hi guys,

i'm still new to drawing up layouts and a friend asked me to make him a digital reverb, so i thought i'd at least try making a layout for my own use, as there don't seem to be any for any non-Belton digiverbs. so i was wondering if maybe someone could take the time to have a look at this strip/veroboard layout for Merlin's Solstice and see if maybe there's something you spot that i haven't? it'd be really appreciated, although i understand it might be a tall/annoying order.

a few points: i've gotten into the habit of grounding both pins 3 & 4 of PT2399s just in case the internal link failed (as they sometimes seem to). as this isn't in the Solstice schematic, should i just omit the link? the Little Angel Chorus is an example of where i've seen pins 3 & 4 joined together. also, i've inferred from posts that the 78L05 is even more temperamental in this circuit than single-PT ones - should i go for the 7805? it'd be harder to score one (the whole "shipping for one part" dilemma),  but needs must. lastly, would an MPF102 for the JFET be ok?

i get really confused when checking over this stuff, and it's late at night, so there may be some really stupid errors. possibly some forgotten trace cuts. DIY Layout Creator only has an oversized trimpot graphic, i'd be using the small, round ones. i'll shut up now:



thanks if anyone goes for it! schematic and parts list are here: http://www.freewebs.com/valvewizard2/solstice.PDF (3rd & 4th pages, respectively)

Are 3 & 4 Dground and Aground pins?
If so
Different chips have them linked via internal resistor, some don't - best practice would be assume not and link.

Quote from: mistahead on August 20, 2013, 12:28:40 AM
Are 3 & 4 Dground and Aground pins?

they are indeed. it's all down to the insane amount of variation between PT2399s - some counterfeit, some bad batches.. in my own experience, linking em brought some chips back to life. as i mentioned, the Little Angel has them connected permanently - maybe i should look up reports about that, as most of the stuff i've read about PT lockups etc. was focused around the Small Time Delay circuit.

i see where you're coming from... it's a bit of a catch-22, either way could count as better safe than sorry!

i'm going through it just now - have only spotted a few minor errors (i hope...) so far.

i'm a bit concerned about this - is this an okay way to connect R15/16 with R17? just unsure as it passes through the PT2399 in a different way from the schem:

Quote from: MrStab on August 21, 2013, 09:30:01 PMi'm going through it just now - have only spotted a few minor errors (i hope...) so far.

i'm a bit concerned about this - is this an okay way to connect R15/16 with R17? just unsure as it passes through the PT2399 in a different way from the schem:

The junction of r16 and 17 should hit pin 15 of the 2399., You have them on pin 16. The junction of r15 and C9 should hit pin 16 you have them on 15

Also you do not have pin 14 and 13 linked

Quote from: pappasmurfsharem on August 21, 2013, 11:49:12 PM
The junction of r16 and 17 should hit pin 15 of the 2399., You have them on pin 16. The junction of r15 and C9 should hit pin 16 you have them on 15
Also you do not have pin 14 and 13 linked

yknow what's annoying? i actually did move that jumper up a row, but for some reason i posted an older version! damnit! thanks for confirming it though, i still wasn't sure. i would've totally overlooked the 13-14 link. got it on the other PT but not this. cheers!

current layout:

Quote from: MrStab on August 20, 2013, 12:22:59 AM
a few points: i've gotten into the habit of grounding both pins 3 & 4 of PT2399s just in case the internal link failed (as they sometimes seem to). as this isn't in the Solstice schematic, should i just omit the link?

You should ground both pins 3 and 4. I now concede that this is a good idea, as some PTs apparently argue with you if you dont. I intend to update the Solstice to include this at some point.

Quotei've inferred from posts that the 78L05 is even more temperamental in this circuit than single-PT ones - should i go for the 7805?

I have not heard any reports like this. The 78L05 is good for 100mA, and even two PTs don't suck nearly that much current.

Quote
would an MPF102 for the JFET be ok?

Possibly not. You need a FET with a low Vgs(off) rating, not greater than -3V really, unless you're willing to hand-select some that happen to be better than the data sheet maximum.

sweet, i'll be sure to ground those pins then.

it's just a few posts i've read about the 78L05 generally here & there, with regards to the PT2399. this thread is off-topic, but usually just i search round google for keywords & this particular post mentions an issue with the Solstice:  http://www.diystompboxes.com/smfforum/index.php?topic=89687.msg908003#msg908003. i have a bunch of 78L05s anyways so i'd rather not have to buy anything else lol.

just having a look over datasheets: would a 2n3819 suffice, with its max VGSoff of -8 (no typical rating)? or 2n5458 with between -1 & -7? (taking the literal meaning of "no greater than" w/ regards to the negative figures here, that's probably a given but i fail with numbers)

cheers!

Quote from: MrStab on August 22, 2013, 03:39:43 PM
just having a look over datasheets: would a 2n3819 suffice, with its max VGSoff of -8 (no typical rating)? or 2n5458 with between -1 & -7? (taking the literal meaning of "no greater than" w/ regards to the negative figures here, that's probably a given but i fail with numbers)

No greater than -3 means only zero to -3 is acceptable. -8 is waaaay out. The 2N5458 would work if you were willing to hand select them.

ah right, i get you now. i have a bunch of 2n5952s which range from -1.3 to -3.5, hopefully one of those should work. or a J201 might be more guaranteed. i did think switching was like in the Small Time and J201 would be fine, i just misunderstood which way you were approaching the negative from.

i would just get a J112, but i wanna try and source everything from one place which doesn't stock that, unfortunately.

is R12 (68k) on the schematic the feedback resistor you mentioned modding for different sounds on your Solstice thread?

Quote from: MrStab on August 22, 2013, 04:55:42 PM
is R12 (68k) on the schematic the feedback resistor you mentioned modding for different sounds on your Solstice thread?

There are two feedback resistors: R12 and R14. I can't remember if I recommended modding them or not, but you might want to have a play with them in any case!

duly noted, maybe i could stick em both on a dual-g pot and "resize" one half with a resistor or something. but i probably won't be bothered to go that far. lol
fixed a few more minor bugs with my layout but so far everything seems to check out... fingers crossed!

thanks for the help

anyone have voltages for this? the buffer section works fine, something dies after the JFET (i have it shorted atm so it's out of the equation). i got R19 wrong from the last layout i posted, cant find any other issues though. haven't audio-probed yet, but i have a suspicion the problem lies somewhere between entering the 2nd PT2399 and the output opamp

Reviving this thread, did you come up with a final verified Solstice vero layout?

i can say i have a working Solstice reverb as a result of this layout, but i can't actually confirm the layout itself as it was so long ago, and i vaguely recall having to correct a few things. in any case, this was my first or second attempt at stripboard layouts, and i really wouldn't recommend following it. there's zero regard for ground paths, feedback, crosstalk or general reliability.

here's a layout of the sister reverb, the Equinox: http://tagboardeffects.blogspot.co.uk/2014/04/valvewizard-equinox-ii.html, if you're up for building that instead. i think the Equinox has the PT2399s in parallel, as opposed to series in the Solstice (or the other way round), so it sounds different. apologies if you've already read the background stuff.

FWIW, i found the Solstice VASTLY more usable by making one of the feedback resistors into a pot. i can't remember which one, but contrary to my rambling earlier in the thread, it was just one of the feedback resistors and not both.

damn... was only a coupla years ago, but feels like a lifetime ago! now i draw PCBs and ask some nice Chinese folk to make em, and have learnt that asking forumites to verify stripboard layouts results in a swift stone-kicking.

Thanks, I was deciding between the Equinox and Solstice variants and decided the latter seemed more to my liking. I've only built a dozen or so stompboxes; if I can't find a pre-existing layout and the end result is this makes me practice making my own vero layouts, more's the better I suppose.   

Quote from: M.Spencer on September 23, 2015, 04:20:16 AM
Thanks, I was deciding between the Equinox and Solstice variants and decided the latter seemed more to my liking. I've only built a dozen or so stompboxes; if I can't find a pre-existing layout and the end result is this makes me practice making my own vero layouts, more's the better I suppose.

FYI, I think the Equinox is the superior of the two in terms of sound and versatility, which is why I don't really support the Solstice any more.
http://valvewizard.co.uk/equinox.html