MC275 vs MC2301

What I am sharing here is a comparison I had done back in 2014 in Taiwan. Now with this dedicated space, I am posting this again, hoping to hear from fellow audiophiles about their perspectives and observations.

Early in the afternoon in Feb 2014 on a sunny day, the MC2301s arrived and settled into the audio room and yes they were big and very formidable; at a bulky 116lbs each, CDs into two technicians were required to move them into position. All the content was cued and waiting. The analog including Reel to Reel and Vinyl with digital content including hi-res downloads, CDs, and SACDs. After my audiophile friends arrived and the system warmed up we started with the reference system familiarizing ourselves one more time with all the content and sources. My reference system consists of 4, 2 Horizontally Bi-Amped and 2 monoblock, vintage 1960’s MC275 amplifiers feed by a vintage C22 pre-amp.

After calibrating ourselves to the reference system we moved to the MC2301s reconfiguring the speaker wires so that the MC2301s were the only amps in the audio chain. We warmed them up and started with the Reel to Reel, Yarlung Records Smoke & Mirrors, 15ips/CCIR. Immediately you could hear the detail of this beautifully captured recording with the warm tube and detailed sound from the MC2301, but the sound stage depth/width, power, and feel seemed shortened considerably. It was dynamic but skinny and the super tweeters seemed to be sleeping as if there was no data provided at that frequency. We paused the audition and re-checked all the connections. I even called the dealer to check if this was indeed the “broken-in” system I had requested and they confirmed. Alas nothing amiss and we moved to the vinyl source playing Exotic Dances from the Opera by Eiji Oue Minnesota Orchestra. Again the MC2301s demonstrated fast response, with detail, and a warm tube sound but still lacking in providing, comparatively to the reference system, a big window of performance, energy and feel. We went through more vinyl selections but the results were consistently the same; David Roth-Pearl Diver-Bake Sale, Mal Waldron-Left Alone, Peter/Paul/Mary-Ten Years Together-Lemon Tree, Cat Stevens-Tea for the Tillerman-Into White, Sara K- in the Groove- I Can’t Stand the Rain, Chuck Mangione-Children of Sanchez-Lullabye, Esther Ofarim-Esther-Kinderspiele, etc…We then moved to Hi-Restube-like digital Carlos Santa-Shape Shifter-Mr. Szabo and the MC2301 picked up the detail with speed but not the image depth which adds to perceived detail being less. Again not as much power and yes quick and responsive but not the punch I had expected. A smaller window of performance albeit nice with a tube-like sound but not the full rich lush enveloping sound and energy that you can feel and stirs emotion, that’s what comes from the vintage MC275s.

At this point it was time to try a different configuration; both MC2301s were directed to supply just the low end and two MC275s were set up to supply the mid and high. There was an immediate improvement in the mid and high but that’s the MC275s and the base with the MC2301s was starving when compared to the 275’s. We tried a few other configurations but wherever we placed the MC2301s they were lacking in audio quality when compared to the MC275s in the same positions.

I never anticipated this audition result. I was fully prepared to praise the MC2301, purchase them and switch out the MC275s. Even my friends had high expectations from MC2301, then how could this be? Past audition comparisons between MC275s and MC2301s consistently applauded the MC2301 awarding it high marks. I looked back at some of these comparisons and two patterns quickly emerged; the comparisons were typically 1 or 2 MC275s not 4 and not vintage MC275s from the ’60s. This adds some clarity for me since I have auditioned later generations of the MC275 and found them inferior and a bit clinical sounding and I would put the MC2301s on top of those without hesitation. Furthermore, the MC275s in my reference system are not completely standard nor is the C22. Capacitors and resistors have been replaced as needed but more importantly, the tube selection is not stock and has a significant impact on the audio quality. The tube selection is detailed to the tube design, material, factory location and year of production. Lastly, I do believe there is some magic in the materials used back in the day especially in the transformers, no printed circuit boards just point-to-point wiring, and hand-crafted.

As nirvana sounding as the vintage MC275s are I cannot recommend we all head in that direction. The good ones are almost impossible to find, maintaining them is a choir and tube rolling is a constant experiment. If I did not have the MC275s I would seek the MC2301s. I would also encourage McIntosh Labs to look back and reconsider future designs. And if McIntosh reads this write-up with disbelief then I welcome them for an in-person audition of their past at is very best.

I would like to thank Mr. Wu who maintains my vintage equipment here in Taipei; he is truly a master of vintage tube audio gear. My friend Josef who has listened to my non stop insane audio questions for 4 years, JJ at the Stereo Shop in Boise Idaho who made me a believer in Transparent Audio Cables, Steve in Australia who is an encyclopedia of all things audio especially tubes and my wife Robin, yes dear I will have this mess cleaned up before you return :-)

System set-up for testing

MC2301 in action

Good old days with friends in Taipei

Taiwan Reference System Details

4 vintage MC275 amps (1960s) (Horizontal configuration for the mid and high range monoblock mode for base), McIntosh Vintage C22 Pre-Amp custom tube selection and placement, ATC 150 speakers, Lyeco ST-777 super tweeters, McIntosh D100, McIntosh MCD301, MacMini, Audirvana Plus, MMF5.1, Benz Micro Ebony TR cartridge and Bob’s custom SUT, Otari MX5050-BII, Transparent Audio cables, interconnects and power cords, Monitor Acoustics Power filters, and Okki Nokki Record Cleaner.

Tubes in the vintage MC275s are as follows:

1. Power Tubes: GL Re-Issue's KT88's. I have compared NOS to the GL Re-Issues and have visited the factory in Russia that makes the Re-Issues. These have better performance and of course big savings on $$. From my listening tests here the Re-Issues have a faster and punchier bass and extended mid/high range. I have heard similar opinions including those backed by signal measurements.

2. The signal tubes are where the real work is. The current setup is as follows by position:

1- 12AX7 (The first tube and most important): Amprex Bugle Boy 12AX7 long plate D Getter made in Holland at Heerlen. I have tried others including the Telefunken ECC803S and the Bugle Boy adds that lush warm sound while still maintaining clarity without being too bright.

2- 12AU7: Telefunken ECC802S from Ulm Factory

2- 12AT7: Telefunken ECC801S From Ulm Factory

2- 12BH7: RCA 12BH7 Black Long Plate

3. I have not disclosed the tubes selected or configuration in the C22. My kids can tell you after they inherit my system.

#music #vinylrecords #vinyl #turntable #semiconductor #mc275 #mc2301 #taiwan

New Turntable? Wait...

Hunting for a new Turntable is a popular sport and there are for sure many videos and articles that can help you choose an entry-level to high-end Turntables. But before you jump at your next Turntable review allow me to give you some other areas to focus on that may encourage you to improve your current Turntable or be more comprehensive with the next or new Turntable.

For me, the cartridge is where I start; are you a moving coil or moving magnet fan. That decision impacts your next investment and decisions in a pre-amp, cables, and perhaps a phono preamp or step-up transformer. I am a moving coil fan; I believe the level of detail is greater regardless of the lower output needing some external gain. And for that gain I don't look at the pre-amp to do it all, I look for a dedicated step-up transformer matched specifically to the cartridge. You will have other options like a phono preamp with solid-state or tube capabilities and that may be your decision but for me, it’s a step-up transformer; no solid-state electronics and a dedicated specific use device equals better performance.

Next, I recommend revisiting the cables that feed the signal from the TT and ultimately to your pre-amp. Keep them short and invest in these with the materials that align with your system and the performance you are looking for. All cables are not created equal, experiment with Silver vs. Copper and that will give you a starting point on if you need brighter (Silver) or warmer (Copper) cables. Yes, I simplified this a bit but it’s a good way to start and see which end of the spectrum to head for. Try different cables and make sure they have gone through a burn-in process if possible.

At this point measure your turntable speed to ensure it has a consistent speed. Believe it or not, the best belt drive systems drift overtime/temp/humidity and require adjustments. It is easy to check the speed as well as any wow/flutter with your cell phone/app (I use RPM). Following that, I would recommend a custom linear power supply and not a wall wart power supply (Read more about clean power supply here).

Vibration control, this one can drive you crazy pending on the room, your rack set up, the weight of the turntable, and its feet. Spend some time on this. Eliminating vibration to the turntable has a tremendous effect on sound clarity. Look at the rack, the feet on the turntable, and rack, is an isolation table needed? Or do you just have to move to a different room? You can measure vibration as well and I recommend it with your smartphone/app.

Finally, the matt that sits on the platter. Experiment with different materials that are either compatible with the platter material or enhancing. For example, an acrylic platter should produce a warmer softer sound and with a metallic mat that can be sharpened up dramatically. I use an Asai AMG 2000 Disc Sheet on an acrylic platter (will post a pic of this soon). I found this “disc sheet” at a Tokyo Audio trade show several years ago.

These are inexpensive experiments and do impact the final performance. Improving items around the turntable can often make better improvements than purchase a new one. More importantly, many if not most of those surrounding improvements can migrate with you as you upgrade over time.

Are there any other areas that you consider while upgrading or buying a new Turntable? Will be glad to learn from fellow audiophiles about how you go about fine-tuning or upgrading your Turntable. Please do share your experiences in the comments section.

To see the complete details of my set-up, you can visit the System Gallery & set up details section of my blog.

"The only truth is music" - Jack Kerouac

#music #vinylrecords #vinyl #turntable #AMG2000 #analogmusic

The Hickok 539B aka the Equalizer

A vintage tube-based stereo depends on strong balanced tubes. Newly manufactured tubes make this straightforward, however vintage even if NOS (new old stock), requires testing to ensure a balance between the plates within a tube but among its companion tubes in the same amp and in the other active amps. The vintage MC275 amps use 7 signal tubes with the lead tube, a 12AX7 followed by 2-12AU7, 2-12BH7, and 2-12AZ7, (USA Tube Reference #). The tubes following the 12AX7 are paired in groups of 3 for the left and right channel, (L = 1-12AU7, 1-12BH7, and 1-12AZ7). Within each of these tubes they have 2 plates that need to be measured and must be within 3% of mutual conductance with no shorts or leaks, and then tested to within 3% of the next companion tube in the same amp and then 3% to the next 3 amps and their corresponding tubes. With 4 amps and a pre-amp having a total of 34 signal tubes and 16 power tubes the amount of testing required to keep the amps balanced for best imaging is significant and requires a large inventory of tubes. 34 signal tubes is 68 tests at about 2 min each assuming all tubes were accepted/matched; Time-wise, that’s over 2hrs of testing for a total system rebalancing. The 3% tolerance is my number determined via trial and error; 10% is too much to keep optimum imaging and less than 3% is hard to find or maintain. The 3% maybe a little tight but when running 4 independent amps it’s a must; think of it like 4 artists painting an image simultaneously where the brush strokes are aligned else the image will be blurred.

Once the amps and pre-amp are loaded with balanced tubes I check the dB of the left vs. right channels for each driver at different frequencies at the listening position. That along with reference recordings with strong imaging confirms the tube selection and balancing.

At this point, I also want to introduce my biggest support tool, the Hickok 539B. The 539 was a popular tube testing tool for many technicians who repaired TVs, Stereos, radio’s and other tube driving appliances. This 539 is also point-to-point wiring and operates on tubes requiring its own tuning and is critical. Check out the photo, it’s definitely a bit off-putting but it’s a champion for testing tubes for leaks, shorts, and mutual conductance matching.

McIntosh MC275

Set of 4 MC275

Hickok 539B

As for the inventory of tubes, the KT88 power tubes being manufactured today can be ordered in matched lots of 16 for the setup as I have. It’s the vintage signal tubes from the 1960s that take time to find. There are plenty of tubes selling online but a knowledge of what you are buying to the detail of the plate size and color, pin layout and coating, getter shape and location, tube markings, etc. is critical. It does not take long to figure out that one may have purchased the wrong tube or the performance is below sub-optimal levels. Over time I have found great sellers and collectors and have tried all kinds of tubes to enhance the system but the selection I have now seems to be the end game. To know more details on signal tube selection, see my blog on “What makes a unique setup?"

#music #vinylrecords #vinyl #turntable #analogmusic #hickok539b #mc275