Where Have All the Serious Audiophiles Gone?

[CDMC]

Why not use a very clean class-A amp and then null the performance around that using something like feed-forward technology.
There is an objective standard, its called linear amplification with zero distortion. That's the target not some gigantic 25 watt space heater.

- Rich

Keep in mind that for most here that is true. There is a whole group out there that doesn’t want the best objective standard, some who believe their high distortion amps are truer to the source, other who acknowledge that they are not, but like the distortions they provide.

 

[sergeauckland]

Why not use a very clean class-A amp and then null the performance around that using something like feed-forward technology.
There is an objective standard, its called linear amplification with zero distortion. That's the target not some gigantic 25 watt space heater.

- Rich

You've just described the Quad 405 current dumping amplifier!

S.

 

[MSTARK]

Little off topic but I think it might be just as interesting (controversial) to hear some opinions on David Berning’s ZOTL amplifiers.
I don’t know if he’s actively building amplifiers under his brand, but he does consulting/designs for LTA.
They market these amps as a combination (sound characteristics) between “SET” and SS. I guess what they are referring to is a usual “color/bloom” of tubes in midrange region and SS authority/definition in lower frequencies. They also claim superiority in high frequency resolution in comparison to other tube amp designs.
Any thoughts?



https://www.lineartubeaudio.com/products/zotl-40-reference-amplifier

 

[SIY]

The Mcintosh tube amps also run relatively cool because the Unity Coupled output transformer allows them to run the tubes closer to class "B".

Likewise, screen drive amps can run quite cool. My last big one was 150W per channel output, but idled at 3mA. No measureable crossover distortion.

 

[SIY]

Little off topic but I think it might be just as interesting (controversial) to hear some opinions on David Berning’s ZOTL amplifiers.
I don’t know if he’s actively building amplifiers under his brand, but he does consulting/designs for LTA.
They market these amps as a combination (sound characteristics) between “SET” and SS. I guess what they are referring to is a usual “color/bloom” of tubes in midrange region and SS authority/definition in lower frequencies. They also claim superiority in high frequency resolution in comparison to other tube amp designs.
Any thoughts?



View attachment 78044https://www.lineartubeaudio.com/products/zotl-40-reference-amplifier

I reviewed the LTA Ultralinear for AudioXpress. It did a few things very well, but a few things very poorly. It had the oddest distortion performance I've ever seen. $7000 for 25 watts.

They were apparently not happy with the review.

 

[sergeauckland]

Little off topic but I think it might be just as interesting (controversial) to hear some opinions on David Berning’s ZOTL amplifiers.
I don’t know if he’s actively building amplifiers under his brand, but he does consulting/designs for LTA.
They market these amps as a combination (sound characteristics) between “SET” and SS. I guess what they are referring to is a usual “color/bloom” of tubes in midrange region and SS authority/definition in lower frequencies. They also claim superiority in high frequency resolution in comparison to other tube amp designs.
Any thoughts?



View attachment 78044https://www.lineartubeaudio.com/products/zotl-40-reference-amplifier

A 1.6 ohm output impedance and 0.5% THD (frequency not specified) tells you all you need to know about the amp.
Oh, and $6800 for something I can get for a tenth of the price with better performance and much less power consumption
S

 

[MSTARK]

I reviewed the LTA Ultralinear for AudioXpress. It did a few things very well, but a few things very poorly. It had the oddest distortion performance I've ever seen. $7000 for 25 watts.

They were apparently not happy with the review.

Can you provide link to your review? I would be very interested to read it.
It’s a little odd as my impression after some email exchanges with their rep. was that their amps are low(er) distortion designs.

 

[MSTARK]

A 1.6 ohm output impedance and 0.5% THD (frequency not specified) tells you all you need to know about the amp.
Oh, and $6800 for something I can get for a tenth of the price with better performance and much less power consumption
S

Not sure if that tells all the story as at the end, it will be judge by our ears.
But I do agree that their pricing is quite rich. I’m just wondering how they perform in real life scenario. 6moons raved about them, so I got a little curious. From topology side that is.

 

[RichB]

You've just described the Quad 405 current dumping amplifier!

S.

Quad and some amps found in my signature

Tube amps used to alter the sound if just fine by me, but I want accuracy not tone controls.

- Rich

 

[JeffS7444]

Little off topic but I think it might be just as interesting (controversial) to hear some opinions on David Berning’s ZOTL amplifiers.

It's been years since I've encountered them, but recall the sonics from the demo being pleasant. Found this schematic of MicroZOTL on Superbestaudiofriends and don't understand it - is it a switching amplifier?

 

[MSTARK]

I just want them to sound good to my ear without spazzing out over spec-sheet.

 

[SIY]

Can you provide link to your review? I would be very interested to read it.
It’s a little odd as my impression after some email exchanges with their rep. was that their amps are low(er) distortion designs.

Print magazine. But all the cool kids subscribe.

I would not describe it as low distortion except maybe compared to fashionable single ended amps. Besides high harmonic and intermod, every spectral line had a group of sidebands.

 

[MSTARK]

It's been years since I've encountered them, but recall the sonics from the demo being pleasant. Found this schematic of MicroZOTL on Superbestaudiofriends and don't understand it - is it a switching amplifier?

I’m obviously technically handicap but I think so.

 

[MSTARK]

Print magazine. But all the cool kids subscribe.

I would not describe it as low distortion except maybe compared to fashionable single ended amps. Besides high harmonic and intermod, every spectral line had a group of sidebands.

Maybe that’s what he meant when he mentioned lower distortion. It will probably smoke my Electra Print 300b DRD monos as far as THD is concern.
And I will subscribe. I just never came across this publication. It shows how much I care about latest trends.

 

[SIY]

I’m obviously technically handicap but I think so.

It uses a switching converter in place of an output transformer. But the circuitry is normal analog.

 

[sergeauckland]

Not sure if that tells all the story as at the end, it will be judge by our ears.
But I do agree that their pricing is quite rich. I’m just wondering how they perform in real life scenario. 6moons raved about them, so I got a little curious. From topology side that is.

I'd rather not judge using ears as I might like it, and that'll never do. I much prefer to go by the numbers, and if they aren't right I won't even listen to it.

S.

 

[MSTARK]

It uses a switching converter in place of an output transformer. But the circuitry is normal analog.

It must be a nightmare to put it all together..... Is it similar to common OTL design? What’s so special about it? There is very little information out there except patent papers/schematics which I obviously don’t understand. In language rest of us poor souls can understand pls.

 

[MSTARK]

I'd rather not judge using ears as I might like it, and that'll never do. I much prefer to go by the numbers, and if they aren't right I won't even listen to it.

S.

Totally understand. But without fully understanding technical aspect of a particular design or critical testing for that matter, the only tool at my disposal are my flawed ears.

 

[SIY]

It must be a nightmare to put it all together..... Is is a similar to common OTL design? What’s so special about it? There is very little information out there except patent papers/schematics which I obviously don’t understand. In language rest of us poor souls can understand pls.

I’m on my phone, so can’t type it all out. But in simple terms, you can use a switching buck converter instead of an output transformer. The output tube sees what’s basically a perfect transformation of the speaker impedance as its plate load. It’s a very clever idea, and the amp shows very good bandwidth as a result.

Totally different than a conventional OTL circuit.

 

[MSTARK]

I’m on my phone, so can’t type it all out. But in simple terms, you can use a switching buck converter instead of an output transformer. The output tube sees what’s basically a perfect transformation of the speaker impedance as its plate load. It’s a very clever idea, and the amp shows very good bandwidth as a result.

Totally different than a conventional OTL circuit.

Copy. So basically tubes are “sort of directly” coupled to speakers and somehow match their impedance without help of transformers. Very interesting. Thanks.