Whilst we're discussing the DOS, I recently powered my output stage with a sep power supply (15V toroidal + smoothing caps + power regulator – all mounted externally in a sep box – hard-wired down to the circuit board at U216 and U218). I have also fitted LME49720HA op amps as well as bypassed the HDAMs.
Anyone done what I have done and then gone on to fit a sep DOS? Will a separate DOS sound better than my current set-up? I'm wondering whether the SQ improvement will make it worthwhile.
Anyone done what I have done and then gone on to fit a sep DOS? Will a separate DOS sound better than my current set-up? I'm wondering whether the SQ improvement will make it worthwhile.
I think the SQ from your mod should sound good when compare with DOS. if you want some more improvement why not change all the 120pf filtering caps around the opamps to MKT ones. If you have also changed the 7812 and 7912 regulators with low noise regulators like the one from Fidelity Audio you can try discrete opamps (like Burson or GD-Audio) for further improvements in SQ.Whilst we're discussing the DOS, I recently powered my output stage with a sep power supply (15V toroidal + smoothing caps + power regulator – all mounted externally in a sep box – hard-wired down to the circuit board at U216 and U218). I have also fitted LME49720HA op amps as well as bypassed the HDAMs.
Anyone done what I have done and then gone on to fit a sep DOS? Will a separate DOS sound better than my current set-up? I'm wondering whether the SQ improvement will make it worthwhile.
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I think the SQ from your mod should sound good when compare with DOS. if you want some more improvement why not change all the 120pf filtering caps around the opamps to MKT ones. If you have also changed the 7812 and 7912 regulators with low noise regulators like the one from Fidelity Audio you can try discrete opamps (like Burson or GD-Audio) for further improvements in SQ.
Thanks Higlander for the advice. I have set up low noise power regs on my daughter boards in my 'power supply' box. I will discuss with my guru putting different filter caps around the opamps. I'll stick with my present opamps for now, having only recently purchased them... but I'll definitely consider this change for the future.
C6 in Rays DOS
Black Gate or EXTERNAL mkp film cap
as Black Gates are nigh on impossible to get, looks like getting the mkp, but what is meant by EXTERNAL (is it some sort of weatherproofing)
Black Gate or EXTERNAL mkp film cap
as Black Gates are nigh on impossible to get, looks like getting the mkp, but what is meant by EXTERNAL (is it some sort of weatherproofing)
I think it just means not on the board. They're typically very large.
I'm just wiring straight to the output socket at present because I have good quality blocking caps on the input to my amp.
I'm just wiring straight to the output socket at present because I have good quality blocking caps on the input to my amp.
I thought it was maybe some special part as it is down as being available from PCX and Percy Audio and not Farnells.
Yes, Mundorf Silver/Oils are especially good. I think Brent used 2.2uF on his, and I have 3.3uF ones in my amp. Watch the size though because they can get pretty big as the value goes up.
Yes, Mundorf Silver/Oils are especially good. I think Brent used 2.2uF on his, and I have 3.3uF ones in my amp. Watch the size though because they can get pretty big as the value goes up.
I also used Mundorf 3.3uF to ensure Low Frequency can pass through better.
re polystyrene cap
ive just obtained a few phillips styroflex 2n2 caps for c505 does the outef case go to the output?
😕
ive just obtained a few phillips styroflex 2n2 caps for c505 does the outef case go to the output?
😕
ive just obtained a few phillips styroflex 2n2 caps for c505 does the outef case go to the output?
😕
I'm hoping it doesn't matter. it's not a polorised cap so i can't think why it should.
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Don't worry, any direction can do.ive just obtained a few phillips styroflex 2n2 caps for c505 does the outef case go to the output?
😕
Got my new 12v regs installed into my DOS board now. Just a quick and dirty job for now.
It's pretty busy in there now!
Sounds really proper lovely now 🙂 Real good sense of the ambience of the environment the recording was made in now 😎
The output with the DOS plus the SRPP valve stage is pretty damn loud. 25% volume on my preamp is kind of as loud as I'd ever want it.
I could lose 20db and it would be about the right level. I guess I can change something in the SRPP circuit to adjust it's gain, but that's way over my head...


It's pretty busy in there now!

Sounds really proper lovely now 🙂 Real good sense of the ambience of the environment the recording was made in now 😎
The output with the DOS plus the SRPP valve stage is pretty damn loud. 25% volume on my preamp is kind of as loud as I'd ever want it.
I could lose 20db and it would be about the right level. I guess I can change something in the SRPP circuit to adjust it's gain, but that's way over my head...
nice job
getting a bit busy in there lol.Nice job tho😀
Got my new 12v regs installed into my DOS board now. Just a quick and dirty job for now.
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It's pretty busy in there now!
![]()
Sounds really proper lovely now 🙂 Real good sense of the ambience of the environment the recording was made in now 😎
The output with the DOS plus the SRPP valve stage is pretty damn loud. 25% volume on my preamp is kind of as loud as I'd ever want it.
I could lose 20db and it would be about the right level. I guess I can change something in the SRPP circuit to adjust it's gain, but that's way over my head...
getting a bit busy in there lol.Nice job tho😀
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