Hi,
have some ALPS RK27x adapter pcbs left for sale.
Pot and connector strip not included, this is just the PCB.
Cost: 2€ each pcb
Shipping in a padded envelope (not tracked or insured):
have some ALPS RK27x adapter pcbs left for sale.
Pot and connector strip not included, this is just the PCB.
Cost: 2€ each pcb
Shipping in a padded envelope (not tracked or insured):
- germany (without islands) : 2,50€
- world wide (without UK, sorry guys to much paperwork for the customs): 4,50€
Well you can sell me 1, yes one... Eins🙂 Not exactly the start of being rich but anyway...
If you ever consider to have these made again please have an RC filter included. It can either serve as an input filter to prevent pickup of unwanted signals in todays RF ridden aether or just the resistors as attenuators in case of a too high gain of the amplifier. Or as a way to up the input impedance a little in case that RK27 10 kOhm is a tad too tough for the wimpy tube device in front of it.
If you ever consider to have these made again please have an RC filter included. It can either serve as an input filter to prevent pickup of unwanted signals in todays RF ridden aether or just the resistors as attenuators in case of a too high gain of the amplifier. Or as a way to up the input impedance a little in case that RK27 10 kOhm is a tad too tough for the wimpy tube device in front of it.
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@jean-paul
1. one / ein pcb is possible => I write a conversation
2. nice idea, how did you thing should the schematics looks?
1. one / ein pcb is possible => I write a conversation
2. nice idea, how did you thing should the schematics looks?
Just an SMD resistor in each channel to the potentiometer and a TH film cap to GND. It gives more than 2 extra possibilities at almost no extra cost.
If the chain is DC coupled input caps are also possible. IMHO there should be DC protection somewhere in the chain, the power amplifiers inputs being the most obvious place. Also to prevent "scratching" of the RK27 in case of slight DC offset. If PCB pads for 2 molex 3 pin input connectors are used one does not need jumpers either when deciding for input caps or no input caps.
* In some circles people laugh at input filters (you can't hear RF 🙂) and they just don't use them but a measurement in ones own environment will stop the laughing.
For input caps Wima 4.7 µF 5 mm pitch work OK with RK27 10 kOhm. GND reference resistors can be 100... 220 kOhm SMD 0805. RC filter can be dimensioned to be -3 dB at 100 kHz like 1.5 kOhm and 1000 pF/1nF styroflex/polypropylene/polyester.
If the chain is DC coupled input caps are also possible. IMHO there should be DC protection somewhere in the chain, the power amplifiers inputs being the most obvious place. Also to prevent "scratching" of the RK27 in case of slight DC offset. If PCB pads for 2 molex 3 pin input connectors are used one does not need jumpers either when deciding for input caps or no input caps.
* In some circles people laugh at input filters (you can't hear RF 🙂) and they just don't use them but a measurement in ones own environment will stop the laughing.
For input caps Wima 4.7 µF 5 mm pitch work OK with RK27 10 kOhm. GND reference resistors can be 100... 220 kOhm SMD 0805. RC filter can be dimensioned to be -3 dB at 100 kHz like 1.5 kOhm and 1000 pF/1nF styroflex/polypropylene/polyester.
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Ok, will remember this for the next batch ... but I don't think this will happen in the near future.