

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bajaman
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Post by bajaman »

Hi AG
I have heaps of ROLAND /BOSS schems from this era - let me know if you want any in particular
Steve

hgamal
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Post by hgamal »

I looking for some internal photos from BOSS DM-2, mainly the copper circuit side.

Can anybody help me?

andre
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Post by andre »

There's a good picture of the copperside here:
http://www.bossarea.com/

At this moment however, the website appears to be down.

If you're planning to clone the PCB, you can save yourself the trouble because
I recently succesfully cloned the DM-2.
Since my PCB is an almost exact copy of the original, I don't want to post it,
but I can mail it to you if you want to.

André

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Post by hgamal »

I have a board design already, but I want to see yours... Please send it to my e-mail: xxxxxxxxxxxxxxxxxxxxx
I have one doubt about MN 3005 operation. Its datasheet states the power supply voltage is something about -15 or -14 Volts (it is designed to be used with positive ground), but the DM-2 is designed to be operated using 9 V batteries. As in the service manual there is the word "selected" when it mention the MN 3005, I would like to know if can any MN3005 to be operated with only 9 volts? Does exist an special version of the MN 3005? (not the MN-3205 which is negative ground)

Did you use the DM-2 MN3005 circuit? or does yours use the MN3205 chip?

Is there any other opinions?

andre
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my favorite amplifier: Hughes & Kettner Statesman Quad
Completed builds: Dist + overdr.: Distortion+, BSIABII, Shaka III, Bluesbreaker, Box of Rock, Highway 89, DS-1, Proce Rat, Omnidrive, TS808, Bluemagic, Fulldrive 2, big muff
Delay: DM-2, Rebote 2.5, PT-80
Modulation: Ross Phaser, Small Clone, CE-2, Zombie chorus, FL-301, Easyvibe, Ultraflanger
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Post by andre »

Haroldo,
I will sent my PCB design later today.
It's on another computer than the one I'm writing this reply on.

I can show you a picture of the parts side though:
Image

I did use an MN3005. This design would not work without it.
What they did is just reversing the MN3005 and MN3101's power connections and some other changes.

The MN3005's were "Selected" on minimal distortion at 9V.
I only tried 1 MN3005, and it sounds good to me, although I have a couple of them lying around.

André

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Post by kidblue »

Hello André

I'm planning to clone the DM-2.I found PCB on japanese website
http://wlst.jp/effector/dm-2/DM-2.pdf

website says some people reported that DM2 does not do a self-oscillation.

I'd love to build your version to save myself the trouble.

when you have a moment could you possibly send PCB to my e-mail:xxxxxxxxxxxx
sorry for my broken english.

kidblue

elfo106
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Post by elfo106 »

maybe i try this one later

thanks

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Post by hgamal »

bajaman wrote:Hi AG
I have heaps of ROLAND /BOSS schems from this era - let me know if you want any in particular
Steve
do you have the DM-2 schematics/service manual using 3205?

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Post by miwanone »

I'd love to have this PCB! Could you email me at daanvanhasseltxxxxxxxxxxxxxx thanks a lot! :D

TXEMA
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Post by TXEMA »

Hello
I would build a DM2.
Can any of you send me the PCB to txemasred@teeeees?

tambey
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Post by tambey »

Please, me too. Send it to zulkifleo@

guiteff
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Post by guiteff »

Please, me too. Send it to guiteff@xxxxxxxxxx

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Post by MOSFETapocalypse »

http://revivalelectric.tumblr.com/post/ ... -schematic

Hi All,

I have a copy of the service manual, hope it helps!

Feel free to email me for a copy, travis@xxxxxxxxxxx

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Dirk_Hendrik
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Post by Dirk_Hendrik »

Hold it,

With all blind horny requests for that layout by (mostly) first time posters,
Does thhat mean that in the near future there will be a whole new generation of DM builders which is finding out the MN3005 is a) impossible to obtain and b) all those chips seen in ebay adds happen to be fake?
Sorry. Plain out of planes.

http://www.dirk-hendrik.com

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Post by jrc4558 »

can i possibly too have the pcb? thank you muchly!

jrc4558@xxxxxxxxxxxx

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Post by modman »

I was almost going to say that DH spoiled all the fun, but dem deaf it seems...
To everybody in this thread:
Don't post your email on the forum!
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harpplayer
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Post by harpplayer »

Hello!

I just built my DM-2 (actually, I am still waiting for the MN3005 and NE570 to arrive), and I am getting a slightly lower volume with the effect engaged (more like a small bass boost and treble/bright cut)

From the schematic, I don´t think the lack of IC´s in the delayed bit is responsible for it, since I am just cutting the connection between the direct signal and the effect per se input. I´ll probably have to mess with the capacitors around the opamp, but I am not sure which one.

I tried to lower the resistor (47k) just before the op amp´s second input, and I could even the bypassed and engaged volumes, but it is not quite right - it gets too mellow on the effect side.

Anyone have a clue on which cap should I mess with? I guess the input cap can remove some bass content, but it won´t help bringing back the bright freq´s.

Thanks very much!
André

meursault42
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Post by meursault42 »

I have a Boss DM-2 (MN3005 chip) that is in need of calibration. I have a copy of the calibration instructions as well as supplementary instructions from Boss expert Laurie Streitberg. All I need is someone with the willingness, the gear (sine wave generator and scope), and the savvy. I'd also like to avoid spending outrageous bench fees if at all possible ;)

Anyone want to take a crack at it or know someone who might? Drop me a line!

Thanks! :)

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Zokk
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Post by Zokk »

Hi
why don't you go with software stuff like that:
http://www.sillanumsoft.org/

there are also many simple softs which can produce basic waveforms which can do their job quite well.

Cheers
Z.

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