Sonab amplifier information?

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Ultima Thule said:
I happen to have a Sonab 4000R-2/S, the one to the right in the picture Bandit added.

I found a schematic inside my receiver, it was taped under the cover.

The ouput transistors are some strange Motorola 7320001 in TO3 "cans" and marked as well in my schematic 7320001...
A friend of mine asked me about 7320001 Motorola and I started to search. Found nothing. Anybody who knows more? :confused:
 
i have the p4000, along with the p75 turntable & i think oab10 speakers, not being at home i can't check that. i struck gold really, someone dropped the lot at a charity shop i was in & they were going to throw it all out as they couldn't pack test it. it all even came with the brochures & schematics, but one house move later and they haven't shown up as yet. gotta say i love the sound, i have a much newer system in another room & it doesn't compare.
 
Sonab P4000 ...what does the "linear" button do ?

Hello all,

I also have recently acquired a Sonab P4000 in pretty good working order, and I wonder what the 'linear' button on the front panel is supposed to do ? My guess is that it works as a "reverse loudness button" (or perhaps a "tone control defeat/bypass ?) since when I press it in at lower volume levels it thins out the sound, compared with the sound when it's inactive. Would it be fair to assume that Sonab have engineered in a permanent loudness curve as the default, normal operation mode, which is cut out and restored to flatness when the 'linear' switch is pushed on ? That's exactly opposite to the way most loudness switches have worked in my experience, where you push them in to activate the effect ? In addition, when the volume is raised above 12 noon the linear switch has little or no impact, which would be in line with the Fletcher-Munson loudness effect, which is more pronounced at lower volumes. It's a curious effect, and I wonder if anyone out there has an operating manual or can offer some insights based on their knowledge of this device :confused: ?
Cheers,
Ray
 
Can anyone help with failing Sonab amp ?

Well, I've had around 5 months good service from the Sonab P4000 integrated amp, however in recent days it's been manifesting a quietly grumbling background white noise/ hashy kind of interference behind the music, and tonight about 5 mins after switch on the noise went 'full-scale' ie damn loud, speaker threatening volume and that's with the volume control at it's 'off' setting. I tried re-jigging to different speaker outputs (ie set B instead of set A), and different inputs but nothing can reduce the level. I'm afraid to turn the thing on now with speakers connected, in case it takes out drivers ! Any ideas about where I should start with troubleshooting ? Fortunately I have the complete schematic diagram...this came supplied with the amplifier...so I can locate and replace key components, which are all on discrete boards. Any advice on components I should measure and/or replace in the first instance ?
Thanks,
Ray in Glenelg, South Australia
 
Hi. My first post. I have a Sonab P4000 which has become ill. I purchased it second hand about 13 years ago. I love it. Good sound and good looking. I live in Gympie about 2 hours north od Brisbane and spent 10 weeks in Melbourne recently. When i returned home it refused to output to the speakers.

As most Qlanders will know, rain has been plentiful this year and i suspect condensation and/or mold has oxidised a few of the essential bits.

I am back in Melbourne for another 10 weeks and brought the amp down with me to get looked at here. I spoke to a very knowledgable young chappy at Clarke Audio who informed me that Sonab was actually made in Sydney and marketed as Sonab Sweden to sell it.

Am taking it in tomorrow so will keep you updated.

I see there is one for sale in Cape Town but i guess shipping would be high. I lived there for 14 years and wish i could go and pick it up. A beautiful place!!!
 
thanks Wahab.
Could please quantify? I would like to know whether it is a good deal. the vendor is asking for 300 USD.
best

That s pricey , i suppose that it has a vintage value.
There s an amazing web page that display the construction
and complete schematic in high definition.

Have fun with the pictures !! It was a very , very good amp at the time..

SONAB R4000 receiver annual service....

The 4000 version dont use a Darlington VAS , it seems..
 
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I have loads of patches etc but to be honest I could not and can not stand DIn plugs etc !
Cheap and chearfull yes Quality Never !! Give me phono ,s and 4 mm spk jacks every time
regards Trev

One advantage that the DIN coonectors have is that you can plug them in and out with the power on. The signal connections break before the earth connection does, so no heart-stopping loud noises with the potential to damage speakers and/or electronics. But that's not important in a domestic setting.

On the other hand, the phono plug of today started life as a speaker connection. It got used in low-level circuits and nobody came up with anything better, so it stuck around. Some Naim pre-amps had BNC connectors at one stage (maybe still do). Apparently that is/was a better impedance match.
 
Sonab p4000 schematic diagrams

i have the p4000, along with the p75 turntable & i think oab10 speakers, not being at home i can't check that. i struck gold really, someone dropped the lot at a charity shop i was in & they were going to throw it all out as they couldn't pack test it. it all even came with the brochures & schematics, but one house move later and they haven't shown up as yet. gotta say i love the sound, i have a much newer system in another room & it doesn't compare.

Hi there , i am new here and found your post regarding the p4000 schematic.
I am wondering if you still have it and would i be able to have a copy of it. I live in Ausltralia. my email is souane@yahoo.com. My name is Suan.
many thanks .
 
Hi, First post here, I ve just acquired a Sonab R4000 mk1 with my Sonab R75 TT and AO-4 speakers, unfortunately in transit to me the amplifiers lights seem to have stopped working,rest of amp works fine, does anyone know if it"s an easy fix with perhaps a loose internal connection,or anyone know a good repairer in the UK,I"m based near Exeter.
The other less urgent problem is a low hum on phono,checked the usual probs too near amp, other electrics in house,sockets et, is it from the cartridge?
 
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