Vintage Pioneer SPEC 4 Power Amp Repair

Description

Still the best value for Spec 4 repairs! This is your chance to get a quality repair for a fair price on your spec 4 power amp.
This service is for the repair of one complete unmolested amplifier
, or if you wish to save shipping costs you can send me the two amp channel assemblies. The most common problems I have found for the Spec power amps are with the components in the channel amplifier assemblies. Many of the transistors run hot and get leaky over the years. Occasionally protection and meter circuits need some attention, but generally it is the Power amp assemblies.
If you are looking for a reasonable cost to repair your prized Pioneer Spec 4 Amplifier, purchase this repair service.
I have been repairing and restoring vintage electronics for over 20 years. I also provide services to local shops that do not have a “repair department”.
My repair service covers many items covered in others restoration service for much less. My repair services rival others costing as much as 3 times more than the cost of my service. (Compare Bolded Red items with others restoration service)
Here is what is included in my service.
Replace all the Pre-drivers in both channels with quality on-semi replacements. These get leaky over time.
Correct any problems with the Spec channel amplifier assemblies, meter board or protection circuit.
Replace all Electrolytic Capacitors on the channel amps with quality replacements.
Replace resistors, small signal and pre-driver transistors (matching gains as required) to get your amp assemblies working reliably again using quality name brand components.
Replace Bias Muting relays as necessary for stable bias setting (This is a common problem on the Spec 2)
Re-seat output transistors with new heat sink compound.
Clean the connector pins to ensure proper connections
Adjust the DC offset on Spec 4 amps , If it is a spec 2, new differential pairs will be installed as needed to achieve +/- 35mv offset or better..
Adjust the Idle Current (bias current) to the manufacturer specified settings
Adjust the Current limiter sensitivity adjustment to the manufacturer specified settings
Install new potentiometers for current limit and idle current adjustments (The old potentiometers usually cause inaccurate results when final adjustments are done)
Stress testing of your amp for 24 hours of non-stop burn-in following service. to assure they are working properly
Optional Items
As needed replacement of Output Transistors.   In order to keep this service as reasonable as possible replacement of output transistors is provided on an
as needed basis
for a reasonable additional cost. Quality On-semi replacements will be installed for replacements. Output transistors will be replaced in complete closely matched sets for each channel to achieve proper current sharing. You will be notified if output transistors are needed.
·
Spec 4 per channel extra (This includes labor )
Repair of physically damaged boards, will be a reasonable additional cost dependent upon the extent of the damage.
Power supply filters capacitors are not included. They will be quoted and added to the repair on an as needed basis. On your approval
Rework of poor quality repairs previously made from other Techs, and reassembly of removed items.
Should others have worked on your amp previously lets discuss to avoid surprises for both of us.
Power transformers, VU meters, knobs, painting, faceplate, switches, missing or broken feet, broken speaker posts or missing panels are not included in this service, However  these items can be repaired or replaced for additional cost
Repair of lifted traces due to excessive heat or previous repair work cannot be guaranteed. (However Lifted and burnt traces can usually be repaired and have high reliability)
Replacement of the STV3 and STV4 reference diodes. These are no longer available, however very seldom fail. (If these have broken leads there I have good success at repairing them) Please contact me to make sure you know where these are located to avoid damage to these parts.
Note this is a
repair service only
for the electronic internals and does not include cleaning other than what can be dusted using compressed air or a soft brush. (I offer equipment detail and restoration services upon request. Contact me to discuss pricing)
Warranty 30 days on repaired parts. Extended warranties up to a year are available for an additional cost
Please feel free to contact me to discuss your amplifier specifics.
If your amplifier is deemed un-repairable for any reason, I will gladly issue a refund. All you will be out is return shipping costs plus a small evaluation fee.
Please Insure and pack your item carefully to insure a damage free trip. I will also use your packing and box for return shipping to keep costs down for you.
Typical time for this service is between 4 to 6 weeks depending on backlog. However I will strive to beat that estimate.
**When my Full Recap service is ordered in conjunction with this repair service I will extend the Warranty to 1 full year.**                                                               *** Only one return shipping charge will apply***
Flat rate return shipping is for the continental USA, and includes insurance for the price of the auction only. This is an estimate only and will be adjusted to reflect actual shipping and packing charges. ( I do not charge for my time to pack and will refund any difference between what was paid and the actual cost of shipping and packing materials once shipped. ) If you desire additional insurance please contact me.
I also repair other vintage receivers and amplifiers. I will list an auction for other vintage repairs for you as needed. Please contact me to discuss your vintage repair needs.