I know. I’ll use the Aleph J with less sensitive speakers. It’s going to take me way too long to get around to building a buffer.
My DAC puts out 2 Volts. As I mentioned to Zen Mod, I’d rather not build a buffer at this point.
I see. If you have other speakers, well good. But you have made a real effort with the J, real nice. You could simply put a 25k in a box between the dac and amp, and just let it sing. That way you can avoid digital volume control.
I believe even the best of digital volume controls (64 bit etc) need at least 60-80% of full volume iot not loose sq. Ime, dynamics also suffer. So with critical listening I only use analog volume controls.
Easy enough. How about a voltage divider or a single resistor in series instead of a volume pot? A set amount of drop that will get me in the right gain neighbourhood is fine as well. I can fine tune with the volume control in Tidal. Is this reasonable?
I see. If you have other speakers, well good. But you have made a real effort with the J, real nice. You could simply put a 25k in a box between the dac and amp, and just let it sing. That way you can avoid digital volume control is fine as well. I can fine tune with the volume control in Tidal. Is this reasonable?
That’s easy enough. How about a voltage splitter or series resistor instead of a pot. A fixed voltage drop is fine as well. As long as it gets me in the neighbourhood gain wise. Is this an acceptable option?
This is diy after all, so give it a try.
Just curious, what amplifier were you using before, and what was its gain? And were you using PC and Tidal to Dac and then to amplifier? And was there hum and hiss with that setup?
The Aleph J has a gain of 19.6dB (9.55X) and an input of 1.5Vrms outputs 25W into 8 Ohms. With your extremely sensitive speakers 1W would be loud. For 1W output to 8 Ohms, only 0.3Vrms input is needed.
Just curious, what amplifier were you using before, and what was its gain? And were you using PC and Tidal to Dac and then to amplifier? And was there hum and hiss with that setup?
The Aleph J has a gain of 19.6dB (9.55X) and an input of 1.5Vrms outputs 25W into 8 Ohms. With your extremely sensitive speakers 1W would be loud. For 1W output to 8 Ohms, only 0.3Vrms input is needed.
at this point or never, your choice
I've just wrote what is proper way to do it
Of course, you made one proper choice**** ..... no reason to make habit of that
**** having Klipsch Horn in room
sacrilege, if you ask ZM
Signal Energy Preservation (term coined by your truly, just small step for me but enormous for Audiophoolkind)
your speakers are made 158% by that rule, starting with enclosure, continuing with xover (autoformer instead of crude L-Pad in most critical place) then even with tricky true that PWK intended to use no more than mid class quality drivers to achieve superior results, and succeeded in that)
way of doing it is - (any) volume in front of present amp , without positive gain contribution
then, if result shows that you still have a hiss, determination what's hiss source - things upstream or amp itself
changing source for any other will tell is source proper or not, regarding hiss
if needed, gain of Aleph J can be decreased, easily
with KH, World is your Turtle, all you need is just little patience
It sounds excellent. Soundstage is very good, as is imaging. It seems more extended in the high frequencies than the tube amps in my stable. It picks up more noise from my primary source than any of my other amps, probably because it has higher gain. It has very low self noise. I am very pleased with it overall.
I agree. I suppose it's similar to an exhaust system in a sports car. Any restriction to the flow has costs to horsepower. Changing the source to a an iPhone's audio out through a dongle leaves the speakers as quiet as if the inputs on the Aleph J were shorted. Switching to PC through my DAC is obviously more noisy. The noise is obviously coming from the source. It could be some sort of a ground loop that the iPhone avoids because it is not plugged into anything except the audio cable, and through an Apple dongle that I think is buffered. The iPhone is quiet, but it sounds dead inside. Not good at all. I do have a few pairs of speakers that are less sensitive than my Khorns and La Scalas. My Klipsch Quartets are 97.5 DB/W/M, and my Heresy II are 97 DB/W/M. Would 6.5-7 DB less do it? I haven't tried yet. Lowering the gain sounds like an interesting option.
This is very true. I have the pots and the ability, so why not. I have several amps that I ran with PC and Tidal to DAC. I have two ACAs. One was built with the old kit from DIY Audio that was two monoblocks, and a newer DIY build that used a single case made in China. Both of these are quiet through my Khorns. My other amps are all SET tube amps. I have several EL84 based amps of around 2 Watts per channel, a KT120 amp with about 6 watts per channel, and a 5998 amp with 3-4 watts a channel. All of these amps are quiet to very quiet with the same source. Apparently my DAC puts out a bit more than its specified 2V.
I am concerned about your sources. I found my iPhone noisy and my computer/dac quiet. If your iPhone is quieter than the dac something is not right.
Then it's a combination of the source and the AJ... or the AJ. If it's quiet with your phone, then you almost certainly have some potential for improvement with grounding schemes or other solutions. Nice find on the transformer shielding solution.
Why do you say this? I'm not doubting you, but it would be odd. Measure it if you're curious. I'd suggest one measurement with a full-scale test tone (it should measure ~2V or to the spec of your DAC). You can do that with a DMM. Then, take one or two ballpark measurements with music, so you can see the variability and get a general idea of what it looks like. That's way more fun and revealing with an oscilloscope.
FWIW - Different people have different views of digital attenuation. Technically, it does reduce dynamic range, which many people choose as their primary (or sole) argument against digital attenuation. I find that particular argument to be generally irrelevant in your specific use case (and many like yours). If the digital attenuation is done properly, and not to extremes, I can't see it causing meaningful/audible deterioration to the signal. In many cases (and I'd dare say most actual use cases), attenuation while still in the digital domain is superior in measurable and meaningful (to me) ways than most applications of a standard analog pot. However, that gets into a subjective / objective argument that I'd choose not to take part in. Giving credit where it's due, one key benefit of an analog pot after the source is that it will also attenuate the noise from the source in addition to your signal. However, it's unlikely (to me) that your noise is coming from your source (the DAC) directly. It's likely a combination of small things that you're sorting through. Hum/Buzz/Hiss chasing is my least favorite exercise, but you've received some exceptional advice on getting it sorted out.
tl;dr - IMO, reducing the overall gain in your system in combination with reducing its overall noise floor is likely a very good approach. I just wouldn't rule out also using digital attenuation if it's not objectionable (to you).
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please, differentiate noise ( hiss) and buzz
noise/hiss is random, highish F, while buzz is either your mains F or double that ( due to rectification)
so, what you have?
noise/hiss is random, highish F, while buzz is either your mains F or double that ( due to rectification)
so, what you have?
My problem is likely due to a ground loop issue and not the actual source. I doubt the Aleph J is the issue, although it has too much gain in my system.
I do think it’s an overall grounding issue and not a fault in any one component. The DAC is a Musical Fidelity V90-DAC. It was reviewed by Stereophile a while back, and Atkinson found it to put out a bit more than the normal 2 Volts.