ESS9018 I/V

[merlin el mago]

Hello guys,

I'm just looking for an easy and cheap tube I/V for the DAC ESS9018: I own Buffalo III DAC, I'm interested in your opinions about Lukas Fikus schematic using 6sn7, any suggestions to improve or other ideas to have better sound will welcome.

TIA
Felipe

 

[tomchr]

The schematic you attached doesn't look much like an I/V converter. It's also not differential. As I recall the ESS9018 has differential output.

Unless you don't care about performance, I suggest you implement the circuit shown in the ESS datasheet or eval board schematic. Even then you have to be very, very careful with the layout and component selection in order not to screw up the performance of the DAC. By careful component selection, I mean selecting precision components where it matters and keeping the layout clean such that you get the performance you pay for.

You can then feed the output of the I/V into a tube preamp if that suits your fancy.

~Tom

 

[merlin el mago]

I don't need differential output. I want to make the I/V all tube if possible, suggestions will welcome. Tom thanks for answer, I have Legato 3.1 without caps with the BIII DAC but I want to experiment with tubes.

Felipe

 

[kumori]

I think Lukas design only uses one phase for a single ended setup and both phases for differential output. If you only need single ended output you can save yourself some money here. This method also works well with the SEN-IV stage for buffalo, which I use.

I have one of Lukas kits lying around for a few month now, but had no time to build it yet.
I think his kit designs are pretty "mature", because he uses it for years.
You can also always improve on the PSU.

 

[merlin el mago]

Thanks Kumori, could you link me to the Lukas kit?

 

[kumori]

This is what I have lying around: Lampizator - High End Lampizator Kit ver 3.0

There are is also a cheaper version without choke supply and balanced versions available under diy kits.

 

[merlin el mago]

Thanks for the link, surely sounds very good, Wavebourn recommend me this tube to make one headphone amp. I don't have this tube on stash but I have 6H8C metal base black holes to try. Have you used other tubed I/V stage?

 

[kumori]

Well, I have not built it yet. It would be my first tube-build at all.
So, can´t give you any information about tube choices at all.

Only used discrete solid state for I/V until now, Legato and SEN. (SEN being more my taste)

 

[merlin el mago]

DAC with tube output I only used Audionote DAC with PCM63K and tube output using ECC88, with SS I use PCM1704 NOS with Erno Borbely I/V (sounds very good) and BIII with Legato without caps with double TP0604.

 

[analog_sa]

I'm interested in your opinions about Lukas Fikus schematic using 6sn7, any suggestions to improve or other ideas to have better sound will welcome.

IMO if are looking for any kind of performance beyond the pathetic you should look elsewhere. Lampizator circuits may be great at masking the distortion of lesser dacs but why would anyone want to hamper a 9018?

With this in mind you have to first answer the question: do you actually need an I/V with the 9018 and are tubes suitable at all?

As tubes are inherently inadequate at presenting ultra-low impedances by themselves you can only rely on a passive resistor I/V and a subsequent hi gain tube stage.

Or forgo the I/V and choose to amplify/buffer the output in voltage mode. There will be a drop in quality, insignificant to the issues of a high gain tube stage. Broskie's unbalancer seems to be quite popular and is certainly much better engineered than anything from Lampizator.


Then again, the 9018 in voltage mode does not necessarily need any active electronics between itself and a balanced input power amplifier.

 

[merlin el mago]

You are right, I know 9018 is very good (for DSD), for PCM I prefer PCM1704 with Borbely I/V, I suspect that doesn't exist an I/V for 9018 with same perfomance that Erno did for PCM1704.

I like more the current ouput DACs than the voltage output DACs but I can be wrong with 9018 because never tried with voltage output, do you know how can be done? it's easy?

About passive resistor for I/V and hi gain tube stage I agree with you and I think is the way to go, do you know wich resistor value for 9018? wich hi gain tube stage do you recommend?

In voltage mode the 9018 can drive 300ohms headhones?

Could you link me or post the schematic Broskie's unbalancer?

Thanks for support.

Felipe

 

[BrianDonegan]

Unless you are presenting a near-zero-ohm load the the output of the ES9018, it will be acting as a "voltage-output" DAC.

Whether not not you need differential outputs for you next stage (amplifier), not correctly utilizing the differential outputs of the DAC for common mode cancellation of noise is truely a waste.

 

[merlin el mago]

Thanks Brian, so my Buffalo III (ESS9018) operates as voltage output not current output.

 

[s3tup]

And, it converts the DSD to PCM prior to do it's internal things (DF, DS modulator).
So... ES9018 is meaningless with DSD, and is meaningless without low-Z I/V.
So screw it, use the lampizator thing - it won't do any more harm than already done 🙂
Distortion/artefacts masking isn't that bad per se, you can get away with some PCM2704

Or do extremely fast, extremely linear, extremely high-current, low-Z I/V, which ES9018 demands.

 

[merlin el mago]

What do you want to say: ES9018 converts all to PCM?

 

[s3tup]

Yes

 

[merlin el mago]

If so I don't understand why PCM1704 NOS sounds better playing PCM than 9018

 

[jpak]

And, it converts the DSD to PCM prior to do it's internal things (DF, DS modulator).
So... ES9018 is meaningless with DSD, and is meaningless without low-Z I/V.
So screw it, use the lampizator thing - it won't do any more harm than already done 🙂
Distortion/artefacts masking isn't that bad per se, you can get away with some PCM2704

Or do extremely fast, extremely linear, extremely high-current, low-Z I/V, which ES9018 demands.

I've asked ESS engineers this, and they said it does DSD native, no conversion to PCM.

 

[merlin el mago]

My friend Javier told me ES9018 doesn't convert to PCM, one thing is PCM and other is what does the 9018 that is multiple SDM, don't convert to PCM only does a wide SDM.

 

[merlin el mago]

I've asked ESS engineers this, and they said it does DSD native, no conversion to PCM.

Javier told me also ESS9018 is multi SDM not 1bit, that's can't say play DSD native.