ECQP were the first polypropyle caps i have ever used. Recommended by Nelson Pass, used it for the Pearl phono 1. Still one of my favourite caps, sadly discontinued 🙁
Curious about the Crescendo, we bought one to find out.
Did not change any of the power supplies, etc.
Only rewire the mains connections properly.
And replace the analogue part with 4x matched discrete Sallen Key for balanced stereo.
Caps are all WIMA FKP2 and MKP2.
Resistors are Nikkohm RP44 (one of them not correct value and hence paralleled by a PRP).
Buffers are 4 pairs of matched 2SK170BLs with ~7mA Idss.
No audible background noise even when listening with headphones via a headphone amp.
3D Imaging is spot on, both with headphones using Danyuk crossfeed, and stereo speakers.
Bass is tight, vocals are life like, and violins are smooth.
At the moment, we are happy to leave it as is and do some listening first.
Patrick
.
Did not change any of the power supplies, etc.
Only rewire the mains connections properly.
And replace the analogue part with 4x matched discrete Sallen Key for balanced stereo.
Caps are all WIMA FKP2 and MKP2.
Resistors are Nikkohm RP44 (one of them not correct value and hence paralleled by a PRP).
Buffers are 4 pairs of matched 2SK170BLs with ~7mA Idss.
No audible background noise even when listening with headphones via a headphone amp.
3D Imaging is spot on, both with headphones using Danyuk crossfeed, and stereo speakers.
Bass is tight, vocals are life like, and violins are smooth.
At the moment, we are happy to leave it as is and do some listening first.
Patrick
.
Attachments
Forgot to mentioned that the opamp was removed, as were the 4x 6.2k SMD resistors at DAC out.
And power for the JFETs were taken from opamp socket pin 4 & 8.
Patrick
And power for the JFETs were taken from opamp socket pin 4 & 8.
Patrick
Nice output stage there!
I’ll bet that changed things for the better.
It looks like the 12s lines could be made shorter. Can’t see entirely, but they run against the case, away from the boards when they could go more directly perhaps.
What is supplying the lt1963 looking regulators on the dac board?
It looks as if the diode bridge and pre-regulator is missing(?)
I’ll bet that changed things for the better.
It looks like the 12s lines could be made shorter. Can’t see entirely, but they run against the case, away from the boards when they could go more directly perhaps.
What is supplying the lt1963 looking regulators on the dac board?
It looks as if the diode bridge and pre-regulator is missing(?)
The next stage will involve cutting away all the on-board regulators, a complete new layout, power supplies with separate transofrmers, a larger case, ......
And then you can keep the I2S wire length to within 30mm or so.
But later.
Patrick
And then you can keep the I2S wire length to within 30mm or so.
But later.
Patrick
I see you have bigger plans now...
I like the volume control enabled into the remote, is a very nice feature.
Are these boards or similar are offered without the case?
I would still recommend one of these to a friend however, a bargain considering.
I like the volume control enabled into the remote, is a very nice feature.
Are these boards or similar are offered without the case?
I would still recommend one of these to a friend however, a bargain considering.
That was me... many thanks
EUVL!!!
I m very tired of the sound of opamps.. i need to try other ways..
From an independent audition :
"The DV20A beats the Pono (by Ayre, ES90182KM) used as a digital source.
And it is due to the new output stage , a very major improvement over stock.
The DV20A is utterly transparent, it displays micro detail with ease.
Tonality-wise I think it is on par with the Pono, but has much better control over
the very low registers (sub-60Hz?).
It has control bordering brutality.
The control in the bass region clears up the entire image.
I can listen to well recorded Jazz music (Michael Wollny Trio: Oslo) at Live levels
even with the Senn HD800.
Nothing bright or harsh, but drive and great atmosphere at its best.
Hats off, another full hit.
What a few parts and well matched Fets can do...
I am not sure whether I will continue modding the DV20A down the road...
But I like it as it is."
You have to use the right filter setting though. 🙂
Patrick
"The DV20A beats the Pono (by Ayre, ES90182KM) used as a digital source.
And it is due to the new output stage , a very major improvement over stock.
The DV20A is utterly transparent, it displays micro detail with ease.
Tonality-wise I think it is on par with the Pono, but has much better control over
the very low registers (sub-60Hz?).
It has control bordering brutality.
The control in the bass region clears up the entire image.
I can listen to well recorded Jazz music (Michael Wollny Trio: Oslo) at Live levels
even with the Senn HD800.
Nothing bright or harsh, but drive and great atmosphere at its best.
Hats off, another full hit.
What a few parts and well matched Fets can do...
I am not sure whether I will continue modding the DV20A down the road...
But I like it as it is."
You have to use the right filter setting though. 🙂
Patrick
First player done with the new SMD Sallen Key board.
The entire opamp filter circuit was removed.
Then replaced by first order RC and CR on board.
And finally added the Sallen Key to get 3rd order filtering.
Great sound,
Patrick
.
The entire opamp filter circuit was removed.
Then replaced by first order RC and CR on board.
And finally added the Sallen Key to get 3rd order filtering.
Great sound,
Patrick
.
Attachments
People asked about the SMD board by PM.
1) This is meant for our own team internal used. No intention to sell unless a substantial interest (>10 boards).
2) The reason for the SMD board is only for convenience, not better performance.
3) It uses Susumu thin film 0805 resistors, Panasonic PPS, Murata C0G and WIMA FKP2 caps.
4) The 2SK2145GRs used need to be Idss matched, and is the same as 2SK117GR used otherwise, except for lower bias.
5) This board is of NO use to anyone else except for those who has a DV20A DAC board.
6) This board only contains 4x Sallen Key, other parts of the filter is placed on the original DAC board.
7) The schematics is published in post #48.
Please ask questions here, not by PM.
My post box is rather full and needed for some other purposes.
We are in the process of a much more extensive mod when we shall go back to full hole version (more space).
But the verdict is still out as to whether it is worthwhile.
And the mods will cost 3x more than the original player, so marginal gain for a lot more money.
(The case is from ebay, just for testing only.)
Thank you for your interest,
Patrick
1) This is meant for our own team internal used. No intention to sell unless a substantial interest (>10 boards).
2) The reason for the SMD board is only for convenience, not better performance.
3) It uses Susumu thin film 0805 resistors, Panasonic PPS, Murata C0G and WIMA FKP2 caps.
4) The 2SK2145GRs used need to be Idss matched, and is the same as 2SK117GR used otherwise, except for lower bias.
5) This board is of NO use to anyone else except for those who has a DV20A DAC board.
6) This board only contains 4x Sallen Key, other parts of the filter is placed on the original DAC board.
7) The schematics is published in post #48.
Please ask questions here, not by PM.
My post box is rather full and needed for some other purposes.
We are in the process of a much more extensive mod when we shall go back to full hole version (more space).
But the verdict is still out as to whether it is worthwhile.
And the mods will cost 3x more than the original player, so marginal gain for a lot more money.
(The case is from ebay, just for testing only.)
Thank you for your interest,
Patrick
Attachments
Phase 2 mod now completed and playing.
The changes are :
Separate transformers for digital and analogue circuits.
Separate power supply for the display board.
Off-board SD card slot and push buttons.
Replace all regulators with LT3045 and LT1117 pre-preg, except for the analogue filter.
Replace SMD XO with a LMK00105 based XO with separate local LT3045 regulator.
Own AK4495 DAC board with different Gnd plane layout and 4x LT3045s on board.
Result is a very dark background, and very tight control for deep bass.
Will eventually get a new F5XP-type case.
Patrick
.
The changes are :
Separate transformers for digital and analogue circuits.
Separate power supply for the display board.
Off-board SD card slot and push buttons.
Replace all regulators with LT3045 and LT1117 pre-preg, except for the analogue filter.
Replace SMD XO with a LMK00105 based XO with separate local LT3045 regulator.
Own AK4495 DAC board with different Gnd plane layout and 4x LT3045s on board.
Result is a very dark background, and very tight control for deep bass.
Will eventually get a new F5XP-type case.
Patrick
.
Attachments
No.
I am not a fan of large single-piece PCBs.
It makes sense for commercial production, but not for DIY.
A modular approiach will allow me to change part of the circuit easily without affecting the rest.
And I do not have detailed info for the ESS chip, plus the display firmware etc.
The DV20A without DAC (SPDIF out option) is just too low-cost to bother with redesign.
P.
I am not a fan of large single-piece PCBs.
It makes sense for commercial production, but not for DIY.
A modular approiach will allow me to change part of the circuit easily without affecting the rest.
And I do not have detailed info for the ESS chip, plus the display firmware etc.
The DV20A without DAC (SPDIF out option) is just too low-cost to bother with redesign.
P.