|
Repair, Overhaul, and Upgrade : An Overview
We have extensive repair experience with audiophile and
tube equipment and understand both the distinctive quality of
these products as well as the technical aspects of repairing
this level of equipment.
We repair and restore vintage and tube audio gear and bring the
classic item back to "original" condition but with more reliable
modern components.
We also repair and modify modern solid state and digital
equipment and offer custom modification services to meet
specific customer requirements and system balance.
Please see the table at left if you have a specific brand
in mind as we have our recommendations of service level listed
for many items. Please contact us for any item or question not
covered.
Repair, Upgrade and Modification: Options
We feature
conservative upgrades of equipment that enhance sonic properties
without completely altering the original design. Depending on the
equipment involved we replace generic resistor types with high
quality metal film types. Capacitors in the signal path and critical
bypass points are replaced with polypropylene caps of superior
quality. Power supply upgrades include UltraFast and Hexfred/soft
recovery rectifiers, multiple poly cap bypass and low ESR
electrolytic upgrades. Volume and balance controls can be replaced
with high quality potentiometers or multiple position stepped switch
attenuators. A wide variety of jack and binding post replacements
are available.
We have
devoted a great amount of time to selecting components and
upgrades that give the maximum return in audio quality for the
money.
We believe that selective replacement of critical components
(and minor circuit tweaks when appropriate) yield better cost
effective results than radical redesign and reworking of
equipment.
Our standard service cap brands are Mallory 150 or Panasonic
polypropylene for standard tube replacement, with AudioCap
Theta, MultiCap RTX or Auricap for upgrade, and WIMA MKP
for low voltage and solid state circuits. Electrolytic caps are
replaced with Nichicon Muse, or Nichicon or other
premium low esr / impedance types as required. Resistors used
are metal-film, metal-oxide or non-inductive wire wound as
required.
We use
Tesla, Sovtek, Sevtlana/SED, EH or genuine NOS tubes
as required. We do not
recommend most Chinese tubes and will not use them in any repair
in our shop.
Prices for
these services vary and depend on the type of equipment,
component choices and if a repair is involved or needed. Please
feel free to contact us if you have any questions as to your
specific item.
Basic Service:
This option is designed to replace only parts that are
defective, and to leave all other stock components intact. The
basic service is limited to repairing the equipment. Any item
undergoing this service will be warranted for a period of six
months on the work performed. This service includes replacing
defective parts, cleaning all switches and controls, adjusting
bias, resoldering printed circuit boards, and a complete
function check. We replace all parts with original OEM types or
carefully chosen replacements that will not cause any electrical
or sonic imbalance. Most solid state high end products and
modern tube high end products will only require this level of
service.Prices for this level of
service are usually in the range of 150-225.00, depending on
item and parts required
Repair, Upgrade: Standard
Service
This option is designed as a service to partially rebuild a device. In
addition to the work outlined in the paragraph above, coupling, blocking, bypass, and filter capacitors are replaced and
updated with standard upgrade or our premium types.
Overheated or changed value plate,
cathode, PS, and bias resistors in tube equipment are replaced and
updated with premium types. Rectifier diodes are replaced with UltraFast or HEXFRED
types when needed. This service offers a
six month warranty (excluding tubes). We perform all basic services
as listed above and replace input jacks and speaker terminals with upgrade parts as needed
and/or requested.
The
usual price range for this level of service is 225-350.00, depending
on item and parts required.
Repair, Upgrade: Custom
Service
This service provides modifications requested by the customer, and
components may be selected by the customer. These can be supplied by
the customer or we will attempt to supply. Aftermarket third party
kits can be installed.
You can also ask us to examine your equipment and see what we can
do to go above and beyond the usual upgrade.
Some custom modifications we offer are; power supply stiffening,
bias adjustment for each individual output tube, circuit
engineering, filter and EQ bypass, custom resistor and cap options,
remote power supply mounting etc.
Please inquire for other custom modifications. While we will try to
honor your request we will not attempt any modification that we feel
will either not have any audible effect or cause potential damage to
your equipment. Please contact us for questions in this area.
As
work of this nature is varied and complex, it is difficult to give a
accurate idea as to price, but most jobs we have done at this level have
ranged between 500-1,500.00
About Stereo Repair - In House Service Company:
We are located in the
Stony Brook Technology Center, a medical and R&D park in South
Setauket, NY.
Centrally located, we are easily accessible from all major highways
in Suffolk County. We are open 9-5Tuesday through Friday, Saturday
10AM-2PM. We accept cash, MC/VISA, AMEX, and Discover. Major
repairs are guaranteed for six months. We have been in business over
thirty years, the past twenty at our present location.
Although we repair
all types of consumer electronics, well over 90% of our work is
repair, restoration, upgrade and modification of High-End and
vintage audio equipment and vintage tube musical amplifiers.
In the past ten years the diminishing quality of most consumer audio
products has resulted in increased demand for restoration of older
equipment. These items were actually built to sound good and last
for years rather than to fit a price point in a marketplace filled
with disposable junk.
Our service area is clean,
attractive and well lighted. We maintain an extensive service
library on paper and CD-ROM. We are well stocked with replacement
parts. We use original quality parts when replacement is made,
either supplied by Mfgr. or the same item from OEM sources. We also
maintain type integrity in our replacement of passive components,
never using a carbon resistor in place of a film or bulk metal type
or using a Mylar cap in place of a foil polypropylene, for example.
We use high quality, low residue solder from reliable suppliers and
silver bearing solder where required. We have (and routinely use) a
comprehensive array of test equipment, specially designed test
fixtures and standard and custom made test CD’s. We are very
familiar with vacuum tube equipment and have extensive experience in
this technology that pre-dates the current "Revival". We have
applied much time and effort in the setup of our shop in order to do
our work in a efficient professional manner. Taking pride in our
work and the relationship we have with our customers, we provide
prompt and professional service for the consumer in need of repair
of audio equipment.
Description of our repair shop:
The
main audio bench is a 15ft.triple station workbench. There is
sufficient equipment and flexibility so that any audio item can be
serviced at all three stations. The flexible nature of the repair
stations is due to the custom made test fixtures on each bench.
These allow the item being repaired to be connected to monitor
speakers, dummy loads or internal monitor amplifiers. The item being
repaired can be connected to Level Meters, Distortion Analyzers,
O’Scopes, CD audio sources or Audio Generators. This is
accomplished by relay switching or patch bay switching of I/O
sources . High level (speaker level) signals are input via 6
pin Alacatel 20A pro audio jack or heavy duty binding posts then
switched to monitor speakers or internal 200W Dale non-inductive
wire wound resistors. The instrument relays and switches connect the
various pieces of test equipment to the appropriate source. Low
level sources are input through high quality input jacks, then
routed to the internal monitor amps and, as above, the signal is
sent to the desired test equipment. All bench connection cables are
made from rope-braid copper cable of 12 or 14 gauge. Audiophile
grade cables are used for low level signal sources. A system of
adapters or designated cables provides secure connection to any
equipment regardless of the type of connector on the item under
test. All important tests can be done quickly and without having to
find patch cords, hook up equipment, search out adapters, etc. This
enables us to do complete and thorough tests on all equipment we
repair. All test equipment can be disconnected from the fixtures and
directly connected for special tests or equipment requirements. The
fixtures and wiring are of high quality, making use of heavy gauge
and low loss wiring. All instruments are well grounded to a common
bus consisting of dual 12 gauge solid copper wire. 12 gauge rope
braid wire is used for individual grounds to the bus. Equipment
under test can be connected to a heavy duty AC isolated supply that
includes a Variac and AC leakage tester.
Each bench has identical monitor speakers using Morel drivers and
custom made crossovers.
In addition there
are burn-in racks and benches reserved for rebuild / fabrication
jobs.
Basic Connection:
Connect all equipment with the power off. Never connect speakers
while a receiver or amp is powered up. Check speaker wires
carefully as a single strand of the finest gauge wire will look like
a direct short to your amp. Start out with good quality cables and
interconnects:
Speaker wires:
After years of futzing around with every kind of speaker cable made
this is our basic idea; LESS REALLY IS MORE! . Time and time again I
have seen that the simplest type of construction of speaker cable is
the best. Ohms law really works and the basic requirements for
speaker cable are low resistance and high current carrying
capability. Get these right and add some care about magnetic
induction and 90% of the problem is solved. I am always wary about
cables that have any black box at one or both ends of the cable A
few times I have cut these " matching devices or stabilizers" open
and have found just plain wire imbedded in epoxy. Point is : beware
snake oil audio!. I make my own wires and on request will do up a
set. No big secret: I use high grade CLV-3 rated speaker wire of 16
or 12 gauge twisted pairs, tripled, or up to five separate pairs for
runs over 15ft, interleave the conductor pairs and try to bi-wire
on unusually long cable runs. I usually use ten feet as a minimum
length for any speaker wire, it is my impression that cables under
six feet do not sound as good as a longer cable. Feel free to
disagree, but give it a listen first.
Of cables on the market I like Kimber cables best. Their entry level
cables are fairly inexpensive and use the type of multi-conductor
interwoven construction I prefer.
I do not find any advantage to any
speaker cable set over 800.00. Over this price range any advantage
is so far down on the cost / return scale that I consider it a waste
of time and money.
If you just want decent wire that works and will not blow up
anything, Radio Shack 16 gauge Megacable or "Stereo Speaker Wire "
at Home Depot will work well. I disagree with some writers who
praise the virtue of solid gauge wire ( telephone, hook-up wire, or
Romex).
Interconnects:
I really feel that very heavily shielded interconnects squeeze the
life out of music. The interconnects I use at home and for my
customers usually consist of (feel free to try out secret recipe!)
three twisted pairs of stripped out cat 5e wires, one strand of each
to ground, the other to signal hot. Terminate to good quality RCA's
and cover in nylon braid to protect and to damp vibration. Dozens
of my customers have really liked the result, and have had me make
up replacements for all his interconnects. You will have to use good
wiring practice (see below) if you use this type of interconnect to
prevent hum.
Again, I like Kimber interconnects, for the same reasons as stated
about their speaker cables.
I have come to believe that any cable with a bandwidth greater that
10 MHZ or so will work for digital signals just fine. At times I did
think I heard a difference between digital cables, but could not
confirm in any subjective manner. I have used very expensive digital
cables in my reference system and have used standard video patch
cords, but have found little difference between them.
I prefer Coax for all purely audio digital connections, but use
Toslink for anything that touches satellite or cable TV, due to
safety issues in case of lightning strikes ( glass = insulator,
copper = conductor = common sense )
Good wiring practice:
Run all AC leads to a single outlet strip to prevent ground loops.
Use a surge protector. The computer grade units by Belkin you can
get at Home Depot for about 75.00 are OK to use.
Never parallel run speaker wires or low level connectors with AC
lines, never bundle RCA and speaker wires together. If dissimilar
lines come near to each other, cross at 90 deg angle.
Never coil up speaker wires into loops, you are just building a
choke coil (inductor). You do not want this but it would take a
long, long time to explain why, trust me on this one.
Spray every single connection with Caig Labs D5. This stuff really
works, I use it on my equipment, and use only Caig products in my
shop. Do not use anything else,
especially never use WD-40, this will really louse up your gear!.
I
have noticed
countless times that both speaker wires and interconnects sound
better if lifted off a floor and either suspended or lifted on
blocks of wood, Dixie cups, anything but clumped on the floor.
Others have commented on this and suspect pickup of vibration as a
cause of this problem.
Vibration damping:
No skepticism here, this really works and is important. In my shop
it is standard procedure to use a variety of damping materials when
we upgrade and modify equipment. All conductors carrying
electromagnetic energy are capable of modulating signals when
subject to mechanical vibration. Sometimes this is severe such as in
preamp tubes, much less in output transistors for example.
Stone or heavy wood bases , vibration damping such as Dynamat, and
damping feet can all be important to better sound.
I usually use dense live rubber under power amps, stone base with
small silicone feet for CD players and preamps. Big receivers
usually work out well with stone or heavy wood with multiple
silicone feet. My best speaker mount technique is using construction
adhesive to bind heavy maple or oak block to the bottom of floor
standing speakers or speaker stands, and then bolting directly to a
floor, cutting through carpet if necessary. Best results with at
least six bolts/lag screws right over a stud or setting with bondo
body filler to a slab floor.
I take a lot of time in setting up internal damping in a upgrade
component and I well know how much labor it can take to kill
resonance in some equipment. Some of the well known tweaks of discs,
stones, goo and such are useless junk designed to remove money from
the pockets of the more gullible among the audiophile public.
Tubes:
Any time we retube a set I usually use new production tubes from
Sovtek/New Sensor, E-H , Svetlana /SED. and Tesla JJ. I WILL USE
CUSTOMER SUPPLIED TUBES BUT DO NOT GUARANTEE RESULTS WITH THEM.
I do not use "NOS" tubes unless the type is not available in new
production. Quite often "NOS" tubes are really just used or
discarded, and there are some far east companies that offer to make
brand new "NOS" tubes with any branding desired on them.
90% of my tubes are purchased from
www.tubestore.com. They are fast shippers, provide excellent
customer service and all their products are genuine and reliable.
They also rate and review every item they sell and provide a lot of
tube and audio info on their website. I do have confidence that any
NOS tube from them is indeed genuine NOS.
I always like to send a repaired set back with the output and driver
tubes that are going to be used in the set. This just makes sense
considering the chance of a customer having a bad tube and not being
satisfied with a repair.
Preamp tubes last much longer than usually thought. I receive
Fishers and Mcintosh preamps with 30 year old
Telefunken and Mullard tubes that perform and test as well as new.
Lesser brands and many imports do not perform nearly as well. I will
usually change out preamp tubes if they are mismatched or actually
defective in some way.
|
