I got Euvl´s ES9022 board and had some listen. The sound is very wide band with very good extension in the bass and good extension in the treble. Tonal balance is neutral, this is no smoothed over candy sound and no fake "magic". Image focus is outstanding, so is depth perspective so micro detailing must be very good. What really surprised me is the bass performance especially considering that i used simple 9V blocks to supply it and there are no huge capacitors or regulators on this tiny boards. It goes as deep as i heard it, has slam and power and is precisely structured and rhythmic. After i had digested the first shock i was able to find small remaining problems, namely a little more artifice and less liquidity and naturalness then my 30.000,-€ Forsell rig. This are minor problems and may be solved by buffering the output. The Forsell also has one of my time domain buffers at the output. The Forsell alone without my buffer has a rather soft treble and compared to that the Euvl board is a huge bargain. I call that progress.
Thank you Joachim for the feedback.
We also agree that some form of LP filter like a discrete JFET Sallen Key filter at the output may improve the smoothness slightly.
But these are all very personal.
Glad you like our work.
FYI, Joachim had a ES9022-48MHz module with frequency divider to feed 12MHz to the WM8804 module with the same XO.
The two modules had 4x LT1761 regulators on board, close to the ICs. Identical to the one on the right in Post #219.
Patrick
We also agree that some form of LP filter like a discrete JFET Sallen Key filter at the output may improve the smoothness slightly.
But these are all very personal.
Glad you like our work.
FYI, Joachim had a ES9022-48MHz module with frequency divider to feed 12MHz to the WM8804 module with the same XO.
The two modules had 4x LT1761 regulators on board, close to the ICs. Identical to the one on the right in Post #219.
Patrick
Last edited:
Member
Joined 2006
When you know what you want, and I have time, and you are prepared to wait for a few months, yes.
I takes 4 hours to make and test one set like what Joachim has.
And I don't have much free time.
People have asked for boards. The effort to support those is too much.
And I doubt many can solder 0402 caps at the legs of a TSSOP package (of the WM8804).
So no boards. Sorry.
Patrick
I takes 4 hours to make and test one set like what Joachim has.
And I don't have much free time.
People have asked for boards. The effort to support those is too much.
And I doubt many can solder 0402 caps at the legs of a TSSOP package (of the WM8804).
So no boards. Sorry.
Patrick
When you know what you want, and I have time, and you are prepared to wait for a few months, yes.
I takes 4 hours to make and test one set like what Joachim has.
And I don't have much free time.
People have asked for boards. The effort to support those is too much.
And I doubt many can solder 0402 caps at the legs of a TSSOP package (of the WM8804).
So no boards. Sorry.
Patrick
How do you solder those tiny little things without burning them up. How much would performance suffer with standard parts?
Sheer hand skill.
That is why it takes so long.
Patrick
And a tiny little elf soldering iron
What about performance comparison vs standard sized comppnents? I have 5 of the chips and need a multi bit complimentary to my NOS dac.
I would certainly not use an output transformer. It is expensive and clumsy so why make this very small to begin with ?
I have made good experiences with inductive filtering though. The inductor is in series with the signal and i found that more effective then putting a cap to ground that is parallel to the signal. I think it has to do with HF not letting go into the amplification chain. I am certainly not a fan of non oversampled DACs with a lot of aliasing noise.
That inductor is very small. I will make a photo with EUVLs board as size comparison.
I have made good experiences with inductive filtering though. The inductor is in series with the signal and i found that more effective then putting a cap to ground that is parallel to the signal. I think it has to do with HF not letting go into the amplification chain. I am certainly not a fan of non oversampled DACs with a lot of aliasing noise.
That inductor is very small. I will make a photo with EUVLs board as size comparison.
I designed a little anti aliasing filter - buffer with inductor. It is a second order flat delay filter with -3dB @ 100kHz, - 12dB @ 200kHz. Group delay is 24usec lowering to 9usec @ 20kHz. Frequency response is down -0.2dB @ 20kHz. I assumed an output impedance of the ES9022 analog output as 20 Ohm. If that is not the case and the output impedance is zero Ohm because of internal feedback then a series resistor of 20 Ohm has to be added. Other wise the 68nF has virtually nothing to do. I use the LME49713 current feedback opamp.
It performs admirably. It is available in SMD but the metal can version sounds better.
It performs admirably. It is available in SMD but the metal can version sounds better.
Joachim,
The output impedance of the ES9022 is approx. 240R.
Probably some resistor built-in after the opamp output stage.
I think you need to change a few things in the passive filter.
And I would probably use a pair of 2SK372V as JFET follower to replace your LM49713.
But that's just me .....
Patrick
The output impedance of the ES9022 is approx. 240R.
Probably some resistor built-in after the opamp output stage.
I think you need to change a few things in the passive filter.
And I would probably use a pair of 2SK372V as JFET follower to replace your LM49713.
But that's just me .....
Patrick
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.