Visit to Henk van der Hoeven -- Apogee Acoustics Re-builder/Restorer

Argonaut · Aug 25, 2016

LoL, facts over fairy tails eh micro

microstrip · Aug 25, 2016

morricab said:
A single ended amplifier will not drop into Class B at all. It cannot as it must trace the whole waveform, unlike a push/pull amp where one tube turns off in Class B. The NAT SE2SE seems to be go into Class A2, where the grid is driven positive (normally not an option for most SETs). When this is done much more power can be generated but with a significant increase in disotortion (but it is not clipping).

Whether or not the Transmitter or Magma can do more depends on the design and whether it leaves Class A1 and go into Class A2 or not.

I seem to remember that the SE 1 MKI never left A1 and made 15 watts...pretty normal for a 211 SET. Also, the bigger SE3 made far less power than the SE2SE was able to do.

You are correct - as I had seen two tubes in the NAT amplifier photos and read about class AB I assumed it was a push-pull amplifier - my comments and the referred threads addressed this type of amplifiers. I saw now it is a parallel single-ended.

Zero000 · Aug 25, 2016

Diapason said:
It just so happens there's one going for a very keen price on audio-markt (well, keen by European standards). I've been quite tempted myself.

Being an Levinson user it isn't hard to understand why. I owned one for a while. I've also heard it driving MBL 116Fs, where I wasn't so keen on it. It was the MBL owner that brought one round. Had to get one after that.

microstrip · Aug 25, 2016

Harlequin said:
LoL, facts over fairy tails eh micro

spiritofmusic · Aug 25, 2016

Micro, what is the practical relevance of the NATs SE2SEs triodes being parallel single ended 211s, rather than push-pull?
Does this make them more suitable to Apogees duties?

Zero000 · Aug 25, 2016

Check this out Marc, if you haven't already.

To this day I am not 100% sure whether my 211s are PSE or PP.

Zero000 · Aug 25, 2016

Other SS amps come and go. The 211s never seem to want to leave. They must be quite good.

spiritofmusic · Aug 25, 2016

Justin, they stay because they obviously do some things very well, and your SS can't match them completely
Fascinating re application of SET/PSET to Apogees
Will keep an open mind, and if I do indeed end up with a pair (and I'm veering toward Duettas over Divas for ergonomic reasons), I can start with my 60W Class A1/100W Class A2 NATs SE2SEs, demo 120W NATs Transmitters SETetrodes, consider SS Gryphon Antileons as single amp or biamping with the NATs on the MRTWs

microstrip · Aug 26, 2016

spiritofmusic said:
Micro, what is the practical relevance of the NATs SE2SEs triodes being parallel single ended 211s, rather than push-pull?
Does this make them more suitable to Apogees duties?

We know that the main distortion spectra of a push-pull topology is quite different of that of a single ended amplifier, but I have little experience with SE's and Apogees, I can not be of help concerning your second question.

I have seen big powerful 500W SS amplifiers that could not drive properly some speakers and the same speakers driven with success to loud levels by 70W tubes, IMHO in this hobby we have more exceptions than rules.

morricab · Aug 27, 2016

microstrip said:
We know that the main distortion spectra of a push-pull topology is quite different of that of a single ended amplifier, but I have little experience with SE's and Apogees, I can not be of help concerning your second question.

I have seen big powerful 500W SS amplifiers that could not drive properly some speakers and the same speakers driven with success to loud levels by 70W tubes, IMHO in this hobby we have more exceptions than rules.

One of the big mistakes audiophiles make (including many on this forum) is that high power = dynamics and therefore "live" sound. They think that compressed dynamics, which give a flat and boring sound, is solved by more power having been taught that compression occurs when one reaches the clipping point of the amp.

What seems to not be generally realized is that amps can sound compressed right from the first mW and it has to do with circuit topology and not power. I had an amp in the past that would sound "constipated" and the sound would not express regardless of the level. You always felt the urge to turn it up more sound the sound could get out...but it never did. This was an extreme case of an affliction from which most amps suffer.

The reason most amps don't sound live has nothing to do with power output and everything to do with circuit and power supply design.

On the right speakers (there are limits related to clipping with low power) a 2 watt SET will sound more alive and dynamically expressive (particularly for microdynamics) than pretty much any big SS or tube amp.

FrantzM · Aug 27, 2016

morricab said:
One of the big mistakes audiophiles make (including many on this forum) is that high power = dynamics and therefore "live" sound. They think that compressed dynamics, which give a flat and boring sound, is solved by more power having been taught that compression occurs when one reaches the clipping point of the amp.

What seems to not be generally realized is that amps can sound compressed right from the first mW and it has to do with circuit topology and not power. I had an amp in the past that would sound "constipated" and the sound would not express regardless of the level. You always felt the urge to turn it up more sound the sound could get out...but it never did. This was an extreme case of an affliction from which most amps suffer.

The reason most amps don't sound live has nothing to do with power output and everything to do with circuit and power supply design.

On the right speakers (there are limits related to clipping with low power) a 2 watt SET will sound more alive and dynamically expressive (particularly for microdynamics) than pretty much any big SS or tube amp.

Not my experience. Within the constraints of speaker power compression ( In itself a serious and poorly understood issue) and of amplifier quality , I would just say it ain't so. Perhaps we should open a thread on this.

fas42 · Aug 27, 2016

I agree with morricab's viewpoint - and would appreciate a thread discussing this.

LL21 · Aug 27, 2016

I think DDK has often said he has not found a high powered SS amp he likes...i hope i'm not taking that out of context.

I agree it would be good to read a new thread about amp design. Perhaps in the spirit of a here's WHY something happens as a result of the circuit design, power supply build, etc...and also the practical implications on the speaker of differing types and the speaker interface which i have read repeatedly (and reliably, i believe) is absolutely crucial to get right.

microstrip · Aug 27, 2016

FrantzM said:
Not my experience. Within the constraints of speaker power compression ( In itself a serious and poorly understood issue) and of amplifier quality , I would just say it ain't so. Perhaps we should open a thread on this.

Yes, we should have a thread on it, including also the speaker efficiency - an even less understood subject!

ddk · Aug 27, 2016

LL21 said:
I think DDK has often said he has not found a high powered SS amp he likes...i hope i'm not taking that out of context.

I agree it would be good to read a new thread about amp design. Perhaps in the spirit of a here's WHY something happens as a result of the circuit design, power supply build, etc...and also the practical implications on the speaker of differing types and the speaker interface which i have read repeatedly (and reliably, i believe) is absolutely crucial to get right.

Actually Lloyd I was referring to both tube (100w Class A max) and ss (Class A, 150w max), I haven't heard anything beyond those power ratings that I can live with, in reality aside from the Lamm M1.2/M2.2 my sweet zone for amplifiers, tube or ss is from around 20 watts to 50 watts. As I mentioned earlier reason I gave up on Apogees was because no amplifier in that power range I know of can drive them to satisfactory levels.

david

Zero000 · Aug 27, 2016

What would be a satisfactory level, in decibels, for you, Dave?

Ron Resnick · Aug 27, 2016

ddk said:
. . . my sweet zone for amplifiers, tube or ss is from around 20 watts to 50 watts. As I mentioned earlier reason I gave up on Apogees was because no amplifier in that power range I know of can drive them to satisfactory levels.

david

20 to 50 watts just ain't enough for them Apogees!

I am struggling to understand why your perfectionism about amplifiers caused you to give up on your favorite speaker.

FrantzM · Aug 27, 2016

microstrip said:
Yes, we should have a thread on it, including also the speaker efficiency - an even less understood subject!

I agree with you. Speaker efficiency is a very abused metrics

ddk · Aug 27, 2016

User211 said:
What would be a satisfactory level, in decibels, for you, Dave?

Mid 90's db continuous and distortion free but its not just about sound pressure levels, you can get that from many amplifiers today but the sound quality isn't there with most. The best sound I achieved with the Divas was with two pairs of Lamm M2.1s, passive bi-amping but even that became boring in time, low powered SETs and Class A amps are so much richer sounding to me...

david

ddk · Aug 27, 2016

Ron Resnick said:
20 to 50 watts just ain't enough for them Apogees!

I am struggling to understand why your perfectionism about amplifiers caused you to give up on your favorite speaker.

It came down to a choice Ron, in the end I went as far as I could go with the Apogees and it didn't quite get me there. Over a decade with them was long enough to know!

Edit- If you spend some time with a quality SET and the right speakers you'll know why.

david

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