This preamp is in tip-top working condition and was sidelined by a Emotive Sira. I've used it with Thor TPA-30 and Quicksilver monos it actually - replaced the QuickSilver tube line stage I was using. All contacts will be cleaned with Deoxit. Below is reprinted from the Response Audio page about the job performed.
Response Audio has been working with the Ming-Da preamps for several years. The Extreme was brought about after numerous customers have asked for the very best this product has to offer. The Extreme upgrade more than doubles the cost of the MC-7 but we have yet to have a customer with buyer's remorse. The Reference and Extreme MC-7 can be found in high end systems across the globe.
You would never think such an affordable stock preamp could sound as good as it does after such upgrades. The Extreme MC-7 is for the most critical, dedicated audio enthusiast who wants the absolute best this no frills preamp has to offer, bar none. Match one of these dedicated two channel preamps to any power amplifier of your choice and you will have a high resolution system that will satisfy your listening enjoyment for many years.
What you can expect from the Ming-Da preamps is a full body presentation that brings forth exceptional resolution, detail and transparency. In fact, it is greatly enhanced as compared to the stock unit. Due to being a tube rectified unit, these pieces will not have the same level of dynamic "speed" as their solid state counterparts which gives you a bit more overall body and fullness.
If you already own one of the Ming-Da preamps and looking to bring out the most potential it has to offer, you owe it to yourself to consider our Extreme upgrade that will leave you with an audio value of a lifetime.
You can look under the hood of any high-end tube preamp or amplifier and realize they have nothing over our modified products, in fact, many of them do not even come close to the standards of our modified units in terms of internal components, sound quality and attention to detail and quality control.
At this time, we are offering the Extreme upgrade to the MC-7 preamp only. We are no longer offering upgrades to other Ming-Da products other than the 2A3-X8. I have found these two preamps to be exceptional values, offering the end user a truly musically involving presentation.
Input Signal path coupling capacitors replaced with VH Audio V-Cap TFTF Reference Grade Teflon Capacitors.
Output stage capacitors are replaced with VH Audio V-Cap TFTF Reference Grade Teflon Capacitors.
All electrolytic power supply capacitors upgraded to higher quality Panasonic units and then all these capacitors bypassed with Audience AuriCap capacitors.
Signal tube cathode bypass capacitors replacing with ELNA Cerafine units.
Output signal wire is replaced with our custom shielded OCC Silver or Copper.
Inner stage capacitors replaced with Clarity Cap high voltage units.
Feedback capacitors replaced with Clarity Cap film capacitors.
Critical resistors are replaced. Type of resistor is determined by it's application.
First stage power supply filter capacitor off rectifier tube (main power supply filter capacitor) is replaced with high quality, low ESR Panasonic unit. It is then bypassed with a VH Audio V-Cap TFTF Reference Grade Teflon Capacitor.
Volume attenuation circuit added on an individual basis to best match the amplifier being used and personal listening habits. Contact us prior to ordering for information. Standard attenuation is 10dB. Also available is 6dB and 20dB attenuation.
Warranty - 5 year parts and labor on modification workmanship (This is Response Audio's guarantee which has expired)
Modification Price: $895