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