True Dimensional Sound - Harmonic Enhancement

[velo]

Lots has probably already been discussed about this box but perhaps not from a DIY perspctive?

I am considering patching this into my RME rig near the final mastering stage. Upon seeing what is inside I think this would be an easy project for first-time DIYers.

But.. Thoughts on turns ratio, windings, and proximity of each? Is there any crosstalk between the two when processing stereo? (Short answer is yes of course since, well, physics...but what in terms of discernable THD?)

TDS could be step up/down in series with down/up or 1:1 in series with 1:1. I am still catching up on all this.

Here's the patent: https://image-ppubs.uspto.gov/dirsearch-public/print/downloadPdf/5361306

It is odd since at first glance the patent seems to be for a bit more than two transformers in series yet the abstract reads like a patenting for the most basic idea of a transformer circuit.

Interesting discussion here:
https://www.diyaudio.com/community/...s-true-dimensional-sound-how-it-works.194478/

 

[JohnRoberts]

floobydust?

JR

 

[velo]

floobydust?

JR

a heavy mixed bag of iron

 

[velo]

It can add harmonics to things that one may prefer to remain buried. I have experienced a multidimensional hum that takes me back.

 

[ccaudle]

Thoughts on turns ratio, windings, and proximity of each?

You would need a unit to measure, there is no way to guess without some measurements of output vs. input.

TDS could be step up/down in series with down/up or 1:1 in series with 1:1

Or could be L-R and L+R with different turns ratio to enhance the sense of width in the stereo signal (i.e. mid-side processing with slightly higher side gain) and of course back to L and R at the end.

Here's the patent

That patent shows a single transformer (per channel) with active electronics around it, so it obviously does not match the picture you have shown.

 

[velo]

You would need a unit to measure, there is no way to guess without some measurements of output vs. input.



Or could be L-R and L+R with different turns ratio to enhance the sense of width in the stereo signal (i.e. mid-side processing with slightly higher side gain) and of course back to L and R at the end.



That patent shows a single transformer (per channel) with active electronics around it, so it obviously does not match the picture you have shown.

I have the TDS in the photos referencing the patent. 100% passive. It bears little resemblance to the patent. The patent is 1) worthless regarding the TDS, and 2) a bit of a joke to me since it reads like an application for a patent for a simple transformer-based amplifier described as if it were then novel. It wasn't.

I am scratching my head over why this patent was issued since both op amps and transformers have been used in amplifier circuits since well before the timeframe when the patent was issued. I find it hard to believe that this patent was the first time someone mentioned harmonic distortion in a straightforward amplifier circuit. Concluding that the patent and a lot surrounding this device are marketing hype would not be uninformed. They had a patent. They stamped the number on their box.

I suppose I should use my true rms multimeter to check voltages with various input signals. I'm sure I could figure out the ratios. As far as the number of windings, by measuring flux or something...I'm not sure how to do that but there have been claims these were "cheap guitar amp transformers".

 

[ruffrecords]

The patent has expired and appeared to claim an op amp driving a transformer whose secondary is connected to another op amp with some EQ. Hardly novel.

Cheers

Ian

 

[gyraf]

The US patent- and trademark system is really whacky at times

Like tonelux getting a us exclusive trademark on "tilt" eq - and even aggressively upholding it

/Jakob E.

 

[k brown]

For a minute there, I was getting 'Aurally Excited'.

 

[velo]

You would need a unit to measure, there is no way to guess without some measurements of output vs. input.



Or could be L-R and L+R with different turns ratio to enhance the sense of width in the stereo signal (i.e. mid-side processing with slightly higher side gain) and of course back to L and R at the end.



That patent shows a single transformer (per channel) with active electronics around it, so it obviously does not match the picture you have shown.

The two channels are joined only by the DPDT switch that does not join them and whatever quantum field effects occur within the box.

For a minute there, I was getting 'Aurally Excited'.

So far everything I've retroactively mastered through it (i.e. put it between my main outs and the monitors) DOES sound richer. I am not going to say if it is warmer or punchier but it certainly is harmonically enhanced.

I drew this simple schematic of one channel. I don't know if these are both 1:1 or if there is a step up step down. One thing I noticed interesting about the wiring between the two transformers is that the same white and yellow wires are soldered to each other rather than going from secondary to primary.

My hunch right now is that these are both 1:1 and the unit is going to hysteresis- and eddy-up a bit of the lower end in the larger transformer and a bit of the higher end in the smaller transformer. Well, that is just physics that we know to be true. What I don't know is if putting them in series somehow "saves" bandwidth for the low end that would typically be eaten up by higher frequency saturation in smaller transformers. (?)

The bad news is the hum. I'll run more tests to see if the hum is due to nearby PSUs but I did try to isolate. I'll run some high-quality cables 15 feet away and back for more inverse square law.

Please ignore the step up/down implications of the schematic. I've not yet run voltages.

 

[ruffrecords]

So it doesn't even disconnect the primary in bypass position?

All transformers produce more distortion at low frequencies. Steel produces less low frequency distortion than nickel-steel alloys of the same core size. On the other hand, steel produces some distortion even at mid frequencies but nickel-steel alloys of the same core size produce a lot less. And in all cases the amount of distortion produced is very level sensitive.

Cheers

Ian

 

[velo]

So it doesn't even disconnect the primary in bypass position?

All transformers produce more distortion at low frequencies. Steel produces less low frequency distortion than nickel-steel alloys of the same core size. On the other hand, steel produces some distortion even at mid frequencies but nickel-steel alloys of the same core size produce a lot less. And in all cases the amount of distortion produced is very level sensitive.

Cheers

Ian

Would it matter since the switch closes the circuit that bypasses the transformer uh "ladder"?

 

[JohnRoberts]

The US patent- and trademark system is really whacky at times

Like tonelux getting a us exclusive trademark on "tilt" eq - and even aggressively upholding it

/Jakob E.

don't know about trademarks, but I once scratched out a circuit for a tilt EQ in the side chain of a noise gate. Not to listen to, but to preferentially suppress or enhance instruments to better trigger, or not trigger the gate.

JR

 

[velo]

I ran a noisy sweeping pattern* through the TDS trying to get a sense of what it does with various harmonic intervals but was only able to get a very crude qualitative reinforcement of what I was hearing. RME DigiCheck NG spectral analyzer revealed a low pass filtration, a dip somewhere between 1k-5k, and an attenuation across the entire frequency response.

I've more audio engineering/electronics theory to dig up and re-remember to connect the dots but I think I was seeing two overlayed curves which would make sense as there are two transformers. All we're doing here is looking at what a pair of passive transformers are doing to the signal.

The richness I mentioned above comes with the price of this quite noticeable low pass filter effect. I put some drums through it. The closest thing I could think of to another product I've heard would be the Hairball Audio Elements Bronze preamp.

More to come as time permits.

*I need a better test signal generator. I had one but free trial expired so I was using Studio One's Oberheim software synth.

 

[Tubetec]

Have you tried Room Eq Wizard ?
Its got a good generator section along with FFT, distortion measurement and ossciloscope
Even though it was concieved as a tool for speaker/room measurement its equally applicable to audio path testing .
Best part is its free to use in its entirety ,

 

[freshtapescent]

Especially if they’re step-up…wiring secondaries together and I/O on primaries will ‘cancel out’ and give you your signal back minus losses, however not until you’ve undergone a potentially large voltage gain and gotten up closer to core saturation. The way these are cross-coupled I’m curious as to what happens to the stereo image when the core begins to saturate…also shouldn’t there also be some serious IMD because of how the signals are driving each other? Almost like like a weird transformer coupled ring modulator with the ring.

 

[velo]

Have you tried Room Eq Wizard ?
Its got a good generator section along with FFT, distortion measurement and ossciloscope
Even though it was concieved as a tool for speaker/room measurement its equally applicable to audio path testing .
Best part is its free to use in its entirety ,

Thanks for the hint I will check it out

 

[ccaudle]

The schematic posted above is a little difficult to follow. I think this is how it is connected, which seems really bizarre to me. Pin 2 (hot) is connected straight across? Other than that it would be back to back transformers.

 

[velo]

The schematic posted above is a little difficult to follow. I think this is how it is connected, which seems really bizarre to me. Pin 2 (hot) is connected straight across? Other than that it would be back to back transformers.

View attachment 109795

yes, pretty close, back to back transformers it is, but you're top trace there from 2 to 2 is only engaged if the switch is in the "off" position

[EDIT: I must have meant 3 engaged in the "on" position. 3 is also thru when in "off" position.]

 

[ccaudle]

top trace there from 2 to 2 is only engaged if the switch is in the "off" position

The picture in post #11 very clearly shows a connection from input pin 2 to output pin 2 without traversing the switch.