Equinox: Easy PT2399 Reverb

[gtangas]

Do you think i fried the PT´s??? is there a way to check it?

I wouldn't expect them to be damaged, since they received nothing more than 5V. But some PTs are just bad. Plug 'em in, and if they don't work, well, then they're kaput.

I dont notice a big change on tone using the switch. I think i read that you made some mods... any tips?

Yes, I reduced C33 to 10nF I think. You could try even smaller.

ok, i will try changing the value of the cap i see the dif. I saw that you design the solstice. In your opinion witch sound best?

I haven't receive from ebay my boxes, knobs, etc... but improvised and built a home for this baby. i have to paint the box but... it´s working!





Thx

[bluebunny]

I haven't receive from ebay my boxes, knobs, etc... but improvised and built a home for this baby. i have to paint the box but... it´s working!

Paint?  Why?  It looks great already!      Just shield the inside (if it needs it) and varnish the wood.

[gtangas]

thx man

Its second wood box that i use... cheap! hehe The only cons its the length of the wires... to open it!

here is another box. the thunder puss booster by Madbean

[Big Thurs]

It worked for me once I figured out the same thing that Mark did regarding the switch integration, then I got it in the rack and it didn't work.  Long story short, cobexonly's jumper between 2 lugs of the pot and 2 diodes in a series to drop the 5v down a bit got it working reliably so far on the bench.
Very cool circuit!  This will definitely have a permanent place in my rack

[Oerlikon]

People, from Argentina

Try with HT8970 INSTEAD OF PT2399, its soo vintage 

[blue_tokai]

Etched up the board for this baby tonight and populated it. Worked first shot upon applying power. Will need to get the box done up for it next.

Thanks Merlin, great reverb!!!!!!!


Cheers,

Russ

[alparent]

I've noticed that the Bass Cut switch in my build doesn't change the sound much?
Should I lower C4 after the switch or raise it to get a more pronounce difference?

Thanks

[blue_tokai]

I've noticed that the Bass Cut switch in my build doesn't change the sound much?
Should I lower C4 after the switch or raise it to get a more pronounce difference?

Thanks

Since its cutting the bass before the actual reverb circuit, there isnt a pronounced big difference in the sound. I think it also depends on the guitar. I notice with my acoustic the difference is more noticeable than with my Gretsch or tele :\
You could try playing with cap sizes, but I would not expect a huge difference in the bass.

[roroofox]

Easier way to the soundclip: http://www.freewebs.com/valvewizard2/Equinox.mp3

What a great little circuit! Viva DIY!

Edit! Will someone please put me out of my misery and tell me which Zeppelin song that is?

BABE I'M GONNA LEAVE YOU!!!

[Lbzg]

Sorry if it is said before, but can Equinox reverb as on this post be build with 3pdt switch and how? Also if this is impossible than which is input, ground, and output on PCB board?

[Canucker]

I gathered all of the parts in the first version posted here accept for the TRANSISTOR BC337....any advice on substitutions? I did a search and it came up with nothing. Thanks in advance for any assistance!

[Jdansti]

Sorry if it is said before, but can Equinox reverb as on this post be build with 3pdt switch and how? Also if this is impossible than which is input, ground, and output on PCB board?

Here it is.

http://www.diystompboxes.com/smfforum/index.php?topic=93868.msg815477#msg815477

[merlinb]

I gathered all of the parts in the first version posted here accept for the TRANSISTOR BC337....any advice on substitutions? I did a search and it came up with nothing. Thanks in advance for any assistance!

Any high gain transistor will work. You can also use a JFET if you replace R23 with a diode.

[Vikt0r]

Hi everyone!
Thanks for the circuit, made and managed it running finally, now works like a charm.
I have figured out something while trying to bring up this nifty thing. My circuit was built
around the alternative layout by "crazy russians", a perfectly made PCB, some 11pc. of PT2399 (one came from
different year/manufacturer) - but I have also ran into weird oscillating problem... It was the R11 which should have
been 15k, but I have put a 75K there (easy to mix up the two) - the oscillation has gone. But that was not everything.
The only chip working in this circuit was my older PT2399 pulled out from a rebote delay, while all the 11 were
perfectly working in the rebote delay!!! Mystery? No! It turned out that the "russian" layout inherited something that
is strictly speaking a design mistake. This mistake finally leads to so many hassle about "latching", faulty PT2399,
playing with V+ etc. - which is too bad, because it's useless, so many potentially working circuits were thrown away -
the problem is not there.
The problem is is the non-existent connection of pin 4 of each PT2399 to the ground (nearby pin 3). Pin 4 represents the digital ground of
the circuit and seems to be internally connected to analogue ground only in SOME of the PT2399( and such a case
is not a rule but rather an exception that shouldn't be ever exploited), while others
REQUIRE connecting DGND and AGND pins (4 and 3 respectively) to the ground. I'm just curious why this was not
implemented in the original circuit (could have saved so many lives ) while the datasheet states black&white this has to be done?
Especially considering it's all about 2 traces 2 millimeters each...
Anyway, I recommend the author to update the design layout and everybody try again your all "faulty" PT's just have their pins 3 and 4
connected by a solder bridge.

Hope this could be helpful.

BR,
Vikt0r

[Vikt0r]

Do you think i fried the PT´s??? is there a way to check it?

No, you didn't.

I dont notice a big change on tone using the switch. I think i read that you made some mods... any tips?

That's because there is NO CHANGE - the PT's are not working.

Resuming... I´m learning... and making mistakes it´s the best way!!  BS.... Is much better to finish the build... fire it up and play! hehehehe

It's actually not your mistake, but still good for learning. First, short pins 3 and 4 of each PT2399, then check again.

[merlinb]

SOME of the PT2399( and such a case is not a rule but rather an exception that shouldn't be ever exploited), while others
REQUIRE connecting DGND and AGND pins (4 and 3 respectively) to the ground.

Thanks for the info, I have updated my website

[attila]

Hello

I have bought all the parts for this build....and I am a total Noob at this ... Would like to know if anyone can help with a Vero board layout PLEASE ....  I


Attila 

[peterg]

http://www.aronnelson.com/gallery/main.php/v/Schematics-etc/equinox+mother.jpg.html
http://www.aronnelson.com/gallery/main.php/v/Schematics-etc/pt2399+boxes.jpg.html
http://www.aronnelson.com/gallery/main.php/v/Schematics-etc/equinox+daughter.jpg.html

Attached (I think - first time uploading) are photos of my Equinox build (centre of PT2399 group photo - others are Madbean Cave Dweller Delay - black knobs and Frequency Central Little Angel - white knobs). Here are the details:

Bypass switching - deleted Q1 and it's resistors and cap. 
Socket for C13 - 1uF cap used
Socket for C33 - .1uF cap used
Deleted C4 and it's switch
1590B box
Daughter board for the OpAmp section and the LED underneath the mother board.
"Room Type" pot off boarded to save board space
I have been having issues with the 78L05 overheating and have an LM7805 to replace it.

Thanks Merlin et al for your input over the last week.

[JFace]

Is there any reason not to use the 5V as the bias supply (for this or any project with a 5V reg)? It would save on parts and possibly simplify the tracing.

[psychedelicfish]

Don't quote me on this, but when you're working with mixed mode (part analog, part digital) circuits it's generally best to keep digital parts separate from the analog parts. What I mean  is having separate grounds, supplies and such is a good idea. This is why the PT2399 has an analog ground pin and a digital ground pin. If you have common grounds etc. you'll find that noise from the digital parts of the circuit will creep into the analog parts. So yes, there is a reason why you shouldn't use the 5V as the bias. Also, what's the point? How much will 2 resistors and a capacitor cost?