Hey Anatech
I don´t use feedback because I wanted to make a balanced amp (first balanced in) and with a circuit without feedback I can easier optimize every stage to perform at their best -> every step I take give it´s result in listening and measurements.
Therefore I think I can make a great circuit for me without Negative feedback and avoids thinks like TIM distortion and delay time in feedback and so on, thats degrade sound and lower stability (Hard said understand me wright)
Best regards
Kim
I don´t use feedback because I wanted to make a balanced amp (first balanced in) and with a circuit without feedback I can easier optimize every stage to perform at their best -> every step I take give it´s result in listening and measurements.
Therefore I think I can make a great circuit for me without Negative feedback and avoids thinks like TIM distortion and delay time in feedback and so on, thats degrade sound and lower stability (Hard said understand me wright)
Best regards
Kim
Hey
Thanks Anatech for your input.
I agree with you, and this is what I do with my power amplifier, linear circuit as possible and only 26dB off feedback, butt then no balanced in, So I stick with the principle for now.
Is it possible to rise the value off R8 and then put in a good quality potmeter in parallel with it, and then you can have balanced in and thereby regulate the volume with one single potmeter?
Will this result in a bad thing from the output buffer?
Best regards
Thanks Anatech for your input.
I agree with you, and this is what I do with my power amplifier, linear circuit as possible and only 26dB off feedback, butt then no balanced in, So I stick with the principle for now.
Is it possible to rise the value off R8 and then put in a good quality potmeter in parallel with it, and then you can have balanced in and thereby regulate the volume with one single potmeter?
Will this result in a bad thing from the output buffer?
Best regards
Hi Kim,
Well, you are changing the load on the vas. You really don't want to load that because the THD can increase. As you try a higher value for R8 watch the DC offset without the integrator connected and disconnected from the front end. Then try to get a balance with the front end connected by playing with those components. The integrator shouldn't need to do much work (or it may not be required at all).
If you can get your offset down to 40 - 50mV with 100K for R8 you may find your THD goes down with better sound quality. Once everything is naturally balanced near o V output your integrator can be reconnected. This will give a more stable circuit.
For my amps I try to run less than 10dB feedback if possible. The dynamics seem to be better.
-Chris
Well, you are changing the load on the vas. You really don't want to load that because the THD can increase. As you try a higher value for R8 watch the DC offset without the integrator connected and disconnected from the front end. Then try to get a balance with the front end connected by playing with those components. The integrator shouldn't need to do much work (or it may not be required at all).
If you can get your offset down to 40 - 50mV with 100K for R8 you may find your THD goes down with better sound quality. Once everything is naturally balanced near o V output your integrator can be reconnected. This will give a more stable circuit.
For my amps I try to run less than 10dB feedback if possible. The dynamics seem to be better.
-Chris
Hey
I mean if R8= 2.7k and in parallel with a 10K potmeter, the potmeter will holds its 10k input and varying its output ressitance.
So the vas load is still seing a 2K resistor at it´s collector
The DC servo will then take care off the small dc offset at the output, and the output will hold it´s dc offset low
Best regards
I mean if R8= 2.7k and in parallel with a 10K potmeter, the potmeter will holds its 10k input and varying its output ressitance.
So the vas load is still seing a 2K resistor at it´s collector
The DC servo will then take care off the small dc offset at the output, and the output will hold it´s dc offset low
Best regards
Hey
I thought about it, it can only do as a outputstage in a cdplayer with constant output voltage.....
So i put the potmeter in the positive input and later i must do a dubble volume control so I can make it balanced in.
About the sound it´s very fast clean and analytical, I think the diamond buffer likes the high tones very much, The bass is fast and deeb butt to light in my taste.
Can I do anything to make a more warm sound?
Kim
I thought about it, it can only do as a outputstage in a cdplayer with constant output voltage.....
So i put the potmeter in the positive input and later i must do a dubble volume control so I can make it balanced in.
About the sound it´s very fast clean and analytical, I think the diamond buffer likes the high tones very much, The bass is fast and deeb butt to light in my taste.
Can I do anything to make a more warm sound?
Kim
Hi Kim,
Yes, I use LED based current sources. They isolate the signal from the supply thus giving lower noise. The input impedance becomes higher and high level signals are handled better. The current level depends on the application and supply voltage. I like using higher supplies around 30V bipolar to handle peaks.
It's hard to go wrong withthe basic diamond buffer. Just theramally couple the transistors to stabilise the bias in the outputs.
-Chris
Yes, I use LED based current sources. They isolate the signal from the supply thus giving lower noise. The input impedance becomes higher and high level signals are handled better. The current level depends on the application and supply voltage. I like using higher supplies around 30V bipolar to handle peaks.
It's hard to go wrong withthe basic diamond buffer. Just theramally couple the transistors to stabilise the bias in the outputs.
-Chris
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