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Re: So what are you using for computer audio?

Mon Apr 08, 2019 1:16 pm

Back when I was playing WOW I was listening through Grado SR60's and later SR80's. It kept the noise down for the rest of the house and made the whole experience much better. I thought Blizzard did a fine job of making sound cues and ambient sounds very useful. I know some people liked to play with sound off but I really liked how sounds added to the immersive realism. I hung a cheal plantronics headset around my neck for its noise cancelling mike for talking to other players.
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Re: So what are you using for computer audio?

Mon Apr 08, 2019 2:23 pm

Right now using a Sound Blaster ZxR to drive a pair of Klipsch R15PM speakers paired with a 100 dollar Polk Audio 10 inch subwoofer. When playing with groups in wow and chatting with them on discord I use the Sennheiser GSP 600 headset.
 
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Re: So what are you using for computer audio?

Wed Apr 10, 2019 3:11 am

G8torbyte wrote:
I'm using an XLR adapter that takes the left and right XLR outputs into one 4-pin XLR connector direct to my headphones.

Ah, so you are using the XLRs on the back. Interesting.
Does it sound better/different compared to the single ended front output?

I've read that going balanced for cans is rather useless b/c cable runs aren't long enough for common mode rejection to be needed and that balanced doubles THD and output impedance, thus actually degrades sonic quality.
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Re: So what are you using for computer audio?

Wed Apr 10, 2019 11:32 am

Ifalna wrote:
G8torbyte wrote:
I'm using an XLR adapter that takes the left and right XLR outputs into one 4-pin XLR connector direct to my headphones.

Ah, so you are using the XLRs on the back. Interesting.
Does it sound better/different compared to the single ended front output?

I've read that going balanced for cans is rather useless b/c cable runs aren't long enough for common mode rejection to be needed and that balanced doubles THD and output impedance, thus actually degrades sonic quality.


Whether balanced headphones are worthwhile really depends on the signal path and the cans in question. There is no 1-size fits all answer. If you have a balanced source (e.g., parallel DAC chips with isolated and properly filtered power) and a balanced amp design with similarly isolated power (after DC conversion) then you have complete separation of left and right channels, making the benefit potential more than being solely about common-mode rejection. If THD is low enough to begin with, which it should be with decent source and amp, any added due to a balanced design is negligible.

It's hard to say whether balancing headphones has any discernible advantages in theory, but in practical terms, many high end amps are balanced (ie, have balanced as well as SE out) and the balanced almost always sounds better with more power hungry headphones as the amps are normally designed to be balanced (ie, separate amplifier circuits for each channel) which means that the balanced connection is going to get you close to 2x the power.

I have a fully balanced DAC/AMP setup attached to my PC, and even with something like the Sennheiser HD650s, balanced sounds a lot better due to lower noise floor and just being more responsive due to the drivers seeing higher current when balanced. But if I was comparing a single-ended comparable AMP pushing as much power as the balanced mode of my AMP, who knows whether I would tell the difference.
 
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Re: So what are you using for computer audio?

Thu Apr 11, 2019 12:14 am

One amp per channel is just dual-mono. It's great, but not yet 'fully balanced'.

A true fully balanced design will actually have two amps per channel, with separate amps handling the normal and inverted outputs (for a total of four amps driving two channels). Basically take the dual-mono concept and apply it again to the normal and inverted outputs of each channel.

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Re: So what are you using for computer audio?

Thu Apr 11, 2019 7:53 am

As long as you have a separate return wires for the L and R drivers, having the "fully balanced" (4 amp) configuration should make no difference vs. dual mono. The headphone drivers only respond to the difference in electrical potential, and don't care how it is generated.

Well OK... with 2 more amps, you have two more potential sources of distortion and interference. So it might sound different... but it isn't necessarily going to be better unless the inaccuracies happen to cancel out. And if you've got enough systemic noise or distortion that you need that cancellation, you've got other bigger issues to worry about.
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Re: So what are you using for computer audio?

Thu Apr 11, 2019 9:45 am

I can see where slew rate and dynamics could be better with quad amps, but two slightly larger amps in dual mono are easier to calibrate (and less likely to have a DC bias in one direction or the other).

I'm sure a lot of it comes down to personal preference and historical reasons for going with balanced outputs (amps today are far nicer than 30-40 years ago where this tech became commonplace).
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Re: So what are you using for computer audio?

Thu Apr 11, 2019 9:51 am

jihadjoe wrote:
One amp per channel is just dual-mono. It's great, but not yet 'fully balanced'.

A true fully balanced design will actually have two amps per channel, with separate amps handling the normal and inverted outputs (for a total of four amps driving two channels). Basically take the dual-mono concept and apply it again to the normal and inverted outputs of each channel.

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I mean...if you need to think of the + and - signals as having their own amps, that's fine, but in practice those signals are going to be linked, and the "pair of amps" function as a singular amp. The "magic" of a balanced setup is the independent returns for each channel (as JBI mentioned). In a single ended setup, the signals share a common return path.
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Re: So what are you using for computer audio?

Thu Apr 11, 2019 10:29 am

I actually do think that having separate amps for + and - is a bit silly. It just increases the chance that one of the two amps might amplify a signal in a slightly different way. Without that though the remaining benefit is the differential signaling, precisely what balanced was built for to begin with.
 
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Re: So what are you using for computer audio?

Thu Apr 11, 2019 12:13 pm

I was including the input/amplification/output analog stages under the "AMP" umbrella. I have no idea whether my particular headphone amp has 2 actual amplification stages per channel, or is dual mono with separate "grnd" (OK, return for balanced). All I know, is that when you open the thing up, all of these stages are doubled relative to the SE version of that design (so I assume it has 2x as many amplification stages).
 
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Re: So what are you using for computer audio?

Thu Apr 11, 2019 2:14 pm

Balanced vs unbalanced is all about dat noise control. I've yet to hear about that ever being a problem with headphones. To me it just sounds like a feature that exists for the sake of selling something.
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Re: So what are you using for computer audio?

Thu Apr 11, 2019 3:29 pm

morphine wrote:
Balanced vs unbalanced is all about dat noise control. I've yet to hear about that ever being a problem with headphones. To me it just sounds like a feature that exists for the sake of selling something.

Yeah, unless you're using, like, onboard realtek from 2007 it's probably not an issue most of the time now.
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Re: So what are you using for computer audio?

Thu Apr 11, 2019 4:10 pm

Waco wrote:
I can see where slew rate and dynamics could be better with quad amps, but two slightly larger amps in dual mono are easier to calibrate (and less likely to have a DC bias in one direction or the other).

I seriously doubt that modern opamps would be slew rate constrained on sth. like a 22KHz audio signal.
Esp not at the low voltages normal headphones operate on. Oo

@morphine: exactly. The reason one uses balanced is for long PA runs past a lot of noisy equipment. That does not happen with short headphone cables.

DancinJack wrote:
Yeah, unless you're using, like, onboard realtek from 2007 it's probably not an issue most of the time now.

A balanced setup would not help against that. The distortion is already in the signal before it hits the amp.
Differential amping is only useful to filter out distortion that is added between amp and target because any injected noise will affect both, + and - and subsequently the difference between the two will be the same. The target thus never "sees" the injected noise because only the difference contains the actual information. IIRC that is called "common mode rejection".

Say you have to run your analog cable past a HF light on a stage. No matter how well you shield, that light will induce noise. Going balanced eliminates that noise from the light and you can feed your speaker a "clean" signal.
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Re: So what are you using for computer audio?

Thu Apr 11, 2019 4:56 pm

Ifalna wrote:
Waco wrote:
I can see where slew rate and dynamics could be better with quad amps, but two slightly larger amps in dual mono are easier to calibrate (and less likely to have a DC bias in one direction or the other).

I seriously doubt that modern opamps would be slew rate constrained on sth. like a 22KHz audio signal.
Esp not at the low voltages normal headphones operate on. Oo

Agreed. I was just saying that they *could* be better with more amps (more power supply capacitance, less drive per amp, etc), not that it would generally matter. As you said, headphones are pretty easy to drive. :)
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Re: So what are you using for computer audio?

Thu Apr 11, 2019 5:14 pm

In a previous life I was working on interesting applications for my company's switching amplifier technology. Since the output stage operated in differential mode and we had a stereo pair on the chip, I modified a set of AKG 240 headphones for 4-wire drive to see how it sounded. It sounded great. These were about 8 of the cleanest watts available from a single 12-volt supply, with negligible offset and over 100 dB of supply rejection.

Unfortunately, nearly no one puts a differential connector on consumer electronics and nearly every headphone sold uses a common ground. It was a good idea, but there was literally no market for it at the time (which, yeah, meant it was not really a good idea). Looking through head-fi and similar sites it appears that some people are running balanced drivers, but it's still a small fraction of users.
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Re: So what are you using for computer audio?

Thu Apr 11, 2019 5:33 pm

Ifalna wrote:
DancinJack wrote:
Yeah, unless you're using, like, onboard realtek from 2007 it's probably not an issue most of the time now.

A balanced setup would not help against that. The distortion is already in the signal before it hits the amp.
Differential amping is only useful to filter out distortion that is added between amp and target because any injected noise will affect both, + and - and subsequently the difference between the two will be the same. The target thus never "sees" the injected noise because only the difference contains the actual information. IIRC that is called "common mode rejection".

Say you have to run your analog cable past a HF light on a stage. No matter how well you shield, that light will induce noise. Going balanced eliminates that noise from the light and you can feed your speaker a "clean" signal.

Even in that situation, it's not going to make much difference as long as the effective output impedance of your single-ended amp is decently low. The voice coil of a speaker is inherently differential (responds to the difference in voltage between its two terminals), so even with a single-ended amp, any noise which is induced on the cable run should cancel out at the speaker end.

If your single-ended amp has high output impedance, then the induced noise may affect the signal leg of the circuit a lot more than the return, and then you've got a problematic situation where differential drive may give some significant benefit. But if you've got high output impedance, then you're also gonna have other issues (poor damping factor, which will massively accentuate any mechanical resonances in the loudspeaker drivers).

Differential signaling is way more important when you're dealing with high impedance sources and/or low signal levels, which can easily be overwhelmed by induced noise.

Also note that differential amping is actually a separate (though related) issue from a 4-wire setup (for headphones). As sluggo's post notes, the point of 4-wire is to provide a separate ground return for the two channels. Since the ground return in the headphone cord has non-zero resistance, a common return allows the signal for one channel to affect the ground reference for the other channel, which causes crosstalk. 4-wire connection with separate ground returns fixes this...
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Re: So what are you using for computer audio?

Thu Apr 11, 2019 6:02 pm

sluggo wrote:
In a previous life I was working on interesting applications for my company's switching amplifier technology. Since the output stage operated in differential mode and we had a stereo pair on the chip, I modified a set of AKG 240 headphones for 4-wire drive to see how it sounded. It sounded great. These were about 8 of the cleanest watts available from a single 12-volt supply, with negligible offset and over 100 dB of supply rejection.

Unfortunately, nearly no one puts a differential connector on consumer electronics and nearly every headphone sold uses a common ground. It was a good idea, but there was literally no market for it at the time (which, yeah, meant it was not really a good idea). Looking through head-fi and similar sites it appears that some people are running balanced drivers, but it's still a small fraction of users.


Many (most?) higher end consumer headphones have "balanced" drivers, just like all speakers. The connection to the driver (or crossover) itself has a +ve and -ve connection. It's the cable that combines the +ve into a common grnd. So you can do what you describe with many consumer products. It's just easier to do with headphones that have cables (or detachable cable connectors) with with the +ve and -ve separate (eg, HD 650, and plenty of others). I also have an amp with old school switching technology (not class D, but a Tripath chip). This also sounds pretty good as a balanced headphone amp (eg, if you terminate the speaker terminals as XLR), even though it is only SE. Again, for headphones, I agree that the benefit in perceived sound is not as much from noise defeating but because you have a "push-pull" more articulated control of the drivers (and often more power).
 
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Re: So what are you using for computer audio?

Thu Apr 11, 2019 6:31 pm

I thought Tripath was essentially Class D with some minor tweaks?
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Re: So what are you using for computer audio?

Thu Apr 11, 2019 6:52 pm

superjawes wrote:
DancinJack wrote:
Those HE-4XX's are only 35 ohms so it shouldn't be that hard to drive them. The Jubilee's on the other hand are 150. Might need an amp to get real quality of those.
Pet peeve: using impedance alone to determine how hard it is to drive a set of headphones.

Sure, it's part of the equation--high impedance models generally need higher voltages to drive properly--but you really need to consider efficiency/sensitivity as well. The 58X Jubilee is listed at 104 dB (at 1V, 1 kHz), and the HE-4XX just lists 93 dB (also, the AKG K7XX is shown at 105 dB/V).

Specs can be wonky and non-standardized, but wrt to the HE-4XX, you have a less efficient planar driver that might need some extra power. The 58X Jubilee is more efficient, but that higher impedance indicates a desire for higher input voltage to get the best drive.

And G8torbyte...why aren't you using the headphone output on the ADI-2? I'd imagine that output is probably better at driving both sets of headphones without distortion...


True, the RME’s single ended output is better configured for powering the headphones since the output impedance is 0.1 Ohms and the XLR jacks have 200 Ohms output impedance according to the specs. I’m going back to the headphone output since I’m reading more that the inverted output/input impedance difference is not the correct way. I read somewhere that a general rule should be that output impedance should be 10X less than the input impedance for headphones.
It was out of curiosity that I wanted to hear if there was any difference connecting direct to balanced XLR and I can hear a slightly wider presence in the Sennheisers. The Hifiman planars respond much better to the SE headphone out. For headphone output the RME allows selectable Hi-Power, Low-Power and Auto Reference Level mode switching. Even though the Sennheisers have higher input impedance it does not appear to need as much power and sounds fine in the Low-Power mode but I find the planars need the Hi-Power setting probably due to the magnetic driver requirements. The transient response in the planars is fun to listen to and it does very well with electronic/synth music but for overall imaging, sound-stage, vocals etc the Sennheiser Jubilees are a nice price for the performance in my experience and very comfortable on my head. I also use some older AKG 702’s, Beyerdynamic DT770 Pros and Fostex closed cans.
Last edited by G8torbyte on Thu Apr 11, 2019 7:47 pm, edited 1 time in total.
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Re: So what are you using for computer audio?

Thu Apr 11, 2019 7:31 pm

cynan wrote:
sluggo wrote:
In a previous life I was working on interesting applications for my company's switching amplifier technology. Since the output stage operated in differential mode and we had a stereo pair on the chip, I modified a set of AKG 240 headphones for 4-wire drive to see how it sounded. It sounded great. These were about 8 of the cleanest watts available from a single 12-volt supply, with negligible offset and over 100 dB of supply rejection.

Unfortunately, nearly no one puts a differential connector on consumer electronics and nearly every headphone sold uses a common ground. It was a good idea, but there was literally no market for it at the time (which, yeah, meant it was not really a good idea). Looking through head-fi and similar sites it appears that some people are running balanced drivers, but it's still a small fraction of users.


Many (most?) higher end consumer headphones have "balanced" drivers, just like all speakers. The connection to the driver (or crossover) itself has a +ve and -ve connection. It's the cable that combines the +ve into a common grnd. So you can do what you describe with many consumer products. It's just easier to do with headphones that have cables (or detachable cable connectors) with with the +ve and -ve separate (eg, HD 650, and plenty of others). I also have an amp with old school switching technology (not class D, but a Tripath chip). This also sounds pretty good as a balanced headphone amp (eg, if you terminate the speaker terminals as XLR), even though it is only SE. Again, for headphones, I agree that the benefit in perceived sound is not as much from noise defeating but because you have a "push-pull" more articulated control of the drivers (and often more power).

I guess I was unclear about what I did. I understand that most speakers (including headphone drivers) are two-terminal devices. The AKG's I modified were handy in that they connected the common ground at the 1/4" plug and not further up in the harness. Modifying them was then a simple matter of cutting off the stock connector and replacing it with a TRRS, keeping all the lines separate.

BTW, the amplifier I was talking about was the Tripath TA1101, which operates in bridge mode in each channel (each channel has high- and low-side drivers). Tripath amplifiers are not SE.
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Re: So what are you using for computer audio?

Thu Apr 11, 2019 7:59 pm

just brew it! wrote:
I thought Tripath was essentially Class D with some minor tweaks?

True, depending on your definition of "minor". Class D amplifiers operate their output devices in saturation or shutoff, as do Tripath and other more recent switching amps. Tripath, largely to get out from under fifty years of poor class D reputation (unreliable, sounds like poo, etc), called their devices "Class T". I was around for this decision and it was not something we (the engineers) really talked about a lot, but our CEO thought it was needed, and he was probably right.

Class D got a bad rap from audio people back in the day when the fastest affordable power devices could only switch at speeds appropriate for subwoofer applications. With the advent of high-speed (>1 MHz), high-current, inexpensive power mosfets, switching amps could be used for quality full-range audio. Add some relatively sophisticated and inexpensive delta-sigma modulators and clever support/control circuitry and you basically have a Tripath amp. I say that, but in fact there are a lot of things going on in the Tripath die (BiCMOS, a pain to source) that differentiate it from vanilla class-D. Another time, perhaps.
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Re: So what are you using for computer audio?

Fri Apr 12, 2019 3:48 am

just brew it! wrote:
Since the ground return in the headphone cord has non-zero resistance, a common return allows the signal for one channel to affect the ground reference for the other channel, which causes crosstalk. 4-wire connection with separate ground returns fixes this...

I wonder if crosstalk is an actual problem in headphone applications.
When I am sitting in front of a stereo speaker setup, my right ear does not just hear the right speaker, it hears both + a gazillion reflections of the room wall.
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Re: So what are you using for computer audio?

Fri Apr 12, 2019 4:47 am

Interesting talk about Class D amps since they are now pretty popular as power amps in bass and since guitar amplifiers.

I'm using a Darkglass Microtubes bass amp, and it's a 900 W beast in a light enclosure the size of a set-top box. The actual power module is smaller, made by Bang & Olufsen, called ICEpower, I think.
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Re: So what are you using for computer audio?

Fri Apr 12, 2019 5:13 am

Used to be a Class-A/B diehard, but after getting the NuForce DDA I'm now totally sold on PowerDACs, which are essentially Class-D. The next step up in this category seems to be the NAD M32.

Planning to have a visit to a local hi fi shop to have a listen to some HypeX stuff in the near future.
 
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Re: So what are you using for computer audio?

Fri Apr 12, 2019 6:11 am

G8torbyte wrote:
True, the RME’s single ended output is better configured for powering the headphones since the output impedance is 0.1 Ohms and the XLR jacks have 200 Ohms output impedance according to the specs. I’m going back to the headphone output since I’m reading more that the inverted output/input impedance difference is not the correct way. I read somewhere that a general rule should be that output impedance should be 10X less than the input impedance for headphones.

Excessive output impedance (relative to transducer impedance) has two effects:

1. It significantly limits the amount of power which can be transferred from source to load. This is more of an issue for loudspeakers, but can also affect the ability of an amp to drive headphones to sufficient volume.

2. It reduces the ability of the amp to control mechanical resonances in the transducers (you may see the term "damping factor" used to refer to the ratio of amp output impedance to transducer impedance). So all else being equal, lower amp output impedance will generally result in smoother effective frequency response. Whether this actually sounds better to you is, of course, subjective.

Ifalna wrote:
I wonder if crosstalk is an actual problem in headphone applications.
When I am sitting in front of a stereo speaker setup, my right ear does not just hear the right speaker, it hears both + a gazillion reflections of the room wall.

That's a different situation, as the reflections are delayed and phase shifted depending on the path each reflection takes. Even taking reflections out of the equation, there are subtle phase and frequency response shifts between what your two ears hear depending on the direction of the sound source; this is what allows our brains to determine the direction of a sound using only two "sensors".

I do tend to agree that the crosstalk effects of a 3-wire vs. 4-wire headphone cord are likely going to be pretty subtle, and completely unnoticed by most listeners. It might matter more for virtual surround audio applications (where you're using a HRTF to simulate directional cues via headphones).
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Re: So what are you using for computer audio?

Fri Apr 12, 2019 11:12 am

sluggo wrote:

BTW, the amplifier I was talking about was the Tripath TA1101, which operates in bridge mode in each channel (each channel has high- and low-side drivers). Tripath amplifiers are not SE.


I meant the input/preamp portion of the unit was SE. But yes, the amplification chip (TA1101 chip) section itself is balanced. Even more interesting, you worked for Tripath? The Tripath based amps I have are branded as Virtue Audio (now essentially defunct). Their business model was to buy up a lot of Tripath chips (probably the TA1101, but they would never say) and run them at up to 30V (when they were designed for 12V, I think). Essentially, an "overclocked" Tripath chip with fancy input capacitors. Being interested in overclocking CPUs at the time, this naturally caught my interest. The result was that the AMP could deliver something like 50+ watts per channel into 4 ohms (considerably more than any other Tripath design I've seen). Heat dissipation was accomplished by attaching a CPU-like heat-pipe cooler attached to the aluminum enclosure. They were a bit overpriced, but the build quality was good, components were of high quality, and (like most class D) were extremely efficient (i.e., easy to power on batteries within reason), and I still think they sound great.
 
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Re: So what are you using for computer audio?

Sat Apr 13, 2019 1:41 am

cynan wrote:
sluggo wrote:

BTW, the amplifier I was talking about was the Tripath TA1101, which operates in bridge mode in each channel (each channel has high- and low-side drivers). Tripath amplifiers are not SE.


I meant the input/preamp portion of the unit was SE. But yes, the amplification chip (TA1101 chip) section itself is balanced. Even more interesting, you worked for Tripath? The Tripath based amps I have are branded as Virtue Audio (now essentially defunct). Their business model was to buy up a lot of Tripath chips (probably the TA1101, but they would never say) and run them at up to 30V (when they were designed for 12V, I think). Essentially, an "overclocked" Tripath chip with fancy input capacitors. Being interested in overclocking CPUs at the time, this naturally caught my interest. The result was that the AMP could deliver something like 50+ watts per channel into 4 ohms (considerably more than any other Tripath design I've seen). Heat dissipation was accomplished by attaching a CPU-like heat-pipe cooler attached to the aluminum enclosure. They were a bit overpriced, but the build quality was good, components were of high quality, and (like most class D) were extremely efficient (i.e., easy to power on batteries within reason), and I still think they sound great.

If the Virtue product was running at 30V, then it was not using the TA1101. The 1101 had two die inside - the control/logic die, which ran at 5V, and the power die (sourced from ST), which was rated at no higher than 14.4V max operating, iirc. Go higher than about 19V under any conditions and smoke leaked out.

The Virtue amp was likely using the TK2050, which was a two-package design with a max operating point of 36V, but only with optimal layout. Safer to stay at 30-32V, which provided about 40W per channel into an 8 ohm load at nothing-ish THD. I think a dual TK2050 design with paralleled outputs per channel would get you to 70w per channel into 4 ohms, so I'm guessing that's how your amp is set up. The power dies are current limited and so are not rated under 6 ohms in stereo mode for a single TK2050.

I worked at Tripath from '98 up until things went kablooey. I really liked the 2050 and thought it was one of the best things we did. It had the sound quality of the Overture parts with a far less expensive bill of materials. Put it together with a spare laptop supply and you have a cheap 20W DIY amp with fantastic sound quality.
There is nothing more frightful than ignorance in action - Goethe
 
cynan
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Re: So what are you using for computer audio?

Sat Apr 13, 2019 11:08 am

sluggo wrote:
cynan wrote:
sluggo wrote:

BTW, the amplifier I was talking about was the Tripath TA1101, which operates in bridge mode in each channel (each channel has high- and low-side drivers). Tripath amplifiers are not SE.



If the Virtue product was running at 30V, then it was not using the TA1101. The 1101 had two die inside - the control/logic die, which ran at 5V, and the power die (sourced from ST), which was rated at no higher than 14.4V max operating, iirc. Go higher than about 19V under any conditions and smoke leaked out.

The Virtue amp was likely using the TK2050, which was a two-package design with a max operating point of 36V, but only with optimal layout. Safer to stay at 30-32V, which provided about 40W per channel into an 8 ohm load at nothing-ish THD. I think a dual TK2050 design with paralleled outputs per channel would get you to 70w per channel into 4 ohms, so I'm guessing that's how your amp is set up. The power dies are current limited and so are not rated under 6 ohms in stereo mode for a single TK2050.

I worked at Tripath from '98 up until things went kablooey. I really liked the 2050 and thought it was one of the best things we did. It had the sound quality of the Overture parts with a far less expensive bill of materials. Put it together with a spare laptop supply and you have a cheap 20W DIY amp with fantastic sound quality.


I'm sure you're right. Great to finally know what the chip in the amps are.

But 20w, at least with a parallel 2050 implementation, seems to discernably limit performance. I started with 24V/30W switching PSU, then went up to a 30V/100W switching PSU and the improvement was definitely more than just a bit of increased volume. I found that running them on batteries (higher current than the switching supplies - 2 5AH lead acid in series producing about 27V on full charge) provided the best results so its interesting that you say there's a hard current limit.

BTW, do you know how widely the 2050 chips were adopted? As stated, aside from the virtue AMPS, I've not seen Tripath designs rated for that much power..All the Chinese versions seem to be using the TA1101...
 
sluggo
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Re: So what are you using for computer audio?

Sat Apr 13, 2019 2:49 pm

cynan wrote:
sluggo wrote:
cynan wrote:


If the Virtue product was running at 30V, then it was not using the TA1101. The 1101 had two die inside - the control/logic die, which ran at 5V, and the power die (sourced from ST), which was rated at no higher than 14.4V max operating, iirc. Go higher than about 19V under any conditions and smoke leaked out.

The Virtue amp was likely using the TK2050, which was a two-package design with a max operating point of 36V, but only with optimal layout. Safer to stay at 30-32V, which provided about 40W per channel into an 8 ohm load at nothing-ish THD. I think a dual TK2050 design with paralleled outputs per channel would get you to 70w per channel into 4 ohms, so I'm guessing that's how your amp is set up. The power dies are current limited and so are not rated under 6 ohms in stereo mode for a single TK2050.

I worked at Tripath from '98 up until things went kablooey. I really liked the 2050 and thought it was one of the best things we did. It had the sound quality of the Overture parts with a far less expensive bill of materials. Put it together with a spare laptop supply and you have a cheap 20W DIY amp with fantastic sound quality.


I'm sure you're right. Great to finally know what the chip in the amps are.

But 20w, at least with a parallel 2050 implementation, seems to discernably limit performance. I started with 24V/30W switching PSU, then went up to a 30V/100W switching PSU and the improvement was definitely more than just a bit of increased volume. I found that running them on batteries (higher current than the switching supplies - 2 5AH lead acid in series producing about 27V on full charge) provided the best results so its interesting that you say there's a hard current limit.

BTW, do you know how widely the 2050 chips were adopted? As stated, aside from the virtue AMPS, I've not seen Tripath designs rated for that much power..All the Chinese versions seem to be using the TA1101...

Yeah, you wouldn't need to run parallel 2050s if you're only going to use a 20V supply. You'll get all you can get from a 20V supply with a single 2050. I don't remember precisely what the current limit was on the power die, but I do remember them going into protection even with resistive 4 ohm loads at mid-throttle.

The 2050 came out not long before things really got bad financially for Tripath, and pretty well after customers had already starting worrying about our survival. The product didn't sell well because customers did not want to commit a design around a part that they might not be able to get when their design was ready to go into production. Kind of a catch-22 for Tripath.

The 2050 and the single-package TA2022 (a dual-rail 100W 4 ohm design) were the highest-power "compact" designs from the company. However, we also sold high power hybrid modules with all of the critical design and layout rules already implemented, including the driver stage - just add power mosfets, filters and a supply, basically - and these ran up to +/- 90V (maybe more?). Something on the order of 500W/channel at 90% efficiency. Bel Canto used these in their Evo 200.2 amplifier that won Stereophile's "Product of the Year" award in 2001.
There is nothing more frightful than ignorance in action - Goethe
 
Ifalna
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Re: So what are you using for computer audio?

Sun Apr 21, 2019 4:53 pm

Mr Bill wrote:
Back when I was playing WOW I was listening through Grado SR60's and later SR80's. It kept the noise down for the rest of the house and made the whole experience much better. I thought Blizzard did a fine job of making sound cues and ambient sounds very useful. I know some people liked to play with sound off but I really liked how sounds added to the immersive realism. I hung a cheal plantronics headset around my neck for its noise cancelling mike for talking to other players.

I use a Logitech Webcam clamped to my 55" TV screen because I wanted to option of proper headphones.
Aye. audio was always great in WoW, no clue how people could stand playing muted.
The backbone of modern industrial society is, and for the foreseeable future will be, the use of electrical Power.

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