AUDIO REPAIRS, RESTORATIONS AND RE-ENGINEERING.

I can repair the following list of equipment......

Solid state Amplifiers and AM/FM receivers.
Tube amplifiers and tube preamps.
Guitar amplifiers
Speakers, including new surrounds and crossovers
Cable repairs
Old tube radios
New radios
Turntables
Radio-grams
Tape decks and cassette decks
Mixing desks
Electronic Organs
Transformer rewinding
All modifying and restorations

If you are unsure if I may be able to repair your silent or broken equipment, please
email me at info@turneraudio.com.au

Sorry, but there is no service for VCRs, or TVs.
I do charge to pick up and deliver, but it never costs as much as a plumber charges!

Repair costs & quotations......

I charge a minimum fee of $35 to inspect the insides of a given article to
perhaps establish why there is a fault. If you engage me to repair something the minimum fee is included in the total repair bill.
It is not always possible to provide a fixed price quote before repair work is undertaken because unforeseen and extra problems have a habit of appearing while work on equipment is under way, and there is much variation in the prices or availability of spare parts.
And unfortunately searching for parts and information can take time.

But if I can establish what is the cause of a problem I usually will give an estimate which allows a customer
to establish if it is worth having the article repaired.

Examples are :- Fused of burned out and silent channel in an average 10 yr old solid state amp
may cost $120.00 to repair. Cost of new item = $500+, therefore its better to get the old one it fixed.
A new one won't sound any better, and may expire 3 days after the warranty runs out.

Replace the foam surrounds on an pair of 200mm diameter speaker cones are usually $180.00.

(More about speakers below...)
 

Warranty.
All repairs are warranted for 3mths at least.

Suppose I repair dad's favourite 1980 amplifier.
If dad allows an end of school year party where those present  try to find out how loud dad's old hi-fi system can go with full bass boost and then after 20 minutes some smoke pours out of the speakers and amplifier, and I repaired the amp 2 weeks previously,  then don't expect me to fix the system a second time for free.

And if I fix something and the fix does not last 3mths, and the item cannot be fixed, then I refund the repair cost.
Unfortunately, a small % of items fall into the category of having a fault such as some intermittent
noise or sound failure whose cause cannot be traced economically.
Modern electronic items are now always extremely complex, and many items from the 1960s
to 1985 are much easier to repair than recently made equipment.

Time for repairs.

Most solid state repairs can be done within 7 working days, but sometimes the time can stretch out to a month because a workshop manual has to be obtained, and perhaps several orders for parts placed as faults are discovered and fixed.

Tube amp repairs can take longer.

I have often got a back log of projects where I am making new amplifiers which takes an enormous number of labour hours.
So I have to interrupt the crafting part of my business to carry out a repair, so some delays can be expected.
I know our Government politicians lament the shortage of skilled people in Australia,
but I lament that nobody offers me the wages of politicians.  And people seem to often think that a repair guy
will work for less than the waiter at a run down cheap restaurant. They are happy paying an apprentice mechanic $90
an hour to change the oil in their BMW but only pay $9 for someone well trained and experienced to figure out which
one of 3,000 parts in an amp had failed.
Everyone wants their favourite old audio gear fixed up like new, and perhaps there would be more skilled people to perform all the fixes if the wages attracted more people to the job.

So please be be *very* patient, I am sure I am earning far less than you are!
 

RESTORATIONS

Usually there is a far longer time scale for restoration simply because
I have to have a queue system for larger projects which is the only fair way
to arrange the work flow. Over the last 3 years I have always felt I have too much to get through in each week.
I have asked God for 100 more hours a week, God is extremely "time challenged"....   

Some clients want their older equipment fully restored to its original functioning condition
without any unsightly changes to the appearance, and this work can be more expensive
than providing just a repair of the equipment to make it functional but nothing else.

This means that with an old amplifier or pair speakers, there may be a need to replace parts which
may threaten the the future reliability of the item, so the repair has to include
preventative work to ensure a happy future. So when I repair an old 1960  tube amp, I don't
just repair the item, I may have to rewire the whole amp to get the performance of the unit to meet
2006 expectations of performance and reliability. The repair job then becomes one of re-engineering since it may require me to re-design the circuit.
This is usually no trouble for me but it all takes time.

Similarly  many old radios I repair have some life in them but have many accumulated faults where the only
professionally correct fix is one requiring that I replace many parts, and do a large amount of re-wiring work.

I will always also try to fit modern safe mains wiring and a fuse so that your ancient
equipment won't give you a shock kill your cat or cause a fire. Much equipment comes to me in terribly unsafe condition.

Radiograms needing re-furbishment of their cabinets can be expensive but I know tradesmen here that can do nice french polishing.

Old radios, and radiograms are a small part of my work, but much care is taken to ensure such old items benefit from restoration for future generations to enjoy. 

RE-ENGINEERING AMPLIFIERS

I have clients who bring me ancient old amplifiers which are in a very poor condition, and it doesn't seem right to perform the minimum repair job, or restore them to exactly the original condition, when a few more hours could make them perform better, so that the audio response is then even and flat
for all frequencies and the item will end up performing better than when purchased, and thus meet modern
expectations of performance.

Hence some ancient Leak, Quad, or Dynaco amps etc are able to be fully stripped down and rebuilt
to a circuit using all modern minor parts such as resistors, capacitors, diodes,
potentiometers, switches, wiring, contacts, sockets and cables and replacing all the vacuum tubes if needed.

Generally, if the basic items like output transformers and power transformers
are sound, then these can all be retained or mounted on new chassis, and a unique amp is thus created.

For those technically minded interested in images and schematics of work I do with old amps,
on my index page there are listed pages for modifications to Quad, Leak, Dynaco and Others.

Replacement or rewinding of power transformers, output transformers, and chokes for power supplies can be done. My costs for rewinding transformers might be higher than a stock item from a maker such as Hammond, who have large scale production lines and stock off the shelf items.
Unfortunately Hammond Engineering is located in Canada, and the local Oz distributor may not have the
item required in stock so there may be a long wait for something to be imported.
I nevertheless would search for the more cost effective and suitable off the shelf part rather than rewind an old transformer, because the cost for a one of a kind re-wind is usually more than the cost of an equivalent part from a supplier.

So if just one output transformer in a pair of mono amps is fused, it would be cheaper to purchase 2 from Hammond if their quality is acceptable than try to rewind one, and then the amps have equal characteristics when the repairs are completed.  It often is difficult to copy an OPT exactly.
And some designs like those used on old Leak amps are not worth copying, since Leak quality was so poor,
and the Hammond solution would be very favourable. But if there isn't room to fit an off the shelf replacement item, then a custom job is the only answer.
If I wind custom output transformers, or import replacements from Lundahll, the quality of the amp and the sound will then equal the highest available, for after all, even the best quality and most expensive high end tube gear is simply some tubes combined with a nice OPT, and other parts, and it is possible to re-engineer an old amp up to the same standard. 

With solid state equipment, only marginal improvements can be made and there are
restrictions on any changes due to the use of printed circuit boards within.
But it is amazing that so many ancient solid state amps can be brought back to life
after some TLC on the work bench. For really serious restoration, all the electrolytic capacitors should all be replaced with modern types, which function with less leakage and distortion than the original types. This is especially true of low voltage rated electrolytic caps used in preamps, and early power amps.
In the case of power amps, I often replace poorly rated power transistors
with modern types of better voltage and current ratings and better frequency response.
RE-ENGINEERING SPEAKERS

I have the right test equipment to analyse what is wrong with the response of any speaker and to make sure
what modifications I do will *always* ensure they sound better when I am done.
Before I got a computer in 2000, I made a purely analog test rig for testing the response of
speakers accurately enough to reveal all the peaks and troughs in the response along the audio band between 20Hz and 20kHz in a room, without reliance on an anechoic chamber.
The method I used involves using a "pink noise" signal fed to the speakers under test and filtering the sound energy at 33 different frequency bands along the audio spectrum between 20 Hz and 20 kHz.
With a calibrated microphone and amp I measure and record the level of energy in each band and plot a graph of the response.
 I take response readings at 4 different microphone positions and average the levels expressed in voltage dB to gain what is a fairly good indicator of the actual acoustic output from a speaker.
The 4 mic positions are usually at 3.5M +/- 0.5M from a speaker and nearly on axis and between 0.7M and 1.2M above floor level.
The response will vary with each of the 4 mic positions because even with randomly varying
test signal frequency and phase shift and level there is still some effect from room resonances and reflections.
Resonances in all domestic rooms will prevent making accurate graphs graphs of responses using steady musical
tones.
The result I get suits 95% of people since their rooms are similar, and with similar resonances and carpet/furniture,
and they find they have little use for a tone control or graphic equalizer, and there are no inexplicable
absences of some musical tones or irritating  peaks or resonances at other tones.
The bass will be tight foundation for the music as the speakers allow, and treble will be there as it must be, but not
too bright or harsh which is sadly the case with many speakers.

In layman's terms, pink noise is a test signal that when played through speakers moderately loudly
sounds just like standing beside a nice big waterfall. Sound energy in this signal contains all frequencies
changing randomly in terms or level and phase and frequency between 20Hz and 10kHz and has the same amount of power for each of the 33 selected bands of frequencies.

For many old loudspeakers, variations of +/- 20% of capacitor or inductor values used in the crossover filters can cause serious peaks or troughs in the response measured in my graphs, and such measurements prove often that no care was ever taken to make the response flat in the factory.
Such problems are identified and addressed in the testing process.

My test room is my own lounge room with sloped ceiling and carpeted concrete floor is what most visitors say is an ideal room for hi-fi, and when i get speakers to sound right in this room the speakers usually
do very well elsewhere because the response has been tailored to suit the common listening position.

Old speakers can sing better than when purchased, especially if the speakers were considered very good quality when purchased and if the enclosure quality is good enough to warrant the technical upgrade.
Old enclosure boxes may need re-gluing, new gaskets, new screws and additional bracing and damping materials to render them less prone to resonances and buzzes which always spoil the sound.
Some enclosures benefit from my process of fitting an internal extra panel layer of fibre board
glued with a pliable and sound absorbent adhesive and in addition to cross braces.

Cone surrounds on old bass or midrange drive units may be needed.
I replace  old deteriorated foam or other materials with mostly butyl rubber surrounds but sometimes I use specially treated and hand formed cotton cloth or fine leather doped with a silicone compound to give
the speaker the correct firmness and compliance.
I do not use cheap foam replacements, which have a short life.
Where the driver unit has a damaged voice coil, ( that party was too loud! ), then it is usually more effective to replace the driver with a factory replacement if available, bit this is seldom possible with 20yr old +
speakers, so a Peerless replacement can be fitted and most often be better quality from
something made 25 years ago. but with substitute drive units there is always a cost of altering the crossover filters to suit the subs different electronic/acoustic properties.

Tweeters, ( high frequency units ),  sometimes suffer open circuited voice coils and are best replaced with a new pair. Sometimes the dome has been pushed in by inquisitive little fingers,and the damage is irreparable. The use of ferro fluid inside the coil gap and better modern cone materials has greatly improved tweeters over samples from the past. I use Peerless tweeter replacements and alter crossovers to suit.

Crossover networks in older speakers are of appalling design and component quality.These networks may need total re-design and rebuilding with new components.
For example, a customer brought me a pair of large Acoustic Research AR9 speakers with the 4 bass speaker foam surrounds all quite perished, and with tweeters burnt out, so I fitted new Peerless tweeters, replaced all the surrounds with rubber types, and then re-wired the complex and poorly conceived crossovers to make these speakers less likely to damage amplifiers when turned up loud even briefly.
Careful tailoring of the crossovers gave a much flatter response and the owner was delighted that the repair converted what was useless junk into what would have cost him much more than the repair if he'd bought new speakers.
The reformed AR9 gave very impressive performance from very low frequencies to
20kHz, and there was no need for a sub-woofer.

Basic prices for the most common speaker repair are as follows: Replace surrounds, 300mm $200,   250mm $190,   200mm $180.
Smaller drivers are usually less. Cross overs can be quoted.

Replacement tweeters from $100 per pair including my labour.

I use replacement drivers purchased from WES components.
See the range of speaker drivers and prices at  http://www.wescomponents.com.au
WES stock a large range of the Peerless speaker drivers made in Denmark, and Scanspeak.
The Peerless range from Denmark includes types which will sound better than 90% of any drivers used in speakers made 20 years ago. The WES price is reasonable, but fitting new drivers into existing boxes requires that I adjust or re-build the crossover frequency filters, and perhaps adjust the size of the hole in the box
for the new driver. So fitting new drivers is usually much more expensive than just replacing the surrounds.
I myself do not do panel repairs on electrostatic loudspeakers. Most ESL needing repairs are Quad ESL 57,and after about 40 years these speakers develop numerous faults.
I recommend Mr John Hall of Melbourne, phone number 03 97726293. He can fix these but the cost is high because of the technical difficulty of the repair.

For a final test of speakers, I use special test signals prepared by Mozart, Beethoven, Bach, Sibelius, Miles Davis, KDLang,Cassandra Wilson, Terence Blanchard, James Carter, James Morrison,  Bob Marley,
Ry Cooder, Buena Vista Social Club, Pink Floyd, etc, etc, etc.    Return To Index Page