On the subject of the output filter cap (C37, C38), post #684 talks about changing R10/R11 and C37/C38 to enhance bass. I built my boards with a 4n7 WIMA PP cap and 100 ohm resistor, per the schematic, and removed the cap this weekend per recommendations. I was surprised to hear much reduced bass.
In retrospect there was a bit more bass than seemed balanced, but I'd actually like to enhance the very bottom of the range to act in the same fashion as KEF's Kube equalizer. Is there a formula or source of information for how to compute the effect of the RC filter on the output EQ?
In retrospect there was a bit more bass than seemed balanced, but I'd actually like to enhance the very bottom of the range to act in the same fashion as KEF's Kube equalizer. Is there a formula or source of information for how to compute the effect of the RC filter on the output EQ?
I agree, the depth and detail of the bass are truly wonderful. So much so that it's a key part of what I've been listening for as I swap around opamps. As of yet, nothing has bettered the 627, although the 6171 and 4898 have proven to be quite nice for a fraction of the price. I will take your point about power supply, and after that may get sucked into a Burson purchase...
Removing the 4n7 C37/C38 was illuminating. In retrospect the bass was a little over-emphasized with the caps in place, but it also allowed the speakers that I'm using (KEF 104/2) to extend lower. KEF actually offered an outboard EQ to boost around 40-55Hz, so if I have time I'd like to play with the output filtering to duplicate that.
Until then, still pretty wonderful
Removing the 4n7 C37/C38 was illuminating. In retrospect the bass was a little over-emphasized with the caps in place, but it also allowed the speakers that I'm using (KEF 104/2) to extend lower. KEF actually offered an outboard EQ to boost around 40-55Hz, so if I have time I'd like to play with the output filtering to duplicate that.
Until then, still pretty wonderful
Those 3 are the oaps you have tested since?
The kef 104 Ref bass are special and not easy to test bass...55 hz f3 but subjectivly big and free...the two 16 cm are punching till 125 hz where the mid section beginns. I think the room gain is working for something correct and the f3 is not giving a lack... at the opposit I find it too much boomy : thought: ir is maybe the tweeter that is wasting thetranscient snappy behavior perhaps. I will not go for a kef Cube at the risk to enhance that boomy behavior...I will more play a little with the 50% stuffing of the two bass cabinets...the donuts are mandatory for a correct bbass if the foam is falling in dust....
The kef 104 Ref bass are special and not easy to test bass...55 hz f3 but subjectivly big and free...the two 16 cm are punching till 125 hz where the mid section beginns. I think the room gain is working for something correct and the f3 is not giving a lack... at the opposit I find it too much boomy : thought: ir is maybe the tweeter that is wasting thetranscient snappy behavior perhaps. I will not go for a kef Cube at the risk to enhance that boomy behavior...I will more play a little with the 50% stuffing of the two bass cabinets...the donuts are mandatory for a correct bbass if the foam is falling in dust....
I've also tried 5534 (dry/thin sounding), 4672 (lacking bottom), and 828 (not bad, not great).
There could well be room effects, my only tuning has been to use REW and a Umik to check response against pink noise - which looked OK. It did also show that the Kube worked, although it's noisy and not very precise. An interesting trick but not worth the effect, it sits on my desk.
The speakers were serviced ~4 years ago: new surrounds and donuts, Falcon matched caps in the crossover, and new ferrofluid. They stand away from the wall.
There could well be room effects, my only tuning has been to use REW and a Umik to check response against pink noise - which looked OK. It did also show that the Kube worked, although it's noisy and not very precise. An interesting trick but not worth the effect, it sits on my desk.
The speakers were serviced ~4 years ago: new surrounds and donuts, Falcon matched caps in the crossover, and new ferrofluid. They stand away from the wall.
Fantastic offer Paddy!! That’s the DIYA spirit
I’m sure you’ll have some PM’s coming your way.
Btw, for people who want to measure his speaker through different dacs using a file, here some sources of free sweep tones : can help to look at the low pass filter belows 20 k hz for whom using it for NOS materials ! ... or simply measure his speakers
Sine Sweep - Full Spectrum (20 Hz - 20 kHz)
Audio Test Signals - Genelec.com
Free Online Frequency Sweep Generator | OnlineToneGenerator.com
Sine Sweep - Full Spectrum (20 Hz - 20 kHz)
Audio Test Signals - Genelec.com
Free Online Frequency Sweep Generator | OnlineToneGenerator.com
#917
It is LT3045/3094 LDO DC-DC regulator.
#919
From China, but you know, there is no guarantee if they are fake or real.
by the way, if possible, please kindly advise which power supply shown below may be better for AD1862-:
1. Power supply (+-4.75DCV and +- 11.8DCV) after LDO or
2. Power supply (+-5.05DCV and +-12.1DCV) after LM7812/7912 for AC to DC
Thank You
It is LT3045/3094 LDO DC-DC regulator.
#919
From China, but you know, there is no guarantee if they are fake or real.
by the way, if possible, please kindly advise which power supply shown below may be better for AD1862-:
1. Power supply (+-4.75DCV and +- 11.8DCV) after LDO or
2. Power supply (+-5.05DCV and +-12.1DCV) after LM7812/7912 for AC to DC
Thank You
Last edited: