AD811 IV completed and tested

[zoom777]

Sold Now
Working AD811 IV board, more details can be found here:
https://www.diyaudio.com/community/...s-input-nos-r-2r.354078/page-368#post-7451599
https://www.diyaudio.com/community/...including-burson-audio-op-amps-as-i-v.394295/

Pictures showing two boards,
MELF resistors version : configured for DAC with Iout +/-1mA eg. AD1862, PCM1702, PCM58 etc
1206 resistors version : configured for DAC with Iout +/-2mA eg. PCM63, tda1541 etc

NOTE : I am only selling one of the boards. I am keeping one for myself. All spare empty boards have been given out to some members here at no costs.
I will have to remove the aluminium baseplate which acts as heatsink due to shipping weight, which equates to costs.

Asking for costs of parts + shipping (registered + tracking) + a little more for my time/effort (just a couple of Starbucks latte) = 155 USD
Paypal FF only please.

 

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Pics for your reference

 

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Sold now

 

[acccruz]

If the boards will be available in the future, I will take 2 of them: one for AD1862 and other for TDA1541A.

Thank you!

 

[zoom777]

Hi I am releasing one more of such AD811 I/V with Shunt Regulated PSU because I have moved the AD811 I/V stage on my DAC boards itself.
Prefers to be paid in Singapore Dollars 210 (one I/V board + shipping registered & tracked).
Shipping can only be done early next week (probably Monday) because I am currently not at home.

 

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Pictured here without the AD811 op amps because they have been removed and stored, and I forgot to install them for pics...



These are a pain to build because of the number of tiny parts.

 

[zoom777]

Here are the babies. Heatsinked. 100percent genuine from legit stockists. Not from AliExpress or shady sellers. There are so many fakes selling at very low cost (USD2.10 a pair!!), you go compare it with Mouser , Digikey or Element14...US$34 a pair. Go figure.

 

[acccruz]

OK. I will try to use this I/V stage with one of my TDA1541A - Red Baron DAC, please let me know your thoughts.
It's plug and play job with this DAC chip, or I need to do some resistors updates?

Many thanks for your attention,
Antonio

 

[zoom777]

I have no idea what is on the Red Baron, is there any I-V components? If yes, remove it...take the Iout and connect to the AD811 board and play. As simple as that.

 

[zoom777]

As far as the board I am selling is concerned, give it Iout direct from your DAC. Will work.

 

[zoom777]

I see that you have populated the passive IV resistors.
I do not have the schematic of your board to know what other parts besides these resistors are part of the IV scheme of things. You should have this information, I don't.

 

[acccruz]

The Red Baron TDA1541 board could have (or not) I/V components.
The idea is connecting your I/V board directly to the DAC Iout.

I will take a closer look at some forum comments about this I/V stage, and after dinner (local time) I will let you know more details.

Have a nice day (maybe already night where you live),
Antonio

 

[zoom777]

The Red Baron TDA1541 board could have (or not) I/V components.
The idea is connecting your I/V board directly to the DAC Iout.

Yes, in short you remove whatever IV components on the Red Baron, take the current outputs, feed to the AD811 board. It will work.
How I know? Well, I do have TDA1541 DAC boards.

At this point of time, it is available till it is no longer available ie. someone commits to the boards.

@acccruz we should really move our conversation to our DM which we have already started for this board.

 

[diyiggy]

It can only work if you inject 2 mA in the TDA1541 output as seen in numerous thread to move up the zero between +2 mA and -2mA insteadthe native 0 to -4 mA.

@accruz, You can use a bipolar per channel like the J113 for instance and trim to zero volt. Look at for instance Pedja Rogic's I/V stage free pdf with google.

Red Baron external stage if not tube certainly use the same technic : a bipolar of 2 to 15 mA for that task.

Then the values on the AD811 board are okay for the I/V related to TDA1541A.

 

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Still available for sale.