Hi,
On my beloved Threshold Fet 1 series II preamp, I changed the Noble pot to a motorized ALPS RK27 one, which is theoretically a step backwards.
Reason is the comfort of a remote control of course.
The Noble pot was a 25k, the ALPS is a 50k - didn't have any other in stock.
After several hour of work (had to move the complete PCB to the back and lover it 5mm to fit the much longer ALPS), everything's set, and it works.
I realise that the complete level is done from the zero position until 10 o'clock, with an average listening position of 9 o'clock. The motor is very responsive, and setting the right volume is somewhat pain in the ***.
Thel audio engineering is Germany is selling TKD pots with with hardened conductive plastic tapers. Said to be as good as Noble, but they come wit a motor.
The model is CP-2500 and is available with 10k, 50k and 100k.
Which one should I use, to have a broader volume control?
I could also L-pad the output, with HQ resistors, but that's not so noble (without wordgames).
Thanks for helping me here.
- dan
On my beloved Threshold Fet 1 series II preamp, I changed the Noble pot to a motorized ALPS RK27 one, which is theoretically a step backwards.
Reason is the comfort of a remote control of course.
The Noble pot was a 25k, the ALPS is a 50k - didn't have any other in stock.
After several hour of work (had to move the complete PCB to the back and lover it 5mm to fit the much longer ALPS), everything's set, and it works.
I realise that the complete level is done from the zero position until 10 o'clock, with an average listening position of 9 o'clock. The motor is very responsive, and setting the right volume is somewhat pain in the ***.
Thel audio engineering is Germany is selling TKD pots with with hardened conductive plastic tapers. Said to be as good as Noble, but they come wit a motor.
The model is CP-2500 and is available with 10k, 50k and 100k.
Which one should I use, to have a broader volume control?
I could also L-pad the output, with HQ resistors, but that's not so noble (without wordgames).
Thanks for helping me here.
- dan
You can use whatever value you want, it pretty much won't matter. Choose depending on required input impedance and permissible source impedance (input impedance distortion of following stage) - control characteristic will be just about exactly the same for all of them.
If the volume pot is very fiddly, either you mistakenly installed a linear taper pot rather than a log, or your gain or input levels are too high. With CD levels being what they are these days (easily 10 dB higher than 25 years ago), a lot of people have been cursing their volume pots on typical ~45 dB gain integrated amps.
If the volume pot is very fiddly, either you mistakenly installed a linear taper pot rather than a log, or your gain or input levels are too high. With CD levels being what they are these days (easily 10 dB higher than 25 years ago), a lot of people have been cursing their volume pots on typical ~45 dB gain integrated amps.
The ALPS is a log, for sure.
As I don't have the schematics, and I suppose the pot is ahead of the line stage, increasing from 25k to 50k shouldn't be a problem. As most of the time I'm listening to vinyls and using the integrated outstanding phono stage though, I have have no idea of their respective input/ output impedances.
Hope I will make the right choice...
- dan
As I don't have the schematics, and I suppose the pot is ahead of the line stage, increasing from 25k to 50k shouldn't be a problem. As most of the time I'm listening to vinyls and using the integrated outstanding phono stage though, I have have no idea of their respective input/ output impedances.
Hope I will make the right choice...
- dan
It is possible (permissable even 
to simply insert a wee resistor in line with each of the interconnects.
Readily / easily reducing the input voltage. Experiment further until the result (ohmage) gives you exactly want you want. When fully satisfyined it's possible to bury the required resistor inside the RCA pug.
If neatness matters
Going from 25k to 50k is a very small change. Not worth the effort imo.
to simply insert a wee resistor in line with each of the interconnects. Readily / easily reducing the input voltage. Experiment further until the result (ohmage) gives you exactly want you want. When fully satisfyined it's possible to bury the required resistor inside the RCA pug.
If neatness matters
Going from 25k to 50k is a very small change. Not worth the effort imo.
It is possible (permissable even
Readily / easily reducing the input voltage. Experiment further until the result (ohmage) gives you exactly want you want. When fully satisfyined it's possible to bury the required resistor inside the RCA pug.
If neatness matters
Going from 25k to 50k is a very small change. Not worth the effort imo.
Probably a good idea to do this at the pot end rather than the rca input end that way you keep the signal strength right up to the pot which may help reduce interference.
You might like to check out the L-pad method of attenuation for the Alps pot
http://www.diyaudio.com/forums/anal...osing-potentiometer-passive-preamplifier.html
it's the "sticky" at the top of this section.
it's the "sticky" at the top of this section.
From your description, it's likely that there is already a resistor on the board before the pot.
If so, you can double its value to restore a similar control action, assuming that the taper
of the new control is similar.
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