McIntosh MC240 MC-240 Complete Restoration Service

Description

This listing covers a complete Restoration for your  McIntosh MC240  amplifier; a  complete power supply rebuild, and replacement of all Audio capacitors.  The price does not include return shipping or packing if a new box is required.
If you have just purchased an amplifier, have it sent to us for a complete restoration. Here is what the service covers, there are (2) inspection service groups included in the price:
Inspection Service Part 1
Visual inspection of the top and bottom of amplifier, bottom cover off. Look for burnt resistors, leaking capacitors, blown fuses, defective thernistor, defective rectifier diodes and other defective components etc.
Power the amplifier up in slow stages, with a Variac, to avoid shocking older electrolytic in the power supply, and to allow them to reform.
Check all power supply voltages at the specified operating line voltage, according to manufacturer specifications
Check all resistances at tube pins (when specified by manufacturer)
Check All Electrolytic Capacitors for ESR (Quality) using an 88A Capacitor Analyzer, leakge and value
Check audio coupling capacitors for leakage, quality and value
Check all vacuum tubes on a calibrated Hickok tube tester
Check bias current for all output tubes to ensure it is within normal operating range
Check condition of input jacks and output terminal strips
Check condition of switches and potentiometers
Check for signal throughput and condition of output transformers - inject  1Khz signal at each channel input and check for output at each channel's speaker terminals (loaded at 8 ohms). Check output transformers for continuity and winding shorts.
If anything above is found  NOT correctable by simple means (no significant additional labor and no parts), issue Initial Report to customer by email or call.  If customer decides not to move forward, only a .00 bench fee + return shipping is charged.
At this point the Power Supply is completely rebuilt using our German made capacitor refurbish kit (sold seperately for you do it yourself types in our Ebay Store). The voltage doubler caps are replaced with our exclusive German Made isolated cans, 250 uf / 250V.  We then replace the  2 filter caps with our USA made 80/40/30/20 @ 525V  capacitor can, using the 80/40/20 sections to make 140uf and replace the stock 100 uf.  A significant increase in capacitance.  Bass response, impact and palpability are astonishing. We use the 30 uf section to replace the 30uf stock section. We then replace the selenium rectifier with a silicon diode 1A @1000V PIV. We replace the 12 uf bias capacitor with a high gread ehigh temperature 22uf /250V electrolytic. We then determine and select series a resistor to set the bias to exactly -46V.  The main rectifiers are replaced with 1N5408 3A diodes and the inrush limiter is replaced with a high quality Amatherm unit as well. Everything is neatly wired. We then re-check all power supply and  operating voltages.
In addition, all audio path capacitors, and the 2 mylar power supply snubber capacitors are replaced with high quality Illinois Capacitor MPW polypropylene types, 600 V rated. The cathode bypass electrolytics are replaced with high temperature low ESR electrolytics.
Inspection Service Part II
Re-check Power Supply and operating voltages
Clean tube sockets and switches with Deoxit 5, re-tension tube socket pins as required
Clean potentiometers as required
Measure Output Power into 8 Ohm Loads
Measure sensitivity for full power output
Measure Channel Balance
Measure distortion (THD) @1Khz, half and full power output
Measure frequency response (20Hz,40hz, 100h,250Hz,500Hz,1Khz,5Khz,10Khz,15Khz,20Khz,25Khz 30Khz)
System listening test - Assess quality of sound
Light cleaning of chassis
Issue Final Report to customer by Email or Call
If we find anything seriously wrong in the Inspection Service Part 1, we will call you or email you an initial report, so you can decide if you want to repair things or not and upgrade the power supply. If you decide NOT to go ahead, or your amplifier cannot be repaired, you only pay a .00 bench fee and return shipping charges.
After completion of Inspection Service Part II, we will provide you final a written report, by email (or USPS if desired), of you amplifier's health. A copy will be returned with your amplifier. This report will list recommendations for improvements as well as potential problems found, with costs for possible repair or upgrade. No further work will be performed without your consent. All you pay at this point is the listed price plus return shipping.
This service does not include return shipping or any additional costs for labor and parts/tubes to repair defects found above and beyond those stated in the listing. These will be billed separately should you agree to go forward.
Our pricing is introductory pricing, so take advantage of the low pricing now, and have your amplifier checked thoroughly. Please double box it and ship it to us insured. We will return it to you in your packaging. If your packaging is damaged, there will be a nominal charge for packing materials, so make sure you packing is rugged..
We at CTech electronics have been in the electronics industry for over 45 years, and we are also audiophiles. We stand behind our products and services. You equipment is treated as if it were our own.
Visit our Ebay Store for a large selection of parts, tubes and services. We are a full service company.