ARP 1601 clone Build Thread

From circuitbending to homebrew stompboxes & synths, keep the DIY spirit alive!

Moderators: lisa, luketeaford, Kent, Joe.

Post Reply
User avatar
Kipling
Ultra Wiggler
Posts: 923
Joined: Tue Dec 10, 2013 3:31 pm
Location: South-East England

Re: Build questions

Post by Kipling » Fri Dec 13, 2019 5:07 pm

Robert Gerard wrote:Thanks, I was having trouble with the 250R (so I will use a 249R 1/2 W). Cool thanks the part was missing from the sythcube kit. Also missing was the 2nf cap and the L1 and L2 .
L1 and L2 are wire links with a small ferrite bead on each. We’re there any small black “tubes” in the parts? Not essential if not - you can just link them out.

Can’t recall where a 2nF cap goes. I haven’t got the circuit diagram handy.

Sorry, can’t help with the divider as I’ve not seen one, though I’m sure it got a mention somewhere in this thread.

User avatar
synthcube
you will be assimilated
Posts: 2052
Joined: Wed Dec 21, 2011 6:42 pm
Location: Boston

Post by synthcube » Sat Dec 14, 2019 11:09 am

hello folks- quick errata update (noted above)-- some early kits went out with incorrect R15/R25 sliders--- if you got the incorrect ones and need the correct ones please contact us via email! thank you

User avatar
synthcube
you will be assimilated
Posts: 2052
Joined: Wed Dec 21, 2011 6:42 pm
Location: Boston

Post by synthcube » Sat Dec 14, 2019 11:13 am

r0main wrote:Dear @synthcube, could we get the additional BOM for the divider section?
At least know which design it is based upon?
I have acquired all components for the main 1601 pcb via Dsl-man but the side pcb is still a mystery.
attached here is the divider bOM we use for kitting
You do not have the required permissions to view the files attached to this post.

Robert Gerard
Learning to Wiggle
Posts: 4
Joined: Tue Dec 03, 2019 12:06 pm
Location: Toronto

Divider

Post by Robert Gerard » Sat Dec 14, 2019 4:32 pm

synthcube wrote:
r0main wrote:Dear @synthcube, could we get the additional BOM for the divider section?
At least know which design it is based upon?
I have acquired all components for the main 1601 pcb via Dsl-man but the side pcb is still a mystery.
attached here is the divider bOM we use for kitting
I could not find C4 so I populated the cap into C5, also There are five diodes on the PCB so I added a fifth of the same type, the GIThub site also leaves D5 out?

Anybody know?

User avatar
synthcube
you will be assimilated
Posts: 2052
Joined: Wed Dec 21, 2011 6:42 pm
Location: Boston

Post by synthcube » Sat Dec 14, 2019 4:58 pm

These latest Divider PCBs are designed and made by JMLS, hopefully someone there will be able to confirm that detail

User avatar
Fitchie
Wiggling with Experience
Posts: 313
Joined: Sun Aug 30, 2015 1:49 pm

Re:

Post by Fitchie » Thu Jan 02, 2020 5:00 am

roglok wrote:
Sat Feb 11, 2017 8:02 am
Not sure if this was mentioned earlier, but I found that the pins of the 17 DPTT switches (46313LDRX) I received were long enough to snip them off horizontally, just below the eyelets. However, the pins on the other two types (50212LX and C46206LRX) require the treatment illustrated in the build docs.

For comparison - SW20 was double-cut like in the build docs, the others single-cut just below the eyelet:

Image

PS: I fond that the switches DPTT switches sometimes get stuck between two positions - does this happen to you, too?

I did order the switches with reference 46313LDRX, but it looks they do not fit at all.
Neither in the width nor in the length.

Reference:

Switches 1.png


Length:

Switches 2.png


Width:

Switches 3.png


Based on your photo, it seems that the pcb I received has different dimensions for the switches.
Does anyone have experience with this or experienced the same issue?

:eek:
You do not have the required permissions to view the files attached to this post.

Purveyor2
Common Wiggler
Posts: 209
Joined: Sun Aug 04, 2013 6:11 pm
Location: PDX

Re: ARP 1601 clone Build Thread

Post by Purveyor2 » Thu Jan 02, 2020 11:27 pm

Was I supposed to get the divider pcb with the pcb/panel? Or is it an extra item on synth cube site?

User avatar
synthcube
you will be assimilated
Posts: 2052
Joined: Wed Dec 21, 2011 6:42 pm
Location: Boston

Re: ARP 1601 clone Build Thread

Post by synthcube » Mon Jan 06, 2020 5:04 pm

Purveyor2 wrote:
Thu Jan 02, 2020 11:27 pm
Was I supposed to get the divider pcb with the pcb/panel? Or is it an extra item on synth cube site?
yes-- if you did not get it, please email us!

User avatar
synthcube
you will be assimilated
Posts: 2052
Joined: Wed Dec 21, 2011 6:42 pm
Location: Boston

Re: ARP 1601 clone Build Thread

Post by synthcube » Mon Jan 06, 2020 5:12 pm

latest synthCube kit BOM is v1.5 attached here as of 1/6/2020
1601 synthcube kit bom v1.5.pdf
You do not have the required permissions to view the files attached to this post.

User avatar
r0main
Learning to Wiggle
Posts: 47
Joined: Sat Jul 26, 2014 3:13 pm

Re: ARP 1601 clone Build Thread

Post by r0main » Tue Jan 07, 2020 5:37 am

Hi builders, I have troubles on the quantizer calibration step "A Offset & B Offset adjust", the lower voltages I can get are around 0.9v for both Quantized outputs. Any hint, tests?

Also I am getting squares up to about +15v at TP18, whereas +2v max is expected, as per the service manual...

[EDIT: Was a cold solder in the 0.1% resistors "array"]
Last edited by r0main on Sat Jan 18, 2020 1:54 pm, edited 1 time in total.

User avatar
synthcube
you will be assimilated
Posts: 2052
Joined: Wed Dec 21, 2011 6:42 pm
Location: Boston

Re: ARP 1601 clone Build Thread

Post by synthcube » Tue Jan 14, 2020 3:31 pm

updated bom v 1.5.6 as of 14 January 2020
also attached: divider PCB BOM as of the same date

1601 v5 divider pcb BOM.pdf
1601 v5 synthcube kit bom v1_5_6.pdf
You do not have the required permissions to view the files attached to this post.

User avatar
r0main
Learning to Wiggle
Posts: 47
Joined: Sat Jul 26, 2014 3:13 pm

Re: ARP 1601 clone Build Thread

Post by r0main » Sun Jan 19, 2020 12:29 pm

Is it me, or the screws Synthcube provided are way too short to fix wooden cheeks to the metal boat properly?
You do not have the required permissions to view the files attached to this post.

User avatar
synthcube
you will be assimilated
Posts: 2052
Joined: Wed Dec 21, 2011 6:42 pm
Location: Boston

Re: ARP 1601 clone Build Thread

Post by synthcube » Sun Jan 19, 2020 4:18 pm

hmmm... they appear to have shrunk during shipping :(

we do have the correct size screws here of course, so if you will email us we will get them replaced

User avatar
synthcube
you will be assimilated
Posts: 2052
Joined: Wed Dec 21, 2011 6:42 pm
Location: Boston

Re: ARP 1601 clone Build Thread

Post by synthcube » Sun Jan 19, 2020 4:19 pm

slight revisions to BOMs-- updated SKUs, etc

as of 1/19/2020

1601v5 Divider synthCube BOM 1_5_8.pdf
1601v5 Divider synthCube BOM 1_5_8.pdf
You do not have the required permissions to view the files attached to this post.

User avatar
Kipling
Ultra Wiggler
Posts: 923
Joined: Tue Dec 10, 2013 3:31 pm
Location: South-East England

Re: Re:

Post by Kipling » Thu Jan 23, 2020 2:23 pm

Fitchie wrote:
Thu Jan 02, 2020 5:00 am
roglok wrote:
Sat Feb 11, 2017 8:02 am
Not sure if this was mentioned earlier, but I found that the pins of the 17 DPTT switches (46313LDRX) I received were long enough to snip them off horizontally, just below the eyelets. However, the pins on the other two types (50212LX and C46206LRX) require the treatment illustrated in the build docs.

For comparison - SW20 was double-cut like in the build docs, the others single-cut just below the eyelet:


PS: I fond that the switches DPTT switches sometimes get stuck between two positions - does this happen to you, too?

I did order the switches with reference 46313LDRX, but it looks they do not fit at all.
Neither in the width nor in the length.


Based on your photo, it seems that the pcb I received has different dimensions for the switches.
Does anyone have experience with this or experienced the same issue?

:eek:
Sorry for the delay - the new Forum doesn't inform you of new posts it would seem.

It looks like you probably have a Rev 5 PCB (the latest revision revised by Jammie) which should have the CW switches instead of the NKK switches that you have. You will need 17 x G-628S-0001 (DP3T), 1 x GF-342-0037 (4PDT) and 2 x GF-326-0001 (DPDT) as per the recently posted BOM.

User avatar
FactoryDefault
Common Wiggler
Posts: 154
Joined: Tue Mar 29, 2016 12:37 pm

Re: ARP 1601 clone Build Thread

Post by FactoryDefault » Sun Jan 26, 2020 3:17 pm

sequencer bom update needed on line 46:

Keystone Electronics 5123 PCB COMPACT TEST POINT GRAY .063"

there should be quantity 22 of these. currently that line says quantity 1

User avatar
elmegil
Super Deluxe Wiggler
Posts: 2888
Joined: Sun Apr 29, 2012 2:57 pm
Location: Chicago

Re: ARP 1601 clone Build Thread

Post by elmegil » Sun Jan 26, 2020 3:33 pm

In the build I'm doing I just put the one in the ground, with the tought that my meter can hit those other holes just fine, but it's nice to clip the ground.

But yeah, if you were to cover all the possible test points + ground.....

Purveyor2
Common Wiggler
Posts: 209
Joined: Sun Aug 04, 2013 6:11 pm
Location: PDX

Re: ARP 1601 clone Build Thread

Post by Purveyor2 » Sun Jan 26, 2020 7:35 pm

Got the divider built and installed. Very cool additional functionality, thanks for adding synthcube!

User avatar
FactoryDefault
Common Wiggler
Posts: 154
Joined: Tue Mar 29, 2016 12:37 pm

Re: ARP 1601 clone Build Thread

Post by FactoryDefault » Sun Jan 26, 2020 11:02 pm

elmegil wrote:
Sun Jan 26, 2020 3:33 pm
In the build I'm doing I just put the one in the ground, with the tought that my meter can hit those other holes just fine, but it's nice to clip the ground.

But yeah, if you were to cover all the possible test points + ground.....
Yeah I just made some out of component legs but it looks sexier with proper test points.

The original BOM had 22 test points...

User avatar
elmegil
Super Deluxe Wiggler
Posts: 2888
Joined: Sun Apr 29, 2012 2:57 pm
Location: Chicago

Re: ARP 1601 clone Build Thread

Post by elmegil » Sun Jan 26, 2020 11:35 pm

Yes I don't disagree that per the spec they should all have it, just suggesting how I worked around the lack :)

User avatar
solar1
Learning to Wiggle
Posts: 41
Joined: Fri Jul 31, 2015 5:14 pm
Location: USA

Re: ARP 1601 clone Build Thread

Post by solar1 » Mon Jan 27, 2020 12:42 am

Hello Folks, I finally got around to building my 1601 Rev 3 board.
Many thanks once again to Kipling and jhunk for this fine project.

The unit calibrated fine and appears to be completely operational, although I must admit, I have ran not thru every function yet.

One thing I noticed is the output from both Quantizer's A and B seem to have a very slight "glide" or "droop" at every step.
This is not present at the non-quantized sequencer outputs A and B. Clocking speed makes no difference.

I'm not a technician be any means so I'm hoping someone here can chime in.
I'm assuming this is not correct operation.

Seeing that the circuit utilizes some type of memory/sample circuit, I expect maybe there is a component value issue?
Any suggested items to check would be appreciated.
Thanks

User avatar
elmegil
Super Deluxe Wiggler
Posts: 2888
Joined: Sun Apr 29, 2012 2:57 pm
Location: Chicago

Re: ARP 1601 clone Build Thread

Post by elmegil » Mon Jan 27, 2020 12:53 am

C30 and C31 are the hold caps for the quantized output memory sections, A & B respectively.

Supposed to be 5nF (5000pF is a more common marking for this type of cap) per the service manual.

They're the two Polystyrene caps on the left of the board as you're looking at the back of the mounted PCB (I'm referring to v5, if you have an earlier one, I'm not sure entirely where they would be, but they're the only two polystyrenes).

It is worth noting that polystyrene caps are VERY heat sensitive, and I've seen some builds of other modules using them actually melt the caps -- if this is the case it will be visually pretty obvious.

Other parts relevant to this are the 10K resistors R202 & R203, Z30 (part of a CD4016 before the caps) and Z32 & Z33 both of which are CD4007's.

All these chips and things are in the same vicinity as the caps on a v5 board.

I suppose other things in the Output Selector section (before the cap) could also be misbehaving.

Have you checked all the test points for good outputs (see the service manual for an extensive table)? Test Points 18 & 20 seem most relevant.

Hope this helps....

User avatar
solar1
Learning to Wiggle
Posts: 41
Joined: Fri Jul 31, 2015 5:14 pm
Location: USA

Re: ARP 1601 clone Build Thread

Post by solar1 » Mon Jan 27, 2020 11:22 am

thanks.

I don't have any spare ic's to test swap at the moment, but I did visually inspect the chips/sockets/soldering etc. and all looks ok.
I check resistor values.
I did check the caps for visual damage and found none.
today I will put the scop on the test points to see if anything looks off.

I will also check the c30 and c31 values.

Edit: I am missing sliders at position 1 & 2 doe to bad sliders found in my set, but I did set the step position to 3/10, and checked the scope...waveforms exactly as in the test point illustrations in the service manual.

Also, in checking operation, I have found that the start/stop switch is not working. Although I don't have the pedal jack yet connected, I did short the tip to ground and still not working, so I also have a problem there as well.
Last edited by solar1 on Mon Jan 27, 2020 11:53 am, edited 1 time in total.

User avatar
elmegil
Super Deluxe Wiggler
Posts: 2888
Joined: Sun Apr 29, 2012 2:57 pm
Location: Chicago

Re: ARP 1601 clone Build Thread

Post by elmegil » Mon Jan 27, 2020 11:52 am

Re: Start/Stop switch -- do you have the footswitch jack wired? If not, you need to short the footswitch header. If so, double check that it's correct. When nothing is plugged in, it should be shorting the tip to ground via the tip switch.

User avatar
solar1
Learning to Wiggle
Posts: 41
Joined: Fri Jul 31, 2015 5:14 pm
Location: USA

Re: ARP 1601 clone Build Thread

Post by solar1 » Mon Jan 27, 2020 11:59 am

No foot switch jack wired, so I shorted the footswitch header pins with no affect. Unit sequences immediately upon power up if in gate position; is switched to trigger, sequence stops. Start stop switch has no effect. Checked switch; it is good.

Post Reply

Return to “Music Tech DIY”