McIntosh MA230 Integrated Amplifier as a gift
 

It wasn't long ago that we had a thread on Audio Aficionado that asked us what audio gear we regretted letting go. My post included the McIntosh MA230 integrated amplifier. I had owned one for years and loved it. The MA230 has a solid state preamplifier and a tube power amplifier. The amp is rated at 30 watts per channel.

Fast forward to a few weeks ago when I received a PM from member GaryProtein. He asked me if I would like to have his father's MA230 that Gary had stored in his basement for the past 30+ years. Gary had read my post earlier and thought of me. Of course I said I would be thrilled to have the MA230. I bought new shipping boxes from Audio Classics and had them shipped to Gary. He packed the MA230 and shipped it to me. It arrived this morning. It didn't take me long to unpack it and get it on my bench. Surprisingly, after 30+ years of storage in a basement, the MA230 was in fair condition, needing a good cleaning. I got right to it.


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I removed all the knobs, disassembled the face plate, pulled the cover off the premplifier section, and removed the bottom cover from the amplifier section. I performed a thorough cleaning of the chassis, parts, rocker switches, rotory switches, potentiometers, glass, knobs, and metal trim. Once clean, I reassembled the MA230. She's looking good.


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While I had the MA230 dissembled I tested the tubes. The single 12AX7 and the two 12AU7 tubes tested strong and the 12AU7's were closely matched. The 7591 outputs tubes did not test so good. All four were very weak. After the tests I reinstalled all the tubes and decided it was time to try powering up the amp. I have a Variac transformer that allows me to bring the voltage up from zero, so I slowly raised the AC volts over about 20 minutes until I had 120 volts on the amplifier. No noises and no smoke. That's always a good sign. I tested the bias on the four 7591 output tubes at the test points and made adjustments, but none of the four tubes could be properly adjusted for 0.7 VDC at the test points like the schematic said I should have.

I shut off the amp and connected two speakers to the speaker terminals and a CD player to the AUX input. With my fingers crossed I powered up the MA230 from its front panel switch with a full 120 volt power line input. So far so good. I pressed Play on the CD player. Uh oh! No sound from the speakers until the volume knob was well past 12:00 o'clock and then what was coming from the speakers was distorted badly. I shut the MA230 down.

I really wasn't disappointed at these results because I had anticipated problems due to the amplifier's age and the fact that it had been basement stored for over 30 years. It was too much to hope for that it would jump right up and play perfectly under those conditions. I suspect some power supply issues, capacitor issues, and output tube issues. Since I don't have all the necessary test equipment to go through the amp thoroughly I contacted Terry Dewick. I am going to ship the MA230 to him for a complete restoration.

I am so excited to own another McIntosh MA230 integrated amplifier. I am humbled and thrilled by Gary's gift of his father's McIntosh component to me. I'm going to get this integrated amplifier singing again for me, for Gary, and for his father. It is the very least I can do. I have had a smile on my face all day. This is great. Thank you so much, Gary.

Great amp with a great story. An AA moment for sure.

Congratulations Dan. Nice work.

Gary is a very special individual. It appears he is just as generous with physical objects as he is with his knowledge and time when a member here needs guidance or assistance. :bowdown:

Great story !

Yet another example of the cool people in this community.

Great gesture Gary!

Look forward to hearing your joy once you get it up and running Dan.

Craig

Wonderful story in process. Can't wait for the result. Way to go, Gary and Dan!

What an amazing act of generosity & kindness - utterly speechless. It looks almost like new.

:thumbsup: on the decision to send out to Terry. I recently had him refurbish a MAC 1500 and I couldn't be more pleased.

For replacement output tubes, I recommend the EH 7591 which are very attractively priced and sound wonderful. Terry recommends them as well. Only issue is that you'll not be able to install the cabinet with the EHs in. If that's an issue, you'll probably have to pick up a vintage quad.

Congrats on your windfall and I hope you'll enjoy it for many years to come.

Eric

Dan....

Lucky guy !
Gary's offer is tremendous.
I have been looking for a 230 for a while. They are very rare.
I am sure that when you'll get the unit back from Terry you will be thrilled again as you were probably years ago by this gem.
I would personally have bought a set of EH new power tubes before sending the amp to service but chances are high that the caps at least should be changed anyway.
Waiting to read the rest of the story when the amp will come back from Terry.

( you see why I stated that the 225 is actually a 2x30W ? The power section of the 230 is the same. Plus on the bench they actually show 30W before clipping...).

Eric.......Thanks for the info on the Electro Harmonics 7591 power tubes. I also have seen some 7591's made by JJ. I'll go with whatever Terry thinks is best.

I received an email earlier this evening from Terry. He said, "Will make it sing." . :banana:

Jérôme.......Yes, I feel most fortunate that Gary thought of me when it came to his father's MA230. I'm on a mission now. When it returns from Terry it will replace the MA5100 in the vintage system.

The McIntosh MA230, manufactured between November 1963 and April 1966, was their first stereo preamp-amplifier on one chassis and their first stereo component to combine a solid state preamplifier with a tube and transformer power amplifier on the same chassis. The MA230 also provides two headphone jacks that are connected to the amplifier outputs through 100 ohm resistors. Best of all, the MA230 is one sweet sounding amplifier. I may have to start searching for another pair of Altec Valencia speakers. :p