Tubes Asylum

Questions about tubes and gear that glows. FAQ

Return to Tubes Asylum

Message Sort: Post Order or Asylum Reverse Threaded

McINTOSH MC-30 & FISHER 90-C REBUILD by MIKE SAMRA

96.27.85.101
Posted on February 23, 2016 at 18:45:53
ssimon@wideopenwest.com
Audiophile

Posts: 30
Location: Michigan
Joined: February 2, 2016















Last year I bought a set of cabinet stored McIntosh MC-30's and a set of Fisher 90-c preamps from a friend of the family. After asking around the Detroit area audiophile groups I found Mike Samra up in Saginaw who has a passion for rebuilding these and other tube amps. After talking to him I knew he was the guy to rebuild these beautiful pieces of audio art. During the rebuild Mike was always available to give me updates on how things were going. These are some of the things he did: installed 100% film caps in the power supply, with an added choke, along with new carbon film resistors and a combination of paper in oil and film and tin foil coupling caps. Installed a Shotkey rectifier in the Fisher preamps along with film cap bypass. Also put in a bus-bar ground. Mike also replaced some lights and bad control switch on the preamp besides new power cords on all of them. He installed some new 6p3s-e Russian power tubes. He says I have almost 50 watts of power coming out of each amp with about .15% distortion. Amazing! He personally drove them down to help set them up and wow do they sing! I am running them through a set of re-capped Pioneer HPM-150's. I have had them for a while now and I just got done listening to Al Kooper's "I Love You More Than You'll Ever Know" and I thought I was going to cry it sounded so good. The detail and depth is astounding. I also just listened to John Mayall's "Crying" with Don "Sugarcane" Harris on the violin and it was so 3-D I thought the violin was floating in front of me. Anyway I love my new/old amps and will never part with them. I just wish I never sold the Altec Lansing Valencia's I picked up at a garage sale a couple years ago. Looking for some now. And God bless Mike Samra the master of audio electronics for doing a superb job.

 

Hide full thread outline!
    ...
RE: McINTOSH MC-30 & FISHER 90-C REBUILD by MIKE SAMRA, posted on February 23, 2016 at 19:52:47
DannyR
Audiophile

Posts: 611
Joined: January 21, 2001
 Nice stuff. I wish that I could hear em in action.

 

RE: McINTOSH MC-30 & FISHER 90-C REBUILD by MIKE SAMRA, posted on February 24, 2016 at 04:54:06
RavenDave
Manufacturer

Posts: 17
Location: Chita, Texas
Joined: April 21, 2015
 Man, that's beautiful. Wish I could sit there with you and listen to that new old system. Fantastic. Thanks for sharing.
RavenDave

 

RE: McINTOSH MC-30 & FISHER 90-C REBUILD by MIKE SAMRA, posted on February 24, 2016 at 06:24:46
maxhifi
Audiophile

Posts: 584
Location: Alberta, Canada
Joined: August 4, 2004
 This man puts his money where his mouth is, look at all those Russian PIO capacitors. Can't wait to try mine when they show up! How do you find you like using two mono preamp? I have thought about it, but I am not convinced that using two volume controls isn't awkward... Did you get used to it fast ?

 

Nice System!, posted on February 24, 2016 at 08:01:47
geezerrocket
 Very nice system!

We at Audio Asylum are very lucky indeed to have a gentleman of Mike Samra's expertise.

Aside from the fact that Mike is one of, if not THE premier rebuilding/restoration experts of vintage vacuum tube gear in the country, he is also very generous always willing to share his knowledge.

When Mike was rebuilding those beautiful McIntosh monos of yours, I would get a updates on them when I happened to be talking with him. He was blown away and almost giddy describing them to me - you can't fake that stuff.

When Mike rebuilds a piece of gear, whether it's a pair of McIntosh MC-60's with a C-20 preamp, or a humble little Stromberg Carlson integrated, you can rest assured that Mike will squeeze every drop of potential out of it.

I have a Audio Research SP3-a1 packed in a box ready to be shipped to Saginaw, MI; But first I have to find a nice pair MC-60's or Heathkit W6's to pair with it. I like you, want monos because they afford the space for a all film cap power supply. Until then I will just have to blissfully listen to my Samra rebuilt Sherwood S5000.

Congratulations on your system. It should give you faithful service for the next 30 years before your kids will have go find the next generations Mike Samra.

By the way, I love the LP frames. Where did you find them?










 

RE: Nice System!, posted on February 24, 2016 at 09:35:18
ssimon@wideopenwest.com
Audiophile

Posts: 30
Location: Michigan
Joined: February 2, 2016
 I believe I got the lp frames at Michaels. If you look for their coupon you can get them for about 50% off. I have a Sherwwod s-8000 that I wanted him to work on for a second system and he said I would like the S-5000 sherwood even better. During Mike's rebuild of my equipment he would mention a Sherwood S-5000 that he worked on. Must have been yours? He gave a bunch of technical reasons, which I didn't fully understand, (I don't know electronics)of why it would be better. He said it sounded really nice also. So I might just sell the 8000 and look for a nice 5000 for Mike to rebuild. Regards

 

RE: McINTOSH MC-30 & FISHER 90-C REBUILD by MIKE SAMRA, posted on February 24, 2016 at 09:39:30
ssimon@wideopenwest.com
Audiophile

Posts: 30
Location: Michigan
Joined: February 2, 2016
 Yes Mike does not cut corners when it comes to caps. Only the best will do. A few extra bucks but well worth it. And it is a little awkward using two volume controls but the sound that comes out of them is well worth the slight hassle.

 

RE: McINTOSH MC-30 & FISHER 90-C REBUILD by MIKE SAMRA, posted on February 24, 2016 at 09:41:40
maxhifi
Audiophile

Posts: 584
Location: Alberta, Canada
Joined: August 4, 2004
 Cool, am thinking of going in that direction. Vintage mono preamps are still fairly affordable compared to their stereo cousins of a similar quality.

 

RE: McINTOSH MC-30 & FISHER 90-C REBUILD by MIKE SAMRA, posted on February 24, 2016 at 09:46:48
ssimon@wideopenwest.com
Audiophile

Posts: 30
Location: Michigan
Joined: February 2, 2016
 Stop on by anytime. I could always use some ideas/recommendations on to get the best sound out of these. This is my first experience with tubes. What a way to go, hugh?! Looking to buy a new MC cart for the Thorens right now. What do you have?

 

RE: McINTOSH MC-30 & FISHER 90-C REBUILD by MIKE SAMRA, posted on February 24, 2016 at 10:05:01
RavenDave
Manufacturer

Posts: 17
Location: Chita, Texas
Joined: April 21, 2015



Right now I am using a Soundsmith Paua Special Edition - high output (+2.7mv) cartridge on an old 1970's Infinity Black Widow arm~!

Not really a recommended application, but our older preamp with a "built in" phono stage - the 2012 Shadow Reference Preamplifier - is for high output MM,MI & MC carts only.

So I have a few different MM carts sitting around here. Denon, Ortofon black etc. Lower-priced but still really nice sounding cartridges... and if they are matched well they can still sound really nice and satisfying.

It's about synergy, as you know~!

Our newer line of preamps will be much more flexible - and we are coming out with a standalone phono stage soon called "Stratus", that will match our Cirrus Preamplifier, built into the same chassis (its only 8.5"W x 11.5"D x 5" T), and uses the same 6X4 rectified power supply.

We are still the "new kid on the block"... but we're getting there.
RavenDave

 

My S-5000 Inards, posted on February 24, 2016 at 10:27:15
geezerrocket












The reason you would want the S-5000 (with 5 preamp tubes) over the 5000II or 8000 is for the huge ultra linear transformers and GZ34 rectification. If your going to go to the trouble to get a piece of vintage gear restored by a guy with a waiting list, you may as well get the best piece of gear (within its class) to begin with. You did it right with your Mac monos!

Once I decided to get a vintage integrated tube amp and have it restored and hot rodded, I emailed Mike and he made it pretty clear which one he would choose.

Once I find a pair of nice MC-60s, I'll get back in line for Mikey to work his magic.







 

RE: McINTOSH MC-30 & FISHER 90-C REBUILD by MIKE SAMRA, posted on February 24, 2016 at 14:12:25
Michael Samra
Dealer

Posts: 36118
Location: saginaw michigan
Joined: January 30, 2005
 Why thanks..The Fisher preamps I couldn't do film cap supply except in a couple places because of room constraints.I use good caps tho.
"For every complex problem there is an answer that is clear, simple, and wrong" H. L. Mencken

 

Just a couple things., posted on February 24, 2016 at 14:22:09
Michael Samra
Dealer

Posts: 36118
Location: saginaw michigan
Joined: January 30, 2005
 On the 50 watts I was getting,that was with a 5AR4 rect and the AC on the 125vac tap with 6L6gcs.The 6P3Se tubes made like 3 less watts is all but their sonics are superb.
"For every complex problem there is an answer that is clear, simple, and wrong" H. L. Mencken

 

RE: Nice System!, posted on February 24, 2016 at 15:27:46
airtime
Audiophile

Posts: 11287
Location: Arizona
Joined: February 4, 2003
 I think that was my Sherwood S-5000.

This tiny little unassuming stereo really does put to shame a VAST number of high priced hyped stereos. It IS one of the best stereos I have ever heard.

But it only got that way (the 60 years of aging not the sound) with the help of Mike's passion to rebuild these beauties.

Mike is one of many valuable treasures on this forum.

Thank you all that come here~!!!!!

charles

 

couple more...:), posted on February 25, 2016 at 10:12:53
PakProtector
Audiophile

Posts: 12365
Joined: May 14, 2002
 I thought I was going to read how the 12AU7 got ditched in favour of the 6CG7...:) The PS stuff mirrors what got done to my W6m's. Added a Hammond choke, and improved the capacitance. Those amps will next get some Russian POI couplers next time I have the hoods up( fortunately, they're 2-stage, and I'll only have to cram 2-each under there).
cheers,
Douglas

Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.

 

RE: couple more...:), posted on February 25, 2016 at 13:26:33
Michael Samra
Dealer

Posts: 36118
Location: saginaw michigan
Joined: January 30, 2005
 I asked him about that and he wanted to leave that and maybe run a 12BH7.I run the 6CG7 in most of my Macs and I totally agree but I'm also making up adapters where they can run a 6CG7 in place of the 12AU7.Your setup sounded incredible and the bass was some of the best if not the best I have ever heard..You had just moved in the house and your room wasn't even done yet and I couldn't get over those base horns and then the RCA compression drivers on the horns for mids driven with your 4E27 amps..
"For every complex problem there is an answer that is clear, simple, and wrong" H. L. Mencken

 

RE: couple more...:), posted on February 25, 2016 at 16:34:00
rosendds@frontiernet.net
Audiophile

Posts: 599
Location: North East
Joined: November 13, 2010
 Congratulations on your beautiful vintage system.Mike is very talented in his ability to make tube amps better than they were new while not altering them in ways that compromises collectability.Mike rebuilt a Mc240 for me which is dynamite,but I needed more power to drive Magnepan 1.7's.He recently worked his magic on a Mc275 for me that is truly magnificent! I need to sell the Mc240,but I can tell you that I will keep that Mc275 until my ears are too old to appreciate it!

Dave

 

RE: couple more...:), posted on February 26, 2016 at 04:37:57
PakProtector
Audiophile

Posts: 12365
Joined: May 14, 2002
 Fair enough...:) I would have been worried if you didn't offer...LOL

In addition to the set up being new when you heard it, you were also slightly sleep deprived thanks to the AK Fest going on that weekend.
cheers,
Douglas
Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.

 

RE: McINTOSH Resistors, posted on February 26, 2016 at 14:55:43
deafbykhorns
Audiophile

Posts: 1067
Location: Florida
Joined: October 17, 2003
 Notice all the resistors that Mike changed.
He didn't change these "just because". The resistors in these amps drift in excess by 20-30%. Not good, especially in the phase splitter circuit!
Don't convince yourself that your old Mcintosh needs to stay original and sounds good, they don't perform anywhere near specifications without these updates!

 

RE: McINTOSH Resistors, posted on February 26, 2016 at 16:40:00
rosendds@frontiernet.net
Audiophile

Posts: 599
Location: North East
Joined: November 13, 2010
 Mike is mindful of which type of replacement resistor is best used in a particular part of the circuit.

 

RE: couple more...:), posted on February 29, 2016 at 04:05:18
PakProtector
Audiophile

Posts: 12365
Joined: May 14, 2002
 The 50-50 split between cathode and plate loading of the McIntosh unity-coupled power stage delivers quite enough NFB. There is of course positive FB delivered to the 12BH7 stage; this bit should go away, and with it the loop of global NFB.

While you're at it, the phase splitter stage can benefit from a proper CCS tail load, and repair of the deliberately imbalanced plate resistors( put there to deal with the imperfect tail load.

After all this you'll likely discover an overabundance of gain still exists. Change from a 12AX7 input tube to a 12AY7( the cathode R will need adjusted ), will be useful.

The amp will be more stable, and thanks to removal of the gNFB, and local PFB it will sound better too.
cheers,
Douglas


Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.

 

RE: McINTOSH MC-30 & FISHER 90-C REBUILD by MIKE SAMRA, posted on March 2, 2016 at 09:03:34
el34eh@yahoo.com
Audiophile

Posts: 1933
Location: Michigan
Joined: September 6, 2003
As always, a wonderful example of Mickey's ears and eyes for detail, I too have an integrated that he was able to wave his magical hands over and bring back to life. And is someone to whom I proudly view as not only a great technician, but as a friend as well.

O_o scar

 

Page processed in 0.036 seconds.

[ Top Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]
[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]