Digitally controlled preamp/headphone amp

[BrianDonegan]

The Kook didn't have them and worked fine.

 

[alexcd]

Does anyone see an issue with using two PGA2310's per PIC? All signals are split with no resistance between them.

 

[BrianDonegan]

adding the Rs wouldn't be a bad idea, but controlling two PGAs from a single pic in and of itself is fine.

 

[Russ White]

Hi Alex,

I would need to see your schematic and layout to be able to help you out.

If you schematic matches the kookaburra schematic, it should work.

Cheers!
Riss

 

[alexcd]

Here is my schematic. I left off the audio stuff cuz it's really just some opamps that I'm using for buffers. I really hope you can help. I'm getting a very VERY distorted output (seen on scope.)

 

[Russ White]

Hi Alex your partial schematic seems correct (as far as it goes). You need to double check your PCB and your analog circuit.

 

[jaudio]

Here is my schematic. I left off the audio stuff cuz it's really just some opamps that I'm using for buffers. I really hope you can help. I'm getting a very VERY distorted output (seen on scope.)

I'm running mines one pic(outputs of the PIC are split.) + two pga's,so far everything OK. It been running a total of 24hrs.

 

[alexcd]

Here's my PCB layout of the PIC -> PGA2310 interface (the 2nd VC chip is directly above the lower) I'm worried the runs are a bit too cluttered.

 

[breez]

Russ White,

If you don't mind asking, how did you implement the sleep/wake up with PIC? I can't think of an easy way to wake up on pot turn.

Referring to this comment early from this thread:

The PIC now sleeps until the pot is moved at which time it wakes up, sends the serial data to the PGA2311 and goes back to sleep.

 

[Russ White]

Russ White,

If you don't mind asking, how did you implement the sleep/wake up with PIC? I can't think of an easy way to wake up on pot turn.

Referring to this comment early from this thread:

Keep in mind, I was a complete beginner with PIC programming at the beginning of the thread. 🙂

I think I was simply mistaken when I posted that, as I can tell you with certainty it is not possible without modifying the circuit significantly or using a different PIC controller. What I probably meant was that no serial communication to the PGA was happening unless the pot position changed, which is true.

You would use a comparator and a change notification pin, if you had one available for input.

There is also another newby mistake I made regarding the zsen pin in my initial design, but its pretty harmless. 🙂 The astute will see it right away (As some already have). The pin that is supposed to be driving it is an input only pin. Rookie mistake.

Cheers!
Russ

 

[breez]

Thanks for clearing it up, Russ. I think I won't bother adding any external circuitry for my own project (a no frills 8 channel volume control).

 

[kestrel200]

So on the outside chance someone might be able to help me I thought I'd take a shot and ask.

I bought a Kook kit last year and for various reasons just got around putting it together and can't get it to work. I then read that some of the PICs were inadvertantly shipped without being programmed. How do I figure out if this is the problem? If it is, I how do I go about getting it programmed? Before someone suggest I e-mail Russ..let me say I did and am still waiting for a reply.


Thx

Mike

 

[BrianDonegan]

Hi Mike-

I have tried emailing you three times but the emails get bounced. Is your mailbox full?

I am willing to take a look at your Kook if it needs it. It does nothing when you power it up?

 

[kestrel200]

Hi Brian! I appreciate the quick reply. I just registered on the Twisted Pear site an it replied to my e-mail address so I don't know why you can't get through.


Pls make sure your typing metzlerm1@comcast.net not .COM.

Anyway I haven't taken any pics yet but I'll take some and e-mail to you if you'd like or post them which do you prefer?


Thx again


Mike

 

[hungmao]

Hi,

when I try to compile the C code with Hitech PCCC, it shows the following error:

Executing: "C:\HT-PIC\BIN\PICC.EXE" -C -E"pga2311.cce" "pga2311.c" -O"pga2311.obj" -Zg9 -O -ASMLIST -Q -MPLAB -12F683
Error[000] D:\pga2311\pga2311.c 72 : undefined identifier: TRIS1
Error[000] D:\pga2311\pga2311.c 73 : undefined identifier: TRIS2
Error[000] D:\pga2311\pga2311.c 74 : undefined identifier: TRIS3
Error[000] D:\pga2311\pga2311.c 75 : undefined identifier: TRIS4
Error[000] D:\pga2311\pga2311.c 76 : undefined identifier: TRIS5

How can I define the TRIS1-5?
Actually, what TRIS1-5 are?

Thanks a lot.

 

[ragaman]

Hi Dcibel, im checkinjg your code and I dont understant some parts of the code, I need change the code for use the PGA4311, Can you help ??

 

[andyr]

Thanks for clearing it up, Russ. I think I won't bother adding any external circuitry for my own project (a no frills 8 channel volume control).

Hi breez,

I'm a bit late to the party but hopefully you will pick this up.

A no-frills, 8 channel (preferably analogue?) volume control is exactly what I am looking for, to go between my miniDSP unit and 8 amp channels.

Is what you implemented suitable for this? If so, can you give me more details?


Thanks,

Andy