Hi all,
I implement my own hybrid headphone amp base on the Schiit Vali schematic, but the sound of Schiit Vali is much better then mine so i wondering why.
In my implement, i use 12au7, ccs load plate at 3.8ma, 400r cathode resistor without bypass, 100V B+ regulated using maida regulator, 30V for output stage regulated by low noise TPS7a4901. So everything seem to be better but mine sound worse, Schiit Vali just sound more expansive, vivid, slam harder, so i wonder can that be the 6088 or DHT special sound? Something also that make me lead to that thought is the vali 2 which use 6dj8 type tube also sound quite boring compare to the vali.
Here is the Schiit Vali schematic, i want to post mine but i have lost it when my hdd die, only gerber file left https://www.schiit.com/public/upload/PDF/Vali Mini Schematic.pdf
I implement my own hybrid headphone amp base on the Schiit Vali schematic, but the sound of Schiit Vali is much better then mine so i wondering why.
In my implement, i use 12au7, ccs load plate at 3.8ma, 400r cathode resistor without bypass, 100V B+ regulated using maida regulator, 30V for output stage regulated by low noise TPS7a4901. So everything seem to be better but mine sound worse, Schiit Vali just sound more expansive, vivid, slam harder, so i wonder can that be the 6088 or DHT special sound? Something also that make me lead to that thought is the vali 2 which use 6dj8 type tube also sound quite boring compare to the vali.
Here is the Schiit Vali schematic, i want to post mine but i have lost it when my hdd die, only gerber file left https://www.schiit.com/public/upload/PDF/Vali Mini Schematic.pdf
Should 6088 sound better than 12au7
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Only if you have both Bat's ears & a good imagination. 👍
The reality is that each will have a degree of distortion but a different signature.
What kind of non-linear path we put the performance thru to an extent will determine the sound perceived.
But the loudspeaker, its enclosure & the listening space will have far more influence.
And a good glass of wine always enhances the result.😀
Too most people the bottom line sez 'After a couple of Beers, no one cares'.
--------------------------------------------------
Only if you have both Bat's ears & a good imagination. 👍
The reality is that each will have a degree of distortion but a different signature.
What kind of non-linear path we put the performance thru to an extent will determine the sound perceived.
But the loudspeaker, its enclosure & the listening space will have far more influence.
And a good glass of wine always enhances the result.😀
Too most people the bottom line sez 'After a couple of Beers, no one cares'.
proid,
Your link schematic shows a DH 6418 pentode, not a DH 6088 pentode. Note, the diagram for both of those tubes shows beam formers (like a beam power tube; not a pentode)
But you are not going to easily shoe-horn either a 12AU7 or 6DJ8 into that schematic.
Please post your 12AU7 amplifier schematic.
Note, there are lots more solid state devices than tube devices in that link.
Not including the power supply, the ratio is 4 SS versus 1 T.
If devices 'have' a sound, does only the tube have a sound?
If you do not want to use either a 6418 or a 6088, you might consider:
A completely different circuit that uses a 6DJ8 (different than the 6DJ8 circuit that you say sounds bad).
Alternatively, consider an all solid state circuit.
Your link schematic shows a DH 6418 pentode, not a DH 6088 pentode. Note, the diagram for both of those tubes shows beam formers (like a beam power tube; not a pentode)
But you are not going to easily shoe-horn either a 12AU7 or 6DJ8 into that schematic.
Please post your 12AU7 amplifier schematic.
Note, there are lots more solid state devices than tube devices in that link.
Not including the power supply, the ratio is 4 SS versus 1 T.
If devices 'have' a sound, does only the tube have a sound?
If you do not want to use either a 6418 or a 6088, you might consider:
A completely different circuit that uses a 6DJ8 (different than the 6DJ8 circuit that you say sounds bad).
Alternatively, consider an all solid state circuit.
Last edited:
hi 6A3sUMMER,
Although 6418 is use in that schematic but it can be substitute by 6088
Here is quick redraw the schematic as i have lost my schematic when my hdd die. The servo is there to center output stage at 15V, one thing that is not in the schematic is after Q102, i also add one pair of npn, pnp transistor as emiter follower to prevent loading Q102, also mean D102 is duplicate to have enough voltage headroom to bias output transistor.
There is many transistors in this schematic but the tube do most of voltage amplification, and the transistor i used are all low noise audio type so think it's good enough and don't matter much as the tube.
Although 6418 is use in that schematic but it can be substitute by 6088
Here is quick redraw the schematic as i have lost my schematic when my hdd die. The servo is there to center output stage at 15V, one thing that is not in the schematic is after Q102, i also add one pair of npn, pnp transistor as emiter follower to prevent loading Q102, also mean D102 is duplicate to have enough voltage headroom to bias output transistor.
There is many transistors in this schematic but the tube do most of voltage amplification, and the transistor i used are all low noise audio type so think it's good enough and don't matter much as the tube.
proid,
Agreed.
Parts should be selected for their functionality (and if preferred, for their sound), regardless of whether they are solid state, or tube.
There are lots of successful Hybrid amplifiers.
Is R101 only 10k Ohms?
That would make the high rp plate give very low gain.
My own preference is to only use tubes, except to use solid state rectifier diodes for the B+.
Happy Listening!
Agreed.
Parts should be selected for their functionality (and if preferred, for their sound), regardless of whether they are solid state, or tube.
There are lots of successful Hybrid amplifiers.
Is R101 only 10k Ohms?
That would make the high rp plate give very low gain.
My own preference is to only use tubes, except to use solid state rectifier diodes for the B+.
Happy Listening!
