Plinius III 80 watt p/c class AB Amplifier

[Butcher]

Hello!. Would anybody have any information, schematics or bias information on this New Zealand made amplifer?

If so, this information would be usefull.

I have set it up at 150mA p/c (per channel) and it goes well, doesn't run too hot.

Also information on the matching Plinius II preamp would also be nice. Schematic etc.

Thanks on the help with my Playmaster 60/60 on previous posts guys.

Tony.

 

[tiefbassuebertr]

I have found this:
AudioEnz - Sound history: New Zealand's history of audio
Is it the amp showed there?
From this amp I want to have a schematic diagram.

 

[Butcher]

Er, yes it is. Plinius III. Do you want a shematic too?

 

[tiefbassuebertr]

Er, yes it is. Plinius III. Do you want a shematic too?

Yes. Here my e-mail address:
kirschner-hifi@tiefbasswiedergabe.de
In this case this interview could be also of interest:
AudioEnz - An interview with Gary Morrison of Plinius

 

[Butcher]

I have schematic for Plinius III if anyone wants it...

I still need schematic for Plinius II preamp.

Or another copy of Plinius III schematic.

Or any more info, cheers guys.

Maby one of you two can post the schematic I sent ya here for others. I can not figure out how to

Check your email fellas...

Tony.

 

[audiobard]

Hi Butcher,
I'd like one
audiobard@yahoo.com
Thanks

 

[tiefbassuebertr]

I have found this:
AudioEnz - Sound history: New Zealand's history of audio
Is it the amp showed there?
From this amp I want to have a schematic diagram.

This link is death. I have save this as PDF:
Archive: Sound History
New Zealand's history of audio
By Simon Brown
April 2004. Originally appeared in print in October 1996
New Zealand hi-fi... old and new

 

[win33]

Can I have a copy ?
my email irwint3@yahoo.com

Thanks

 

[Butcher]

There ya are you other two chaps, check your email.

tiefbassuebertr thanks for the info.

Tony.

 

[RSK]

Hi Tony,
Please can I have a copy of the schematic?
rajrsk7@gmail.com

Thank you very much.

 

[Butcher]

Check your email RSK

 

[RSK]

Many thanks Tony -)))
I got your mail.

 

[audiobard]

Hi Butcher,
Thanks for the schematic

 

[tiefbassuebertr]

There ya are you other two chaps, check your email.

tiefbassuebertr thanks for the info.

Tony.

You are welcome. About
AudioEnz - Sound history: New Zealand's history of audio
I read:
The first Plinius II preamp and III power amp (the Plinius III pictured) looked like an electric fence controller.
I doubt, that the designations for the model numbers "II" and "III" are really correct, because nothing informations outside of NZLD are to find online by this model numbers, also not by the Arabic numeral "Plinius 2" and "Plinius 3", as written about
http://www.pliniusaudio.nzld.com/history/index.asp

What is exactly to read on the rear pannel of both devices (mayby a Arabic numeral with the Roman numeral II and III, e.g. like "The Preamp MK-II"/"Plinius 200W MK-III") ?
It also raises the question, which audio amplifier device was "Plinius I" if "Plinius II" and "Plinius III" would be complete as model number.

 

[Butcher]

Hi tiefbassuebertr. They are known as read. The Plinius II is the preamp. The Amplifier supplys it with +- 15 volts DC to power the preamp.

The Amplifier is the Plinius III.

My amp is brown. My friends one is black.

Twin toroid transformers. Twin bridge rectifiers. Two DC resovoir caps at 8000uF each. Totalling 16000uF per channel.

Power supply = +- 50 volts. 100V p-p.

Bloody good power supply if anything!

VAS into darlington driver stage then into MJ15003, MJ15004.

Bias. I set mine to 150mA. 0.033V (33mV) across emmiter resistor (0.22 Ohm)

Amp runs quite warm! but not hot.

This is higher than Plinius set it to. It is safe to set this high (NO AUDIO! wait 30 mins for warm up) Then check. Readjust again for 150mA.

My amp completely rebuilt. New transistors except for metal ones (are low noise anyhow).

I replaced ALL caps with polyethylenes OR Polystyrene. Input coupling 10uF p/c. Some Plinius III amps have this, some don't.

I fitted a stereo Alps volume pot to the front of mine. Bypassed twin level pots at back.

Rewired with 50 ohm double shielded coax (foil).

Gold RCA sockets.

Beefed up wiring on power supply boards. REPLACED caps on dethump (was not working when I got her!)

Heat sinks on bridge rectifiers.

Metal oxide resistors or 5W wire wound)

Argh, she kicks **** now fellas!

Any more info, just ask...

Tony.

 

[Butcher]

Oh, one afterthought. These amps have blimin' problem with s**t PCB traces. Replace with wire etc.

Tony.

 

[Butcher]

Oh, one mod I'd reccomend is to to with DC offset.

Solder a 22K variable resistor across R12 (4K7). Adjust for zero voltage across the speaker output terminals.

Alternativly replace R12 (4K7) with a 5K6 and solder a 47K variable resistor across it.
Adjust for zero voltage across the speaker output terminals.

One channel of my amp had 45mV. My poor speakers! Speakers don't like the extra heat dissipated by DC across them! Now it is 0V!

(p/c = per channel . Just to clarify one of my previous posts).

Anyway, enough for now, enjoy yer stereos guys! Not how big it is, only the way it's used! Go vintage amps!

Tony, New Zealand.

 

[Butcher]

Should read = 40W per channel!

Tony.

 

[Butcher]

Power supply update:


200VA
33-0-33V
3.0 Amps

Also bypassed the 10uF polyethylene input coupling cap, what a difference!!

 

[srh]

Hi Tony, would you please send me a copy of the schematic. Thanks.
tonyhopkins-at- xtra.co.nz
Regards, Steve.