PRIMOVA - GKPX-14 a smarter GKP-4 clone/4 channel GK distribution box

Started by CodeSmart, August 06, 2014, 10:50:52 AM

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CodeSmart

V-Amigos, all units are now sold. Thanks!
I will make another round of abt. 10+ units.
Probably available sometime in December.

If you want to show interest in the new batch (no obligations) e-mail me at sound@primova.se

But I got more gear than I need...and I like it!

Pete1959

Great box! Finally got it working as planned!

The following advice was key and had plenty of time to set up and review. I was jamming with friends last night and not trying to hurry as I would be in a rehearsal.

Applies to my setup of GR-55 on "A" and GP-10 on "B"

Stomp short once - A is toggling on/off
Stomp short twice - B is toggling on/off
Stomp short 3-times Both on/off

To move the S1/S2 focus:
Long stomp - S1/S2 on A
Short+long stomp - S1/S2 on B

In a nutshell... brilliant!
Hope you sell out the next batch Robert and thanks again!

CodeSmart

As I'm doing another batch of this thing I did another iteration of the PCB.

As discussed elsewhere on this forum there is a slight chance for ground loops when connecting several synth units.
So now I've added Ground Lift Jumpers on GKB, GKC and GKD.

These jumpers and companion resistor and capacitor (I think I go for parallel 100 ohms and 10nF as discussed here: http://www.epanorama.net/documents/groundloop/groundlift.html) will be located on the underside of the board.

To do a ground lift you will have to unscrew the 4 Phillips screws, lift the top off and remove a jumper.
Unfortunately there's no room for external switches on this unit. It's really crowded  :P

For you guys already using the unit, if you have any suggestions or ideas on how to improve the "stomp-software" please drop me a note.

But I got more gear than I need...and I like it!

big_jan

And so it arrives :) testing tonight. Took 11 days to reach Singapore.
Thanks Robert.

CodeSmart

Got empty PCB boards (3rd revision) incoming, components from Germany (Reichelt.de has great price), GK-cables in production, this time also a number of 2meter cables in case someone interested. Enclosures already arrived. Ordered pre-painted but they screwed up and I got unpainted enclosures >:(. Hoped for only one layer of paint this time. But noooo....

Got  a gig on Saturday but hope to get some time for drilling on Sunday or some evening next week as the paint and print job is known to take time. Anyhow things look promising for the second batch of units. Email sound@primova.se if interested, no obligations. Building 10-15 units, depending of interest.
But I got more gear than I need...and I like it!

patfoley


CodeSmart

Quote from: patfoley on November 26, 2014, 12:09:55 AM
I would buy one of the next batch.
patfoley@usb.edu

To be sure I don't forget you, please send an email to Sound@primova.se
I received boards and most of the components today and will start production asap.
But I got more gear than I need...and I like it!

CodeSmart

Tonight, while standing in my garage drilling the new enclosures I've was thinking about firmware improvements.

- When turning the thing on, it probably should remember the last state on everything instead of just enabling GKA only. To do this every state change needs to be flashed.(Are there limitations in how many times a PIC controller can be flashed?)

- Since I think the majority of people use this box with just two synths I'll think there should be a new third stomp pattern program with a two channel US-20 in mind.
Single-stomp toggles between sound on GKA or GKB (and SW1/SW2 follows), whereas double-stomp enables sound on BOTH but SW1/SW2 remains tied to the last selected. This would also work for a three or four output configuration but would then prohibit combinations of using two out of three or three out of four etc.

Hm... got to think it over a bit,. Anyhow, it's great to be able to modify hardware behaviour with software, though it's a pity there's no USB interface to upgrade existing units from a PC.
But I got more gear than I need...and I like it!

Elantric

QuoteAre there limitations in how many times a PIC controller can be flashed?)

Yes - which model PIC are you using?

Many are rated for 1million write cycles. But older ones are more like 100K  write cycles.
http://forum.allaboutcircuits.com/threads/programming-cycles-for-pic18f452-issue.102990/


http://dangerousprototypes.com/2010/05/25/prototype-flash_destroyer/

CodeSmart

Quote from: Elantric on December 02, 2014, 04:00:37 PM
Many are rated for 1million write cycles. But older ones are more like 100K  write cycles.
16F1508, just checked, we talk just 100K times. Even though that's a limitation it's quite a lot of stomps...to reduce...could write every X minutes only if there's a change compared to flash memory setup. Got to do some math to figure out how long the chip would last.
But I got more gear than I need...and I like it!

Elantric

Quote16F1508, just checked, we talk/write  just 100K times max. Even though that's a limitation it's quite a lot of stomps...to reduce...could write every X minutes only if there's a change compared to flash memory setup. Got to do some math to figure out how long the chip would last.

http://ww1.microchip.com/downloads/en/DeviceDoc/41609A.pdf
Quote- 100,000 write Flash endurance (minimum)
Many buy PIC in QNTY 100 same Lot # / Date code #

Then use one sample from the batch and run it through one of these Flash write testers to get a ballpark of the available write cycles  - they guaranty 100K write cycles, but its possible to get a bad batch.

http://dangerousprototypes.com/2010/05/25/prototype-flash_destroyer/

CodeSmart

Looks like I should have picked a PIC with EEPROM if to store data between sessions. Lesson learnt.
But I got more gear than I need...and I like it!

CodeSmart

Yikes, the drilling is over :P  Did totally 350 holes while I was at it. I hope they won't sell out immediately.
The War Department dictates an evening without the garage so I gladly handed them over to the painting guy today  ;D

But I got more gear than I need...and I like it!

Bryan

This sounds like exactly what I need too!

So answer me a simple question please.

I want to go from my guitar to this box then to my VG-99, My GR-20, and maybe a GP-10 in the future.

I would like to have at least two active at a time.

Will this do the trick?

CodeSmart

Quote from: Bryan on December 04, 2014, 06:13:35 PM
Will this do the trick?

YES!, it's a microprocessor controlled GKP-4 / 2xUS-20 making everything possible.
Read the manual at the bottom of this page http://www.primovasound.com/gkpx_14.html

+ This small unit may even host an optional Piezo Subsonic Filter board (i.e. GKFX-11) pre-mounted or installed later.
+ The new units also have GROUND-LIFT possibility and a new third stomp pattern program not mentioned in the manual.
But I got more gear than I need...and I like it!

CodeSmart

Proceeding as planned: Painting done. Three layers; clearcole + yellow base + yellow metallic. Looks great. Next stop screen-print, followed by a final layer of clear varnish. Meanwhile the SMT boards are hand-soldered under magnification lamp. My 50+ "old fart eyes" are not what they used to be ::)
But I got more gear than I need...and I like it!

Bill Ruppert

That is a lot of work!
It is such a great box.
Thanks again.


Quote from: CodeSmart on December 04, 2014, 10:46:47 AM
Yikes, the drilling is over :P  Did totally 350 holes while I was at it. I hope they won't sell out immediately.
The War Department dictates an evening without the garage so I gladly handed them over to the painting guy today  ;D



Bryan

I agree Bill.

I really like how it matches the GP-10's styling!

I can't wait to get mine.


Sent from my iPad using Tapatalk

Bill Ruppert

#68
Bryan
I think you will dig it.
I love mine and Robert is a fantastic designer /builder.
Hard to believe one guy can do this. Its unheard of.
This gives me 8 (4 stereo) VG audio outputs to toy with from one guitar.




Quote from: Bryan on December 07, 2014, 06:56:58 PM
I agree Bill.

I really like how it matches the GP-10's styling!

I can't wait to get mine.


Sent from my iPad using Tapatalk

CodeSmart

#69
Most of them (23) made it back from the screen-print/paint-shop. Just need to assemble and do the respiration/sanity check.
Santa (ehh, or someone) accepting me doing whatever required to get some of these guys out of the house before Christmas. Please help me out  ;D











ITEMSEKUSAUDEURGBP
GKPX-14 , Parallel box (excl. cable)850$113$137€113£90
GKPX-14F (excl. cable) /w Subsonic Filter1350$179$218€180£143
GKMX-C1, 1 meter  gold plated GK cable100$13$16€13£11
GKMX-C2, 2 meter  gold plated GK cable150$20$25€20£16
SHIPPING100$31$38€27£22

PayPal fee 3.4% will be added to total price. Send an e-mail to sound@primova.se to order and get the PayPal adress.
EUR and GBP prices already include 25% Swedish V.A.T. (yeah, I know it sucks, but that's the EU tax law).
Any number of cables may be ordered with the box.

HAPPY HOLIDAYS V-AMIGOS!!!
But I got more gear than I need...and I like it!

Bryan

Quote from: Bill Ruppert on December 07, 2014, 07:19:13 PM
Bryan
I think you will dig it.
I love mine and Robert is a fantastic designer /builder.
Hard to believe one guy can do this. Its unheard of.
This gives me 8 (4 stereo) VG audio outputs to toy with from one guitar.

I'm not going to be that ambitious, but now that this exists I've got pretty big plans for it!

vurnt99

Late to the party, but just sent my email/order/request in...Looks AMAZING


V

CodeSmart

Did a new round of the manual adding the new ground Lift option, new firmware with US-20 Stomp Pattern 3 and on how to remove the Filter Board.
http://www.primovasound.com/pdf/GKPX14_Manual.pdf

This is how you do the new ground lift by removing a jumper (only available from unit serial 010+)


This is how you to remove the filter board (if you ever want to do that) be removing two screws,
take the board off and instead connect the 6 red jumpers (found in a small plastic bag inside the unit
starting from serial number 010+).

BEFORE "GKPX-14F" (WITH FILTER)


AFTER "GKPX-14"  (WITHOUT FILTER, INSTEAD 6 RED JUMPERS)

But I got more gear than I need...and I like it!

Bryan

Mine is on the way! I can't wait!!


Sent from my iPhone using Tapatalk

ffata

I'm the proud owner of number 012!! :)

I received my tracking number on the 19th and the package arrived today the 24th.
That was fast shipping from Sweden to New Jersey!!
A very GK Christmas!!

The Thank You note that Robert included was such a nice personal touch.
It tells a bit about Primova and the GKPX-14 components, testing, etc.
Oh yeah, it has that "new paint" smell, I love it!!!

Thank you so much Robert!!!!
Fred