Help with Boss Ce 1 Clone Build

[njkmonty]

i have my MN3002 chip ready to go, board  etched, but was looking at getting +15 & -15v   a little differently, just wondering if someone can confirm what im suggesting as a temporary  work around.

instead or finding obsolete parts  i was thinking of using a regulated 15v  and surge pump  but wasnt sure if it is a matter of just taking it onto the equivalent spot etc.  as i didn't want to have 230v and fusees etc inside  it , and comments would be appreciated!

[armdnrdy]

I'm sure that you noticed the +/- 13V and the +/-14 volts that exists in the original.

Feeding the circuit +/-15V  would probably make a difference in the clock frequency.

You could get the +/- 14V by swapping the LM7815 & LM7915 regulators for adjustable regs. LM317 & LM337.

Here's another easy way to get a bipolar supply without mains voltage and a transformer in your enclosure.
You don't have to go crazy with all of the huge filter caps.
http://musicfromouterspace.com/analogsynth_new/WALLWARTSUPPLY/WALLWARTSUPPLY.php

[Fender3D]

I wouldn't use charge pumps in circuits with HF clock, they're prone to heterodyne.
A proper PCB layout may be more difficult than scoring those rare BBDs...

Use the schematic Larry suggested, or check Alesis microwhatever PSUs

[Mark Hammer]

I'm sure that you noticed the +/- 13V and the +/-14 volts that exists in the original.

Feeding the circuit +/-15V  would probably make a difference in the clock frequency.

You could get the +/- 14V by swapping the LM7815 & LM7915 regulators for adjustable regs. LM317 & LM337.

Here's another easy way to get a bipolar supply without mains voltage and a transformer in your enclosure.
You don't have to go crazy with all of the huge filter caps.
http://musicfromouterspace.com/analogsynth_new/WALLWARTSUPPLY/WALLWARTSUPPLY.php

Nah, just stick whatever 1N4xxx diodes you have/need in series with +15/-15 to drop the supply voltage appropriately.

[njkmonty]

I have made some progress with my ce 1 build and i thought i would share some of my experiences and ask a few more questions..

I managed to populate the pcb, however didn't have any of the power transistors etc in the power section.
without being patient and excited to fire it up, i against advice  quickly made bipolar 15v supply using a surge pump. (schematic i previously posted earlier).
I was ready to add a heap of 4007 power piodes to reduce the voltage, however once it was connected up it was putting out quite close to the 14v.

after stuffying around with transistor orientations, I managed to get it work quite nicely, however i was having trouble with the 3 x 2sk30a  devices working.

Q11,12 &13 were all asking for 2sk30

after reading online i managed to get j201 working perfectly for the switching component q11 and q12.  however the j201 was behaving weird for q12

then i had a closer look and im not that sure but it looked like an inverted signal was going to q12 to rejoin the wet signal??  im not sure , but j201, 2sk30a all had a tempory gated weird effect which sounded unpleasant . i then tried a 2n5457  and   then it worked perfectly!.

i tried it on mono and on stereo amp setup and sounded very nice, couple of questions...

what is q12's role?on ce 2 builds ive done before  you could change ceramic cap values around the clock chip to slighlty change delay length from memory.  is there any quick mods for this on the ce 1 ? changing c18, 19,21,20??

i was looking to have a switch to make it "stock" and "true bypass", also maybe some small other mods which can be switched in and out. so far im quite happy (and sounded great even with the surge pump!)

btw i used  1n4148  instead of 1s1555 diodes
2 x ta7135p
lm1458n ic
2 x 2sa493
3 x 2sa733
subbed 4 x 2sc900 for .. 2sc536

also finally i  remember on my other ada flanger and other modulation builds changing the value of an electrolytic cap can change the rate of the lfo, does that apply to the ce 1s lfo if so is that c35 and c34?

[DrAlx]

Have you drawn the LFO and switches correctly? As it stands I can't see how it works.  An oscillator needs positive feedback, and IC4a has that, but in vibrato mode it is not used and IC4b doesn't appear to have positive feedback on its own (unless there is some phase change or inversion that I can't see). So I don't see how the vibrato mode works. In chorus mode the only cap that matters is C43. The two opamps are then configured as square/triangle oscillator.

[DrAlx]

OK I think I get it. The vibrato section is a phase shift oscillator (but not like I've seen before). The rate is determined by C34,C35 and all the other resistors that precede them. So changing any of those affects the rate in vibrato mode.

[njkmonty]

After a couple of requests here is  a video of my mostly finished ce 1 clone.
Its in a temporary enclosure and rats nest will be neatened etc once i find the right enclosure.
It draws between 180-220 milliamps pending which channel used.

i forgot to mirror the pcb image also before etching hence the copper side on the component side!

there is also a schematic of what i used prior to doing depth mod. ( which is quite simple)

the video is still uploading so it should be ready in about an hour

[njkmonty]

youtube video working now

[daz061]

I'm sure that you noticed the +/- 13V and the +/-14 volts that exists in the original.

Feeding the circuit +/-15V  would probably make a difference in the clock frequency.

You could get the +/- 14V by swapping the LM7815 & LM7915 regulators for adjustable regs. LM317 & LM337.

Here's another easy way to get a bipolar supply without mains voltage and a transformer in your enclosure.
You don't have to go crazy with all of the huge filter caps.
http://musicfromouterspace.com/analogsynth_new/WALLWARTSUPPLY/WALLWARTSUPPLY.php

If you supplied it with 15v and it did alter the clock frequency can't it just be altered using the trim pot that is in the circuit

[armdnrdy]

If you supplied it with 15v and it did alter the clock frequency can't it just be altered using the trim pot that is in the circuit

The answer in this case is no. The trimpot you are referring to adjusts the BBD balance.
There is no adjustment for the clock. The CE-1 uses a discrete multivibrator circuit for the BBD clock.

[njkmonty]

would it be difficult to modify the clock circuit to run a mn3007?

[njkmonty]

WoW!!!

i just thought i would try  (not expecting anything at all)  to put a MN3007 chip into the Mn3002 socket instead.

It actually works and too my surprise it sound quite close  but just obvious enough that the clock needs some modification.

im so happy with it with the mn3007  that i believe it would quite possible doing a "moosapotomus" style MN3007 Ce-1 conversion , enough so that i would consider doing a layout in eagle for it.!

the only thing is that i am not knowledgeable enough to make mods to the clock component of the circuit.

can post a video if anyone interested in the ce-1 with 2 different  delay chips?

[daz061]

Sure

[armdnrdy]

WoW!!!

i just thought i would try  (not expecting anything at all)  to put a MN3007 chip into the Mn3002 socket instead.

It may "work" but....
You are connecting the 3007 ground pin (pin 1) to the VBB voltage needed by the MN3002.
Also...the general consensus was that when the MN3007 (1024 stages ) was "over clocked" to resemble a 512 stage BBD...it sounded different.
There was a noticeable frequency loss...even when buffered.
BBD ICs are designed to perform optimally at certain frequency parameters.
You can run them at a higher frequency but...there is a trade off...quality of sound.

[njkmonty]

attention daz061    by request!

quick video to show ce 1 boss clone working on 9v x2 surge pumps

ie 9v --  bipolar voltages for ce 1

[njkmonty]

From: daz061
ok cool thanks,

ok cool thanks,

are the diodes necessary then or can it just be connected like so.

you can do it without the diodes, they just slightly reduce the voltage, remembering the schematic want +/- 14v

(but that is the voltages under load.
what i did was make 3 series diodes each side and used alligator clips to temp connect , then i measured the voltages at (+14v) and (-14v)  and kept the ones which were closest to the required voltage.

but to be honest sonically i couldn't even tell the difference when it was connected directly to 15=+/-      , i just wanted to make it as close to spec
if you want the exact schematic of what i did for the 2 surge pumps let me know and will draw it up

[njkmonty]

[RLawlor]

Sorry if this is a stupid question, but what is the voltage rating of the zener diode at D4 njkmonty? Using the surge pumps would be amazing for a clone.

[njkmonty]

i just cut and pasted from another madbean layout.  from memory i used a 1watt zener,  (im not even sure its totally necessary)
either
1N4739A 1N4739 ZENER DIODE 9.1V 1W

1N4738 ZENER DIODE 1W 8.2V

i dont think we are going down the dual surge pump route, as it apparently can be done with just one, however we look like we are heading down a more compacted footprint path (see link)

http://www.diystompboxes.com/smfforum/index.php?topic=119236.0