ARP2600 full size

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jhulk
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ARP2600 full size

Post by jhulk » Thu Jan 19, 2017 7:43 am

ok as you know im doing full size pcbs and modules so that they can be used in original arp2600/ and expander single versions of the modules.

need a ideas on what you want from this

1: keep totally original layout exact replica.

2: 3x vco2 with ringmod both sine osc waveforms. extra filter pcb with different filter and cv resonance this will make the unit about 200mm wider.

3: colours whats your preference. white black screen print/blue white marvin/grey meanie/red devil red white screen/black orange and white screen.

more details to follow as i release the pictures of the process.

ok im going to add pictures of original module and the new versionImage
Image
Image
Imagethis is the noise module

its just over 1" square in size and can be fitted to either the front or back of the bd 5-1

HERE IS THE 1339 DOA FOR MY PERSONAL VERSION WHICH IM DOING FULLY DISCRETE

Image
Image

more to follow

led-man found a nice multiturn trimmer in a low size thickness package.

as im doing the pcbs as original for original users and owners of the arp synth so they can repair or replace boards.

so they use the cts thumb trimmers these a single turn not very accurate trimmers i have created a conversion pcb for the new version and old version so that they can be used to replace them with multiturn types.

in this case the 3339p by bournes they can also be used in moogs and all arp synth range and the aries modular that uses them.

Image
Image

these will be sent to fab house this week
Last edited by jhulk on Mon Jan 23, 2017 12:50 pm, edited 4 times in total.

RadekTymecki
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Post by RadekTymecki » Thu Jan 19, 2017 7:51 am

i was thinking about 4 waveforms on vco1, selectable vcf, sync

jhulk
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Post by jhulk » Thu Jan 19, 2017 7:58 am

there is sync i/o on each oscillator at top of panel

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Jaytee
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Post by Jaytee » Thu Jan 19, 2017 10:07 am

Ok, I just bought a TTSH, so I'm not personally in the market for a 2600 clone and as such, my opinion shouldn't count as much as the folks who are actually going to buy from you.

That said, I would vote to keep the clone a clone and keep extra features to an absolute minimum. Sure, there are some design choices that strike one as odd—the only oscillator with pulse width is also the only oscillator that can do a sine/tri LFO, as you point out—but the 2600 is what it is and we love it, warts and all.

The way I see it, if you're already interested in tweaking stuff, just go for modules from the beginning. If you want an ARP 2600, you want an ARP 2600.

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monno
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Post by monno » Thu Jan 19, 2017 10:22 am

My personal preference would be for straight up clone. It would not hurt if extra features could be added, but not at the expense of it being a 1:1 kinda deal. As for color scheme? I am not attached to anything in particular. I´ll go with the flow on that one. Despite just having finished a TTSH, this is something i could see myself building for sure!!! I am looking forward to getting more info on this in the future.

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Post by NekoNeko » Thu Jan 19, 2017 10:27 am

Maybe keep the layout the same so you can use the new boards as drop in replacements for original 2600's.

Any mods can be put on a daughter board.

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tobb
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Post by tobb » Thu Jan 19, 2017 10:34 am

NekoNeko wrote:Maybe keep the layout the same so you can use the new boards as drop in replacements for original 2600's.

Any mods can be put on a daughter board.
dito

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Post by Altitude909 » Thu Jan 19, 2017 10:41 am

tobb wrote:
NekoNeko wrote:Maybe keep the layout the same so you can use the new boards as drop in replacements for original 2600's.

Any mods can be put on a daughter board.
dito
thirded

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MrRoper
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Post by MrRoper » Thu Jan 19, 2017 10:42 am

NekoNeko wrote:Maybe keep the layout the same so you can use the new boards as drop in replacements for original 2600's.

Any mods can be put on a daughter board.
I agree with this, only real thing I would want different from a stock 2600 would be a gate booster. Maybe there could be headers on the main board where daughter boards would need to connect to to implement the mods? No cutting of traces (if possible) would be great!

As for colour mine would be (in order of preference)

1. Black on white
2. Grey Meanie
3. Black/ Orange
4. Blue Marvin
5. Red

You could definitely count me in for one each of the first 3!

Amazing work Jammie, really can't wait to see this come to fruition mate! :hail: :hail:

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Post by jhulk » Thu Jan 19, 2017 11:22 am

all layouts are original so they can be used for original arp2600

the oscillator boards i have done the 3x version and also broke them in to single versions for the expansion range.

the only differ in that there are foot prints for the 142a jacks for sync i/o and the associated circuits for the sync function it has input and out put for each oscillator so you can sync it any way you like.

all original foot prints if it has can 08 opamps then the new pcb does.

the only thing different is dc offset trimmers. and by pass caps which i have done as smd

but if through hole are preferred then i can do dual foot prints.

there are adapter boards to replace the cts thumb trimmers these can be used on old arp2600 to allow multi trimmers to be used.

the foot print for the tz81/581 are ecb the replacements 3904/6 are ebc

so for available ecb types the 2n5172 and the 2n6076 ill keep the same but have re-routed for 3904/6 foot prints which makes the new potted module boards 2 layer had to use the top layer to change the foot print.

have made conversion boards to fit the foot prints for using the matched smd 3904 pairs and the complementary pairs. if you dont want to match.
with foot print for tempco. on the complimentary pair.

done a doa of the 1339 audio opamp if you want to use that in the vca filter and the spring delay circuits like original.

mta100 headers for the interconnections of the normalised connections.

the original is a night mare to service because its hard wired so if you need to remove the board for service you have to either cut them or desolder them. on this version i cut them and fitted headers and dupont pin sockets.
on the new version i fitted mta100 dual headers so that you can fit a dual socket and using screened cables for inter connects making it easy for service. all the pcbs are singles so you only need to remove the pcb you require to service unlike the ttsh which you have to remove every jack nut to get at it.

option for either 4027 oscillators or the 4027-1 the 4027 require an extra trimmer which is provided on the 2601/2 oscillator boards later revision pcbs that went to the 4027-1 omitted them. they are provided on my version to accommodate both types.

this is for the owners who have defunct 4027 oscillators.

the pcbs have psu headers for each part the sample and hold and noise and speaker board has 3 connections. will use a new psu with external power brick.

foot prints for original sliders or a conversion board to use equivalent sliders.

option for original knobs or led sliders if using trhe conversion boards with the circuits for led sliders it has its own power headers and will have a dedicated psu just for that to keep it separate from the psu for the arp circuits. keep current noise away from the arp circuits.

expansion board for different filter types add-ons.
Last edited by jhulk on Fri Jan 20, 2017 8:17 am, edited 1 time in total.

jhulk
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Post by jhulk » Thu Jan 19, 2017 11:30 am

gate booster board need the foot print for it and the connections will add mill max socket connections to the pcb so you can plug it in just like any other of the potted modules.

this allows easy removal and insertion unlike the original that only soldered to the bottom pcb traces and pads because there was no through hole via the traces could lift

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Post by MrRoper » Thu Jan 19, 2017 12:31 pm

jhulk wrote:gate booster board need the foot print for it and the connections will add mill max socket connections to the pcb so you can plug it in just like any other of the potted modules.

this allows easy removal and insertion unlike the original that only soldered to the bottom pcb traces and pads because there was no through hole via the traces could lift
I have a couple of the gatebooster with added midi implant boards knocking around so if you want I can send you one or just bring it with me next week?

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Post by jhulk » Thu Jan 19, 2017 12:49 pm

ok great ill use to add the foot print to the correct board i take it fits to the vca envelope board.

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Post by fuzzbass » Thu Jan 19, 2017 1:48 pm

jhulk wrote:ok great ill use to add the foot print to the correct board i take it fits to the vca envelope board.
I would sure like it, but would not demand it, that a booster footprint fit my booster :) I'll even send you samples. Willing to color coordinate solder mask colors! :hihi:

I'm not sure if I'm in on this yet, and you would have to put me firmly in the TTSH camp. But if I were to make recommendations:

1. Start the design with the sliders. Find some that are ruggedly constructed, reasonably priced, available retail, and supporting slider knobs that are also reasonably priced and available retail. Or else, source what you use, provide with the kit, and be ready for all kinds of replacement parts inquiries.

2. Blue Marvin panel / steel case / wooden handle. I'd buy that.

3. Find an alternative to the UJT, rarest of the rares in the TTSH.

4. Speakers - don't go oval. Spec ones that have concave surrounds, and mount directly to panel. Avoid grilling the panel such that perforations are outside of the speaker's frame. Way-out idea: skip the speakers and put a consumer audio connection so a sound bar can be placed atop.

5. Use board mount, not panel mount jacks. Use spacers and screws, not jacks, to secure boards to the panel. Use spacers and screws, not headers, to support your secondary boards (if any).

6. Multi-turn trimmers for VCO/VCF frequency and 1V/Oct adjustment.
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jhulk
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Post by jhulk » Thu Jan 19, 2017 2:08 pm

can fit a line balanced audio output through some sowter traffos

the speakers will be panel mount like original

jhulk
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Post by jhulk » Thu Jan 19, 2017 2:11 pm

yep multiturn trimmers as they use the cts thumb adjustable trimmer on the original i have made conversion boards so that multiturns can be used on new and old arp2600.

i made them for minimoogs and the aries modular

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Post by jhulk » Thu Jan 19, 2017 2:21 pm

which ujt is that

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tobb
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Post by tobb » Thu Jan 19, 2017 2:56 pm

wow,this is a cool project.

I have 3 ARP's 2600

looking forward to built me an expander cabinet with several extra osc's etc. in the same look/size

:goo:

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discop
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Post by discop » Thu Jan 19, 2017 5:07 pm

I'd say stick to the original as much as possible.

Can't wait.

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Post by Jarno » Thu Jan 19, 2017 5:07 pm

Nice project! Keen on seeing it.

Wrt the UJT, can you use a different UJT there? Or a PUT?

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Post by fuzzbass » Thu Jan 19, 2017 5:41 pm

jhulk wrote:which ujt is that
2N4870, starting to get silly prices on ebay. I'm all set with these, but others might be having trouble finding a trusted source.
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jhulk
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Post by jhulk » Thu Jan 19, 2017 6:26 pm

NTE6410 is nte replacement

you can get the 2n4870 for a little as $1

the nte part is $2.75

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Post by GryphonP3 » Thu Jan 19, 2017 9:21 pm

Fix PWM and sine/tri only being available on the same VCO! Swirchable filters like on the new TTSH and hard sync would be great.
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Post by diablojoy » Fri Jan 20, 2017 1:11 am

the oscillator boards i have done the 3x version and also broke them in to single versions for the expansion range.
option for original knobs or led sliders if using trhe conversion boards with the circuits for led sliders it has its own power headers and will have a dedicated psu just for that to keep it separate from the psu for the arp circuits. keep current noise away from the arp circuits.
Hope I am reading this right and will be able to get 3 x single oscillator boards with LED sliders - aiming to expand my TTSH

if so :yay: :tu:
It probably wont happen today but if it does it definitely wont go smoothly.

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Post by ultravox » Fri Jan 20, 2017 5:11 am

I already have a full stable of TTSH's and I may not have a place for a full-size 2600. That said, I'm following this with interest and looking forward to seeing the prototype!

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