How come noone is cloning McIntosh? - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 23rd September 2005, 02:47 AM   #1
JZatopa is offline JZatopa  United States
diyAudio Member
 
Join Date: May 2003
Location: Chicago
Default How come noone is cloning McIntosh?

I am surprised not to see more mcintosh like amps on this site. Is there any reason for this?
  Reply With Quote
Old 23rd September 2005, 02:57 AM   #2
Leolabs is offline Leolabs  Malaysia
diyAudio Member
 
Leolabs's Avatar
 
Join Date: Dec 2004
Location: Bukit Mertajam
Send a message via MSN to Leolabs
The problem is:"How about the output transformer???"
  Reply With Quote
Old 23rd September 2005, 04:09 AM   #3
diyAudio Member
 
Join Date: Feb 2001
Location: Columbia, SC
The unstated assumption here is that you're talking about building the solid state ones. Trust me, it's not worth the effort, sound quality-wise. The tube pieces were another matter, entirely, but the funky transformer is still a serious limitation.
Having owned a number of solid state McIntosh pieces, I can say that they rarely give trouble, but they can't compete in terms of sound quality. The one category where they absolutely cannot be beat is cosmetics. In my not-so-humble opinion, the glass-front McIntosh designs are some of the sexiest looking gear ever, at any price. Period. Unfortunately, looks and performance are two entirely different animals.
Let me put it this way. Imagine that you had a Mc circuit in an ugly chassis. Would you still be impressed?
I remember the revelation when I got rid of my Mc stuff and went with 'real' high end gear. Less money (true, believe it or not). More sound. The only downside was that I didn't have those beautiful black/blue/green faces to look at any more.
If the things weren't so expensive, I'd pick up a piece or two on ebay just to look at. As it is, the advertising (and looks) has done its job and people believe in Mc with near religious fervor. They bid even the least worthy items up to ridiculous prices. Oh, well. I don't really need it that badly. It's cheaper to go buy a piece of art glass at the local gallery.

Grey
  Reply With Quote
Old 23rd September 2005, 11:41 AM   #4
djk is offline djk
diyAudio Member
 
djk's Avatar
 
Join Date: Feb 2001
Location: USA
The output transformers are not what is holding a McIntosh back, it is the caps.

"Which caps are they DJK? I'll try them in my 2125."

Add one 47F across each 42V rail at the main filter caps

Add a 0.01F~0.1F film cap in parallel with C239, 240 (little board on the input jacks, very tight for space)

Add a 0.1F film in parallel with C203, 204 (input coupling cap to impedance buffer)

Add a 0.1F film in parallel with C207, 208 (output coupling cap from impedance buffer)

Add a 0.1F film in parallel with C219, 220 (feedback cap)

Add a 0.1F film in parallel with Q215, 216 (bias transistor)

Add a 0.1F film in parallel with C305, 306 (15V regulator outputs)

Add a 0.1F film in parallel with D304, 305 (reference diodes for regulators)

I cut off all the push on connectors in the power supply and speaker relay and soldered them direct. I soldered a pair of 0.1F film across the speaker relay contacts and cleaned the relay contacts with a sheet of paper and applied De-oxit.

I sprayed De-oxit on the RCA jacks, cleaned the input sensitivity selector switch (very important), and the edge connectors for the L and R amp boards.

I removed the 10-32 screws on the main filter caps and used De-oxit before replacing.

Do not move the chassis with the bottom off, the glass could crack. Put it on a small piece of carpet to help turn at different angles.

The 47F are under a lot of stress, I used 100V caps even though they only run at 42V.

Even though this changes no measurable performance specification, it will change the sound more than you can believe.

Jackhammer bass from an amp with a DF of only 14?
  Reply With Quote
Old 24th September 2005, 12:26 AM   #5
MikeW is offline MikeW  United States
diyAudio Member
 
MikeW's Avatar
 
Join Date: Sep 2002
Location: North of Boston
Default Mac's sound

I have 3 of them(5100,754,2505). I don't think they sound bad. Maybe a little thin in the midrange compared to some of the class A amps. You can get one on Ebay for what it would cost you to build it. There are some schematics up on the web. Which one did you want to build?
The 2505 is a great looking amp.
__________________
MikeW
  Reply With Quote
Old 24th September 2005, 04:41 AM   #6
diyAudio Member
 
Join Date: Sep 2001
Location: Salt Lake City
I was once told "off the record" at a MAC amp clinic by a McIntosh factory person that they sacrificed sound quality in favor of reliability....... For instance... the output stage in most of their solid state amps are class B to prolong the life of those early silicon devices.....

I owned half a dozen MAC pieces over the years most of it in the early to mid 70's... C-11, 240, 2505, 50W2's, and a pair of MAC 40's. The MAC 40's were the best of the bunch in terms of sound quality by a long shot.

I doubt that I would buy any more of their equipment unless it were really a good deal!

Mark
  Reply With Quote
Old 24th September 2005, 01:19 PM   #7
djk is offline djk
diyAudio Member
 
djk's Avatar
 
Join Date: Feb 2001
Location: USA
The MAC 40's sounded better because they didn't have electrolytic coupling caps, they're a tube amp.

"that they sacrificed sound quality in favor of reliability....... "

The person that told you that may have believed what he told you, but I think he was wrong. MAC amps can sound great if you do something about the electrolytic caps. I was a MAC dealer in the 70s and the 80s, and figured out the cap thing around 1985.

You will be stunned with the changes in the sound from the caps.

A cap list for the MC2105

The sound would benefit greatly from replacing a few dried out electrolytics, and adding a few film types here and there.
C301, 302 is the main input coupling cap. It is a Mylar type so it is likely to be OK, upgrading it to a Polypropylene type with give a smoother sound to the high end (0.47F).

C307, 308 are emitter bypass caps, 100F 15V. Replace with same type and add a 0.1F film bypass.

C309, 310 are the output coupling caps for the pre-driver section, 10F 25V. While a film type would be better, size is a problem. The DC bias across this cap also helps out with its being an electrolytic. Replace with same type and add a 0.1F film bypass.

C303, 304 are the DC power supply caps for the front end, 470F at 25V. Replace with same type and add a 0.1F film bypass.

C1, 2 are the feedback loop caps, 330F at 3V. The signal goes through these so replacing these with new ones and adding a 0.1F film bypass really opens up the sound. Go with as high a voltage as what space permits.

C11, 12 are the DC supply caps for the voltage gain stage, 150F at 50V. Replace with same type and add a 0.1F film bypass.

C201, 202 are the main filter caps, 39,000F at 40V. These may be quite expensive new, although I have seen them surplus for very low prices. I would use then unless signs of leakage or amplifier hum are there. Add a 47F at 50V cap in parallel with each.

C203 is a multi-section cap that will be very hard to find a fresh date code. New caps are small enough that they may be wired to the terminals of the old one, leaving the old one in place. This cap is important as it provides the current for the diff pairs and the VAS. The sections go 80/80/150/50F with the voltages being 200/200/150/150V. If you measure the voltages 100/95/90/80V are typical, so 200V caps are not really needed, but 100V is not enough.
  Reply With Quote
Old 24th September 2005, 01:47 PM   #8
diyAudio Member
 
Join Date: Sep 2001
Location: Salt Lake City
I don't doubt at all that they sound alot better with parts upgrades but you're still stuck with the class B output stages and their own set of problems. Also I wold think that an unaltered MAC piece would be more valualable than one that has been altered, at least in the realm of their tube gear....... Of course caps and other parts don't last for ever, but you can't convince a collector of that..... If I ever run into a 2505 at a good price I will try your suggestions though.

Mark
  Reply With Quote
Old 24th September 2005, 03:44 PM   #9
djk is offline djk
diyAudio Member
 
djk's Avatar
 
Join Date: Feb 2001
Location: USA
The MC2205/2200/2125/2120/502 that came out around 1977 all use the same driver card. These sound quite a bit better than the earlier MC2105/2100/2505/250 (which are all similar, but very different from the other group) which date from 1967.

Of these, the MC2120 is the most reasonable priced on the used market, and seems to have even more 'slam' than the bigger MC2200.

Speaking of class B, have you read D. Self on this subject? I think he's right.
  Reply With Quote
Old 24th September 2005, 04:25 PM   #10
diyAudio Member
 
Join Date: Sep 2001
Location: Salt Lake City
Am not familiar with him but I certainly remember the huge crossover notch at 20 khz.

Mark
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Cloning a HF-60 petera77 Tubes / Valves 19 5th June 2008 10:50 AM
Cloning transformers jon_010101 Tubes / Valves 29 31st May 2008 03:48 PM
Need help cloning a Gibson g-20 amp DeadSpeaker Solid State 41 8th March 2008 08:37 PM
Help needed in cloning the XRT22 from McIntosh tool49 Multi-Way 10 15th July 2004 04:06 AM


New To Site? Need Help?

All times are GMT. The time now is 06:58 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2