That is biamp.
You will need an extra 0.1R after the feedback loop.
And use 0.1% resistors.
See PA100 for LM3886 :
https://www.ti.com/lit/an/snaa021b/snaa021b.pdf
I would first experiment with parallel devices before biamp.
You can simply do a bench test first.
But all 4 devices per channel would have to come from the same quad.
Patrick
You will need an extra 0.1R after the feedback loop.
And use 0.1% resistors.
See PA100 for LM3886 :
https://www.ti.com/lit/an/snaa021b/snaa021b.pdf
I would first experiment with parallel devices before biamp.
You can simply do a bench test first.
But all 4 devices per channel would have to come from the same quad.
Patrick
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It is pointed out to me that D1 and D2 are swapped on the PCB compared to the schematics.
This has been made known to me before, but since they are identical parts (SMD 1N4148), it has no impact on the circuit.
I therefore do not see the necessity to change the Gerber files.
Cheers,
Patrick
This has been made known to me before, but since they are identical parts (SMD 1N4148), it has no impact on the circuit.
I therefore do not see the necessity to change the Gerber files.
Cheers,
Patrick
smalll update in concern to opamp rolling. (see post #297, #317 with LM329..)
For me it is worth it, because the OPA 828 beats all....really sounds fine and precise
(LT1793 is also better than OPA604 but some time I do have small shut down plop, sometimes not ??- dont know why....)
For me it is worth it, because the OPA 828 beats all....really sounds fine and precise
(LT1793 is also better than OPA604 but some time I do have small shut down plop, sometimes not ??- dont know why....)
some days ago, I had a sound session at my place.
Please understand, that I have in some weeks up to 20 hours of listening and that for more then 30 years.. in this room for 11years, so the following impression are subjective...
gear to be tested:
Combo
1) Pre amp BA3-with Fairchild Mosfet and power amp M2OPS with Fairchild (FQA16N25/FQA9P25 self selected -B-grade)
2) Pre amp BA3-with Toshiba Mosfet and power amp M2OPS with the famous Toshiba (only 14,8W/4R)
3) for comparison AVM Ovation A6.3
Hifi Chain-
Audioquest Niagara 1200- Power conditioner
Source-Streamer-DAC Auralic Vega G2.1
Loudspeaker KEF R11
cabling Furutech-DIY
The audience had a lot of fun and impressions on this day
The biggest jump was to change the power amp from Fairchild to Toshiba because IMO the possibility in the Toshiba to have the OPA828 inside!!
The differences between the pre amps was smaller but there. - Toshiba sounds alway more darker and had more low end especially the power amp, and again because of OPA828.
-Toshiba was more able to produce the contours of the actor clearer, but some found the mids are louder....
- Fairchild has also fine sparkling high end with more airiness and is a bit faster...
at the end we want to challenge the "man of the house"-----AVM, but all agree that the Tosiba combo makes more fun and more liveness and super details. -If you like class A you stay there
I was host in my house and was not all the time especially with the acting of the AVM in the listeening area, and busy with preparing beer and food. -So I was confuse that someone shout "through away this AVM crab" in a funny way of course.
Next day I try it by my self -- and can confirm, that in some situations the Toshiba combo is clearly the better one!!! with all the benefits of smooth and very dedailed sound
PS. for me is the next step the modify the power amp with fairchild, to be able to insert the OP-amp rolling possibility. the con s are the POwer swing of the opamp is limited and so you have limited power, particulary for 8R speakers..
And adding a better PS with Cap Multiplier....
Please understand, that I have in some weeks up to 20 hours of listening and that for more then 30 years.. in this room for 11years, so the following impression are subjective...
gear to be tested:
Combo
1) Pre amp BA3-with Fairchild Mosfet and power amp M2OPS with Fairchild (FQA16N25/FQA9P25 self selected -B-grade
)2) Pre amp BA3-with Toshiba Mosfet and power amp M2OPS with the famous Toshiba (only 14,8W/4R)
3) for comparison AVM Ovation A6.3
Hifi Chain-
Audioquest Niagara 1200- Power conditioner
Source-Streamer-DAC Auralic Vega G2.1
Loudspeaker KEF R11
cabling Furutech-DIY
The audience had a lot of fun and impressions on this day
The biggest jump was to change the power amp from Fairchild to Toshiba because IMO the possibility in the Toshiba to have the OPA828 inside!!
The differences between the pre amps was smaller but there. - Toshiba sounds alway more darker and had more low end especially the power amp, and again because of OPA828.
-Toshiba was more able to produce the contours of the actor clearer, but some found the mids are louder....
- Fairchild has also fine sparkling high end with more airiness and is a bit faster...
at the end we want to challenge the "man of the house"-----AVM, but all agree that the Tosiba combo makes more fun and more liveness and super details. -If you like class A you stay there
I was host in my house and was not all the time especially with the acting of the AVM in the listeening area, and busy with preparing beer and food. -So I was confuse that someone shout "through away this AVM crab" in a funny way of course.
Next day I try it by my self -- and can confirm, that in some situations the Toshiba combo is clearly the better one!!! with all the benefits of smooth and very dedailed sound
PS. for me is the next step the modify the power amp with fairchild, to be able to insert the OP-amp rolling possibility. the con s are the POwer swing of the opamp is limited and so you have limited power, particulary for 8R speakers..
And adding a better PS with Cap Multiplier....
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