Hi Guys,
I would like to know if i change my volume control ( Black beauty ) by stepped attenuator Elma, will I improve a lot my sound quality? And if yes what's the best shunt or serie. it's my preamp at this link post 32:
http://www.diyaudio.com/forums/showthread.php?postid=1541169#post1541169
Thank you in advance! Maxpou
I would like to know if i change my volume control ( Black beauty ) by stepped attenuator Elma, will I improve a lot my sound quality? And if yes what's the best shunt or serie. it's my preamp at this link post 32:
http://www.diyaudio.com/forums/showthread.php?postid=1541169#post1541169
Thank you in advance! Maxpou
stepped is always better than plain pot
you'll hear difference as much your next stage is good ;
real shunt is always better than plain series
you'll hear difference as much your next stage is good ;
real shunt is always better than plain series
alps black beauty is a stereo rotary switch with laser trimmed resistors, unless its a fake (there are plenty counterfeits) .
Thank you guys for reply,
but the shunt stepped attenuator change my input impedance and change the sound too depending Charles Hansen, but if i read the borbely document he said there was no difference. Somebody can tell me who said true? Thank you! Maxpou
but the shunt stepped attenuator change my input impedance and change the sound too depending Charles Hansen, but if i read the borbely document he said there was no difference. Somebody can tell me who said true? Thank you! Maxpou
maxpou,
is this your best shot for a good sounding circuit? I would in the first place make topological changes to get significant improvement.
is this your best shot for a good sounding circuit? I would in the first place make topological changes to get significant improvement.
Lumba Ogir said:
Hi,
thank you for reply Lumba Ogir, what do you want to change for improvement? thank you Maxpou
maxpou, this is my guess:
> You should change it, so it will be like one of Lumba Ogir JFET amplifiers
... the only drawback, is that it will no longer be your design
Lumba Ogir JFET amp circuits & projects topics,
which we have seen plenty many of (do I need to provide links?)
are those that can work very well and so not get critical comment from Lumba.
In fact, they are above John Curl class, if I have understood Lumba's posts correctly.
Personally, I like your amplifier very much.
You have done most everything possible to improve JFET Stages.
Using cascodes.
Maybe you have mentioned what Supply voltage you use?
It is not in schematic
http://www.diyaudio.com/forums/attachment.php?s=&postid=1541169&stamp=1213720316
My guess is like +- 18-20 Volt, regulated.
> You should change it, so it will be like one of Lumba Ogir JFET amplifiers
... the only drawback, is that it will no longer be your design
Lumba Ogir JFET amp circuits & projects topics,
which we have seen plenty many of (do I need to provide links?)
are those that can work very well and so not get critical comment from Lumba.
In fact, they are above John Curl class, if I have understood Lumba's posts correctly.
Personally, I like your amplifier very much.
You have done most everything possible to improve JFET Stages.
Using cascodes.
Maybe you have mentioned what Supply voltage you use?
It is not in schematic
http://www.diyaudio.com/forums/attachment.php?s=&postid=1541169&stamp=1213720316
My guess is like +- 18-20 Volt, regulated.
Hi guys!
thank you for fast reply!
I use 23V supply voltage look at: http://www.diyaudio.com/forums/showthread.php?postid=1524207#post1524207
I'm not sure if i need a voltage gain stage, i change the DAC in CD player and i think that i have 1,4Vp-p output.
thank you! Maxpou
thank you for fast reply!
I use 23V supply voltage look at: http://www.diyaudio.com/forums/showthread.php?postid=1524207#post1524207
I'm not sure if i need a voltage gain stage, i change the DAC in CD player and i think that i have 1,4Vp-p output.
thank you! Maxpou
Hi guys,
i found this website for calculate the resistors for my shunt attenuator, but what's the best serie value and how many DB between each step because i have 24 step. Thank you! Maxpou
http://homepages.tcp.co.uk/~nroberts/shunt.html
i found this website for calculate the resistors for my shunt attenuator, but what's the best serie value and how many DB between each step because i have 24 step. Thank you! Maxpou
http://homepages.tcp.co.uk/~nroberts/shunt.html
Hi Max,
do you know what range of attenuation values you currently use?
Design each step to suit your needs.
It could be done with equal steps of 1dB giving a total attenuation -23dB.
or
steps of 1.5dB giving -34.5dB
or
steps of 2dB giving -46dB.
or
unequal steps.
Use big steps in the range you rarely or never use and small steps in the range you typically use. eg, 0, -6, -12, -18, -20, -22, -24, -26, -29, -30, -31, -32, -33, -34, -35, -36, -37, -40, -43, -46, -50,
-55, -60, -70.
You choose what best suits your use and your system.
do you know what range of attenuation values you currently use?
Design each step to suit your needs.
It could be done with equal steps of 1dB giving a total attenuation -23dB.
or
steps of 1.5dB giving -34.5dB
or
steps of 2dB giving -46dB.
or
unequal steps.
Use big steps in the range you rarely or never use and small steps in the range you typically use. eg, 0, -6, -12, -18, -20, -22, -24, -26, -29, -30, -31, -32, -33, -34, -35, -36, -37, -40, -43, -46, -50,
-55, -60, -70.
You choose what best suits your use and your system.
Lumba Ogir said:
Lumba, I'm happy to see you recommending JFET/bibolar CFP, the best input stage. Just make it differential, and everything's honky dory.
that calculator does not make it easy to have constant Zin, nor does it take account of the Zin of the next stage.maxpou said:
Find a better calculator.
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