Hi,
I'd like to ask for some good schematic for active tone control, for treble and bass (cca+-20dB) with loudness compensation, I have saw several designs, but all of these designs uses elements that I want to avoid.
I don't like to use:
1. tone control ic's like tda1524 or lm1036
2. center tapped pot, because it is hard to find in My country.
3. "center tapped" attenuator for volume control
4. dsp
Exactly I am not sure is it possible to build this (loudness compensation is important) avoiding things from My list ?!
Thanks for help.
I'd like to ask for some good schematic for active tone control, for treble and bass (cca+-20dB) with loudness compensation, I have saw several designs, but all of these designs uses elements that I want to avoid.
I don't like to use:
1. tone control ic's like tda1524 or lm1036
2. center tapped pot, because it is hard to find in My country.
3. "center tapped" attenuator for volume control
4. dsp
Exactly I am not sure is it possible to build this (loudness compensation is important) avoiding things from My list ?!
Thanks for help.
thoronx said:Hi,
I'd like to ask for some good schematic for active tone control, for treble and bass (cca+-20dB) with loudness compensation, I have saw several designs, but all of these designs uses elements that I want to avoid.
I don't like to use:
1. tone control ic's like tda1524 or lm1036
2. center tapped pot, because it is hard to find in My country.
3. "center tapped" attenuator for volume control
4. dsp
Exactly I am not sure is it possible to build this (loudness compensation is important) avoiding things from My list ?!
Thanks for help.
Loudness compensation is simply lifting the bass and treble at lower listening levels. This is to compensate for the hearings losses at low sound levels.
Try this
http://www.redcircuits.com/Page67.htm
Play around with caps to suit your Bass-Treble taste.
http://www.redcircuits.com/Page67.htm
Play around with caps to suit your Bass-Treble taste.
From My point of view Loudness Compensation (with Tone Control) is a 'must' for an amp, specially when I listen music at low volumes as I do frequently ...
I had extreme amount of Google (web and image) queries in the past few months about Loudness compensation or practical implementation of Fletcher–Munson curves,
maching my requirements (no tone control ic, no center tapped pot, no tapped attenuator, no dsp), but without any significant result (schematic+pcb), what was found is a few interesting schematic:
1. PC Preamp Project By Dave Erickson http://www.djerickson.com/pcpreamp/, the schematic is http://www.djerickson.com/pcpreamp/pdf/Pc_preamp.pdf
2. ON Semiconductor's document "Audio Circuits Using the NE5532/4" http://www.eetasia.com/ARTICLES/2007FEB/PDF/EEOL_2007FEB26_ACC_AN_01.pdf
...then I gave up google.
Next I had an idea to find some service manuals for any legacy amplifiers that uses Loudness button (amps mainly produced in the 70's 80's 90's ...) so I went to
http://www.eserviceinfo.com/ and with help of Google (to find model of the amp) downloaded different service manuals, and now I am analysing them ... Sony's implementation in amp model TA-FE210 is looking good ...
I had extreme amount of Google (web and image) queries in the past few months about Loudness compensation or practical implementation of Fletcher–Munson curves,
maching my requirements (no tone control ic, no center tapped pot, no tapped attenuator, no dsp), but without any significant result (schematic+pcb), what was found is a few interesting schematic:
1. PC Preamp Project By Dave Erickson http://www.djerickson.com/pcpreamp/, the schematic is http://www.djerickson.com/pcpreamp/pdf/Pc_preamp.pdf
2. ON Semiconductor's document "Audio Circuits Using the NE5532/4" http://www.eetasia.com/ARTICLES/2007FEB/PDF/EEOL_2007FEB26_ACC_AN_01.pdf
...then I gave up google.
Next I had an idea to find some service manuals for any legacy amplifiers that uses Loudness button (amps mainly produced in the 70's 80's 90's ...) so I went to
http://www.eserviceinfo.com/ and with help of Google (to find model of the amp) downloaded different service manuals, and now I am analysing them ... Sony's implementation in amp model TA-FE210 is looking good ...
This looks very interesting as loudness controls are always avoided due to the poor reputation they got when first implemented. Signal conditioning opamps are very good nowadays. For the tone control look at the LM4562 datasheet[ http://cache.national.com/ds/LM/LM4562.pdf ] page 28. For the loudness control i have no idea so i will keep reading the thread.
1. PC Preamp Project By Dave Erickson (http://www.djerickson.com/pcpreamp/)
Attachments
I was just surfing around, and found another interesting variable loudness compensation solution used by Yamaha in AX-596 integrated amplifier the service manual is here .... http://www.audio-circuit.dk/Schematics/Yamaha_AX-596_int_sm.pdf (4M, page 16)
Could I change a component in one of these to get boost at 100 and 10,000hz?
tone control, Amplifiers, Turntables. Great deals on eBay!
tone control, Amplifiers, Turntables. Great deals on eBay!
Read this thread for discussion on loudness control:
http://www.diyaudio.com/forums/multi-way/154209-reverse-old-loudness-control.html
http://www.diyaudio.com/forums/multi-way/154209-reverse-old-loudness-control.html
Thronx, I built many pre-amps based on the Baxandall bass/treble boost and cut circuit and back in the early 80's it was relatively easy to get log pots with a CT to do loudness control. Looking at the above circuits, I'd say the Dave Erickson circuit looks quite good - classic Baxandall but with the added loudness control for low levels. As in all things, make sure you don't overdo the loudness - you really don't want this having any effect (or minimal effect) once you get to normal listening levels (but of course, you can alway turn the loudness off if you want). You can also downwload LTSPICE and experiment with the values to fine tune your final effort.
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