1970's Vintage New Zealand Alron rejuvenate

[nuryev]

Hi srh, there are four transistors, two TO-92s and two TO-220s

The TO-220s mounted on the heatsinks are BD262 and BD263,
while the TO-92s are BC317B and BC320B. Pics are attached.

Thanks for the offer.

 

[nuryev]

Correction - BD262 and BD263 are TO-126 NOT 220

 

[ubergeeknz]

Gosh, they're pushing those little guys hard to get 50W [emoji33]

 

[srh]

That will be 50W peak for one millisecond.
Nuryev, give me a couple of days to redraw the schematic to make it legible and I will post it up.
Steve.

 

[nuryev]

50watts?

Gosh, they're pushing those little guys hard to get 50W [emoji33]

Yeah! I also wondered about that. Probably explains the unusual heat sink design required to cope with the heat.

 

[nuryev]

Alron schematic

That will be 50W peak for one millisecond.
Nuryev, give me a couple of days to redraw the schematic to make it legible and I will post it up.
Steve.

Thanks for that - the effort is appreciated.
Thanks again to all the interest, views, suggestions and responses.

Take care.

 

[nuryev]

50watts?

Gosh, they're pushing those little guys hard to get 50W [emoji33]

Yeah! I also wondered about that. Probably explains the unusual heat sink design required to cope with the heat.

 

[mobyd]

Gosh, they're pushing those little guys hard to get 50W [emoji33]

Everything in NZ audio manufacturing in the 1970s was about extracting a quart out of a pint pot. I should know as I worked in the design dept of Consolidated Electronic Industries (Bell) in Dominion rd. If a cent could be shaved off the build cost of a product, it was. Designed by engineers, redesigned by accountants. Most NZ transistor products were awful, though some of the earlier valve stuff (Jansen guitar amps spring to mind) was rather good and retains value today.
M

 

[srh]

Hi nuryev, here's the schematic for the model 250. It should enable you to reverse engineer your board.
Steve.

 

[nuryev]

schematic

Hi srh,

Thank so much for the amazing effort!

I am impressed with the professional presentation and detail...

Do you have any ideas to improve this amp without compromising its authenticity or its character?
I haven't played through it long enough to know the strengths and weaknesses - but while i have it apart and a box full of caps, resistors, inductors and potentiometers.....your schematic is giving me ideas

Thank you again for the time and effort invested in supporting me with this project.

 

[ArcticBreaze]

while there is a captive kiwi / ozy contingent, anyone got a schmatic for a Holden 100 reverb vlave amp

 

[mobyd]

This one ? https://ozvalveamps.org/holden/schematc.gif

 

[ArcticBreaze]

unfortunately not allrdy found that one. this has 2 kt88's for power valves not 4 el34's thanks anyway

 

[nuryev]

Good luck ArcticBreaze. Someone will have what you are looking for!

 

[thoglette]

Good luck ArcticBreaze. Someone will have what you are looking for!

Try asking over in Aussie Guitar Gear Heads : In The Shed

 

[PRR]

...this has 2 kt88's for power valves not 4 el34's

What's the difference??

(I know the difference, but very often 6550/KT88 is considered a more-rugged upgrade to EL34. Ampeg VT40 was marked for both.)