SpeakerTalk Forum Index SpeakerTalk
This forum has been set up to facilitate discussion of 1970s KEF speakers and drive units. The owner of the Forum has no connection with KEF Audio.
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

new member - recent ebay purchase - any info appreciated
Goto page Previous  1, 2
 
Post new topic   Reply to topic    SpeakerTalk Forum Index -> KEF Speakers from the 1970s
View previous topic :: View next topic  
Author Message
NIPPRO
Introductory Contributor


Joined: 23 Dec 2010
Posts: 2

PostPosted: Fri Dec 24, 2010 12:51 am    Post subject: PRO 9TL Reply with quote

I was searching for information regarding loudspeakers I built and had a hand in designing way back in the mid 1970s and I found this forum. I set up NIPPRO ACOUSTICS and produced 2 models using KEF B200 base units and T27 HF. I called them the PRO 4 and the PRO 6 as the second one had 3 drivers.

I also got involved with building the Hi Fi Answers TL cabinets in 1975 and because our build quality was so good, Chris Rogers contacted me directly and said he was working on a new model. So he came to see me from London and I paid his train fare to Southampton. He thought my cabinet work was excellent and even better than he thought.

He then outlined the design of a TL unit that contained the KEF B139, Peerless Mid and T27 HF unit. I suggested that we put in various structures to strengthen the cabinet and ease the flow of rear energy. I built him a pair and gave them too him and even delivered them to his flat in London.

All along he assured me that he would mention the great help I gave him when he wrote the article and revealed the plans in the Magazine. When it was published he did not mention me at all and only put a little mention at the end saying cabinets can be obtained at Nippro. I even gave it the name PRO 9TL and that became quite famous during the late 70s and 80s.

Later I met Alan Willis a great designer who worked with me to form Integrated Audio Systems and we produced special Horn Loaded speakers that got rave reviews in the Gramaphone (John Borwick) and other mags. Our successful speaker was the Beaulieu. I just found that the review is on the web after all these years.

Just joined the forum to give you Guys some facts about the history of this speaker.

Dave Hall
_________________
Former Designer of Nippro Acoustics and Integrated Audio Systems famous in the 80s for the IAS Beauileu
Back to top
View user's profile Send private message
Wiesiek Lipowski
Intermediate Contributor 25+


Joined: 10 Dec 2006
Posts: 39
Location: Poland

PostPosted: Fri Dec 24, 2010 9:39 am    Post subject: Reply with quote

Hello Mr Hall

I myself built a pair of PRO9 TL back in 1977 and still have them. I remember Nippro Accoustics adverts in a monthly HiFi Answers, that I loved reading so much.
However, I made some changes to the speakers during those years. For example, the upper foam covers went away and the low singals come out that way too.
Your voice from the past here brough back lots of memories.
I wish you many happy returns, Mr Hall.
_________________
Kindest regards
Wiesiek
Back to top
View user's profile Send private message Send e-mail
NIPPRO
Introductory Contributor


Joined: 23 Dec 2010
Posts: 2

PostPosted: Fri Dec 24, 2010 10:34 am    Post subject: Reply with quote

Nice to hear from you Wiesiek. It has been a strange few days for me as it has been like visting a long lost Island or home that I lived in years ago.

When I eventually got out of the HiFi business owing to the previous recession in the early 80s, I studied Complementary Medicine along with my wife who had been very ill during the 70s. She had been diagnosed with Rheumatoid arthritis, but we got her well again and now she is a sought after Practitioner here in Cyprus, where we now live.

However this has now awakened my interest in HiFi once again. In those days we persoanally knew Julian Vereker (Naim Audio) John Hadcock (Tone arms) Roy Gandy (Rega) John Dawson (A&R Cambridge later ARCAM) We also knew and the President of the Japanese manufacturer Dynavector who made incredible Moving coil cartridges and amazing tone arms. We did a HiFi show with him in Harrogate Yorkshire and later he used a pair of our IAS Beaulieu speakers in his shows in Tokyo.

During 1981 we also met Stevie Wondor in Hammersmith London when he came to listen to our range of speakers. So they were exciting times for us and also worrying as we put so much hard work into the designs, but because of the recession could not sell enough to make any money.

I am looking at possibly bringing in Drive Units and building TL speakers over here in Cyprus. There is a really good Guy in the UK who sells kits and Drive units for speaker systems. I built a pair when we still lived in the UK, but sold them before we moved over. I am very rusty now as to the latest Drive units, but we used the 10" Volt base unit in the Beaulieu and Peerless Mid and Audax HF units.

Our IAS speakers used a special Horn Loading that we developed, it would be good to try and bring it back as the base was amazing.

Good to be on here.

Have a great Christmas and lets hope the New Year is good for all........

Dave
_________________
Former Designer of Nippro Acoustics and Integrated Audio Systems famous in the 80s for the IAS Beauileu
Back to top
View user's profile Send private message
mikep
Introductory Contributor


Joined: 01 Mar 2012
Posts: 1

PostPosted: Thu Mar 01, 2012 3:10 pm    Post subject: Re: PRO 9TL Reply with quote

NIPPRO wrote:

Later I met Alan Willis a great designer who worked with me to form Integrated Audio Systems and we produced special Horn Loaded speakers


Dave, don't know if you're still monitoring (!) this forum, but I was your first customer for the horns - the black and white finished ones which you then called QWR10s.

I still have them - but they have mutated somewhat since I left Southampton. They spent a brief period being tri-amped with Krimson Electriks - which blew out quite a few of the soft-dome tweeters.

The amps died eventually and the speakers reverted to being wired through the original 3-way crossover which I designed for you.

More Audax soft-domes died - there was no high-end roll-off in my design - and my then penchant for electronica drove them hard so they were replaced by something cheap and cheerful from Maplin - by then my top-end hearing was going anyway!.

Next disaster was that mice got into the doped and enclosed (?Rogers) 4incher on the one side and the rubber surround disintegrated on the other - time for drastic measures!

After lots of listening tests I bought a pair of Ruark Swordsman , which now live on the top of the horns (coupled with modded Goodman's crossovers) replacing the original "top hat" arrangement for middle and top. The extended bass (for bookshelf speakers) of the Ruarks integrates nicely with the natural mid roll-off from the horns

For the curious - the Ruark crossover is left in place - I'm just using the Goodmans ones to split between the Ruarks and the horn unit.

My hearing is quite bad now - over exposure in my youth, working as a roadie for Tull, loud motorcycles and a couple of minor strokes are not good for discriminating hearing - but they still sound good - and impress visitors as the solidly brick built detached house starts to move - but not in the boom-boom way that so many experience extreme bass power.

Regards to all - as Dave said:

NIPPRO wrote:

it has been like visting a long lost Island or home that I lived in years ago.


MikeP
Back to top
View user's profile Send private message
clubsport911
Senior Contributor 100+


Joined: 26 Aug 2012
Posts: 157
Location: Cheltenham, UK

PostPosted: Wed Aug 29, 2012 9:50 pm    Post subject: Reply with quote

Aaa Crimson Electrics. Had a few of these "giant killing" amps until one day woke up to find my hifi room laying in a pool of smoke ! It seems the emitter resistors decided to emit no more. Killed my tweeters with 170w of instability ! Eeek!

What happened !
Back to top
View user's profile Send private message
proffski
Über Contributor 1000+


Joined: 22 Aug 2003
Posts: 1297
Location: Tewkesbury UK

PostPosted: Thu Aug 30, 2012 5:38 pm    Post subject: Reply with quote

clubsport911 wrote:
Aaa Crimson Electrics. Had a few of these "giant killing" amps until one day woke up to find my hifi room laying in a pool of smoke ! It seems the emitter resistors decided to emit no more. Killed my tweeters with 170w of instability ! Eeek!

What happened !


They were amazing value for money, I Tri-Amped a large 3 way KEF system with them once. Six of the 170/4 modules with masive torroidal transformers, 1 for each amplifier. I still have the paperwork somewhere.
The emitter ballast resistors were just coiled resistance wire on the PCB.
The smaller modules used the ubiquitous 2N3055 output devices whilst the larger ones used rarer output transistors.
The CE 100/8 used 2N3773

CE 170/4 - I have two in the workshop I am repairing now, came from up the road from MOOG!
_________________
I contend that for a nation to try to tax itself into prosperity is like a
man standing in a bucket and trying to lift himself up by the handle.
-Winston Churchill
Back to top
View user's profile Send private message Send e-mail
clubsport911
Senior Contributor 100+


Joined: 26 Aug 2012
Posts: 157
Location: Cheltenham, UK

PostPosted: Fri Aug 31, 2012 9:19 am    Post subject: Reply with quote

How strange... I'd forgotten all about these amps until now.. and here they are close to where I live. In fact, I swapped a Sansui A80 Amp (65wpc) to the CE100/8's modules... and then Crimson modified them to CE170/4's.

Coupled with my (own design, own built) 400va 1% regulated transformers, 100,000mf caps / channel PSU, the sound was sweet. On this PSU, all caps were bypassed, the 65A FWBR was itself bypassed with high speed flywheels as well.

So, then they went "bang", they went bang in a big way.

I still think they are / terrific amps and very neutral (also had the CPR1-S pre-amp as well)

Nice post.


Last edited by clubsport911 on Fri Aug 31, 2012 9:35 am; edited 1 time in total
Back to top
View user's profile Send private message
proffski
Über Contributor 1000+


Joined: 22 Aug 2003
Posts: 1297
Location: Tewkesbury UK

PostPosted: Fri Aug 31, 2012 9:29 am    Post subject: Reply with quote

We are dangerously off thread and topic here, so I'll move this convesation in due course. Compare the O/P stages to early NAIM amplifiers... topic moved!
_________________
I contend that for a nation to try to tax itself into prosperity is like a
man standing in a bucket and trying to lift himself up by the handle.
-Winston Churchill
Back to top
View user's profile Send private message Send e-mail
Display posts from previous:   
Post new topic   Reply to topic    SpeakerTalk Forum Index -> KEF Speakers from the 1970s All times are GMT + 1 Hour
Goto page Previous  1, 2
Page 2 of 2

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group