ahofer I've tried a variety of preamps and the only real difference I noticed was an increased noise floor (that was with a Spectral preamp, not a tube unit, interestingly enough) and some tube bloat.
ahofer, that's all they can do, increase noise/distortion/colouration and give tube bloat, against going direct if it's a match, and 99% of the time it is a match. Many tube preamps aren't a match with low input impedance amps also.
I use a Wadia 321 DAC and a RP-1 as a pre/phono stage. The RP-1 doesn’t have balanced capability but the Wadia and my amp do. I put the RP-1 in line for the phono stage, which was rated good, and so I could roll some tubes and hopefully warm things up as I my amp is class D. I proly been running the RP-1 and using streaming sources 80% of the time for nearly a year. Just the other day I pulled the RP-1 out of the system and went back to balanced connections from the Wadia to the amp as I been streaming a bunch. I like having both capabilities but wished I could afford an RP-5 with balanced.
I've done it for years, started with my Theta DS Pre in the early 1990s, and doing it now with the Cambridge Audio Edge NQ (which also styles itself a DAC/preamp). I've never bought the claims that introducing a preamp improves the sound, unless it provides better impedance matching, which is unlikely, or eliminates design problems such as distortion in the gain phase. I've tried a variety of preamps and the only real difference I noticed was an increased noise floor (that was with a Spectral preamp, not a tube unit, interestingly enough) and some tube bloat.
I am using my TEAC NT-505 DAC as a pre-amp in front of two CARY 805AE mono amps. I am very happy with it. It replaced a Modwright SWL 9.0 tube pre-amp, which is no slouch pre-amp. I moved the Modwright to my other system which is all SS. A better fit to soften the SS sound with a but of tube sound. But the TEAC does great as a pre-amp. And you can configure it to by-pass the preamp/volume option to use it as a straight DAC with another pre-amp if you choose.
It’s your right to, but fact is digital domain volume controls in dac and cdp’s are the most transparent way of controlling the volume. But like with anything there are proviso’s.
To make sure they don’t go into "bit stipping" (resolution reduction from 16bit to 14bit to12bit the lower they go ) they should be use at or above 75% of full level. Wadia and Mark Levinson and Bricasti ect ect in their flagship dac/cdp’s models, know this and is why they give a user option of pre-setting the analog output buffer gain/level reduction or increase, to then enable the digital domain volume control to be used at or above 75% of full. EG: Wadia’s way of doing this. https://ibb.co/VQpdGHz. Mark Levinson was similar and Bricasti was a different way, from memory via the back panel.
I used my Bricasti M1 DAC as a volume control so no need for me to add a preamplifier. My amps are the Bricasti M28's and the sound is stunning. However if someone felt that their solid state amp was a little to harsh they might want to mellow it out with a preamplifier.
Well then, I too, emcdade, need to apologize as well, if in fact, this unit, as the one George found on Audiomart, is similar to the one you have. This " exact " Maestro model is not the one listed on their web site, so, a lot of confusion here. The piece looks very nice. Enjoy ! MrD.
Another thing, emcdade, the last paragraph of your 1st post, you even state " how a passive preamp is doing this is a mystery to me ". You are obviously somehow confused. It is OK, we all get confused now and then. Except George. Enjoy ! MrD.
@emcdade...According to Perla Audio's web site of the new Maestro preamp : 3rd word, in the 1st sentence of it's description, it states " passive ". In the specification section, it states " gain = 0 ". So, I, too would like to see a link stating otherwise. If not, I accept your apology for being incorrect. If George and I are incorrect, please, just show us ? Enjoy ! MrD.
emcdade, I would also like to see the link where it says " active ". According to the web site, the 3rd word of the very 1st sentence, of the Perla preamp description, says " passive ", so, show me the moneyyyyyyyyyy. Enjoy ! MrD.
George, First of all, Perla’s new preamp has both active and passive inputs. Considering I own it I SHOULD KNOW.
Please show us a link? Sorry, you need to look at what the manufacture says you own, it has a cd input and two auxiliary inputs, there are no active inputs. The only reason it’s powered is because it needs power for the volume control motor and for the remote control receiver circuit and for the blue light on the front. https://www.perlaaudio.com/pre-amplifiers
Secondly as you put it, it’s the T+A Dac 8 that I mentioned about Vishay and Melf. As many manufacturers make Melf resistors as it stands for "Metal Electrode Leadless Face" This had nothing to do with your Perla passive preamp and what resistors are in it.
T+A DAC 8 DSD
We have again further improved the unit’s outstanding pre-amplifier, and incorporated a volume control of fully analogue construction based on High-End Melf resistors. The “State of the Art” output stage is of fully symmetrical design and discrete construction. Its impedance is very low, and it is equipped with symmetrical(XLR) and asymmetrical (RCA) outputs. These features make the DAC 8 DSD more than just a High-End converter: it is also a High-End pre-amplifier of supreme quality.
T+A DAC 8 DSD
Different ladder resistors they are Melf not Visay. But it is a full discrete preamp output stage with more than enough output.
Perla Audio MAESTRO PRE-AMPLIFIER
It doesn't say anything about the Perla Audio Maestro being anything but a passive preamp. It uses power, but that's just for remote receiver and volume control movement duties, it's still a passive looking at the website. https://www.perlaaudio.com/pre-amplifiers
I have a T+A DAC 8 DSD. It has a fully discrete, analog volume control that even uses a vishay resistor ladder. My preamp is the Perla Audio Maestro which has both active and passive inputs. It too has a resistor ladder volume control.
Surprisingly the comparison between the two isn't even close; the Perla Audio preamp just kills the T+A preamp section.
Better tone, bigger soundstage - especially soundstage HEIGHT. More air and space around the instruments, more holographic.
How a passive preamp is doing this is a mystery to me, but it is just much better than my DAC and I've discovered it's the heart of my system. I won't be going to a DAC volume control any time soon.
George has been saying all along, that with today's digital sources, with the lower impedances and 2 volt outputs, the gain stages of preamps are not necessary. I do concur with these findings. 25 years ago, or more, there were passive units available, or preamps with passive as an option ( I owned most of them; PSAudio, Superphon, Mod Squad, McCormack, and many more ). Passive was ok, but back then I preferred a preamp. It is interesting, that I own my 2 older Dacs, since '95 ( Adcom and AA ), and not until I bought ( for shits and giggles ) my 1st Nuforce STA200 this time in '17, did I realize passive was the way to go. As it turns out ( and I know Georgie is very critical on the impedance matching thing ), every power amp in my " still " collection, sounds better than I ever remember then sounding, without a preamp between the dacs and the amps. I have several tuners, and other sources that are just fabulous through the amps directly. And this cheap Douk Audio piece, is killer, for 40 clams. I am told by many ( people I personally know ), that George's LDR unit is the best there is, and I do not doubt it. Anyone today who prefers a preamp, imo, likes a bit of color, and whatever else the additional gain stage adds, or subtracts, or, their source is simply inadequate to drive an amp. Just my take on things. Still, no right or wrong; just go with what your ears tell you. Sorry for the rant, as my testosterone levels are high this morning / early afternoon ( which is good at almost 65 years of age ). Enjoy ! MrD.
As for using a separate pot, same value, for each channel, there is no EE reason that it should be better or worse.
But I get the same thing with owners of two Lightspeed Attenuators, the Stereo version and the Dual Mono version, they swear the Dual Mono sounds better. I think it's because they can dial in an exact central stereo image with the left and right level controls, regardless of room/equipment/ music source influences, and this has an slight influence on the sound to them.
George, I am sure you meant Black. Do those pictures say Black Beauty anywhere ? I cannot find it. I know about the Black bodied attenuators that Alps made, but they are no longer made, as the " Blue " does the trick. A buddy of mine purchased 4 of them, based on my recommendation of trying one, and he is using 2 per system, 1 for Left and one for right ( single channel only of the passive ), and tells me he hears an improvement in sq vs. using one. I have not been over to hear it, as he is out of state of my location, but, George, what do you think ?
I am sorry Georgi, but this device is an EXCELLENT passive unit
As for the sound, I don’t doubt you like it,. and what you get is a bargain, I’m just pointing out the confusion of their ad in what actual value Blue Velvet is used and you get, all values will work as I pointed out, some better than others, because of proper >1:10 impedance matching input and output.
We just have to wait for someone to have a look at what’s inside them.
George, picture is just a picture. Did you know that Alps never referred to the control as a Blue Velvet. Nowhere on their web site have I found it. If you could find it, please post it. I believe some audiophile engineer, in using it, gave it that name. I am sorry Georgi, but this device is an EXCELLENT passive unit, for cheap, according to my ears, and the dozen or more power amplifiers I have tried with it. The control has a sexy, very high end feel, and the little box is non resonant, and built really well. Enjoy ! MrD.
It all over the place, they say 50k input but don’t say which one, which means a 50k pot. Could be the cheap 24mm they have, as you can’t see the value on it. But the pic if you zoom on the Alps (Blue Velvet) says 100kohm A taper (log) pot and it would be a 100kohm input impedance.
Whatever it is (50k or 100k), 10kohm is the best value to have, as all decent sources can handle 10kohm load (save for a couple of silly tube output ones)
A 10kohm pot has "at worse" 2.5kohm output impedance which is fine for any poweramp with >33kohm or higher input impedance.
Would be nice if you open it and find an Alps 10kohm A-taper (log) Blue Velvet for $40 with box and decent rca’s and free shipping.
George, if you look further down on the Douk page of the device, in the specification section, it states that the Alps 27 pot is 50K ohms. I have not taken mine apart, which would be easy, but I am telling you, it sounds quite invisible.
Cleaner than the Sys...Ebay item # 253818627052...HiFi version. $40 or less, shipped. About what you would pay to build one. Promise..
Trouble is the minimum 1:10 impedance ratio. It shows a 100kohm Alps passive!!!! and that will be a problem not for the source but with many poweramps They should have made it 10kohm, that way all is good, except for <33kohm poweramps, which thank god there are not too many of.
It is the only way to go. There is so much fun digital stuff like room control and digital bass management. I send my phono amp to my digital preamp/DAC through a Benchmark ADC. The analog guys are now vomiting. But very few of them have heard digital room control and bass management work. The Best unit out now is the Trinnov Amethyst. The one I use now is a Tact 2.2X. Tact is now defunct but the 2.2X is a jewel. You just have to understand it's idiosyncrasies. Boy does it ever work great.
There is a poster on another thread that uses a 1/3rd octave 31 band eq, as his passive device ( it has dual channel gain controls ). He compared it, flat, to 5 K preamps, and says it is superior to his ears. I have the same eq ( and I tried it via his recommendation ), but did not feel it came close to my Luminous unit in sq. However, it bettered some of my cheapie preamps ( RGR, Hitachi, AGI, Citation, GAS, SAE, Dynaco ). I sold my 2 megabuck preamps, which were both bettered by my Luminous unit.
For late night listening, I currently have a Schiit EQ (Loki) in the effects/tape loop connection of the Rogue. I just boost the lower frequencies a little...basically I use it as a loudness switch. Since the EQ has "true" bypass, I can just use it in line between dac and amp if I decide to ditch preamp.
An excellent choice for late night low volume listening, and the Schiit Loki at $149 is a bargain, does all what you said and more,
just put it between any of these configurations: 1: Between source and poweramp (if you have source volume control) 2: Between source and preamp 3: Between your preamp and poweramp. 4: Or in the tape loop on an integrated amp.
I just found the Benchmark preamp interesting if someone wanted an ultra quiet, active preamp. The volume control seems to be of real high quality as well.
For late night listening, I currently have a Schiit EQ in the effects/tape loop connection of the Rogue. I just boost the lower frequencies a little...basically I use it as a loudness switch. Since the EQ has "true" bypass, I can just use it in line between dac and amp if I decide to ditch preamp.
I had a Benchmark DAC3 and was using that direct into the Benchmark AHB2 amp. It was rather good but had some problems for me at lower volumes. I listen a lot late at night, like right now, and I wanted more granularity in my volume control.
Benchmark has the new pre-amp listed above that I may consider for the 30 day home trial. I would pair it with the Benchmark DAC3B (without volume control) if I went back to Benchmark gear.