Let me end the Premp/Amplifier sound debate ...

Well tube amps (at least this one) certainly seem to sound different than high current soild state through Heil AMTs and I’ve done videos that easily prove this. Everything was held the same. The Vanessa tracks are within 0.1 dB and the SRV are within 0.5 dB using pink noise as a source.

The contenders are a Yamaha RX-Z9 in Pure Direct Mode and a Melton MKT-88 with push/pull KT-88s, Sylvania input and drivertubes, and tube rectifiers.

https://youtu.be/HTxZJBoOywM

https://youtu.be/FDIu2BFbt-Q

https://youtu.be/W66SQS1wDUA

https://youtu.be/ZxhDJ_eOlYw

Tell you what. How many people in this audience do you really think even have those three amps for comparison?

Make a YouTube video of the three playing the same piece with all else being the same. Make sure that each amp first has at least 30 minutes play to come up to temperature and stabilize.

And, use a pink noise source and reputable meter to make sure that all of the amps are being recorded at the same level within 0.5 dB.

You contend that these amps sound so different, so a good YouTube video should easily display this difference. Doesn’t matter which someone prefers, just that they can hear a difference. Because if you can hear it in a YouTube video, you can certainly hear it in person.

BUT! Because the ear has such a poor memory, you may not even realize you hear a difference unless you can instantly A/B the sources as in a recording, be it audio or audio/video such as YouTube.

"How can you expect any sonic differences be heard for the viewers through a recorded YouTube session ( w/ what mics & recording equipment?)which is then digitized & then re / converted back to analog & played through computer speakers or even good headphones?"

I demonstrated that in fact sonic differences can be determined from YouTube videos. Again, it does not matter which one prefers, just that they hear a difference.

How can you listen to my videos and not come to this conclusion unless your playback system is poor?

The contenders are a Yamaha RX-Z9 in Pure Direct Mode and a Melton MKT-88 with push/pull KT-88s, Sylvania input and driver tubes, and tube rectifiers.

This is an SACD played on an Oppo95. The stereo direct RCA plugs (Canare 18 gauge) feed the "Pure Direct" on a Yamaha RX-Z9 solid state receiver (20 years old with well over 30,000 hours), rated at 170 WPC into the 6 ohm load. The speakers are connected with 14 gauge OFC cable.

The Oppo XLR stereo direct plugs (16 Monoprice/18 gauge Canare) feed to the Melton KT-88 (P/P KT-88s) rated at 80 WPC (purchased new last year with ~60 hours now). The speakers are connected with 12 gauge OFC cable.

The volumes were matched using the both the 1 kHz tone and pink noise tracks on the Stereophile test disk and ultimately matched to within less than 0.1 dBA using the pink noise track.

Nothing was moved or disturbed in the room at any time when comparing equipment.

The Vanessa Fernandez track was first played on the Yamaha (digital volume control in 0.5 dB steps) to establish the optimum camera recording level and the values recorded.

The camera was replaced with a professional sound level meter, the Vanessa disk was replaced with the Stereophile test disk and the levels for the Yamaha were recorded for the 1 minute track (Leq, Lmax, Lmin. L02, L08, L25, L50). To be statistically significant, this was repeated twice and the results of the three sets of measurements were within 0.1 dBA.

The track was changed to the Pink noise track and again, the levels were recorded for three sets of readings of the 2 minute track. The Yamaha was then shut off.

The speakers were then switched to the Melton and the amp was allowed to play a disk for over an hour before any testing.

I then put the 1 kHz track on the Melton and after many, many, many back and forth attempts on the Alps dial I was able to get the Melton to play the 1 kHz track within 0.1 dBA of the Yamaha and did three sets of readings. I then did three sets of reading using the Pink noise and of course because of the tube rolloff, this was 0.8 dB less than on the Yamaha.

I feel that Pink noise is better for comparison and brought the Pink noise on the Melton up to the level of the Yamaha (within 0.1 dBA) for the comparison.

So, at this point the Yamaha and Melton are within 0.1 dBA at that particular spot on the dial and I made the recording of Vanessa on the Melton.

I shut off the Melton, changed the speakers back over, and let the Yamaha warm up for an hour before making the same recording without moving the camera nor disturbing ANYTHING in the room other than my presence starting/stopping the recordings.

Know that if you find the recordings bright, both the 10" and Heil have L-pads turned to full, which provides the flattest response across the band, even if it does sound bright. And it may be that you find the tube too dull and the solid state too bright, which shows the importance of matching equipment and speakers for your taste.

Also, realize that when you sit back into the couch, the proximity of the cushions, as opposed to a camera tripod sitting up over the couch) takes a lot of brightness out. Even a few inches can make a difference which is why it was so important not to move the camera between recordings.

If you can’t hear "meaningful" differences, you need to update your playback system or listen on headphones.

https://youtu.be/HTxZJBoOywM

https://youtu.be/FDIu2BFbt-Q

https://youtu.be/W66SQS1wDUA

https://youtu.be/ZxhDJ_eOlYw

djones51, do you not hear the differences in the videos, especially from the Heil? I matched the levels to within 0.1 dB. Do you really think that changing the output voltage on one amp or the other by maybe a couple thousanths of a volt is really going to create that much shift in the frequency spectrum as opposed to one being maybe a tiny bit louder?  Let's be realistic.

Like I said, you are only listening for a difference, no matter how small or which you care for. If you can hear a difference, then YouTube is capable of displaying/resolving this difference.

And no one is saying that either is exactly as how it sounds in the room or that the videos convey the finer points such as soundstage and imaging. Again, we are only listening for differences in what we can hear.

And the original premiss was that all amps sound the same, but obviously, depending on the speakers used, they don’t, and I’ve demonstrated that.

Then you need to "up your game" and listen on better equipment or headphones. The difference is very noticable on even a decent system.

After all, this is an audio forum. No one would expect to go to a gaming site and expect to be competative using less than high definition resolution and a fast video card, nor would they expect others to "dumb down" their systems to accomodate them.

Initially, they were not labled, but everyone on the other forum was still able to hear the differences and pretty much know which was which, so I went back and put the lables on.

holmz,

What plastic? There is a cloth cover over the glass table top, but there are no plastic coverings on any of the furniture.

BTW, my videos were all made using a Nikon D750 SLR.

Atmasphere,

If the 15 dB of negative feedback was meant for discussion of the Melton MKT-88 tube amp used in the videos, I have no idea where you came up with this figure.

Melton advertises 0 dB of negative feedback, and doesn’t appear to have any components in a feedback loop when the chassis wiring is viewed.

MKT88P-80W

Integrated Amplifier

• Description

Product Description Specifications: Model: MKT88P-80W (Push Ball)

Power Output: 80 watt x 2 Output Impedance: 4.8.16 Ohm Amplifying Tube: 12AT7 x 2 pcs, 12AU7 x 2 pcs Power Tube: KT-88 x 4 pcs Rectifier Tube: 5Z4P x 2 pcs

** Tetrode Amplifier Design **

** No negative Feedback Design **

** Vacuum Tube Rectifier Design **

Superbly built integrated tube (KT88) amplifier.. .It employs specially designed simple circuitry for the well known Tetrode KT88 to make it sound at its best performance, coupled with powerful power supply and non-negative feedback design, capable of delivering lucid, melodiac, powerful sound with broad open soundstage.