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$500 amplifiers to test and review?

hege

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Just replace the input with Neurochrome Universal Buffer if it bothers. ;)

(disclaimer: no idea if it fits)
 

rebbiputzmaker

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Just replace the input with Neurochrome Universal Buffer if it bothers. ;)

(disclaimer: no idea if it fits)
Thank you just wondering if you did know. If compatible that would be an option although, if I would take that direction I would probably get the VTV Amplifiers buffet board. It has quality regulation, and allows one to choose and change opamps. I like 1612s, and would start with those, but in the future might be interesting to try others.
 
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Wes

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some old ones - either available on the used market or noteworthy designs

was it NAD that had the "Power Envelope" ?

Nelson Pass designs for Nakamichi & Threshold

Sunfire & other Carverisms
 

Specialcause

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I use mine with the gain controls all at maximum, so that I have a known and fixed amount of gain, and adjust the individual levels on the crossover.
As to noise, my midrange units have a sensitivity of 93dB ( Tweeters 88dB, bass 86dB) and don't get any hiss audible unless my ear's close to the driver. I did get a small amount of buzz on the midrange, cured by increasing the size of the reservoir caps. In the passive version of the 801, the midrange and tweeter are attenuated relative to the bass, but with an active 'speaker, there's no crossover to attenuate any noise, so the buzz was just audible.

Although the A500 is AC coupled to the load, that's through the main reservoirs, so quite enough energy to destroy tweeters, I fitted some series capacitors as protection to the mid and tweeters. The bass unit is big enough to stand DC until the fuses blow, the tweeters wouldn't.

The danger of an amplifier going DC exists with any active 'speaker so protection is necessary. A higher priced amplifier would probably have DC sensing relays that disconnect the load, that's one of the things that an amplifier that cheap lacks.

S
Is there the same danger of blown tweeters when the A500 is connected to a passive 'speaker?

Phil
 

sergeauckland

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No - in a passive speaker the crossover will have a series capacitor as part of the high pass filter to the tweeter, protecting it from DC.
That's right. Almost by definition, a passive 'speaker has one or more series capacitors which will protect the tweeter (and mid range) against DC.

Some 'speakers, like my B&W 801s, even have a large (1000uF) capacitor in series with the bass unit. I can't see the point of that, as all it does is to reduce the damping factor, but will roll off the extreme LF below what the 'speaker can handle, so in studio use, may be useful. I didn't do that in my home system, as I can do that in my active crossover.

S.
 

SIY

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That's right. Almost by definition, a passive 'speaker has one or more series capacitors which will protect the tweeter (and mid range) against DC.

Some 'speakers, like my B&W 801s, even have a large (1000uF) capacitor in series with the bass unit. I can't see the point of that, as all it does is to reduce the damping factor, but will roll off the extreme LF below what the 'speaker can handle, so in studio use, may be useful. I didn't do that in my home system, as I can do that in my active crossover.

S.
Sometimes that cap in series with the woofer is part of the alignment. See, for example, the paper by David Clark and Earl Geddes in SAE Transactions, v95, p 661 (1986).

edit: also Dan Recklinghausen, JAES vol 33, “Low Frequency Range Extension of Loudspeakers “
 
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sergeauckland

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Sometimes that cap in series with the woofer is part of the alignment. See, for example, the paper by David Clark and Earl Geddes in SAE Transactions, v95, p 661 (1986).
Of that I'm sure. It's just that in my application, once I got rid of the passive crossover, I can do the same using DSP.

S.
 

silentt29

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Yamaha integrated line, like the A-S301, A-S501, A-S701, A-S801, A-S1200, A-S2200, and A-S3200?
 

Willem

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Here in the Netherlands the 2x85 watt AS501 has been a best buy at 359 euros. I bought one for my daughter and it is absolutely impeccable for a small to medium sized room. Just for fun I even tried it in our large listening room driving inefficient Harbeth P3ESRs plus a small Kef Kube 8b sub. I could easily live with the combination, particularly in a smaller room (70 sq m was asking a bit much). Measurements would be nice but probably not surprising.
 

Willem

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I just notice that the price has gone up by a third since I bought it about half a year ago. The same also applies to that Kef sub that I bought around the same time. I wonder if this applies to the market as a whole.
 

Alobar

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Here in the Netherlands the 2x85 watt AS501 has been a best buy at 359 euros. I bought one for my daughter and it is absolutely impeccable for a small to medium sized room. Just for fun I even tried it in our large listening room driving inefficient Harbeth P3ESRs plus a small Kef Kube 8b sub. I could easily live with the combination, particularly in a smaller room (70 sq m was asking a bit much). Measurements would be nice but probably not surprising.
I have been running 3 of the Yamaha AS-x01's in my triamped system. I have a AS-301 on each of the MF and HF drivers and a 701 on the LF. They really work nice in this arrangement as since I am using a DSP, I can bypass all tone controls.
Here is a test performed years ago on a AS-500 which is pretty much the same as the 501. Would still love to see Amir's test and opinion.
Having trouble DL'ing the whole PDF so here it is in pieces
 

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Alobar

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Here is the actual test, ran by an independent lab (from the magazine)
 

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trl

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Here is a test performed years ago on a AS-500 which is pretty much the same as the 501.
Same internal architecture inside A-S30x/50x/70x/80x with slight changes on the output stage to reflect the output power, feel free to check this out too: https://www.audiosciencereview.com/...ts-about-the-internals-few-measurements.9459/. Audioholics has a great test on A-S801, worth reading it.

Yamaha integrated line, like the A-S301, A-S501, A-S701, A-S801, A-S1200, A-S2200, and A-S3200?
The high-end A-S1x00/2x00/3x00 series play in a different league and have nothing to do in this thread, they're way above the price tag from the subject. However, I do hope that Amir will test one of these "babies" soon.
 

silentt29

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Same internal architecture inside A-S30x/50x/70x/80x with slight changes on the output stage to reflect the output power, feel free to check this out too: https://www.audiosciencereview.com/...ts-about-the-internals-few-measurements.9459/. Audioholics has a great test on A-S801, worth reading it.

The high-end A-S1x00/2x00/3x00 series play in a different league and have nothing to do in this thread, they're way above the price tag from the subject. However, I do hope that Amir will test one of these "babies" soon.

Absolutely right, my bad. Must've gotten carried away haha
 

PatentLawyer

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SMSL DA9!
 
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