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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
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21st Oct 2019, 7:16 am | #41 |
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Re: "Loud Enough to fill a Small Hall"
One of my transistor radio projects I decided to "beef up" the output stage to 4W.
I used 2 OC16's in push pull with an AC188 driver and a vintage Foster 10F3 speaker, that you can see on page 2, its a 3W speaker but it handles 4W. Despite the lowly 4W this radio can appear to blast you out of a normal sized living room, and even outdoors it seems amazingly loud. It is very surprising what 4W can do with a good speaker: http://worldphaco.com/uploads/THE_AF...OC16_RADIO.pdf |
21st Oct 2019, 9:11 pm | #42 |
Heptode
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Re: "Loud Enough to fill a Small Hall"
I occasionally use a Ferguson 205STA stereo receiver from 1967. I think it's rated at 10 watts per channel and goes plenty loud enough in a domestic environment. Bass goes nice and deep and it sounds satisfyingly "right" with high quality speakers of similar vintage although it's gutsy enough to drive modern speakers without getting out of its depth.
I have more modern amps at my disposal (newest is a 1997 Sherwood receiver) but I never need to play them any louder than the Ferguson and their power capabilities are never even slightly stretched. Even under these conditions things can get uncomfortably loud! I used to have an Akai amp with peak power meters and I rarely got it over 5 watts without getting grief from the neighbours. The selection of speakers I use tend to be inefficient hifi speakers (although that may be a bit unfair on some of the older ones) yet I still maintain huge amounts of power aren't really necessary unless you want to play at Glastonbury! Regards, Paul
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21st Oct 2019, 9:37 pm | #43 |
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Re: "Loud Enough to fill a Small Hall"
Small amplifiers into decent speakers can sound good - in my student-days I would drive from Mid Wales down to a backstreet warehouse in London and return with Teleton SAQ-206B amplifiers/unbranded MDF-cased speakers, Garrard SP25MkIV record-decks etc - then sell them on to other students at a decent profit.
The little Teleton amps only did 7 or 8 watts/channel but in a typical student-bedroom and feeding efficient speakers they sounded good when playing The Police, the Stones, or Floyd/Kraftwerk/Tangerine Dream. |
22nd Oct 2019, 1:00 pm | #44 |
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Re: "Loud Enough to fill a Small Hall"
This thread is worrying me. Does it mean the active hi-fi loudspeakers that I use in my lounge are slightly overkill, given the power amplification inside them totals 8200W?
Per speaker... |
22nd Oct 2019, 1:09 pm | #45 |
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Re: "Loud Enough to fill a Small Hall"
Transiently, I assume, or are they each fitted with a 32A mains plug ?
Cheers, GJ
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22nd Oct 2019, 10:49 pm | #46 | |
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Re: "Loud Enough to fill a Small Hall"
Quote:
Found one still being used in a primary school a couple of years ago. |
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23rd Oct 2019, 12:18 am | #47 | |
Diode
Join Date: Oct 2019
Location: Penarth, Vale of Glamorgan, Wales, UK.
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Re: "Loud Enough to fill a Small Hall"
Quote:
The valves could also be handy for straightening creased film, provided of course it wasn't nitrate stock, which was still around in the 60s especially if you were running a BFI archive copy. Happy days. |
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23rd Oct 2019, 7:28 am | #48 |
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Re: "Loud Enough to fill a Small Hall"
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23rd Oct 2019, 11:28 am | #49 |
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Re: "Loud Enough to fill a Small Hall"
If the system will run via a 3A mains fuse, it can't be capable of much more than perhaps 1kW continuous.
In reality, probably no more than a few tens of watts, maybe less. Wasn't "IHFM peak" the ultimate in power output specmanship? ISTR that referred to what you might possibly get at the peak of a isolated single drumbeat with mains +10% and a following gale. Perhaps someone has come up with something even "better".
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23rd Oct 2019, 11:40 am | #50 |
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Re: "Loud Enough to fill a Small Hall"
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23rd Oct 2019, 12:17 pm | #51 |
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Re: "Loud Enough to fill a Small Hall"
I have always been under the impression that the quoted power of a small HiFi is the at the leading edge of a square wave applied to the amplifier from idle with the smoothing caps fully charged.
I have seen amplifiers quoted for continuous sine wave by honest vendors in the past. |
23rd Oct 2019, 1:01 pm | #52 |
Heptode
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Re: "Loud Enough to fill a Small Hall"
Well, obviously they are not all running flat out all the time, so the likelihood of pulling 8200W from a 13A plug seems relatively slim. Especially as I suspect my ears would give in long before the speakers (or the fusebox) did! However, the fact remains that each speaker has 7 tweeters and 7 midranges that are each powered by a 300W amplifiier module (14 x 300 = 4200W).
There are then four bass drivers that are each powered by a 1000W amplifier module 4200 + 1000 + 1000 + 1000 +1000 = 8200W |
23rd Oct 2019, 2:45 pm | #53 |
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Re: "Loud Enough to fill a Small Hall"
I was wondering why a tweeter needs a 300W amplifier, but perhaps it's cheaper to use the same module for everything. 300W can be had for €70 inc VAT retail https://www.soundimports.eu/en/aa-ab31191.html and they will doubtless be a lot less bought wholesale and in large-ish quantities, so I guess price isn't an issue. As I said above, power is dirt cheap. 14 power supplies per box might set you back a bit more though.
Cheers, GJ
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23rd Oct 2019, 8:15 pm | #54 |
Octode
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Re: "Loud Enough to fill a Small Hall"
Using the same module is going to be much easier to deal with. Not only for spares, but also the certainty that all modules have the same voltage gain, which makes setting up the (active) crossovers easier.
And it must be nice to have 20+ dB of headroom, so nothing ever clips... |
24th Oct 2019, 10:29 am | #55 |
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Re: "Loud Enough to fill a Small Hall"
The first time I remember seeing this phrase was in an old advert for the Walter 303. Given that this was a dreadful old thing with a single EL84 and a skimpy output transformer, I can only assume it was a ubiquitous claim like "hi fi" later became...
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24th Oct 2019, 8:34 pm | #56 |
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Re: "Loud Enough to fill a Small Hall"
A friend had a Walter 303 and it was LOUD. It had a larger than average speaker. Whilst lacking finesse it did make a lot of noise.
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