A Look at the Most Desirable McIntosh Amp - 350W of Glory and History

[@audiohertz2341]

Had back in the 70’s and sold them on in 1984 , they were fantastic and some of the best toobs amps i have ever heard , super build quality , Mil spec parts and power for days ..! Regards

[@danielkinateder402]

I love the layout of your shop. What a beautifully organized and effective space to come to work every day.

[@SkyFiAudio]

Thank you so much Daniel! We spent a ton of time planning out our layout before we even started the move-in process years ago. Thanks for watching.

[@bobsykes]

Whoa! All the gear in your shop looks amazing. I'm on the oposite coast, but it's great to have discovered your business in case I want a smaller piece that can be shipped. Facinating video, too.

[@SkyFiAudio]

Thank you for your feedback Bob. We ship worldwide including the USA all the time. Please don't hesitate to reach out if you have any questions on a specific item. Thanks for watching our channel.

[@carlfuggiasco7495]

The whole idea of selecting the output impedance on the amp is the coolest thing I have ever heard of existing. That is a concept I wish a lot of amps incorporated. You could change speakers without worry. A reviewers dream and an audiophiles dream. I had no idea any amp made had that feature.....thank you so much....food for thought!

[@SkyFiAudio]

Right? First time I see that available through a selector switch. Love it!

[@patrickwalsh467]

Fernando, something of interest. Aboard the USS Archerfish, SSN-678, a Sturgeon class fast attack submarine, there were a pair of these amps with an industrial face plate and fewer controls. They were rack mounted. Their power was used to `ping’ for sonar identification purposes. I remember lusting after them to run my quad set of Large Advent speakers. I served aboard the Archerfish from ‘70-‘74. McIntosh was quite busy with industrial purposes too. There were many of this class submarines commissioned. Those two amps went along on some interesting Cold War missions. Thanks for your great videos.

[@stagesixx]

The development of the Grateful Dead wall of sound was impeded by some shortage of these amps, of which they used many. The story goes, they couldn’t get enough of them at first because the Navy was grabbing them all up.

[@patrickwalsh467]

@@stagesixx Crown DC-300s would have been a good substitute.

[@parttime9070]

@@stagesixx The dead continued to use McIntosh amps well after the wall was no more. Hoping to find one in a surplus store some day..

[@SkyFiAudio]

I wonder if those amp on the sub were MI-3500, the commercial version of these. So cool, thanks for sharing.

[@patrickwalsh467]

@@SkyFiAudio They could have been. On our missions/patrols we of course ran silent so the Macs were never used when on missions. They were probably removed when the boats were decommissioned and then installed on the 688 class boats.

[@kkoller8952]

When going over the price sheet you mentioned the MC-2105 but just above it was the less expensive MC-2100 which was the industrial version of the 2105 sans the power meters and glass faceplate. Internally its the same amp. Great videos ......wish we had a shop like yours in our area....these were the places I would hang out in HS while my friends were hot rodding their cars and listening to their all in one Kraco and Sounddesign stereos!

[@SkyFiAudio]

Thank you so much for watching and your thoughtful comment! Thanks for keeping us motivated to produce more videos.

[@cthulhuismychild]

Never had a chance to her the 350s. I did own a pair of MI-200s though. All 4 chassis, 300 lbs of 200s triode glory. Scary amps with their 1,300 volt 3 amp power supply, but what a sound.

[@SkyFiAudio]

those MI200's sound crazy cool. Pls share picture!

[@cthulhuismychild]

@@SkyFiAudio wish I could. Sold them back in the mid 90s. The few pics I had of them, lost in divorce. They used the 8005 triode tube. Just a pair of them pushed over 200 watts triode

[@AudioElectronicsChicago]

wow, amazing 👍🏻

[@SkyFiAudio]

Thank you! Cheers!

[@bertroost1675]

I enjoyed this video. I never knew about this amp. And your shop looks so cozy.

[@SkyFiAudio]

Glad you enjoyed it! I made the shop to be somewhere I wanted to be all the time. Its a pleasure working here every day.

[@swinde]

17:29 Wow, that rat's nest of cables makes my rack system look very organized.

[@SkyFiAudio]

Temporary setup only, happens.

[@rexoliver7780]

Listened to a pair of these classic monsters at McGuires hi-fi when they came it-being used with a pair McIntosh column speakers. The sound was so powerful,clean and captivating. Yes,6LQ6/6JE6 tubes were used as horizontal output tubes in color tv’s of that time. So wanted a pair of these beasts!

[@SkyFiAudio]

Thanks for sharing!

[@peterc3143]

I want a pair as well 👍

[@AllboroLCD]

For what those amps are, they are in great shape!! The inside has a little surface rust, just clean her up and leave it at that. Very cool you knew these were used @ woodstock, its not very far and well worth a short pilgrimage even just to check out the Altec/JBL bins that were built on-site and yes, still there! I had a short e-mail relay with Mark Levinson last year and he told me the mic preamp used on stage was his design. Also for stage monitoring, Crown DC300's (i believe) were used for amplification.

[@dilbyjones]

I'm sure he won't tear it up.

[@SkyFiAudio]

We've had a lot of inquiries on these already and we might just leave them as-is per the new potential owner's request. We're working on another video soon where we go through the delicate process of powering these up for the first time, plus initial testing and measurements on our tech bench. Stay tuned.

[@AllboroLCD]

@@SkyFiAudio This does raise a curiosity ive had for some time now Fernando, whats up with using pro/DJ amps in the home with HiFi speakers? Is there no sound difference? Is it strictly whether or not your willing to tolerate a little bit more fan noise?

[@briansilcox5720]

Great perspective, please update as restoration or preservation proceeds. Thank you!

[@SkyFiAudio]

For sure and thanks for commenting.

[@shanestephenson8423]

Hi Fernando great video really looking forward to having a listen to those when they're up and running. It was great to see some of the pictures back at Woodstock where they were all racked up and working at that legendary concert. I guess it would be a little easier to find the original amps with the retrofitted XLR inputs after seeing that picture. Now a couple of those would be a real barn find😍. Keep up the great work I'm a fan over here in Australia never miss a video.😁👍🎧

[@SkyFiAudio]

Glad you enjoyed it! Thanks for watching and commenting.

[@phatjbl]

Great video talking about the history of Mc Intosh. I do like their vintage styling more than the slightly bling cues of today. Green LEDs on tubes ... not for me. The Woodstock pics are terrific. Wish I could come in to your shop easy. As I'm in Australia I miss out on so much cool vintage gear. 😢 Looking for to more of your videos

[@SkyFiAudio]

Nice to meet a fan from so far away. We ship stuff to Australia often so I know there are many active audiophiles there. Stay in touch.

[@davidnguyen5028]

Mc3500 mkii are now on my wish list.

[@tcb7750]

I'm happy with my MC-2301's 300 watts per-channel Best sounding McIntosh tub amp I ever heard...

[@SkyFiAudio]

Im a big fan of the 2301s too. More quiet and better looking for sure.

[@s.r.gemmill6246]

Another great classic audiophile gear video. Will you create a high end cassette deck comparison & recommendation? Keep up the great videos!

[@lotusmeta]

Oh hubba hubba! That and a pair of JBL L250 and a Carver holographic preamp, and I am in heaven!

[@SkyFiAudio]

Hahaha thanks for watching!

[@JohnAudioTech]

The 6LQ6 was designed to be a horizontal output tube for television sets but can work fine in an AF amp output stage. I'm sure the tube audio enthusiast crowd drove the price of this common cheap as chips tube up through the roof.

[@ScottGrammer]

It was also used in a lot of inexpensive linear amps used by hams and CB'ers. That drove the price up as well. One amp I knew of years ago used 12 of them.

[@audiohertz2341]

I recall paying 28.00 each at Lafayette for a 6LQ6 in 1979

[@NoOne-sn2si]

It was the CB idiots that drove the price up on these sweep tubes. The linears that used them were inbred engineering at best, dirty output signal and ate these tubes up at an alarming rate... Very few audio amps used sweep tubes, this McIntosh, Traynor had an incredible bass amp for bass guitar, maybe a few others...

[@eshskis1]

The amp that powered woodstock. The stories are now legendary, unfortunately the sound quality at Woodstock not so good. Fantastic video, fantastic amp. Love the content just found this channel

[@SkyFiAudio]

Thanks so much for watching and commenting - keeps us going!

[@danielwilliams1921]

Awesome video!

[@SkyFiAudio]

Thanks for the visit!

[@amplifierexperts1983]

Hands down, this is the best Measured tube amp I've ever tested.

[@SkyFiAudio]

Wow! Thanks for sharing!

[@audiohertz2341]

Yes, we bench tested one back then it was fantastic , easily the best toob amp measured i have ever seen ..!

[@jb.2986]

Wow...great history summary and wrap up of the MC3500. Thank you for uploading this. What a beast and a gem of an amp. Hope to visit your store/audio museum someday. BTW Fernando, speaking of barn-finds, does a Carver Research Lightstar Reference 2.0 amplifier (only 100 were made) ever come across your desk? Thanks again.

[@mitfreundlichengrussen1234]

Black handles go on the left side - keep them as they are, they truly reflect a funky lifetime.

[@camhyde9701]

The mismatching handles are cool don't change that

[@SkyFiAudio]

Very interesting.. will consider for sure.

[@b.powell3480]

Great video! Your sure going to get a workout on lifting the heavy amps onto the workbench!! Time to beef up the workbenches!!

[@SkyFiAudio]

For sure. Notice the hydraulic cart they are sitting on. Blown my back too many times.

[@2247386]

Thank You

[@2006gtobob]

Keep them vintage looking, don't touch them cosmetically. Just get them cleaned out and operating at 100%. Fantastic find!

[@ericanderson2987]

In Ken Kessler's great Book, McIntosh,...for the love of music, there is Photo of Under Stage of Woodstock. Photo shows Handley Sound Technician close to maze of Wiring and Stacks of McIntosh Amplifiers.

[@blackbearbear9313]

Very nice amp they well rock you

[@bobsmoot8454]

Big old Mac glowing amp, sick stuff, talk about melting your speakers and brains, can’t imagine hooking these up to either Altec A4/2 system or a JBL Paragon and opening the amps all the way , good golly miss Molly

[@SkyFiAudio]

Thanks Bob -

[@gatedreverb1]

Thanx for putting all that history into perspective… it’s funny to think that I can load more power (pa system) into my minivan today compared to 1969… you would’ve needed a transport truck or two

[@cgeorge6786]

I found two WE KS-19602 LI amps built by McIntosh for Western Electric. Worth much?

[@808bigisland]

Love the top feed tubes. My quad amps make 3 watts per channel from a single tube. Is this mc self-biasing?

[@stevebeschakis9775]

on the lower one, is the indicator needle stuck? ...broken?

[@JohnLee-db9zt]

Broken

[@dilbyjones]

Word, great investment.

[@SkyFiAudio]

Will probably outperform the stock market over time AND you get to enjoy them vs looking at financial statements!

[@MichaelAChang]

The amps at $1099 each was exactly the price of my EV Patrician 800s in that era.

[@EmilioGarcia-fr5po]

Did those meters move as your finger pointed to it?

[@seano51]

They sure did. The humidity is currently pretty low in NJ.

[@paulstubbs7678]

In the right environment, you can create a static charge on the meter glass, which will attract the needle, I've done it a few times.

[@SkyFiAudio]

Yes! I think the static charge induced by my fingers make the needles move.

[@lwskiner]

I don't believe I would have used the word 'patina' although 'beat to hell' comes to mind !!

[@SkyFiAudio]

haha, thats a better adjective for sure. Thanks for commenting Lance.

[@mikegeary8056]

Keep the rough look

[@SkyFiAudio]

That seems to be the theme with responses so far. Thanks!

[@jackdeath]

I think the 1.1 volts input refers to the preamp single from the strum of a guitar. The AC input of 400 to 900 watts makes me wonder if this was just a Class A amplifier if all it put out was 350W RMRS. I didn't see any push-pull configuration or phase inverters for the brief time I saw the schematics. This seems to be a raw power beast!

[@audiohertz2341]

It was push pull output stage 80 watts class A i recall after setting Bias ..! Plenty heat fan cooled , fan ran continuously..!

[@NoOne-sn2si]

McIntosh ran class AB2 in their tube amps, if it were class "A", there wouldn't be such a power variance between idle and full power...

[@johngalt7382]

Hot Tuna, and the Grateful Dead loved those beasts.

[@bertroost1675]

Can I ask how much you sold that recent Shindo Montille 6v6 amp for?

[@jamband4230]

They had 16 amps and Mabey 30 speakers or so. What was all those wires going to? Looking at those wires I would think they had hundreds of amps speakers with 20 different sound boards and 6 micd up orchestras. I can’t believe they played the whole festival with 16 amps and 10k watts I would’ve thought it would’ve been 10 times back then. Great video

[@SkyFiAudio]

I imagine since drivers were so efficient back them a single amp with the aid of impedance matching could power a whole lot of them.

[@peterrichard3706]

Is that a pair of Bose 10.2 speakers I spy off camera. For sale?

[@LS-ti6jo]

Vote for full restoration, because we'd get to see a year of progress updates :)

[@SkyFiAudio]

noted, thank you!

[@rexoliver7780]

From what I have heard the banks of these amps used at Woodstock for sound reinforcement had to be powered by diesel generators-the power there could not power them.

[@SkyFiAudio]

I believe it, didn't it take place in a random farm field?

[@rexoliver7780]

@@SkyFiAudio maybe that was the situation-the area didn’t have power of any kind.

[@Mr39036ce]

There was over450 kva on two banks and they were backed up by two more banks. Thirteen hundred kva is waaay more than those could use. Had a fellow lineman that had a pole line business and he was on that job. They were up there in June starting things.

[@Mr39036ce]

Very large transformers to bring that back down to 208/120.

[@Mr39036ce]

Kinda doubt that by there were definitely generators for backup there. A few line crews were there and ran 3 phase high voltage in with some lage pole mounted transformers.

[@peterc3143]

My dream amps. Wish I could win the lottery.

[@rickfeith6372]

I scored four of these from a garage sale that didn't happen

[@MervinGriff]

2 different handle finishes? mine only has the black finish handles.

[@SkyFiAudio]

Was thinking of changing one set. Which color should I keep?

[@JonCurcio]

@@SkyFiAudio Keep them both original.

[@robertwang7825]

Signal to noise ratio of 95dB is very impressive, considering that current Line Magnetic amps are only 87dB lol.

[@brandonburr4900]

I heard the new 3500 mk2 will only set you back $15k each. Or $30k per pair. Be curious has these stack up the the new expensive hybrid mono 901s . Those up about as expensive as these I think. Fun to see this eye candy, but to expensive for us mortals 😀

[@NoOne-sn2si]

The EL509S tube isn't anything near what the 6LQ6 tube is... El509S tube can output 500ma of cathode current max whereas the 6LQ6 can swing close to 1400ma max PER TUBE.

[@2ChannelAudio]

Nice 😍😍😍😍

[@SkyFiAudio]

Thanks 🤗

[@slyfoxx2973]

They're beautiful. But they still make my back hurt just looking at them!

[@Krashulka]

Anyone got the schematics for this amp please ?

[@Dr.Bigglesworth]

I would say the Audio Research M300s, or a pair of D250MII bridged would give the MC3500 a good run for its money.

[@jimmyhawke]

I thought Bill Hanley used Crown amps at Woodstock.

[@dilbyjones]

To me this IS the holy grail. ( I'm sure it changes )

[@SkyFiAudio]

On this we totally agree! Thanks so much for checking out our video.

[@bertroost1675]

Are you in the need to some NOS 6lq6 tubes? 🙂

[@SkyFiAudio]

Perhaps, once we service them we will know for sure. Thanks!!

[@ecyfoto]

Why not offer the two units in working order with the option to have refurbed?

[@SkyFiAudio]

Like what we end up doing. Thanks Eric.

[@davidlai399]

@@SkyFiAudiohow much extra to refurbish?

[@digidrum2003]

Such beasts!!! Does anyone here know how I would repair my McIntosh amp meter problem....my left channel meter gets stuck at a higher wattage reading...it will work fine under a that wattage level until I turn the volume up...the right meter works perfectly. When I turn the unit off the meter falls back to read zero. I have cleaned the amp ,air duster and electronic contact cleaner,but I am afraid to use the cleaner on the meter section......thanks in advance.

[@SkyFiAudio]

Often times the oil in the meter bearing dries up requiring disassembly cleaning and lubrication. They are very delicate so proceed with extreme caution.

[@digidrum2003]

@@SkyFiAudio I was afraid of that,I am a newbie to working on the electronics inside audio units.......thank you for the response.

[@wheelsandartchannel]

nice video, done support channel napo, newbie channel here po, Godbless po!!

[@SkyFiAudio]

Thanks for watching and please subscribe to our channel, it keeps us motivated.

[@zuletadic]

Mr.Nestorovic design

[@edd2771]

I understand why these have a storied history, but why are they “most desired” by audiophiles? As you mentioned they have noisy fans, seem like massive overkill even for Maggie’s and the like, and I’m guessing the noise levels are high given their quasi industrial design. I can think of any number of Mac mono blocks I would put into a system before these. But I’m no expert. Which am I missing that makes these sonically desirable in a home setting?

[@NeverTalkToCops1]

Audiophools. Is it clear now?

[@NoOne-sn2si]

The headroom...

[@crooner2007]

These are nice, but take a backseat to the legendary Marantz Model 9 monoblocks. Yeah the 9's aren't nearly as powerful but the sound quality, construction and overall circuit design is superior IMHO...

[@paulstubbs7678]

Nice vid, pity you just shot the computer screen, rather than having a proper screen capture of the web pages.

[@SkyFiAudio]

Sorry mate, I spend my time restoring equipment not editing videos :-)

[@basspig]

15 grand a piece today.

[@SkyFiAudio]

Depending where you're looking right now it's actually double that figure today believe or not.

[@weareallbeingwatched4602]

That's only 0.126 metric tonnes of amplifier.

[@SkyFiAudio]

lol

[@masudashizue777]

You could buy a car for that amount back then.

[@SkyFiAudio]

Yes, yes you could!

[@vintagestereocollector4159]

Lots of MACS….

[@SkyFiAudio]

Yes our Wall of McIntosh is posted a lot on audio forums!

[@vintagestereocollector4159]

@@SkyFiAudio Do u have a good receiever,Vintage one? price pls.

[@Thatrandomwhiteguy]

Restore before you cant in my opinion...

[@mgrsdgfsdafsdgrsdgfsdg6980]

1. 360p video 2. Low volume 3. Turn phone off 4. Wake up 5. More enthusiasm (we're excited to see and you sound like Eeyore) --end transmission

[@SkyFiAudio]

Thanks for your feedback, please note this was recorded in 4K and is showing as an available streaming option right now on YT. Maybe the HD version was still processing when you were watching.

[@garthdev]

Mac sucks and their amps just shouldn't have the status they have.. They are poor.. THERE IS NO GREAT MAC AMP EVER sorry

[@johnshaw359]

The 4 mm binding posts were forward-thinking. $1000 is still quite a bit of money even today. Must have been quite something to behold in the late 60s.

[@SkyFiAudio]

Thanks for this. And not only the price in 1960's to behold, talk about 350W via TUBES!

[@johnshaw359]

Until the mid 1980s most if not all the UK sound systems used massive louvred 1 ohm stable valve amps, they used around 8-12 KT88s to provide 600W-1000W. They used "bulgin" 2 pin Bakelite speaker plugs and had "the mother of all output transformers". Carried a few of them into venues as a young pup, 2 man lift only. I think valve technology was being used for really high power applications in the late 60's until silicon based transistors caught up and TVs for example could become "solid state".