http://www.linearsystems.com/datasheets/ProdSel.pdf
Also crossreferences to LS842, which is a dual N, so go figure...
top left page #8
Also crossreferences to LS842, which is a dual N, so go figure...
top left page #8
I do think that this amp does need a good source because it is very honest in it's reproduction, but the only time I felt it was adding harshness was when I reduced my gate stoppers to 50R. When I changed them to 270R it was fine again.
If digital sources are sounding harsh I would also optimise the i/p filter to -3dB @ 50 - 100kHz
. . . . and take care of any possible PSU noise sources
If digital sources are sounding harsh I would also optimise the i/p filter to -3dB @ 50 - 100kHz
. . . . and take care of any possible PSU noise sources
changes made in the amp.
I have made some changes, so it can get higher supply voltage, a couple more j fets, I have not use the vertical mosfets, she are indeed more harsh on my own hybride amp, a higher idle current wil remove that for a big part.
R8 and R9 can maybe be better current mirrors with bipolairs but it make the schematic again more complicated, driver idle current wil react if set output current..
But audio amps has so much possibilities, I made some combinations of it..
I want to say, try it.
I have made some changes, so it can get higher supply voltage, a couple more j fets, I have not use the vertical mosfets, she are indeed more harsh on my own hybride amp, a higher idle current wil remove that for a big part.
R8 and R9 can maybe be better current mirrors with bipolairs but it make the schematic again more complicated, driver idle current wil react if set output current..
But audio amps has so much possibilities, I made some combinations of it..
I want to say, try it.
Last edited:
It's true, there are some bad recordings out there but in the last couple of years my conclusion has been that in some ways good digital reproduction is actually smoother than reality rather than rougher and there are few, if any recordings I can think of that actually sound harsh.
Also, I'm a bit cautious to deliver a final guilty verdict on any particular digital recording because too often I have witnessed better reproduction transform recordings that I had thought were write-offs
For me this amp has lifted a veil of "grunge" from the sound that I previously attributed to the digital or DAC domains . . . so all in all my opinion of digital as a medium to deliver musical music has risen to level that leaves me, thus far, reasonably content.
here is the vertical version.
Well, change it to vertical is not so bad job, I have a vbe multiplier added, play some with the 82 ohm for stable idle current, it is from a excisting amp here, with the same idle current of the drivers.
But I hear from the hybrides the lateral are more smoother, you are right here.
Well, change it to vertical is not so bad job, I have a vbe multiplier added, play some with the 82 ohm for stable idle current, it is from a excisting amp here, with the same idle current of the drivers.
But I hear from the hybrides the lateral are more smoother, you are right here.
Last edited:
well thank you, now you can use higer voltages with the limitations of the j fets.
My amp starts at 120mV today, over time it will drift to below 10mV, unless something changed while I slept.
It is frustrating to me, not knowing whether the harshness comes from the recording or the amp.
Kenpeter, I took a look at those dual Jfet and it turns out they were 2N5564, not 5464 as you had wrote! So I can use them as either the input or CCS, or both, barring excessive inter-jfet capacitance.
http://www.datasheetcatalog.org/datasheet/vishay/70254.pdf
- keantoken
It is frustrating to me, not knowing whether the harshness comes from the recording or the amp.
Kenpeter, I took a look at those dual Jfet and it turns out they were 2N5564, not 5464 as you had wrote! So I can use them as either the input or CCS, or both, barring excessive inter-jfet capacitance.
http://www.datasheetcatalog.org/datasheet/vishay/70254.pdf
- keantoken
I have gone through many phases of adjusting my headphone amplifier. Generally what happens is I achieve greater resolution and a sense of space, and greatly improved clarity, but then the treble seems greatly emphasized, if not harsh. Is it possible it is because of my speakers?
I cannot be sure whether the harshness comes from the source or the amp. Once I switched back to my old Creative soundcard to help with harshness but again there was the loss of quality. Hmm. I wonder if positive phase shift in the treble is a factor here, because increasing the speed of the amplifier will decrease HF phase lag.
I added the VAS degeneration, and that calmed the sound a bit, but also seemed to lower quality in other areas. I am about to add the CCS.
- keantoken
I cannot be sure whether the harshness comes from the source or the amp. Once I switched back to my old Creative soundcard to help with harshness but again there was the loss of quality. Hmm. I wonder if positive phase shift in the treble is a factor here, because increasing the speed of the amplifier will decrease HF phase lag.
I added the VAS degeneration, and that calmed the sound a bit, but also seemed to lower quality in other areas. I am about to add the CCS.
- keantoken
Are they full range drivers? They look rugged around sibilance frequencies. They also need a lot of step correction. Much higher sensitivity up high.
Have been messing with analogous Hemp FR8s and they needed a low Q wide band in series notch filter (parallel RLC) to tame. Else, they were high forward. Or DSP of course. Try with a parametric EQ module from your PC and do the in/out filter A/B test to get an idea. Using a mic is the key, but you can start by roughly evening out that chart by ear try outs. Just to have a hint if its the amp or not.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.