2. amps-preamps
  3. 150254-46

Need advice in Audio Research Classic C-60Amp

I just purchased a classic C-60 to pair with my old Vandersteen 2CE’s.

Right now I’m just using Blue Jeans biamped speaker cable terminated in spades on the amp end. The classic only excepts wire that are screwed in on the back of the app. This means I’m going to have to cut the ends off the spades, and because it is Bi-amped I’ll then have two positives wires and two negatives  going to one channel. 

So my options are to just not use one of each color (one red one black) or twist the two reds together and twist to blacks together.  My question is what is the best way to attach the wire to the amp. Do I need to buy a different type of termination or is it just the bare wire that gets screwed in. And how do you think I should go about doing this with the wire I have. 

Also one follow-up question, if I just cut one black wire and one red wire from the spade, and tape them up, is there anything I should be worried about, sonically?
last_lemming
last_lemming OP
639 posts
 
I called Mr Scott Frankland, nice fellow, and spoke with him about work that could be done on the Classic 60.  He indicated that the 4 caps aren’t soldered in, but screw in. So, in preparation of getting the amp I have purchased 4 Kemet capacitors that are a direct fit for the Classic 60.  But with a bit more overhead.

On Scott’s recommendation I purchased a variable voltage transformer to slowly bring the voltage up once the new caps are plugged in to make sure the electrolytics disperse evenly.  He highly suggested I do this, so I am.

my question is after the new caps are in and the amp has been brought up to power do I need to rebias the tubes, or is that only necessary if the tubes are replaced?
dweller's avatar
dweller
3,795 posts
 
I'm sure it wouldn't hurt and you need to do it when you install new tubes (tube life is about two years with moderate use). Also, probably a good idea to check bias every six months just to make sure tubes are still working. I traded my Classic 60 in on a new VT-100 Mk-I in the mid 90s. I got a call from the dealer who told me one of the tubes was dead and had blown some kind of resister. I was totally unaware of the problem and offered to compensate him but he graciously declined.
last_lemming OP
639 posts
 
Got the amp!  Damn thing is HEAVY. 

So I plugged it in and went to listen to each tweeter to see if there was audible hum - ear right up to it - NOTHING - ZERO NOISE!!  No hiss or hum at all. I thought hmmm , maybe it’s broke, nope it’s just that quite.  Music sounds wonderful. I can’t tell if the caps have been changed. What color are the stock caps color? Mine are blue.  

As far as being able to connect to the screw type speaker connectors on the back of the amp, I ended up cutting one of the legs off my speaker cables spade termination. This narrowed the spade width just enough to just fit between the fins of the amps speaker connectors   Snug too. Don’t worry about the speaker cables too much, there just old Blue Jeans cable, so no house mortgage was harmed. 
dweller's avatar
dweller
3,795 posts
 
The Classic-60 got rave reviews when released (around 1990) as did the SP-14 preamp (its natural partner). I think I remember blue caps so they may be original (I doubt it). As I stated, Upscale Audio are pros so you should be good in the short run. Did they test your tubes? These pups can run into money especially if you buy them from ARC. Have fun!
last_lemming OP
639 posts
 
The 8 power tubes are new. Thing sounds amazing for a 30 year old amp. Can’t imagine what a modern AR amp would sound like today. Can’t afford new, that’s for sure. 
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