Upgraded My Carver M-1.0t Amplifier

[Big Daddy]

I own three Carver stereo amplifiers (two M-1.0t and one TFM-45). I bought them in 1991 from a high-end audio store in Pasadena, CA that was going out of business. They were open box models and I paid less than $400 for each. I have used them in my HT and two-channel rooms in different functions. I found these pictures of the M-1.0t amplifier on Ebay.

CarverM-1.0t.jpg

The specifications for the amplifiers are as follows:

http://www.carversound.com/carver-amplifiers/m-1-0t/

M-1.0t Specifications
8-ohm FTC rated power/ch: 200W
4-ohm FTC rated power/ch: 500W
Bridged mono power: 1000W
Dynamic headroom: 3.8dB
4/8-ohm rated THD: < 0.15%
Rated full power bandwidth: 20Hz to 20kHz
S/N: 110dB, IHF A-Weighted
Slew Rate: >200
Noise: -100dB
Dimensions: 95 x 483 x 343mm
Weight: 8.6kg

TFM-45 Specifications
8-ohm rated power/ch: 375W
4-ohm rated power/ch: 500W
2-ohm dynamic power/ch: 560W
Bridged mono power: 1000W
4/8-ohm rated THD: 0.5%
Rated full power bandwidth: 20-20kHz
S/N: 110dB
Slew Rate: 180

Many years ago, Bob Carver challenged the Stereophile Magazine that, given enough time to modify the amplifier, he can make his M-1.0t amplifier sound like any ultra high-end amplifier. The Stereophile Magazine took the challenge. Initially, they did not reveal the identity of the high-end amplifier, but later on after the test, they announced that the amplifier was the very expensive Conrad-Johnson Premier Four stereo amp. To make the story short, Bob Carver, being the genius that he is, won the challenge and they ended up suing one another. You can read about it in the following articles:

http://www.carveraudio.com/index.php...carver-history
http://carvermk2.com/docs/Carver%20S...0Challenge.pdf

Over a year ago, I found out that a person by the name of Richard Pecoraro has started upgrading the M-1.0t amplifier. He used to work for Carver and is retired now. He does all the upgrading work in his house. Being a crazy HT nut, I immediately contacted him to make an appointment for an upgrade on my two M-1.0t amplifiers. To my surprise, I found out that he was booked for almost a year. I finally managed to get an appointment for June 2012. The appointment for the second amplifier is in October 2012. He calls the upgrades MkII and MkII Opt 02.

Each amplifier goes through a two track process.

TRAC I

• Troubleshoot: Component level fault isolation.
• Repair: Replace any malfunctioning parts; bring the amplifier to working status.
• Align: Perform all published alignment and service bulletins.
• Calibrate: Verify performance against published specifications.

TRAC II

• Test: Check power diodes and resistors for drift in value due to age and use. Perform initial benchmark
• Restore: Replace all electrolytic capacitors; power resistors and power diodes replaced as required
• Augment: Replace all voltage rectifiers with higher current devices. Boost power supply ‘rail’ voltages. Re-design gain stage for new rail voltages. Replace all electrolytic capacitors and pre-drivers with higher voltage/current devices. Increase capacitance from 26000 uf to 43000 uf. Remove output transistor solder and replace using 7% silver solder. Install M-1.0t's infamous Turn on/off thump fix.
• Calibrate: Benchmark to new specifications. Perform 96 hour burn in at 1/3 power into 4 ohms. Final alignment.

The result is an amplifier with a much higher power rating, more headroom, less commutation distortion, better current sourcing and performance into low impedance loads, as well as tighter bass and transient control.

Bonus upgrade:

5-way binding posts bring the amp into the 21st Century using 7% silver solder

Option 02

This option adds parallel (current sharing) transistors to the low tier rail, as well as higher current transistors to the high tier rail; parallel output devices help prevent the power rail from sagging under heavy loads.

As a result of these additional modifications, the M-1.0t Mk II opt 002 is the MOST POWERFUL Carver amplifier, excepting the Silver-7t/9t monoblocks (selling for $1,200 - $1,400), and the TFM-75 (very rare, selling for > $1,000).

More information about the upgrade is available in the following links:

http://carvermk2.com/
http://carvermk2.com/m10tmkII/m10tmkII.htm
http://carvermk2.com/pricing/pricing.htm

Obviously, I went for Opt 02 upgrade for an additional $50. What the heck? It is only money.

I have already received the first upgraded amplifier. I use it as the main amplifier in my two-channel room. It powers the two large DIY speakers that I built. Its performance has been vastly improved. It is as if my old and tired amplifier has been transformed to a $10,000 amplifier. It sounds richer and fuller, particularly in the lower frequencies. It plays the music with more authority. I can summarize all the improvements in one word, kick-ass. That is actually two words.

I am eagerly looking forward to spending another $360 to upgrade my second M-1.0t amplifier. The only bad news is that he does not do any work on the TFM-45 amplifier. I have to find somebody else to do the work at a reasonable price.