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  • Writer's pictureJim Cathey

Updated: May 27, 2021

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


  • Writer's pictureJim Cathey

Updated: May 27, 2021


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?"


  • Writer's pictureJim Cathey

Updated: Apr 16, 2021

Every setup whether it’s a studio or a home entertainment is unique. I am sharing what I have put together for my 2 channel stereo set-up at my San Diego home. A lot of this has come through trial and error and of course through my experiences with my earlier home studio set up in Japan and Taiwan.


A 2-channel stereo with a vintage heart and soul from the 1960s surrounded by current-day technologies. The vintage is McIntosh 1960s MC275 amps, 4 of them in total with 2 horizontally bi-amped and fed by a McIntosh 1960s C22 Preamp. These are historical products not only talked about today but also re-introduced in later years. These vintage MC275s and C22 products have no printed circuit boards or solid-state electronics. They are handcrafted and loaded with resistors and capacitors constructed with point-to-point wiring and fitted with 50 select vacuum tubes; of which 16 are power tubes and the balance of 34 signal tubes calibrated to within 3%.


The MC275 amps leverage the Gold Lion KT88 tubes manufactured in Russia which is a re-introduction of the original Genalex KT88’s made in the UK. Yet these newer KT88’s have faster push-pull performance and a higher roll-off frequency, making them the only re-issued non-vintage tube I use. The signal tubes are all 1950/60’s starting with the lead tube, 12AX7 from Amprex, which is the Bugle Boy long plate “D” getter from Haarlem, Netherlands. This tube is hard to find, however, they sit in the key 1st position of the MC275 amps and provide a warm rich tone that in my opinion is 2nd to none. Following that lead tube from Ulm Germany are the Telefunken ECC801S and ECC802S tubes originally binned for military and medical applications. These tubes have extremely low microphonics and sharp detail, making them a perfect match to support and follow the 12AX7 Bugle Boy. And the final tube is also from the 1960s from RCA, the 12BH7 black long plate.


The 4 MC275s have split duties. 2 units are in monoblock mode each dedicated and connected to the LF speakers of the left and right speakers. The 3rd amp is in Twin Amp mode dedicated to the mid-range of each speaker with the final amp is also in Twin Amp mode dedicated to the high range of each speaker and super-tweeter. This combination is strong enough to drive the ATC speakers, providing the performance one would expect from these studio monitors.


The McIntosh C22 Pre-amplifier has 6 tubes, all of them not the same, as one would expect. 3 tubes are the famed Telefunken ECC803S and 3 tubes are again the Amprex Bugle Boy 12AX7 long plate “D” getter. The sharper and detailed 803S is dedicated to the analog sources whereas the Bugle Boy 12AX7 is paired to the digital inputs. This combination provides for the typical hard and often-cold performance of digital to be warmed up with the Bugle Boy. The analog vinyl sources may need to be sharpened up and the ECC803S is the right tube for that. It does so without forcing the performance to be cold or harsh.

To put all this together has taken plenty of trial and error with countless tubes and vintages, but the real magic was created by a network of audiophiles around the world, that stretched from Australia through Taiwan, Japan, Korea, across western and eastern Europe and of course North America. I have had a unique enriching experience by meeting many of them in person and receiving opinions online and through calls with folks, I have never met. I thank them all for their knowledge and willingness to share their experience.


Notes:

1) You can check-out detailed specifications of my home studio setup here

2) Also check out this blog www.mcintoshcompendium.com for loads of other resources

3) You can download the manual for McIntosh MC275

MC275_own
.pdf
Download PDF • 316KB

4) You can download the manual for McIntosh C22 Preamplifier

C22_own
.pdf
Download PDF • 826KB







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