Hello everyone, my name is Patrick Turner.
In 2012, I retired and closed my business located in Canberra, Australia.

I do not offer repair services or custom manufacturing to any new customers.

Last update to the site 12 June 2016.
This website provides information
about hi-fi amplifiers, pre-amps, speakers
and test gear made between 1998 and 2012.

There are many useful schematics with details for manufacturers and DIYers.
I do not supply kits for amps or speakers but I do have some parts for sale. 

I have several electronic projects underway which I may get done by 2047.
I may advertise some tube amps for sale during the next 30 years.

My emale address is in the .gif image, to stop spam. 


Recent new or revised web-pages :-
AM Modulation with discrete solid state
, and why I then went back to tubes.
RF generator with AM and FM and with tubes, and sprinkle of solid state.
Kitchen AM radio with added features.
Dynaco MkIV 45W monoblocs.
Total re-engineering of two.
300Watt amps. Work on a pair of 300W amps.
analog voltmeter-1 
Bench-top unit 2013, 1mV to 316V, 1.4Hz to 250kHz.
analog voltmeter-2 
Bench-top unit 2015, 1mV to 320V, 0.5Hz to 3MHz.

Telephone...(02) 6241 2760.......10am to 7pm
I do NOT own a mobile phone, I am NOT at Farcebook, Twatter,
I do not have Skype, so be concise and use email.

About health matters. Polite comments are welcomed.

VELOSOPHY My declining interest in cycling, age + knees catch up.

POWER AMPLIFIERS. Directory to many pages about tube PP and
SE tube amps,
4Watts to 300Watts, plus a few totally solid state amps.
About Hybrid amps, OTL, tube input/driver with mosfet outputs + OPTs.

PRE-AMPLIFIERS.   4  pages for tube line level and phono preamps.

LOUDSPEAKERS.   Several pages about full range premium quality
stereo loudspeakers, DIY speakers and testing speaker performances.

RE-ENGINEERED AMPLIFIERS. Many pages on old amps, Quad-II,
Quad-II-Forty, Cary, EAR509, Manley Labs, Ming-Da, Tranquility, Leak,
Dynaco ST70, Dynaco MkIV, JBL amps, Jadis SET, RCA 30W.

RADIO RE-ENGINEERING.  About re-engineered AM radios.


1 pair revised dynacos, Dynaco MkIV 45W monoblocs.
I will only consider good offers and will not quote for ppl expecting
to get something good for nothing.

AMP CHASSIS METALWORK. A total of 12 chassis and parts for 4 different
types of monobloc power amps.

OUTPUT TRANSFORMERS FOR SALE. 58 types of OPTs for diyers and others.
OUTPUT TRANSFORMER INFORMATION.  About OPT for sale, use, choice.
for sale. 
POWER TRANSFORMERS FOR SALE. 103 types power trans for diyers or others.
POWER TRANSFORMER INFORMATION.  Properties of PT, choice, conditions of sale.
CHOKES FOR SALE.  A page with some new and old chokes for sale.
MISCELLANEOUS FOR SALE.  A small number Junk Items. 

I have small stocks of Russian output tubes and input tubes
for amps and some old tubes for AM radios.

EDUCATIONAL AND DIY.   Directory for pages listed below.
Domestic hi-fi, basic technical issues,
Tube operation, 5 pages on basic to complex,
Output stage configurations, about different tubed output stages.
Load Matching, 5 pages about anode loads for SE and PP output tubes,

Output Transformer theory, about how OPTs work,
PP Output transformer calculations, 5 pages on PP OPTs, with examples,
SE Output transformer calculations, 4 pages on PP OPTs, with examples,

Speaker Matching Transformers, about low Z audio F transformers,
OTL amps, and alternatives, Pros and Cons about output transformer-less amps,
Power Supplies for tube amps,

Power Transformers and Chokes, 1 page on powe
r transformers,
Chokes for CLC filters - 1,
1 page,
Choke Inputs - 2, 1 page,
Chokes for anode DC feed - 3, 1page,
AM-FM tuner, tubed, About re-engineering 1960s AM-FM receiver.
AM Modulation with discrete solid state, and why I then went back to tubes.
RF generator with AM and FM and with tubes, and sprinkle of solid state.
Kitchen AM radio with added features. Much more about AM radio.
THD measurement, Use of analog test gear to measure THD. about 
Amplifier frequency response testing, 1 page with blank page for response graphs.
Analog Voltmeter. 1 page with 5 schematics for a wide bandwidth Vac meter.
Wien Bridge oscillator - SS 1 page on solid state plus Schmitt Triggers,

Wien Bridge oscillator - Tubed, 1page on tubes for 2Hz to 2MHz and square waves.
PSU for testing tubes with variable regulated B+ from +126Vdc to +585Vdc,
Miscellaneous schematics -1, 1 page on power amps, preamps and other items.
Miscellaneous schematics -2,
1 page on power amps, preamps and other items.

REPAIRS  I retired in 2012. I cannot accept any new customers, or repair
new gear which old customers may have purchased. I offer limited repair services
for gear I have made new or re-engineered for old customers before August 2012.