PIONEER SX-1250-----PREMIUM RESTORATION SERVICE

Description

NOTICE---NOTICE----IMPORTANT INFORMATION!!!!! READ THIS FIRST………This listing is for specific electronic services as described below.
The item in the pictures is not for sale, it is an example.
When you purchase this listing, you will be expected to ship or bring in your piece of equipment for service.
At the end of the text of this listing you will find further information about how the listing works and about what you do to initiate service.
Please have a look.
Pay special attention to the parts about evaluating which listing you should purchase, about shipping, and about the backlog.
The Pioneer SX-1250 is one of the most popular large receivers of the ‘70’s.
This one came out during the “receiver wars” when everyone was trying to outdo their rivals to build the biggest and baddest receiver.
I don’t know how many of these Pioneer sold, but it had to be a lot as they roll into my shop constantly.
The 1250 is an ideal choice for folks who want to experience genuine vintage audio today.
It is large enough to drive most any load, it has many inputs so you can plug all sorts of stuff into it, and it can be restored to a high degree of reliability.
It is our good fortune that the parts needed for 1250 restoration are readily available.
It is also true that the original design and engineering on the 1250 was really well done.
As a consequence, restoring one of these to premium condition is not an iffy proposition.
If you replace all the necessary parts, then clean and align it properly, you can pretty much depend upon getting very good results.
Of course, using very high grade parts is a good idea, and contributes very much to getting stunning results.
It is all about the details, being thorough and leaving nothing out.
So following is a description of the details, of just what it takes to get the best out of one of these guys:
During the 70’s, Pioneer made many wonderful receivers, amps, and preamps.
They varied greatly.
Some were large, some not, and they had different features and functions.
Nonetheless, the engineering was pretty consistent throughout.
This being the case, service issues will tend to be similar no matter which model you have.
By now,
these lovely amps and receivers have quite a few years under their belts.
This being the case, we are well past time for repairing this or that and presuming that the rest is ok.
It is now necessary to go into these units from end to end, and address all age related issues very thoroughly.
At the end of this process, we are rewarded with a great sounding piece of equipment.
The very first step in the restoration process is to clean the unit.
You cannot work on it if it is full of dirt or some other residue.
Most of these guys will have a certain amount of dirt in them.
Usually,
the air compressor is your friend.
Compressed air will blow all of the loose dirt right out of there and then you are good to proceed.
I do see extreme cases.
Sometimes, they will have some unknown sticky residue, animal dander, roach droppings, tobacco smell, or they will be oily because someone decided to shoot WD40 into the controls…….ouch!
Extreme crud requires serious cleaning.
In such cases, a pressure washer will work wonders and remove all that stuff.
When doing this, a couple days of drying time will be sufficient to then proceed with the work.
Basic cleaning like this is not to be confused with final cosmetic.
At the end of the process, face plates, knobs, glass, and cases must be cleaned so the unit will look pretty.
Returning a dirty unit is not an option.
Let’s move on to the parts replacement sequence and let’s start with the power supply.
All of these units will have an unregulated power supply.
This is the source of all power.
This is where you will find the large can style capacitors. Sometimes there are two, sometimes there are four.
These should always be replaced.
The new ones will frequently be smaller than the originals.
When that is the case, they must cleverly installed with proper brackets.
It is always desirable for the finished unit to be as original as possible, in the very least, it must be tidy and and finished well.
Next, let’s consider the regulated power supply.
The regulated supply provides small regulated voltages to various parts of the machine.
Regulated supplies of the 70’s tend to run hot, eventually causing them to fail.
All of the electrolytic capacitors in this section must be replaced.
Additionally, the pass transistors (the ones on heat sinks) are no longer reliable so they are replaced.
Sometimes this section is down altogether so whatever bad parts there are must also be replaced.
Another result of the board running hot is that you will find bad solder joints.
The solder becomes crystallized and the connections become faulty.
All of this must be corrected.
Moving on to the preamp section.
This part of the unit includes mode selection, tone controls, and any other control functions.
Here, it is necessary to replace all of the electrolytic capacitors.
Frequently there are signal path transistors which have
a history of becoming noisy or failing in some other manner.
These should always be replaced.
The phono section is a special part of the preamp section which enables the signal produced by phono cartridges.
The same applies, capacitors and certain transistors.
In the preamp we are looking for very quiet operation and a very accurate signal to send along to the amplifier section.
Next, the protection circuitry requires all new caps and the protection relay should be replaced, when available, and cleaned when new ones cannot be had.
From here, we go to the driver section…..that which drives the power amp.
On the driver board, we need the usual, all new capacitors.
We also like to replace certain transistors located in the first stages of the driver board.
This improves DC stability.
For the output transistors themselves, the large puppies at the end of the power amp chain, original numbers are preferred.
The outputs are usually ok, but they are sometimes a bit loose in their sockets so we always like to torque them down.
If any of the output transistors are defective and original numbers cannot be had, it is necessary to be very judicious in selecting the replacements.
The tuner sections in the Pioneer receivers and the stand alone tuners are remarkably stable.
It is rarely necessary to replace significant parts in the tuner, but it is necessary to clean and deoxidize the tuning capacitor and to align the tuner.
At some point during this process, it is necessary to thoroughly clean and deoxidize all of the switches and controls.
Once all of these services are done, the unit is put to the variac and run up slowly, making sure that none of it draws excessive current.
The unit should now play and do it pretty well.
This will be a good time to set it on the cook bench and play for a day or two.
Burning in the unit is best done with the case off so it all may be accessed if necessary.
Once the burn in is complete, and the baby has passed all of its tests, it is good to do final cosmetic and lamp replacement.
So there you have it.
The Premium Restoration on Pioneer.
This pretty much details what goes on.
There are always exceptions.
Sometimes they arrive quite blown up, sometimes they have intermittent problems.
Most of the time, though, they are very cooperative.
Of course, it helps to know them.
My company was under contract with Pioneer to repair the in-warranty failures on new sales when these guys were new.
I have seen them since they came out, so your Pioneer model is familiar to me.
I shall be pleased to make it perfect for you.
HOW THIS LISTING WORKS:
When you purchased a service listing, I will send you complete information about the process and will advise you as to your next steps.
The Premium Restoration is aimed at units that are mostly functional.
If your machine is blown up or severely compromised, the better choice is to purchase a diagnostic.
The diagnostic will get you a full report including the nature of overt defects and what is needed to return the unit to premium condition.
The item number for the diagnostic is 360168376809.
Many overt defects are caused by parts that will be replaced during restoration as a matter of course.
If you are unsure as to whether you should purchase the full service or the diagnostic, call me and describe what your unit is doing.
I will advise.
The price of the restoration does not include packing or shipping costs.
Your unit must be shipped to me with shipping prepaid, and upon completion it will be professionally repacked and shipped to you at your expense.
Local drop off and pick up are welcome and can be easily arranged.
Note that the listing includes .00 for shipping.
This is because eBay requires that you specify something in the shipping field.
Your actual return shipping costs will vary according to size, weight, and postal code.
Packing of your treasure is critical, and I will tell you exactly how to go about it.
Units that are packed well have a very good track record for safe arrival.
As there is great demand for Premium Restoration, there is always a backlog.
Units are evaluated soon after arrival so we will know what we are dealing with.
They will then go into a sequential line based on log in date and will be completed in that order.
If you have time frame concerns, please inquire so you will be fully informed.
If your unit is still in service, you can book a spot in the line and send it when it is getting close to the top.
This will cut your down time.
The service warranty on completed units is one year from the date of return to you, details available on request.
Feel free to address any and all questions to me via eBay messaging .
Thanks, Bill