Stereosound 9000D radiogram Wattage? - UK Vintage Radio Repair and Restoration Discussion Forum

Alanroy · 6th Jun 2020, 2:26 pm

Hi. The 15 ohm speakers on my Stereosound 9000D are shot. There is no information on them regarding wattage.
Can anyone tell me what the wattage on this Stereosound model might be? I can find lots of 16 ohm speakers (near enough to 15 ohm) on the internet, but with a huge range of wattage ratings. Any advice as to what wattage rating I should buy? Many thanks. Alan

samjmann · 6th Jun 2020, 2:39 pm

Most radiograms of the seventies were less than 10W RMS per channel. So as long as you get the impedance match correct, there should be plenty of choice. If you by a speaker with a very high handling capacity, it's likely to be a less sensitive than a lower rated unit. Bear in mind if you change one speaker, it may well sound different to the one in the other channel. It just depends on how much you want to spend!

Regards, SJM.

Herald1360 · 6th Jun 2020, 3:11 pm

I'd pitch the wattage even lower- <5WPC on the basis that the only Stereosound transistor amp info I can find has AC128/AC176 output devices on a 23V rail feeding a 15R speaker.

Any chance of a pic of a shot speaker together with its dimensions?

Alanroy · 6th Jun 2020, 4:12 pm

Hi Samjmann and Herald1360
Thank you both for your very speedy replies and very helpful information.
I found this very useful. Thank you. Alan

simpsons · 6th Jun 2020, 5:21 pm

May I suggest that you measure the size of the existing loudspeakers, including the fixing hole locations. BVWS Members often hold a stock of spares,

The original speakers, now blown, may well been the achilles' heel of the radiogram, the bean counters will have been there. After all it isn't a Grundig. So improving their quality will reward your listening pleasure. The electronics will be similar to many of the era and will hold up well to most makes.

However, don't just stop there. Line the inside of the loudspeaker enclosure with some carpet felt and hey presto any unwanted boom and resonance will be tamed.

Good luck.

Chris

Edward Huggins · 6th Jun 2020, 5:49 pm

Looking at a photo of this model I suspect the speaker size will be the ubiquitous 8" x 5" unit found on so very many Radiograms of this period, Most Thorn Stereograms from c.1968 - 1975 used them.
They can be sourced from those Grams that are listed as non-working (but the speakers in them very rarely fail) from an Auction site for less than the cost of buying NOS.
In fact you will be very hard pressed to find new 15ohm drive units.

samjmann · 6th Jun 2020, 7:15 pm

Got to agree with the last post, most 'grams of that era had no sound damping in the cabinets, fitting felt or similar will greatly improve the sound quality. If you want originality then sourcing a pair of originals is the way to go. Personally I'd go for a pair of modern speakers, the chances are the originals were costed down to keep the price of the unit as competitive as possible. SJM.

6th Jun 2020, 2:26 pm	#1
Alanroy Triode Join Date: Oct 2019 Location: Exeter, Devon, UK. Posts: 25	Stereosound 9000D radiogram Wattage? Hi. The 15 ohm speakers on my Stereosound 9000D are shot. There is no information on them regarding wattage. Can anyone tell me what the wattage on this Stereosound model might be? I can find lots of 16 ohm speakers (near enough to 15 ohm) on the internet, but with a huge range of wattage ratings. Any advice as to what wattage rating I should buy? Many thanks. Alan

6th Jun 2020, 2:39 pm	#2
samjmann Heptode Join Date: Feb 2014 Location: Nottingham, UK. Posts: 648	Re: Stereosound 9000D radiogram Wattage? Most radiograms of the seventies were less than 10W RMS per channel. So as long as you get the impedance match correct, there should be plenty of choice. If you by a speaker with a very high handling capacity, it's likely to be a less sensitive than a lower rated unit. Bear in mind if you change one speaker, it may well sound different to the one in the other channel. It just depends on how much you want to spend! Regards, SJM.

6th Jun 2020, 3:11 pm	#3
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,535	Re: Stereosound 9000D radiogram Wattage? I'd pitch the wattage even lower- <5WPC on the basis that the only Stereosound transistor amp info I can find has AC128/AC176 output devices on a 23V rail feeding a 15R speaker. Any chance of a pic of a shot speaker together with its dimensions? __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

6th Jun 2020, 4:12 pm	#4
Alanroy Triode Join Date: Oct 2019 Location: Exeter, Devon, UK. Posts: 25	Re: Stereosound 9000D radiogram Wattage? Hi Samjmann and Herald1360 Thank you both for your very speedy replies and very helpful information. I found this very useful. Thank you. Alan

6th Jun 2020, 5:21 pm	#5
simpsons Octode Join Date: Feb 2007 Location: Harrow, London, UK. Posts: 1,493	Re: Stereosound 9000D radiogram Wattage? May I suggest that you measure the size of the existing loudspeakers, including the fixing hole locations. BVWS Members often hold a stock of spares, The original speakers, now blown, may well been the achilles' heel of the radiogram, the bean counters will have been there. After all it isn't a Grundig. So improving their quality will reward your listening pleasure. The electronics will be similar to many of the era and will hold up well to most makes. However, don't just stop there. Line the inside of the loudspeaker enclosure with some carpet felt and hey presto any unwanted boom and resonance will be tamed. Good luck. Chris

6th Jun 2020, 5:49 pm	#6
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,326	Re: Stereosound 9000D radiogram Wattage? Looking at a photo of this model I suspect the speaker size will be the ubiquitous 8" x 5" unit found on so very many Radiograms of this period, Most Thorn Stereograms from c.1968 - 1975 used them. They can be sourced from those Grams that are listed as non-working (but the speakers in them very rarely fail) from an Auction site for less than the cost of buying NOS. In fact you will be very hard pressed to find new 15ohm drive units. __________________ Edward.

6th Jun 2020, 7:15 pm	#7
samjmann Heptode Join Date: Feb 2014 Location: Nottingham, UK. Posts: 648	Re: Stereosound 9000D radiogram Wattage? Got to agree with the last post, most 'grams of that era had no sound damping in the cabinets, fitting felt or similar will greatly improve the sound quality. If you want originality then sourcing a pair of originals is the way to go. Personally I'd go for a pair of modern speakers, the chances are the originals were costed down to keep the price of the unit as competitive as possible. SJM.