Hi Gabor,
Can you please place the order via our web-store, using the discount code DIYAUDIO. It will be shipped from New Hamburg as usual ))
Cheers,
Valery
Board Update
I've managed to test most of the boards. Simpelstark and the supplies are good. There's a bug in the Amp Control boards, I'll have replacements early next week. I haven't managed to test the new input adapter board yet, I hope to do that in the morning. I should be able to start shipping out some of the orders tomorrow.
I've managed to test most of the boards. Simpelstark and the supplies are good. There's a bug in the Amp Control boards, I'll have replacements early next week. I haven't managed to test the new input adapter board yet, I hope to do that in the morning. I should be able to start shipping out some of the orders tomorrow.
Attachments
Hello All,
I have slightly updated the build guide for Simpelstark+ in the store for making the ODNF setup more clear. The attached picture illustrates what kind of signals you are going to see at the output of the amplifier and at TP2 test point.
ODNF circuit is balanced as soon as the amplitude of the error signal at TP2 is at its minimum (trimmed by R26).
The signal generator can be very simple - Android application like this is enough (1KHz sine wave is enough for the above procedure):
Frequency Generator - Tone Generator - Apps on Google Play
Cheers,
Valery
I have slightly updated the build guide for Simpelstark+ in the store for making the ODNF setup more clear. The attached picture illustrates what kind of signals you are going to see at the output of the amplifier and at TP2 test point.
ODNF circuit is balanced as soon as the amplitude of the error signal at TP2 is at its minimum (trimmed by R26).
The signal generator can be very simple - Android application like this is enough (1KHz sine wave is enough for the above procedure):
Frequency Generator - Tone Generator - Apps on Google Play
Cheers,
Valery
Attachments
Last edited:
Amp Control 6V2.3 is up and running perfectly. It has an extra 12V switched connector on it that will work nicely to switch the new input adapter boards. I'm going to update the software so a rear panel switch can be connected to one of the pins on the ISP port, the control board will check the switch position on power up and set the input adapter to the correct input before powering up the amplifier.
Debugged input adapter boards should be arriving tomorrow so with any luck I should be able to package everything over the weekend and ship everything out.
Debugged input adapter boards should be arriving tomorrow so with any luck I should be able to package everything over the weekend and ship everything out.
Attachments
I have two versions of surface mount speaker relay boards. The standard board has hole spacings for normal 3/4" (19mm) binding posts with #10 hole size. We also have a version with 30mm spacing 8mm diameter holes for larger binding post like the ones available on our website. If anyone would prefer the alternate hole spacing please let me know.
Nice looking pcb & parts fitting!
I see polygon ground plane but i can't see well if used as gnd referance.
This amp version uses BJT drivers and outputs. The original used latfet drivers.
Nice looking pcb & parts fitting!
I see polygon ground plane but i can't see well if used as gnd referance.
There's no easy answer to a grounding question on a balanced adapter! The planes are power supply ground and ground reference for the THAT 1206 IC. To avoid ground loop issues the audio ground itself isn't directly connected to this plane. I'm going to write up the build guide for this over the weekend with an explanation how to properly connect this board. I spent a lot of hours at the test bench experimenting for best results. The noise floor drops dramatically when using the XLR connection but wiring is critical.
Oh sorry Jeff, i ask for the polygon ground plane (upper side) that i see in amplifier pcb.
On the amp, yes that's signal ground.
Hi Meanman,
This version (v1.3) utilizes the class AB OPS with wider than normal class A region. Outputs configuration may look like CFP at a first glance but it's not. Configuration with "helper" transistors used here is rather low distortion open loop - that was my intention for this amplifier.
You can download the schematic if you register in the store - just let me know as soon as you create your account, I will give you the access for downloading the docs (manual procedure).
Cheers,
Valery