Vintage HiFi Audio Forum
Repair / Help Forum => Repair / Help => Topic started by: Brettl on December 22, 2015, 12:03:25 PM
-
Is there anyone in Pittsburgh that does work on Macs?
Thanks
-
I know of a place however they are super backed up and not currently accepting repairs. On another note, here's some interesting info on the MC2300, The Grateful Dead used, If I'm not mistaken, 48 Mc2300's to power the "Wall of Sound"
http://www.mcintoshlabs.com/us/brand/pages/heritage.aspx?MasterId=4 (http://www.mcintoshlabs.com/us/brand/pages/heritage.aspx?MasterId=4)
http://www.dozin.com/wallofsound/ (http://www.dozin.com/wallofsound/)
-
What needs attention?
-
This is a great amp, slight hiss when sitting idle. It was recapped about 6 years ago
-
When do you hear the hiss? At your listening position, or just when close to the speakers?
I suggest unplugging your pre amp, or any source connected directly to the amp, in order to diagnose the cause of the hiss (in the event it's not the amp).
If you only hear hiss at idle and not when music plays, it may be OK. The Mc 2300 is derived from the Mc 2100 and has a noise and distortion spec of 1/4%. Some minor hiss is normal for gear of that vintage (it was the state of the art in the 1970s-todays Mac gear has no audible hiss). Do the fans kick on when you drive it hard?
-
When do you hear the hiss? At your listening position, or just when close to the speakers?
I suggest unplugging your pre amp, or any source connected directly to the amp, in order to diagnose the cause of the hiss (in the event it's not the amp).
If you only hear hiss at idle and not when music plays, it may be OK. The Mc 2300 is derived from the Mc 2100 and has a noise and distortion spec of 1/4%. Some minor hiss is normal for gear of that vintage (it was the state of the art in the 1970s-todays Mac gear has no audible hiss). Do the fans kick on when you drive it hard?
Agree. Also would be useful to know if the hiss is equal on both channels.
-
Yes, equal in both channels has been there since I bought it. the Fans do come on but I rarely, if ever drive it hard enough. Currently running a pair of JBL performance Series
http://www.audioheritage.org/vbulletin/showthread.php?3272-JBL-Performance-Series (http://www.audioheritage.org/vbulletin/showthread.php?3272-JBL-Performance-Series)
-
(http://i6.photobucket.com/albums/y241/Brettl/000_1357BEst.jpg) (http://s6.photobucket.com/user/Brettl/media/000_1357BEst.jpg.html)
-
Yes, equal in both channels has been there since I bought it. the Fans do come on but I rarely, if ever drive it hard enough. Currently running a pair of JBL performance Series
http://www.audioheritage.org/vbulletin/showthread.php?3272-JBL-Performance-Series (http://www.audioheritage.org/vbulletin/showthread.php?3272-JBL-Performance-Series)
Post #9 shows a picture of the speakers.
Sorry I can't edit posts for some reason
-
(http://i6.photobucket.com/albums/y241/Brettl/000_1357BEst.jpg) (http://s6.photobucket.com/user/Brettl/media/000_1357BEst.jpg.html)
How much does that beast weigh?
-
Very nice system there! I agree with MacGeek's recommendations to do shop hiss trouble shooting.
If the amp were the problem, Audio Classics would be the shop to look at it. It would be a beast to ship, but not too painful. Their prices are not cheap but their service is great. Why not make the 6 hour drive up and ask them to ship it back to you? They will package, insure and ship. The amp is worth a factory refresh.
Look here: http://www.audioclassics.com/ (http://www.audioclassics.com/)
-
Audio Classics is likely to send the amp to the factory, which is right down the street from their store. The trip is a good idea. They will be able to arrange a factory tour while you are there. However, they have a very large assortment of used Mac, new Mac and other brands. You might end up buying something or trading up.
-
I love this amp, it has a lots of power but very musical. Not even a scratch on the unit! 128 lbs see link:
http://mcc.berners.ch/power-amplifiers/MC2300.pdf (http://mcc.berners.ch/power-amplifiers/MC2300.pdf)
I talked to Audio Classics before I posted this, just wondered if there was anyone closer that's all. I have been trying to get to Audio Classics for 5 years now, never can seem to make it. :)
-
(http://i6.photobucket.com/albums/y241/Brettl/Clipboard01_zpsaub06lzq.jpg) (http://s6.photobucket.com/user/Brettl/media/Clipboard01_zpsaub06lzq.jpg.html)
-
Nice looking rig. Are you using the Marantz as a pre amp?
There is a guy in the Akron/Canton area, whose name escapes me, who is supposed to be a certified Mac tech. I have used a guy outside of Harrisburg for vintage R2R tape deck work. He knows Mac as well. About a 3 1/2 hour drive. Terry DeWick is another well regarded Mac tech, in Knoxville TN; waiting time is typically three months. If all you hear is the hiss you have always heard, I am not sure you need service, at least on the amp.
I don't see a CD player in your rack. If you have one and it has a volume control, try connecting it directly to the power amp. I suspect you will hear an improvement vs going through the vintage Marantz
-
Using this as my pre - Emotive Erato tube
(http://i6.photobucket.com/albums/y241/Brettl/erato_zpsdgpqbmcw.jpg) (http://s6.photobucket.com/user/Brettl/media/erato_zpsdgpqbmcw.jpg.html)
-
Does the hiss remain when swapping pre's?
-
Tube electronics typically generate more noise and distortion than solid state, equipment quality being equal. While probably normal, your tube pre may be the source of your hiss, or add to it.
-
A slight hiss inches from the tweeter with tube gear is normal, it's called tube rush.
Spike those speakers!!!
-
A slight hiss inches from the tweeter with tube gear is normal, it's called tube rush.
Spike those speakers!!!
Agree, this may be what you are hearing. If you were using a more mainstream preamp I would suggest rolling the input tubes until you find a type that reduces hiss to a minimum (which often results in degraded overall sound than the tubes that had the hiss!), but this Emotive pre - I am not even sure what the input tubes are, they look special. I say embrace the hiss.
OBG
-
Or just wait a few years until you can't hear the hiss anyway.
-
Thanks for the input. Here is the guys website that makes the preamp. He makes pretty highend stuff. The erato is one of his earlier units, I had him look over this unit a couple years ago and I know it's working perfectly. The tubes you have a Hiss but so does the Mac. It's not terrible I just hate thinking that my gear could have an issue that could be corrected.
http://www.emotiveaudio.com/index2.html (http://www.emotiveaudio.com/index2.html)
-
Tung-sol 27 tubes
(http://i6.photobucket.com/albums/y241/Brettl/Vintage%20TUNG-SOL%20Vacuum%20Tube%2027%20Sm_zpshsjk2vae.jpg) (http://s6.photobucket.com/user/Brettl/media/Vintage%20TUNG-SOL%20Vacuum%20Tube%2027%20Sm_zpshsjk2vae.jpg.html)