Boss - CE-1 Chorus Ensemble  [schematic]

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.
User avatar
sinner
Old Solderhand
Information
Posts: 4709
Joined: 06 Nov 2008, 17:16
Location: ...no more
Has thanked: 1031 times
Been thanked: 909 times

Post by sinner »

No biggy ;-) actually im happy that i don't have to start all over B-) these files took my hell of a time to develope. There was no other replica that too that much of time to investigate. The sad part is I still know nothing about issue order or how many of revisions/versions was back then

User avatar
blackbunny
Resistor Ronker
Information
Posts: 372
Joined: 07 Jan 2011, 07:41
my favorite amplifier: Fender Blackface
Completed builds: Lots of mods to lots of pedals
Location: the garage
Has thanked: 270 times
Been thanked: 108 times

Post by blackbunny »

:secret: Actually, I found an "official" Boss CE-1 v2 schematic, and yours is identical, at least I haven't found any differences between them so far. :applause:

The output diode pairs are drawn as zeners, so I tested them and they are 15v zeners back to back. Static electricity protection for the JFETs buffering the L & R outputs, maybe?

User avatar
sinner
Old Solderhand
Information
Posts: 4709
Joined: 06 Nov 2008, 17:16
Location: ...no more
Has thanked: 1031 times
Been thanked: 909 times

Post by sinner »

im not sure actually what version was first. The one called v1 have no dides, nor that output resistors, and les parts around IC3 (input buffer? Boost section? I canit remember, i have no my pc with me today)

User avatar
blackbunny
Resistor Ronker
Information
Posts: 372
Joined: 07 Jan 2011, 07:41
my favorite amplifier: Fender Blackface
Completed builds: Lots of mods to lots of pedals
Location: the garage
Has thanked: 270 times
Been thanked: 108 times

Post by blackbunny »

sinner wrote:im not sure actually what version was first. The one called v1 have no dides, nor that output resistors, and les parts around IC3 (input buffer? Boost section? I canit remember, i have no my pc with me today)
Yes, no diodes or 470r series resistors, also different op amp types for input IC1 and IC3. First version has TA7504S and 2nd version has TA7136P op amps, which have extra resistors and capacitors for frequency compensation.

Here is the corrected image for the output diode locations, with board solder lug 1 as input, lug 5 as Left / mono out and lug 6 as Right output.
Attachments
CE-1 diodes_small.jpg

User avatar
sinner
Old Solderhand
Information
Posts: 4709
Joined: 06 Nov 2008, 17:16
Location: ...no more
Has thanked: 1031 times
Been thanked: 909 times

Post by sinner »

Cheers mate

Heres picture of so called v.1 schematic example ce1 board

Look at the space around ic3 - one resistor and two caps less, just empty spaces around of it. Thats why I think its later version really. It would be strange to create pads in early unit and not use it at all. Its just a theory, but quite logic

User avatar
sinner
Old Solderhand
Information
Posts: 4709
Joined: 06 Nov 2008, 17:16
Location: ...no more
Has thanked: 1031 times
Been thanked: 909 times

Post by sinner »

Dudes,

First of all, forgive me my spelling - I'm having new job, and I do massive hours recently - I can barely speak my native language :oops:

Anyway...

I decided to upload my replica files. It's early beta version (layout, and updated schematic corresponded to the one posted earlier). Far away from final version I'm going to make - lots of things undone (wiring, add-on diodes, only ones checked values and part numbers), but fine enough to make the conversation easier.

I wont post the final data before I get all needed parts (BBD, and clock, opamps, IC's), even if I get it done as I assumed

Hope it helps to drive the conversation to higher level anyway :)

BTW, the picture I showed in previous post shows more parts dropped off - look at the area around of IC1...

User avatar
sinner
Old Solderhand
Information
Posts: 4709
Joined: 06 Nov 2008, 17:16
Location: ...no more
Has thanked: 1031 times
Been thanked: 909 times

Post by sinner »

The colored pads and traces are the visual voltage dissipation - gray is ground, the rest of colors are explained at the schemo attached (look at the PS part)

User avatar
blackbunny
Resistor Ronker
Information
Posts: 372
Joined: 07 Jan 2011, 07:41
my favorite amplifier: Fender Blackface
Completed builds: Lots of mods to lots of pedals
Location: the garage
Has thanked: 270 times
Been thanked: 108 times

Post by blackbunny »

Your replica files are looking good mate. :applause: :applause: :applause: Joyo or Moen will probably have a CE-1 clone on the market in about 3 months from now. :blackeye

User avatar
sinner
Old Solderhand
Information
Posts: 4709
Joined: 06 Nov 2008, 17:16
Location: ...no more
Has thanked: 1031 times
Been thanked: 909 times

Post by sinner »

blackbunny wrote:Your replica files are looking good mate. :applause: :applause: :applause: Joyo or Moen will probably have a CE-1 clone on the market in about 3 months from now. :blackeye

I would prefer to see dual 512-stage cloned BBD's from coolaudio instead ;)

Blackbunny, could you take IC, and Q's voltages in spare time? It would be nice to have them from actual unit as a future service/troubleshooting data. As well as transformer secondaries reading pre and post rectifier diodes

User avatar
blackbunny
Resistor Ronker
Information
Posts: 372
Joined: 07 Jan 2011, 07:41
my favorite amplifier: Fender Blackface
Completed builds: Lots of mods to lots of pedals
Location: the garage
Has thanked: 270 times
Been thanked: 108 times

Post by blackbunny »

sinner wrote:Blackbunny, could you take IC, and Q's voltages in spare time? It would be nice to have them from actual unit as a future service/troubleshooting data. As well as transformer secondaries reading pre and post rectifier diodes
OK, no problem. We're having a few late night beers over here before bedtime. Will measure voltages tomorrow morning Aussie time...very carefully, probably feeling a bit shabby. Cheers, bb

User avatar
sinner
Old Solderhand
Information
Posts: 4709
Joined: 06 Nov 2008, 17:16
Location: ...no more
Has thanked: 1031 times
Been thanked: 909 times

Post by sinner »

Take your time, don't feel rushed

And remember to keep one hand in your pocket while munky around it ;-)

User avatar
Rude_Mechanical
Information
Posts: 12
Joined: 30 Nov 2009, 00:48
my favorite amplifier: Alembic F2-B pre / Fender TB600 head
Completed builds: BYOC Armstrong Twin - built with switchable bass mod
1976 EHX Big Muff pi (op-amp) - true bypass mod
Reissue EHX BassBalls - external trimpot mod
Ibanez PM-7 - repaired broken switch

On the bench for mods: Crybaby, Danelectro FAB Echo
Location: Brisbane, Australia
Been thanked: 1 time

Post by Rude_Mechanical »

Hey guys, picked one of these up the other day relatively cheaply (it's a US power model bought here in Australia). Looking to get rid of the external 240v-110v step-down transformer that it came with; does anybody know if the original transformer primary has a 240v tap (or near enough to do the job?). There's a blue lead on the primary that is capped and NC to anything. I'm REALLY hoping that's a 240v tap. Failing that, as I see it I have two options:

1) Replace the transformer for one with a 240v primary and +/- 18V secondaries.
2) Remove the transformer entirely and rewire a Boss-style jack to take an 18V AC adaptor.

I've done the latter for a Tubeworks Blue Tube, as there was no way I could find a 240v transformer that was going to fit in the case. That worked a treat, but the Blue Tube doesn't have a centre-tapped secondary, so I'm guessing that puts paid to that idea in this case.

Any help much appreciated, chaps.

Chris

User avatar
Rude_Mechanical
Information
Posts: 12
Joined: 30 Nov 2009, 00:48
my favorite amplifier: Alembic F2-B pre / Fender TB600 head
Completed builds: BYOC Armstrong Twin - built with switchable bass mod
1976 EHX Big Muff pi (op-amp) - true bypass mod
Reissue EHX BassBalls - external trimpot mod
Ibanez PM-7 - repaired broken switch

On the bench for mods: Crybaby, Danelectro FAB Echo
Location: Brisbane, Australia
Been thanked: 1 time

Post by Rude_Mechanical »

Bugger: I just answered part of my own question. The DM-1 bill of parts can be found here: http://www.synfo.nl/servicemanuals/Boss ... _NOTES.pdf

You'll note it has the same transformer, which is clearly marked as 100/117 V. On the plus side, I have a part number for the 240V version now.

So, while I'm tracking down an appropriate part, any suggestions for modding this to take an AC adaptor?

User avatar
blackbunny
Resistor Ronker
Information
Posts: 372
Joined: 07 Jan 2011, 07:41
my favorite amplifier: Fender Blackface
Completed builds: Lots of mods to lots of pedals
Location: the garage
Has thanked: 270 times
Been thanked: 108 times

Post by blackbunny »

You could measure up the existing transformer for size to see if there's enough space to fit an Altronics M2865L, which is available from their online store in Perth, W.A.

http://www.altronics.com.au/index.asp?a ... &sort=code

It would be much easier than trying to modify the pedal to take an external power supply.
Attachments
Altronics M2865L_18-0-18v.pdf
Altronics 18-0-18v 150 mA transformer
(23.49 KiB) Downloaded 181 times

User avatar
electrosonic
Breadboard Brother
Information
Posts: 130
Joined: 28 Nov 2008, 16:53
Location: Vancouver, BC
Has thanked: 27 times
Been thanked: 19 times

Post by electrosonic »

I got my CE-1 for cheap in a pawnshop years ago. The plug and transformer were the European style for 240 volts. (It was also painted black for some reason). I switch out the transformer and plug for use in North America. I think I used a Hammond transformer, I can check to see which one if anyone cares.

Andrew.

User avatar
Rude_Mechanical
Information
Posts: 12
Joined: 30 Nov 2009, 00:48
my favorite amplifier: Alembic F2-B pre / Fender TB600 head
Completed builds: BYOC Armstrong Twin - built with switchable bass mod
1976 EHX Big Muff pi (op-amp) - true bypass mod
Reissue EHX BassBalls - external trimpot mod
Ibanez PM-7 - repaired broken switch

On the bench for mods: Crybaby, Danelectro FAB Echo
Location: Brisbane, Australia
Been thanked: 1 time

Post by Rude_Mechanical »

Great work, blackbunny! The part you listed is about 4mm longer and 10mm wider - it will be a tight fit, but it _will_ fit. I think I even looked at that, but was put off by the incorrect product image.

Again: awesome :)

cheers - Chris

User avatar
armdnrdy1
Breadboard Brother
Information
Posts: 104
Joined: 07 Oct 2012, 00:11
Has thanked: 10 times
Been thanked: 67 times

Post by armdnrdy1 »

I would retrofit the power section to incorporate a 18vac wall adapter.

http://www.jameco.com/webapp/wcs/stores ... QgodjkcAaQ

With the proper filtering, an adequate bipolar supply can be designed from a half wave rectified, non center tapped AC source.


http://www.musicfromouterspace.com/anal ... SUPPLY.php

User avatar
Fender3D
Cap Cooler
Information
Posts: 573
Joined: 08 Aug 2009, 02:40
Location: Helltaly
Has thanked: 121 times
Been thanked: 153 times

Post by Fender3D »

This may be easier (9VAC wall adapter)...
PwrSpply.pdf
Power Supply 9VAC
(16.06 KiB) Downloaded 200 times

BTW
Larry:
did you loose your password? :slap:

User avatar
armdnrdy1
Breadboard Brother
Information
Posts: 104
Joined: 07 Oct 2012, 00:11
Has thanked: 10 times
Been thanked: 67 times

Post by armdnrdy1 »

Yes Federico,
I "lost" my password about a year ago! I couldn't log in so I had to re-register under armdnrdy1.
This circuit is originally powered with bipolar 13 & 14 volts but the 13 volts is only used at the input IC1 and Q1.

Retro-sonics version is powered by 9VDC and at first glance, I really don't see a charge pump. :hmmm:

I'll have to take a second glance.

User avatar
armdnrdy1
Breadboard Brother
Information
Posts: 104
Joined: 07 Oct 2012, 00:11
Has thanked: 10 times
Been thanked: 67 times

Post by armdnrdy1 »

Upon second glance,

I see a rectifier in one gut shot and a DC/DC converter in another.

Post Reply