Suggested speakers for 16 ohm 300B Amp [Archive]

pidge22

10-09-2023, 12:19

Hi all am considering a move to a full tube system with a 300B set Amp with an output of 8 watt Class A & an output impedance of 16 OHMS.
The Amp was origianlly used with AG horns hence the output impedance of 16 ohms but AG horns are not on my agenda at this time.
Decent 16 Ohm speakers seem very rare so was wondering how it would work with an 8 ohm speaker with high sensitivity ie something like Klipsch Cornwall with a sensitivity of 102 db.Or are there better high sensitivity speaker options available or indeed decent 16 ohm speakers I have missed.

As per my other threads I was looking to go down the Tannoy Vintage route but it looks like they won't be sensitive enough for an Amp with a 16 ohm output impedance.

thanks for any advice
Paul

Macca

10-09-2023, 12:39

pidge22

10-09-2023, 12:46

Tannoy monitor black has 15 ohm impedance, as does the original BBC LS3/5a. I think someone is doing a current version of that speaker with 15 ohm I can't recall who.

You might get away with something like the Cornwall although they are not as efficient as claimed so bear that in mind. Results will be hard to predict with any speaker I think.

I'd get a 300B that's designed to work with modern speakers, you're making life difficult for yourself ;)

Thanks the Amp I am looking at is used but set to 16 ohm & certainly wouldn't be out of choice...as to if I buy it will be dependent on finding a suitable speaker ...thats good info on the Cornwall & I think the Tannoy Black... I wish LOL

Macca

10-09-2023, 12:47

Yeah, Tannoy Black are crazy money, if you can even find any for sale.

struth

10-09-2023, 12:50

i'd be inclined to pass on amp. its going to be difficult to match, and then very difficult to find something else to change to...thus to sell on if you dont like.

Lawrence001

10-09-2023, 12:54

Some amps have transformers with multiple taps to change the output impedance. If this is one it might not cost that much to get it changed.

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walpurgis

10-09-2023, 12:57

If you don't mind a project, build your own 16 ohm speakers. Plenty of good 16 ohm or 15 ohm vintage drivers on ebay, bass units, tweeters and full range. I have collected a few myself.

pidge22

10-09-2023, 13:22

If you don't mind a project, build your own 16 ohm speakers. Plenty of good 16 ohm or 15 ohm vintage drivers on ebay, bass units, tweeters and full range. I have collected a few myself.

I wish i was that skilled they would look like something created by Victor Frankenstein

pidge22

10-09-2023, 13:24

Yeah, Tannoy Black are crazy money, if you can even find any for sale.

theres a pair on Hifi Shark 15" would be perfect for 42k...

walpurgis

10-09-2023, 14:57

Tannoy Reds are not so dear and 16 ohm if I recall. There was a ten inch version which may not be too stratospherically priced. Many will have gone to Japan though, there's a big following there.

Macca

10-09-2023, 15:19

Here's the 15 ohm LS3/5a https://dougbradyhifi.com/products/rogers-bbc-ls3-5a-classic

£2.8K - obviously clean SPL will be limited with an 8 watt amp as hardly the most sensitive speaker, with subwoofers and a high pass filter it might work okay.

Leak Sandwich are 15 ohm and not expensive although they're not that great IMO.

I think some old Goodman's models were 15 ohm? Geoff might know.

pidge22

10-09-2023, 15:41

Tannoy Reds are not so dear and 16 ohm if I recall. There was a ten inch version which may not be too stratospherically priced. Many will have gone to Japan though, there's a big following there.

thanks reds would certainly be more affordable...

walpurgis

10-09-2023, 17:07

I think some old Goodman's models were 15 ohm? Geoff might know.

Anything pre about 1968 may well be and Celestion and Wharfedale too.

As to the question of using a 16 ohm matched amplifier, it may well drive 8 ohm speakers that are an easy load perfectly well. If it doesn't like a particular speaker, it may make 'rude noises', but is unlikely to be damaged, unlike a transistor amp. I'd certainly try it myself.

Do a bit of Googling, you'll see what I'm saying, impedance mismatches with valve amplifiers are generally not a big deal. I'd avoid OTL types though.

struth

10-09-2023, 17:20

Anything pre about 1968 may well be and Celestion and Wharfedale too.

As to the question of using a 16 ohm matched amplifier, it may well drive 8 ohm speakers that are an easy load perfectly well. If it doesn't like a particular speaker, it may make 'rude noises', but is unlikely to be damaged, unlike a transistor amp. I'd certainly try it myself.

i sold a great set of 16 ohm celestion rola i put in wharf cabs.. they sounded rather good to me with right amplification. think they ended up out east where they have a following.

i replaced the badges with rola ones i got made too

https://imagizer.imageshack.com/v2/800x600q70/905/awtN7u.jpg

Macca

10-09-2023, 17:36

Do a bit of Googling, you'll see what I'm saying, impedance mismatches with valve amplifiers are generally not a big deal. I'd avoid OTL types though.

I agree not going to harm anything by trying. Most modern speakers won't be suitable though.

walpurgis

10-09-2023, 18:03

You never know how things may work out. My vintage KEFs are only about 83db/watt sensitivity, but my 4 watt Class A valve amp drives them to useful levels in my small listening room, with enough output to suggest the setup would be OK in a roomier environment.

Lawrence001

10-09-2023, 20:23

walpurgis

11-09-2023, 06:29

What valves does your 4W amp use Geoff?

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6V6 Lawrence.

hoopsontoast

15-09-2023, 13:04

Goodmans Axiom 201/301 drivers usually come in 15-Ohm versions, plenty around and often turn up in basic cabinets if you don't want to DIY.

https://live.staticflickr.com/3817/12148990484_08c889d782_b.jpg (https://flic.kr/p/jvyKBb)
System (https://flic.kr/p/jvyKBb) by Robert Seymour (https://www.flickr.com/photos/hoopsontoast/), on Flickr

https://live.staticflickr.com/65535/50332940093_0e1d4a2391_b.jpg (https://flic.kr/p/2jFKtvX)
Goodmans Axiom 301 (https://flic.kr/p/2jFKtvX) by Robert Seymour (https://www.flickr.com/photos/hoopsontoast/), on Flickr

Mika K

03-11-2023, 14:13

The output impedance does not fully determine the possible speakers that can be used with the amplifier e.g. several speakers have really impedance something else that the stated 8ohm ei.g. due to the resistive or capacitive nature. And if it's not OTL amplifier then trying something else won't do any harm.

I would consider some 8ohm speakers that are fairly sensitive and known to behave well regarding their impedance. Audio Note speakers might be one possibility or then some modern BBC variants despite not being 16ohms. Then also Klipsch or Tannoys or some vintage Altecs might do the trick.. ��

stevekr

17-12-2023, 22:27

Falcon Acoustics Q7 are 15 OHM if you're handy with a screwdriver.

Lawrence001

17-12-2023, 23:32

6V6 Lawrence.Sorry just saw this, I'm not familiar with those valves how do they compare with 300Bs?

walpurgis

18-12-2023, 07:53

Sorry just saw this, I'm not familiar with those valves how do they compare with 300Bs?

No idea, not done the comparison directly. I have heard 300B amps though and would say there is a difference. The 6V6 is popular in the States in guitar amps for its pleasing 'tone' apparently. I'd heard the rumours and decided to try it.

Lawrence001

18-12-2023, 08:49

I've heard of the 6L6 which I think are close to the EL34 but never heard of these. Must look them up.

AJSki2fly

18-12-2023, 11:14

If you are still looking and these are still available I would recommend these https://theartofsound.net/forum/showthread.php?73948-FS-Impulse-H2. I had a pair of Impulse H2s with a 300B amp and very they work very well with that type of amp as are very efficient, also the H2 is renowned for be extremely natural and musical. There is a down side which is the size of the speaker cabinet, if that is not an issue then I would certainly consider them. Also I think Stoke is not too far ftom you.:)