Arduino based LDR volume and source selection controller

[t-minik]

Hi zdr.

My board is 2.2z.
I would like to add an op amp buffer just before the two output relays .
As there is no schematics available, can you tell me if there is a best trace to cut?
I don't really understand how mute and calibration relays are used when calibrating, perhaps it's a bad idea and will disturb calibration procedure?

Thanks in advance.
Best regards

 

[wineds]

RMI-FC100 is class A until 8W so there is some heat dissipated, but it can be biased for less dissipation. Better to ask for details in the FC100 thread.

I thought it was only class A until 2w? viz :

Class A power: 2W rms into 8ohm with Iq=0.6A (maximum Iq for optimal B class bias)

 

[rpafenberg]

zdr,

Is there any easy way to test for ldr failure since I can't get past error 20 to measure them. I am getting approximately 5V across the three relays, which should be enough for operation. I am using the NSL-32R3 in this build; which I believe you have said in past posts were slow on calibration but should work.

Regards,

Roy

 

[wineds]

Roy, did you check that the LDRs are orientated correctly? On my last build I had error 20 due to an incorrectly orientated LDR (white dot had worn off).

 

[rpafenberg]

Yes, all my dots are in a row. I have one that has the top engravings reversed from the others but I have seen that on other builds that operated correctly.

 

[zdr]

Measure the resistance of each ldr, I think they should still be in ON state during error 20.

 

[zdr]

I thought it was only class A until 2w? viz :



Class A power: 2W rms into 8ohm with Iq=0.6A (maximum Iq for optimal B class bias)

Indeed, i confused watts with ohms

 

[t-minik]

Hello

@zdr , not any clue for a trace where I can add buffer before the two output relays?
I really would like to add a buffer.

If I refer to Vincent77 schematics it seems calibration relays disconnects output when calibrating, am I wrong?

Best regards

 

[zdr]

No idea, but you can trace it easily with multimeter.

 

[pepenoutte]

R6 relay

Hi,

I have a tube preamp that needs to preheat the tubes before applying full B+ voltage, I want to use the "+ R6" header on the board to connect a SPST low current 12v relay.
Is this model of relay (G2RL-1A-E-ASI DC12) can make the job ?
How I connect the coil ? +12V at one side and R6 at the other side ?

Thanks for ansewering and best regards

 

[zdr]

Last few boards with relays available, I can ship today before leaving for vacation.

 

[zdr]

Hi,

I have a tube preamp that needs to preheat the tubes before applying full B+ voltage, I want to use the "+ R6" header on the board to connect a SPST low current 12v relay.
Is this model of relay (G2RL-1A-E-ASI DC12) can make the job ?
How I connect the coil ? +12V at one side and R6 at the other side ?

Thanks for ansewering and best regards

sounds like it should work!

 

[zdr]

LDR pre mkII SE with RMI-FC100, does not get much better than this.

 

[rpafenberg]

Neb,

Got any boards left?

 

[zdr]

I just got one fully completed board left, used for testing.

 

[zdr]

Ready to move to the next level? Meet LDR mkII SE




4 x16bit dac instead of 8bit, firmware fully operated by remote, all parameters exposed in the user menu and stored in EEPROM, etc.

 

[zdr]

 

[rpafenberg]

Is it available yet?

 

[zdr]

It’s still under test. It requires a hard modified version of Arduino Nano with Atmega328PB to utilise all available 16bit timers. There is no more high/low range switching causing volume bumps, so the dac hardware is also modified. Power supply is fully on 5v, no 12v any more.

 

[marma1961]

Getting a bit closer to the LightStream Mk II from The Vinyl Source I see