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

Did a bit of changes to ground and power wires. Computer is now dead silent.

Added a large capacitor (220 uF) and a resistor (470 ohm) to the common connection of the 8 LED's and it helped a lot to silence the transition from on and off of the LEDS, however still not 100% perfect.

GK systems, especially GP-10 seems to be sensitive to alternating DC loads on the +7V line. GR-55 is a bit more tolerant. Most noticeable in 12-string or Sitar COSM mode just where the noise gate kicks in. With external power there's  no problem, but I want this box to work with just the GK power.

I will now revisit the software and see what I can do. Thinking about ramping LEDs up and down using PWM...will it smoothen the current inrush or just introduce audible noise? Soon find out.
But I got more gear than I need...and I like it!

Bill Ruppert

Wow!
Love watching your work!
Thank you for posting progress reports.
Bill

CodeSmart

Getting the small GKPX-14 enclosures back on Wednesday after printing.
These top quality units will be delivered with gold-plated 1m GK-Cables. Just plug-and-play.

Development update:
Software is working fine. The soft dimming of LED's (using Pulse-Width-Modulation) took away any remaining issues.

With the single footswitch you operate the GKPX-14 to instantly:
* Selects guitar volume or fixed  to one or several synths.
* Direct guitar S1/S2 to one or several synths.

With the same footswitch you also select:
* US-40 or GP-4 operation mode.
* How many output units connected, 1,2,3 or 4
(Settings are permanently stored in flash memory).

Due to things learnt I need to do a second iteration of the circuit boards.
Design and manufacturing will take a couple of weeks... ::)

But it's worth waiting for...it's tiny and it instantly directs your guitar to up to four synths
...and you don't have to drill or build your own enclosure.

Tested with GR-55, GP-10 and GR-33, no worries!
But I got more gear than I need...and I like it!

CodeSmart

New PCB design almost completed last night. Ordering boards and additional components beginning of next week.








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

mbenigni


pappywatts

Quote from: mbenigni on September 17, 2014, 02:22:42 PM
Wow - nice work!
Precious...!!! Wants it!   Now !... :P

Damn...will just have to man up and wait, it will be worth it no doubt..
Yeah I got one of those Smart phones, trouble is it's smarter than the owner....

Variax Kit:JTV69 +GK3,JTV59P +GK2a.
Carvin SH575, Fender Strat USA Roland Ready, Godin ACSA Multiac Nylon usb model.
GR55,GR30,GP-10, VGA7,Baggs Acoustic Reference, Zinky Green Velveteen 18w,JTM45 Head.Yamaha DXR10

CodeSmart

Finally ready with the new board. Sending it to production today. I hope it works better this time.
The digital and analog part is completely separated now. Lot's of shielding ground lines and planes between signals, power feeds and control signals.
Low pass filters added on all LED's. Low pass filter also added to the VOL signal. Also added more decoupling capacitors close to all IC's.

Software uses pulse-width-modulation to dim the LED's smoothly to avoid current inrush.

This was supposed to be a simple one, but it was not.
It's a challange to do this high density stuff in just two layers.
I cross my fingers and hope for the best.

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

PaulNowles

wow !!!! this looks great !!! how can I get one? Currently using a US-20 for my GR-55 and GR-20 and my vg99 is off in the corner and a new GP-10 ordered and on the way... dying to use them all. If you are selling this  GKPX-14 please let us know how to get one from you. Thanks.

CodeSmart

Quote from: PaulNowles on September 28, 2014, 12:58:04 PM
If you are selling this  GKPX-14 please let us know how to get one from you. Thanks.

I will be selling 9 units (the 10'th is my own, just got to have it on my pedalboard beside my GP-10 (replacing Boss GT-10) and GR-55. Boards and components arrives upcoming week. I'll post here when soldered, programmed and ready to ship. (if there's problems I'll let you know also).

GKPX-14 ...........$120
GKPX-14F...........$190
(The F-version includes a Subsonic Filter/Tracking optimizer board
enhancing tracking and ghost note immunity for piezo instrument connected to GR-55/VG-99)

Options/add-on:
GKMX-C1 - 1 meter Gold plated GK cable......$11 each
(unbeatable price for a great cable, this price only when bundled with GKPX-14)

Put yourself in line (no obligations) by emailing sound@primova.se

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

CodeSmart

Update: Boards came in yesterday. After little tweaking they sounded and behaved just AWESOME. Unfortunately we have to live with two revision wires ::) No time for a third round of boards, would take 2-3 more weeks.

Now I need to write a manual, solder the other guys and probably make something for YouTube...I'll be back  ;D
But I got more gear than I need...and I like it!

PaulNowles

Fantastic, really looking forward to getting one !!!
vg99, gr20, gr55, and new GP-10 are all set up and a space for the GKPX-14 on my pedalboard !!!

CodeSmart

Done the first version of the manual. English is not my native tongue. I hope it's understandable.
If someone dare to read it and see something fishy or if there's something you think I should re-phrase/remove/add, please let me know  :)

http://www.primovasound.com/pdf/GKPX14_Manual.pdf

Planning to start selling the box in a couple of days.

Thanks
Robert

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

pappywatts

#37
Hi Robert, just read the manual, makes sense and the unit seems to be relatively easy to operate..

Just a little bit of English on the footswitch section..The first line.. I think it should read " The Footswitch will operate a wide range of stomp patterns", depending on how you prefer...etc.

Happy to place my order as soon as you have available units, let me know how much for UK pricing..regards
Yeah I got one of those Smart phones, trouble is it's smarter than the owner....

Variax Kit:JTV69 +GK3,JTV59P +GK2a.
Carvin SH575, Fender Strat USA Roland Ready, Godin ACSA Multiac Nylon usb model.
GR55,GR30,GP-10, VGA7,Baggs Acoustic Reference, Zinky Green Velveteen 18w,JTM45 Head.Yamaha DXR10

PaulNowles

Hi Robert,
manual looks very good - only minor thing - page 5 1st line - I am sure you meant "repeats" and "of" - not a biggie. Other than that I am really looking forward to getting this unit. It looks great and the functionally is just what I am looking for. Will be watching this space for when you begin selling and I am ready to order.
Thanks.
Paul Nowles.

CodeSmart

Thank you Paul & Paul for checking the manual. I will edit asap.
My wife is the best wife one can have. I love her.
Yesterday (a Saturday) she allowed me sitting doing these guys for 10+ hours while she cleaned the house and made an excellent dinner :)


This particular board is pimped with the optional "Subsonic Filter" (tracking enhancer) board mounted on the extension socket.


Unfortunately I had to order a few missing components, I'll hope to get them on Tuesday.
I'll be back!!!
But I got more gear than I need...and I like it!

CodeSmart

Ok - Check. Ready to take orders - 6 fellow V-Guitarists quoted so if that goes well there are 3 units left.
E-mail to sound@primova.se if interested.

GKPX-14 ...........$120
GKPX-14F...........$190
(The F-version includes a Subsonic Filter/Tracking optimizer board
enhancing tracking and ghost note immunity for piezo instrument connected to GR-55/VG-99)

Options/add-on:
GKMX-C1 - 1 meter Gold plated GK cable......$11 each
(unbeatable price for a great cable, this price only when bundled with GKPX-14)

US/Canada shipping $35, EU shipping $23 Euro, EU Citizens also pays 25% VAT :(
* * *
This is my test setup with a GKPX-14 with built in Subsonic Filter.
Didn't think there would be a difference with a GK-3 guitar but surprisingly I felt a tad cleaner tracking at the lower part of the lowest two strings with GR-55 Piano patches.
The GR-55 and GP-10 sounds GREAT together. Soon both on my floorboard  ;D (Getting rid of my Boss GT-10)
(The Green light indicates sound is on and the Yellow light indicates sound on+S1/S2)



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

cell7


CodeSmart

Got seven gkpx14 and one gkfx11 subsonic filter to ship.
No complaints from war department about stuff all over the house (yet). Things are going smooth  8)
I'll do my very best to get them posted by Monday. Tracking numbers will be sent out.
But I got more gear than I need...and I like it!

GuitarBuilder

"There's no-one left alive, it must be a draw"  Peter Gabriel 1973

CodeSmart

Bye-bye my Babies  :'(


You will always be on my mind, no 001-007  :-\




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

Pete1959

I anxiously await....
Thanks for the updates & tracking info!

pappywatts

Got it !!!!...Robert... You really have surpassed yourself this time,it's a great unit, I connected/setup the programs and was playing within 30 minutes out of the box.

Roland should really take notice of this innovation, and hire you as a consultant.

Cheers!
Yeah I got one of those Smart phones, trouble is it's smarter than the owner....

Variax Kit:JTV69 +GK3,JTV59P +GK2a.
Carvin SH575, Fender Strat USA Roland Ready, Godin ACSA Multiac Nylon usb model.
GR55,GR30,GP-10, VGA7,Baggs Acoustic Reference, Zinky Green Velveteen 18w,JTM45 Head.Yamaha DXR10

PaulNowles

Mine arrived on Saturday, sorry for the delay on giving feedback. OMG - this is the most incredible thing !!!
Having all four units (GP-10, GR-55, GR-20, VG99) at the same time, mixing and matching patches, augmenting each others sounds,
Words have no meaning !!! Plus I just plugged into my VoiceLive 3 (from the 1/4" gtr jack) for the first time and added that to the mix... All of this or course
directly into the mixer that leads to the RC300 looper... I have no excuse now.. I have to make music now..:P)
Robert, I have to hand it to you, the unit is sleek, professional, works amazingly great, and for the first time I have silent units
to create music with instead of a steady back ground hum (my US-20 had a ground loop problem when using with VG99 and GR-20 so I had stopped
using them together).  Cannot thank you enough and I will keep an eye pealed for any new innovations from you.
I will post some pics of my rig later this week.

Bill Ruppert

My GKPX-14 just showed up.
Robert Fransson at Primova is a genius!
The mini box does it all AND is clean as a whistle signal wise.
PLUS he color matched it to the GP-10 perfect.
Hard to believe one man can do this!
Fantastic!

CodeSmart

V-Amigos. You have to stop now, I'm blushing...thanks.
But I got more gear than I need...and I like it!