tuga
Legal Alien
The goal for speakers is nowadays narrower and sources and amplifiers are generally flat.
Croft Line Integrated
- Thread starter Shane2468
- Start date
The goal for speakers is nowadays narrower and sources and amplifiers are generally flat.
tuga
Legal Alien
Not really. That’s just an audiophile myth.
No. It is not a myth, it is a fact. The way the industry reduces output impedance in amplifiers is with feedback.
tuga
Legal Alien
The “industry”? That’s made me smile…
Of course it uses negative feedback (also push-pull) but it was the “a lot” that I was objecting to as well as the demonising of its use which is typical audiophile mythology perpetuated or perpetrated by a particular niche of audio guru reviewers…manufacturers and dealers.
But if you don’t understand the disadvantages of having high output impedance in a full-range amplifier, whose performance is affected by speaker load and can only produce acceptable levels of harmonic and intermodulation distortion when it’s outputting 5 maybe 10% of its power then you are not really fit to comment.
Chris81
pfm Member
To me the Croft Integrated R sounds fast, dynamic has a good timing with a very engaging sound. Tone color isn't as good as with a good valve amplifier, especially compared to an SET, but still good for a solid state. There are amplifiers out there with more overall resolution and more refinement but IMO it is a bargain if you can life without a remote control.
It would seem that my simplistic viewpoint is shared by not just many owners and designers of SET amplifiers but also none other than solid-state amp guru, Nelson Pass:
"There's a certain amount of “zero-sum game” involved. You can have lower distortion, but you have to trade off for it. Maybe you need a more complicated circuit, maybe you need more negative feedback, or both. A subjectivist viewpoint might be that distortion numbers don't matter anyway. Probably this is true, but only up to a point. Somewhere above 1%, distortion gets pretty tiresome. That amplifier may find itself in the closet next to the one with . 0000001% – it doesn't sound that good over the long haul. Complexity and feedback come with their own baggage, and it's a fact that many audiophiles will spend more money on amplifiers with higher distortion. Why is that? My own opinion is that our ears seem to be able to discern something about the process of amplification. Perhaps amplifier that works hard to remove errors sounds different than one that doesn't have to. The more simple and linear amplifier sounds more relaxed, and it makes me more relaxed when I listen to it."
As I have said right from the start, Audio is all about compromises. If you have an amplifier with an output impedance of around 1 ohms for example, then you match it to speakers that will work with that amplifiers traits and you don't use it with speakers that present a difficult load. About 20 years ago I produced a push pull amplifier called the Jubilate. These were mono block amplifiers and used a pair of 807's in push-pull. These amplifiers were quite popular in the USA as they had a 50-watt output and would drive most conventional speakers. I included a feedback switch on the rear where you could use the amplifier with feedback, or without feedback. It was interesting to note that everyone who used the amplifiers chose to run the amplifiers with the feedback switched out. I wonder why they did that?
If you think that using feedback doesn't have any negative performance consequences then you are deluded...
I suggest before making a comment like "you are not really fit to comment", you might like to note that I have been building high end audio equipment including phono stages, line stages, preamplifiers, power amplifiers (SET, Push Pull and Solid State) and DACs commercially for the last 25 years under the Tron Electric brand and the equipment has always received very good reviews. Tron Electric has had worldwide distribution in at least 25 countries so its not like we don't know what we are doing. I am not ignoring your comment about the disadvantages of amplifiers with high output impedance, but there are other factors in amplifier design and Hi-Fi system matching which are more important for maximising audio performance. Some people just get a "bee in their bonnet" about a certain aspect of audio and relentlessly pursue this as if it was the holy grail to solving all the audio worlds problems...
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Elephantears
Trunkated Aesthete
Far from a rant - a clear and sober account from someone who's forgotten more about audio science than most of us have ever gleaned. You've not replied to his points, as far as I can see.
tuga
Legal Alien
No points to reply as far as I can see, only an appeal to authority…
Fretbuzz
pfm Member
Exactly (I couldn't be bothered to respond...)
beammeup
pfm Member
You can have a r/c added - Glenn does not do this, but both Audioflair and Deco Audio do. Which means you get the best value amp on the market with the convenience of a remote.
BigBlue2020
pfm Member
So what speaker model recommendations would be good for this amp ?
Fretbuzz
pfm Member
I've used it at home with ProAc 140 mk2, ProAc D2, and Audio Note AN-E. Also took it to demo other speakers including AN-Js, Harbeth P3ESR and M30.1, Kudos C10. All were fine. The Harbeth P3s were in too large a demo room really and the system ran out puff quite quickly, but not the fault of the amp or speakers. Others seem happy with the combo at home.
Chris81
pfm Member
That depends on the listening preferences, room size, listening distance, maximum loudness which will be achieved.
tuga
Legal Alien
I would start my shortlist with speakers with a sensitivity above 89dB (this of course depending on the nominal impedance), unless you are using the system at very low levels or on a desktop (or you enjoy the high levels or distortion which some people do).
Then go to a couple of dealers and listen to the listed speakers.
I would also look at the impedance curve when shortlisting (Stereophile has a piece explaining speaker measurements if you need to learn how to read the plots).
Denis McKeown
Tone
Curious - did you measure one of Glenn's amplifiers? Please tell what equipment you used, and parameters etc.
Denis McKeown
Tone
Hi I'm new to forum, so just dropping in to bits and bobs I see. Where is the information that men > 50 have hearing curtailed to 13kHz?
Go do some reading/research about the subject, typically some medical information that is written by Doctors or hearing experts. Remember 20Hz-20KHz hearing is what might be possible when you are very young (up to the age of 5) and your ears have not been stressed or abused by loud noises...
Arkless Electronics
Trade: Amp design and repairs.
Yep. Our hearing in fact goes a lot lower than 20Hz but we cannot recognise pitch much below 30Hz ish. At opposite end 20KHz is extremely optimistic as Graham said.. prob no more than say 17-18KHz by 20 years old even and going down with age after that. People tend to think of say 1 or 2KHz as "midrange" as it is in the middle of most log frequency graphs and so far away from the purported 20KHz max but if you listen to 1, 2KHz it's a surprisingly high pitch and the very highest frequencies in music are around 5-6KHz. It's only harmonics, overtones, that extend beyond that... but we'd really miss them if they were missing!