[DaveRedRef-III]

Just read a review of the ‘Ultima Pre 3’ (linked below). It was intriguing to read the comparison with the Dave DAC internal Pre

“If you’re a Chord DAVE user and you’re undecided between the Ultima 6 or 5 power amp, please don’t skip the preamp. I’m dead serious! As good as DAVE’s volume control is, Ultima 3 Pre brought a level of control and refinement that wasn’t present before. The difference was substantial to warrant my purchase and if you can loan a unit like this, please do so, you won’t be disappointed."

https://soundnews.net/amplifiers/po...s-ultima5-power-ultima-3-pre-in-depth-review/

I would be interested to hear if anyone here has experienced the same improvement. Tia

 

[PierreHPfan]

IMO this is not surprising. There are not many DACs out there the can do power amp direct convincingly to my ears. I will leave the technical reasons for that to the experts, but it is not about colouring the sound, adding tube warmth, or solid state speed. It seems to be other things going on. I recommend owners of the DAVE, or any DAC going direct to power amp, try a decent preamp, either tube or solid state, and see how it sounds. You can find a decent tube pre for 3K+ or used for much less especially if you go a bit vintage.

 

[alxw0w]

I will leave the technical reasons for that

There aren't any. When the voltage output is enough to get desired volume you are fine.

The only thing that I can imagine is output impedance mismatch or/and crappy digital volume control - but that's probably not an issue for the last like 10 (?) years

 

[dmance]

Before you assume there is some kind of magic going on ...Consider that the preamp is in the DACs output path. Ask yourself... if Dave has volume that is nigh perfect...noise shaped too ....and the output is not stressed due to it going into a high impedance...then how does adding a pre in the output signal chain make the signal better? Or more true?

Ahhh ...it's because the output is also an input allowing electromagnetic energy back into the DAC where it affects the small signal processing. The pre acts as a filter of sorts from downstream RF noise.

 

[rkt31]

Before you assume there is some kind of magic going on ...Consider that the preamp is in the DACs output path. Ask yourself... if Dave has volume that is nigh perfect...noise shaped too ....and the output is not stressed due to it going into a high impedance...then how does adding a pre in the output signal chain make the signal better? Or more true?

Ahhh ...it's because the output is also an input allowing electromagnetic energy back into the DAC where it affects the small signal processing. The pre acts as a filter of sorts from downstream RF noise.

How does a pre filter noise? Pre can never improve upon the original s/n of dac. Pre can only add it's own distortion and noise into the dac's output.

 

[PierreHPfan]

I say try it, once you get to a good preamp quality level, things really can take off. Don't take my word for it, try. Please report back, I am curious!
There are quite a few DAC owners on this forum who have tried, both direct and via a preamp.

 

[dmance]

How does a pre filter noise? Pre can never improve upon the original s/n of dac. Pre can only add it's own distortion and noise into the dad's output.

Any downstream RF noise from the amplifier AC Mains connection or EM induced thru the speaker leads ...all this permeates to any galvanic connection. So the DAC RCA outputs are also galvanically connected to this mess....and hence the DAC innards as well. Small subtle impact on the circuits responsible for the timing and amplitude ...is audible. Just regard any galvanic connection of a DAC (power, in/out signal) to be a conduit for incoming RF noise.
So the preamp does not directly (by virtue of its role in the signal) change the sound ...but it's presence in the path affects the RF enemy spectrum that makes it back upstream.
So much makes sense if you consider this

 

[jcn3]

I say try it, once you get to a good preamp quality level, things really can take off. Don't take my word for it, try. Please report back, I am curious!
There are quite a few DAC owners on this forum who have tried, both direct and via a preamp.

i agree -- give it a go; go borrow a preamp from a dealer. i found a pre-amp brought an added level of texture and soundstaging with my dave.

 

[johnwillmclean]

Just read a review of the ‘Ultima Pre 3’ (linked below). It was intriguing to read the comparison with the Dave DAC internal Pre

“If you’re a Chord DAVE user and you’re undecided between the Ultima 6 or 5 power amp, please don’t skip the preamp. I’m dead serious! As good as DAVE’s volume control is, Ultima 3 Pre brought a level of control and refinement that wasn’t present before. The difference was substantial to warrant my purchase and if you can loan a unit like this, please do so, you won’t be disappointed."

https://soundnews.net/amplifiers/po...s-ultima5-power-ultima-3-pre-in-depth-review/

I would be interested to hear if anyone here has experienced the same improvement. Tia

I was actually nauseous reading this review, I hope you were able to see through the blatant Ad structure. Perhaps further investigation is needed on your behalf.

 

[rkt31]

Any downstream RF noise from the amplifier AC Mains connection or EM induced thru the speaker leads ...all this permeates to any galvanic connection. So the DAC RCA outputs are also galvanically connected to this mess....and hence the DAC innards as well. Small subtle impact on the circuits responsible for the timing and amplitude ...is audible. Just regard any galvanic connection of a DAC (power, in/out signal) to be a conduit for incoming RF noise.
So the preamp does not directly (by virtue of its role in the signal) change the sound ...but it's presence in the path affects the RF enemy spectrum that makes it back upstream.
So much makes sense if you consider this

Wrong. Preamp shares the same ground as other equipments so can't prevent any leakage of noise from dac. In fact it will add it's own noise also. Best option to prevent noise is to power the dac from battery, like the can be powered by 12v battery. Use plenty of ferrite clips on power cable ( even on battey cord) and usb cable. Don't use ferrite clips on analog signal like rca interconnect as it will affect treble response. The change is sound will be drastic, once you remove noise from the chain.

 

[rkt31]

Pre amps were required when sources had low output level like cassette deck and vinyl. Pre stage used to have 6-10db gain( even many amps still have a pre gain stage) which helped in boosting the low level sources. Now a days most dacs have at least 2v output and many like mojo 2, hugo 2 , dave and benchmark dacs and many more can output 4v+ or even more. So you don't really need pre stage as you need to actually attenuate instead of pre amping. Earlier more source inputs were required for cassette, vinyl, tuner, cdp etc etc but these days one mostly need one source input for dac. So pre amp for dac is not needed anymore. A good digital volume control of hq player, j river or even in built digital volume control of dacs is extremely transparent accurate. There is no need to worry about channel imbalance at low volumes in a pre amp and you remove lot more electronics from the parth like volume pot, buffer, pre amp gain stage rca interconnects etc etc. So a dac feeding directly to power amp is good solution for more transparency.

 

[dmance]

Wrong. Preamp shares the same ground as other equipments so can't prevent any leakage of noise from dac. In fact it will add it's own noise also. Best option to prevent noise is to power the dac from battery, like the can be powered by 12v battery. Use plenty of ferrite clips on power cable ( even on battey cord) and usb cable. Don't use ferrite clips on analog signal like rca interconnect as it will affect treble response. The change is sound will be drastic, once you remove noise from the chain.

You misread my reply. All your other points are good solutions ...but in respect to the wire from the DAC output to the other downstream components...you need to stop RF noise from coming BACK up that wire. Some DACs use a low pass filter or transformer at the output but this takes away transparency. So the solution is to consider what lossless mitigation is possible...and what I am saying is that a preamp (inadvertently) serves that purpose.

 

[Icenine2]

Can everyone hold it down..........I'm trying to listen to music..........

 

[alphaman]

Curious about "Pulse Array".
I have gone thru various posts and videos by Mr Watts and others. Perhaps the CanJam 2023 NYC Rob Watts presentation was best overall--because , near the end, a very basic outline description of PA was shown on slides.
Mr Watts noted use of PWM topology in Pulse Array. PWM was what Matsushita's MASH was based on (PDM, Philips Bitstream). For some reason, I thought Chord PA was based on PDM???
Also ...
Many DAC (IC) datasheets contain block diagrams of the workings of the DAC. I'm curious whether something similar exists for Chord PA (FPGA)? Yes, a manuf. is completely entitled to obfuscate their IP. But that's what patents are for!
https://patents.google.com/patent/US7834789
Also,
https://en.wikipedia.org/wiki/Clarke's_three_laws
"Any sufficiently advanced technology is indistinguishable from magic."

 

[The Jester]

Patents are fine as far as they go, but for an individual, jealously guarded intellectual property is a better option vs releasing white papers in great detail and then having another change a few small items to make it subtly different and the possibility of expensive litigation to resolve any disputes.