McIntosh MC225 Quick Review

[@MikeandTracker]

Thanks so much for your videos, I’ve learned a great deal from watching them.

[@jutukka]

When I turn my old tube amps on, I often use some kind of cold start current limiting, usually a light bulb, or variac. I have noticed that those heater filaments of NOS tubes don't flash if the start current surge is limited only little. Of course, not a surprise.

[@dennisgouveadeazevedo6238]

Howdy! The Valvo ECC83s are likely Made in West Germany or Holland. All Philips tubes have a code etched onto the bottom close to the pins and there's a pdf file online called "Phiiips Tube Data Codes" where you can find exactly who made it and when (Mullard UK codes start with a B and Holland with a Delta). You can also find the dates and the type of tube (if the paint has worn off). Your Valvo is most likely a Delta Code, which means it's made in Herleen in Holland, beautiful tube. Came across quite a bit of those when I lived in Europe. Philps tubes were manufactured under several brands and all over the globe (Brazil, Venezuela, France, Holland, Germany, the Philippines etc....) Mullards are the best ones but all of them sound excellent.... and they all exhibit the "flash"... of all things, it's a way to be sure you have a genuine Philips tube. Some were manufactured in east Europe in the 80's and they do have the cross-hatch pattern on top but they're not nearly as good. Great to see another audio video, thanks!

[@ElPasoTubeAmps]

Very good information - Thank You

[@LdHrothgar]

I heard you on the air a couple weeks ago, forgot to write down the time and freq, you were having a conversation with a guy about microphones and sound quality IIRC. I was cruising through the band looking for DX and I heard your voice, as I passed the freq. I though "Wait, I KNOW that voice!". :) I didn't want to interrupt your QSO so I didn't try to break in. I just through it was funny to catch you on the air and recognize your voice.

[@gregwilliams2746]

I wasn't aware that Mullard tubes had the ribs on the top, so thanks for that! I have a bunch of ECC85s (6AQ8) and three have those ribs - they are branded Valvo, Telefunken, and Matsushita.

[@ElPasoTubeAmps]

I can't say for absolute sure about the Valvo, but no doubt that the 10M series of Mullard tubes have those ribs and the Telefunken have that square/four-sided star on the bottom between the pins - that I am sure of. In those days of tube manufacturers, all the companies made and sold/branded tubes for each other. You can find, for example, ECC83/12AX7/7025, with GE or RCA or whoever, branded but they are all made by the same manufacturer. It is not something we want to believe but the manufacturers knew exactly how to "grade" their tubes and sell the premium ones at the best price. Should be no surprise and they still do today. As a fact, the premium European tubes were actually cheaper than the USA tubes but were superior for audiophile use... I still see that the European tubes of yesteryear are stronger and better balanced than the average USA made tube. Many of those European tubes are found in the best-of-the-best equipment like Tektronix oscilloscopes, that I have, and still work perfectly. It just makes me cringe to think that these tubes are throw away because the filament "flashes" on turn-on.

[@dtg474]

Great test video. Thanks. The Mac 225 is phenomenal. I heard it on electrostatic speakers once. What a dream.

[@harbselectronicslab3551]

How good is it to see a video up from Elpaso Tube Amps !!!!

[@thomastubeworks]

Good to see you again, really enjoy all your videos and been watching for a long time. I was watching one of your old videos again on the Heathkit WA-1, I’m going to build a set of mono blocks like that because I’ve always wanted to try 807s, maybe not that exact schematic but similar. Thanks for all your work!

[@ElPasoTubeAmps]

807 is a great tube and makes a very nice Williamson amplifier. It is essential a 6L6GC with the plate lead on top to allow higher plate voltages. The 12 volt filament version of the 807 is the 1625. They have different socks so they are not interchangeable.

[@thomastubeworks]

@@ElPasoTubeAmps Yes sir! I think I’m going to use 1625s as I can buy them locally NOS for half the money or less of 807s I should have all the parts in stock minus the output transformers. I don’t have any old iron I wish I did, I’ll go with new Hammond OT since they are easier for me to get here in Ontario Canada

[@pauldow1648]

Peace to you in New Year.

[@buskman3286]

Wouldn't you want to test with both channels driven for max power - as per McIntosh specs - as opposed to testing each channel individually?

[@pomonabill220]

Good to see you again! Hope you are doing well and feeling good. Thank you for the post! Never knew that about Mullard tubes and Telefunken (sp?) tubes. I have a couple of boxes of tubes that I need to characterize with a tube tester. Can you recommend a tester?

[@ElPasoTubeAmps]

Bill, Always a pleasure to hear from you. I am doing OK... I try to stay busy building equipment but I am getting tired. My wife always knew I had a special place for cats, so she sent me several. I have six now and they are most beautiful. It is tough being alone but whatever the reason, I believe I still have a purpose for living. I tend to look at life as I am at work and will get to go home someday and all will be well. I guess that is called Faith and Love. The most common high-end tube tester is the TV-7 series tube testers. They can be pretty staggering in price and who knows their condition. I have had mine for number of years and have pampered it but the meter started sticking a few years back and I bought a Chinese replacement that has been good. There are digital readout meters that can be purchased but, again, who knows the price. A tube tester is a first-line device. Kind of a go-no-go start. It can tell if the tube is alive... also, it can be used to compare and grade or "match" tubes but the ultimate test is in the circuit. I have seen many tubes test weak and work perfectly. I never throw away a tube just because it doesn't pass a tube tester. Here is something to look at for a starter. www.ebay.com/itm/166362850827?epid=1382590835&hash=item26bbffa60b:g:ujsAAOSwurllIe6D&amdata=enc%3AAQAIAAAA4JFQ65cGzZsKPYIajtFiEQKDpJTkSyCfcKcBzdH63tsLhXRPMn4UuZXqlWl%2Bv0uTgIgfEdGcoVhVN7pLLXzMhOA5VF5Vk0oC4JvJpfF3dW75GruPd0%2Fw5dboVz7Jbotv4ONTVRchxQB0dtmbXFGnq3Qj65GEw0OvHjl7NRcEpUTCYpnGRuaaXf%2BegO1fALuIjSz4Z7W74T4IcowiKylFrWMpTQz4CkRue4DTOmY3Kh%2BMoaNbftL%2Bxd1%2FQ7ElFX4eOhFs9W6aKYy2lM4kXKFmtsGzK0PASOj11nx0znQPzEbi%7Ctkp%3ABFBM9oWGs4pj My very best to you and your love ones.

[@changsoppyon6979]

Hi thanks for the video, I hear a bit of audible buzz from the transformers of 225, fully restored, when turned on without any input. Is it normal?

[@David-b6y4m]

Hi there. Enjoy your videos very much. Like you have shared, I too have an MC2100, enjoy its sound, and consider it an underrated amplifier by McIntosh. I am curious to learn how the MC225 compares in sound to the 2100? I have very efficient speakers, and wonder if the 225 would sound better.? PS: is it possible to speak with you directly, and learn your perspective here? Thanks!

[@MrMersh-ts7jl]

I have a question regarding things I've seen in a lot of your videos: What is the second trace on your oscilloscope that I often see when you're testing amplifiers? I assume it has something to do with noise. But what settings and what connections are you using for that? Thank you for everything you posted because I also learned a great deal from you

[@ElPasoTubeAmps]

I only have one trace being displayed on the scope but I think what you might be referring to, in this video, is when I first show the display, the horizontal display of the scope is adjusted to a slow sweep rate and we are seeing lots of cycles on the scope screen. In this case, the trace fills the screen top to bottom (amplitude) and left to right (time). With this type of scope, I then press the auto-set button and being a smart-scope, it automatically adjusts the sweep to only two cycles by increasing the sweep rate and there is only one trace but now it is running at a different (faster) sweep rate and the display is not full of cycles like in the first case. Hope this helps.

[@johnstuchlik5828]

Glad to hear that you have good experience with Russian t-sol 7591.i have a fisher and eico that use 7591.did you have to make any changes to use them.where you buy?. how is the match?is change in match comparible to us tubes? thanks.

[@ElPasoTubeAmps]

The four that I bought a few years back tested the same for all four - an actual matched quad... they still test good but not perfectly balanced anymore. I like the original size ones, like the Sylvania, and was one of the reasons I chose the Tung-Sol. All of my amplifiers are open-top chassis so any size would fit. I know some brands are quite a bit larger and could cause a problem fitting is some vintage amplifiers. I buy all my tubes from www.tubedepot.com - they have been excellent to deal with. I am waiting on another set to arrive.

[@johnstuchlik5828]

Thanks for the info

[@jdmccorful]

Always find your work interesting and informative. Thanks for your time!