C500T under the covers and replacing the tubes
- Thread starter leftside
- Start date
leftside
AK Member
The second batch of photos show the line stage. These should also be really easy to replace, but it looks like the previous owner had been in there and not replaced one of the plates correctly. The shiny metal plate should reside UNDER the two screws, not over. This made it very difficult to remove.
Incorrectly fitted plate to the right:
With both plates removed:
With both plates re-attached correctly:
Incorrectly fitted plate to the right:
With both plates removed:
With both plates re-attached correctly:
MACKIE1975
Super Member
Everything looks good except that gooey of glue (epoxy).
Not quiet sure if that's factory as I'v never seen that on any mac gear that I have or others have posted.
leftside
AK Member
Agreed. I also think they used too much epoxy, but I do like the look of the rest of the "modders". I'll see if I can get in contact with the original owner and get the history.
leftside
AK Member
Nailed it! Good eye sir. The guy I bought it from purchased the C500 from these guys, but he was unaware any mods had been performed. Well, it looks like mods were certainly made. I'll contact them and see if they can provide more details.
https://www.upgradecompany.com/
leftside
AK Member
I've never heard another C500T, so I can't compare it to a "regular" C500T. But, I can tell you the unit is amazingly quiet. It's surrounded by potential noise - a tube DAC and a turntable/phono stage as inputs, and a tube headphone amp as one of the outputs. Yet, this system has a fantastic black background.
I was comparing the Audia Flight phono stage to the built-in phono stage of the C500T after I put in the Gold Lion and Telefunken tubes at the weekend. It took quite awhile and a few cable swaps before I could notice any differences. In the end I detected the vocals were slightly more forward with the Audia Flight and the Audia Flight had slightly better bass, but it was very close. This will probably be the last preamp I buy.
MACKIE1975
Super Member
Modding or upgrade an old piece of audio equipment is understandable due to the availability of better parts selection. But messing around with the current design is totally absurd. I don't believe the modders have the same knowledge, time and tools like the McIntosh engineer. It is already a well design audio piece.
leftside
AK Member
I had a chance to call the Upgrade company this morning. We had a great chat, and I found it very interesting. Here are the main upgrades of interest to me:
3) Our RFI/EMI Shielding
4) Our RFI/EMI Dissipation
5) Our RFI/EMI Dampening
6) Our RFI/EMI Attenuation
There is a lot of RFI noise in my house (I'm a bit of a computer geek and have lot's of wireless devices and a wireless network running throughout), so am also thinking about getting these upgrades for my DAC.
3) Our RFI/EMI Shielding
4) Our RFI/EMI Dissipation
5) Our RFI/EMI Dampening
6) Our RFI/EMI Attenuation
There is a lot of RFI noise in my house (I'm a bit of a computer geek and have lot's of wireless devices and a wireless network running throughout), so am also thinking about getting these upgrades for my DAC.
Velocityboat
Super Member
Surprised if they wers so worried about EMI external they did not put a fine mesh wire screen over that pretty tube window grounded to chassis. Or does Mcintosh use metalized glass coatings.
It sounds like they are more worried about EMI internal than external. If they start isolating fiber cable inputs on your DAC for atenuation of EMI. The snake oil is in overdrive.
leftside
AK Member
Who knows for sure without the measurements as damacman says.
For sure there is plenty of snake oil in this business. I also hang out on a lot of computer music forums and some guys swear by their $500 USB cables... Next we'll have audiophile air conditioners to improve the signal for streaming wirelessly.
For sure there is plenty of snake oil in this business. I also hang out on a lot of computer music forums and some guys swear by their $500 USB cables... Next we'll have audiophile air conditioners to improve the signal for streaming wirelessly.
damacman
Resident Psycho
$500 USB cables? Um-k . . .
I'm not ready to call what these guys offer bunk yet. I'd simply like to see some validation. Honestly, it looks like great attention to detail was paid inside your preamp. Why go to all that length if you can't back it up? Obviously, you didn't pay extra for this service as you didn't seem to know it was done until after c_dk pointed it out. Does that mean that the seller didn't value the investment OR does it mean that he felt that folks would be scared off if they knew the unit was modified as it is?
This is one of the things that makes our hobby so easy to buy into - nobody ever verifies any claim made of . . . well, anything. This is where magazine reviews can be handy - did the unit or didn't it meet the manufacturer's specified claims? If it doesn't, then all bets are off when buying this manufacturer's product as you can't really be guaranteed of anything.
If this company wanted to back up their claims, it'd be as simple as providing the customer before and after measurements. SQ is subjective and cannot be quantitatively measured - too easy to brag about how much better a component sounds after a given upgrade was done to it. Who can even remember what something sounded like a month ago when boxing it up to send it in? Hell, I can't remember what a 10 second passage of a song sounded like that I just heard 10 seconds ago ...
I'm not ready to call what these guys offer bunk yet. I'd simply like to see some validation. Honestly, it looks like great attention to detail was paid inside your preamp. Why go to all that length if you can't back it up? Obviously, you didn't pay extra for this service as you didn't seem to know it was done until after c_dk pointed it out. Does that mean that the seller didn't value the investment OR does it mean that he felt that folks would be scared off if they knew the unit was modified as it is?
This is one of the things that makes our hobby so easy to buy into - nobody ever verifies any claim made of . . . well, anything. This is where magazine reviews can be handy - did the unit or didn't it meet the manufacturer's specified claims? If it doesn't, then all bets are off when buying this manufacturer's product as you can't really be guaranteed of anything.
If this company wanted to back up their claims, it'd be as simple as providing the customer before and after measurements. SQ is subjective and cannot be quantitatively measured - too easy to brag about how much better a component sounds after a given upgrade was done to it. Who can even remember what something sounded like a month ago when boxing it up to send it in? Hell, I can't remember what a 10 second passage of a song sounded like that I just heard 10 seconds ago ...
leftside
AK Member
Same here. When tube rolling there has to be very obvious differences with the tubes for me to notice any differences - because it takes so long to swap out the tubes! I've been enjoying playing vinyl at the same time as my DAC with the same tune. With our preamps you can simply press a button to swap the source - and it's quite easy to hear the differences then. Using the trim function works well to ensure each output is at the same level.
Anyway, regarding the mods in the preamp. I certainly like the idea of the extra shielding, but I'm not sure it makes a difference to the sound quality or not. Makes for a good discussion
I took a look at their site. Im OK calling it 99% hokum. 
Anyone that blathers on and on like that and doesn't post ANY measurements, but relies on subjective statements and reviews is suspect in my book.
Anyone that blathers on and on like that and doesn't post ANY measurements, but relies on subjective statements and reviews is suspect in my book.
