Hello DIY friends, I have an interesting story for you all.
Last night, I was discussing with some HIFI friends total system gain structure. I was using Pano’s post on calculating the total gain of his system, mainly because one of my friends was concerned that his new pre-amp project wouldn’t have enough gain. His DAC has a maximum gain of 12db, ie, 2v. His pre-amp project has 6db 1v of gain, and his power amp, has approximately 19db 2+ v.
To me, this sounds like a lot of gain, ie meaning that the pre-amp at full power, you have to attenuate the signal, unless you want to make your ears bleed. Btw, his speakers are 93db efficient.
Well that got me thinking of my own setup. I have a Wiim Mini streaming connected via Toslink, to a topping D30. The topping has 2v output, 12db. My current pre-amp is the ACP+, which has 9db, according to nelson’s article. Power amp is the new Aleph JZM, which I assume, has the same gain as the original, ie, 19.6 db. As for my speakers, currently I have some Emotiva B1+.
Okay back to the so what here. Well, this got me thinking that I probably have a lot of gain, having to attenuate a lot of signal via the Acp+ volume pot.
I’ve been thinking a lot about attenuation, and how you lose signal when you attenuate. I blame Zm for putting those ideas in my head, after learning about the Iron-pre/Iron pumpkin.
Then I remembered something interesting about the wiim mini, a small feature, hidden in the software.
Side note: The wim mini has both toslink, and headphone jack output. I mostly use toslink to feed to my topping d30.
So back to the software feature. In the settings, you can digitally changed the output vrms. Either, 2vrms, 1vrms, 800mVrms, 500mVrms, 200mVrms for the headphone jack. Hmmm well that’s interesting!
Searched to my stash for a headphone jack to rca cable. Unplugged my topping D30, connected directly to wim mini.
Started at 2vrms, full blast on ACP+. Had to turn the pot to 9 a clock. Changed it on the fly to 1vrms. Turn the volume to 12 a clock. Load, but more detail. Eventually, I turn it all the way down to the 200mVrms, and suddenly I really start to hear that elusive low volume listening that people talk about. Volume pot is close to full at this point, its loud, but not extremely loud. The sound information is there. Bass is not impactful, but it’s there.
At this point, I begin to just listen. Pleasantly surprised that 200mVrms from a source is loud, but not egregiously loud, just loud and articulate.
Will this compete with ultra high end DACs. No way! Or better said, how the hell should I know, never heard one!
It does make me wonder, at least food for thought, whether your source really needs 2vrms standard.
At least, if anything, you already have a wim mini laying around and a headphone jack to RCA cable, connected directly to your preamp.
Cannot say if you will be impressed, or pleasantly surprised. Either way, if you try it, let me know how that works out for you. Otherwise, consider me a total audio-fool. I mean I am, but I also like sharing my subjective impressions, which really sound loony!
Edit: My conclusion is the result was reduction of output voltage from DAC allowed higher volume setting on ALPs pot and therefore less "loss" of some content.
Edit 2: If you believe your chain has excess gain, requiring large amounts of attenuation, the wiim mini, and I say may be the right tool for testing.
I also ask, does anyone know of a dac, that has 200mVrms output? I think the only one I know of is the Chord mojo 2.
Cheers!
Jose
To the mods: posted here because my system has FW equipment. Not sure if the more appropriate place is in the digital line level forum or the lounge. I don’t care either way. You can move it if you feel it’s necessary.
Last night, I was discussing with some HIFI friends total system gain structure. I was using Pano’s post on calculating the total gain of his system, mainly because one of my friends was concerned that his new pre-amp project wouldn’t have enough gain. His DAC has a maximum gain of 12db, ie, 2v. His pre-amp project has 6db 1v of gain, and his power amp, has approximately 19db 2+ v.
To me, this sounds like a lot of gain, ie meaning that the pre-amp at full power, you have to attenuate the signal, unless you want to make your ears bleed. Btw, his speakers are 93db efficient.
Well that got me thinking of my own setup. I have a Wiim Mini streaming connected via Toslink, to a topping D30. The topping has 2v output, 12db. My current pre-amp is the ACP+, which has 9db, according to nelson’s article. Power amp is the new Aleph JZM, which I assume, has the same gain as the original, ie, 19.6 db. As for my speakers, currently I have some Emotiva B1+.
Okay back to the so what here. Well, this got me thinking that I probably have a lot of gain, having to attenuate a lot of signal via the Acp+ volume pot.
I’ve been thinking a lot about attenuation, and how you lose signal when you attenuate. I blame Zm for putting those ideas in my head, after learning about the Iron-pre/Iron pumpkin.
Then I remembered something interesting about the wiim mini, a small feature, hidden in the software.
Side note: The wim mini has both toslink, and headphone jack output. I mostly use toslink to feed to my topping d30.
So back to the software feature. In the settings, you can digitally changed the output vrms. Either, 2vrms, 1vrms, 800mVrms, 500mVrms, 200mVrms for the headphone jack. Hmmm well that’s interesting!
Searched to my stash for a headphone jack to rca cable. Unplugged my topping D30, connected directly to wim mini.
Started at 2vrms, full blast on ACP+. Had to turn the pot to 9 a clock. Changed it on the fly to 1vrms. Turn the volume to 12 a clock. Load, but more detail. Eventually, I turn it all the way down to the 200mVrms, and suddenly I really start to hear that elusive low volume listening that people talk about. Volume pot is close to full at this point, its loud, but not extremely loud. The sound information is there. Bass is not impactful, but it’s there.
At this point, I begin to just listen. Pleasantly surprised that 200mVrms from a source is loud, but not egregiously loud, just loud and articulate.
Will this compete with ultra high end DACs. No way! Or better said, how the hell should I know, never heard one!
It does make me wonder, at least food for thought, whether your source really needs 2vrms standard.
At least, if anything, you already have a wim mini laying around and a headphone jack to RCA cable, connected directly to your preamp.
Cannot say if you will be impressed, or pleasantly surprised. Either way, if you try it, let me know how that works out for you. Otherwise, consider me a total audio-fool. I mean I am, but I also like sharing my subjective impressions, which really sound loony!
Edit: My conclusion is the result was reduction of output voltage from DAC allowed higher volume setting on ALPs pot and therefore less "loss" of some content.
Edit 2: If you believe your chain has excess gain, requiring large amounts of attenuation, the wiim mini, and I say may be the right tool for testing.
I also ask, does anyone know of a dac, that has 200mVrms output? I think the only one I know of is the Chord mojo 2.
Cheers!
Jose
To the mods: posted here because my system has FW equipment. Not sure if the more appropriate place is in the digital line level forum or the lounge. I don’t care either way. You can move it if you feel it’s necessary.
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in most scenarios, source is link of which you can least change things
so, just phrase it backwards, and say - do you really need xxxdb sum gain, with sources having 2Vrms out?
and then you're again reading Pano's article, resulting in secision/option to change gain of components you did actually built
decrease gain of your pre, decrease gain of your amp
Iron Pumpkin is having settable gain: 0db, +2db, +4db, +6db, +8db
^ anecdotally, I believe that Wayne said the P3 clips at 8vrms. Maybe I am wrong. Better question I guess is do you need 2vrms for low listening?
Quick clarification about the wim mini setting. The wim mini is set at fixed output 200mVrms. Tried digitally lowering the volume in the amp, that did not sound good!
Part of this is historical.... So called "high level" sources used to run 100-200mVrms, and pre-amps needed enough gain to get those signals up to 2-4Vrms for the power amp. DAC's changed that... Typical DAC chips have outputs of around 2V, and are enough to drive an amp directly, with little or no gain from the pre-amp. As a result, most systems have an excess of gain these days (for digital sources).
Yes, it did. If you think about it, tape decks, radios, phono stages, all start off with very low signal levels, and need significant gain to get them up to audible levels. The DAC chips run off 3.3 or 5 volt supplies, so their output is correspondingly higher.
A 3.3V supply allows a maximum output of just over 1Vrms.
A 5V supply allows a maximum output of 1.78Vrms.
A 5mV typical output cartridge with a 40dB phono preamp outputs 0.5Vrms.
Peaks will be higher. Tape decks will be similar, but tuners will vary.
A 5V supply allows a maximum output of 1.78Vrms.
A 5mV typical output cartridge with a 40dB phono preamp outputs 0.5Vrms.
Peaks will be higher. Tape decks will be similar, but tuners will vary.
Getting off the op topic, but Wayne Colburne/Nelson Pass have advocated for a pre-amp that provides all the required voltage gain, simplifying the power amp to a high current voltage follower.... A very high voltage output DAC, as you propose, would be the same!
Or 2Vrms. Or 4Vrms. Its pretty common for DACs to generate a negative rail internally. Its a clever trick, the DAC clock is used for a switched-capacitor negative supply, being synchronous there is no switching noise except at multiples of the sample rate. So a 3.3V part can have an internal -3.3V rail and thus 6.6V peak-to-peak output (single ended, twice that differential of course).
Single ended no switched caps: 3.3V peak to peak (1V rms),
Differential, no switched caps: 6.6V peak to peak (2V rms),
Single ended with switched cap neg supply: 6.6V peak to peak (2V rms),
Differential with switched cap neg supply: 13.2V peak to peak (4V rms)
I did not understand this passage, sorry.
Furthermore i do not listen to streaming music so my difficulty understanding increases: what's so special about the sound now?
However, I wouldn't be able to feel comfortable with a volume pot almost at maximum and getting a sound level from the speakers "just loud and articulate" even because the dynamic range I guess would be lower: have you ever tried to play your streaming music without the preamp, using the variable output of your DAC?
Even if it seems that DAC and streamer are not very expensive, I would give it a try.
I don’t know that much or understand most things.
I believe you can get more information into a higher voltage signal.
If a 1V and 2V signal both have the same level of noise (50uV), would the 2V signal attenuated to the same level as the 1V signal have half the noise?
I believe you can get more information into a higher voltage signal.
If a 1V and 2V signal both have the same level of noise (50uV), would the 2V signal attenuated to the same level as the 1V signal have half the noise?
it's simple as this - less you choke original available signal, more of it you get in the end - speakers
we are used to control it, but there is necessary amount of signal attenuation and then there is excessive amount signal of attenuation - always as result of excesive gain in particular system
it is not common (due to prevailing situation on market, regarding gain distribution in gadgets) but proper position of attenuator button is around 2 to 3 o' clock, when SPL is as for normal listening session
we are used to control it, but there is necessary amount of signal attenuation and then there is excessive amount signal of attenuation - always as result of excesive gain in particular system
it is not common (due to prevailing situation on market, regarding gain distribution in gadgets) but proper position of attenuator button is around 2 to 3 o' clock, when SPL is as for normal listening session
My advice is to take a look at how much signal you really need coming out of the amplifier.
Spend $30 on a cheap but functional scope like this or similar:
https://www.amazon.com/stores/AUKUYEE/page/4015BC5B-4231-4E60-8A03-E2A8E3AC5D91?ref_=ast_bln
I bought that one and it worked fine. I told Wayne about it, and he reach over on his bench and showed me his -
"Oh you mean this one?" 😉
Hook it up to the output of an amplifier channel and see. I predict you will be surprised.
I can run a pair of SR-1's at 87 dB sensitivity / 3.8 ohm load with 5 volt peaks (3.5V rms) coming out of my
preamp into a Jfet power buffer, and it's plenty loud.
Perhaps that's why my ears are still any good....
Spend $30 on a cheap but functional scope like this or similar:
https://www.amazon.com/stores/AUKUYEE/page/4015BC5B-4231-4E60-8A03-E2A8E3AC5D91?ref_=ast_bln
I bought that one and it worked fine. I told Wayne about it, and he reach over on his bench and showed me his -
"Oh you mean this one?" 😉
Hook it up to the output of an amplifier channel and see. I predict you will be surprised.
I can run a pair of SR-1's at 87 dB sensitivity / 3.8 ohm load with 5 volt peaks (3.5V rms) coming out of my
preamp into a Jfet power buffer, and it's plenty loud.
Perhaps that's why my ears are still any good....
My DAC has about 1v rms output , and it's plenty enough to my F6 to drive my B&W dm7 in an 28 m2 dedicate room
.
.
Under certain circumstances you may need that much voltage. Low sensitivity speakers is an obvious example. Another is that some recordings, but not many, and seemingly always classical, playback at an abnormally low signal volume. Seeming to be as much as 10dB (or maybe more) below other recordings.